RU2834929C2 - Device and method for analysing quality indicators of natural gas product and use thereof - Google Patents

Abstract

FIELD: gas industry; measuring.

SUBSTANCE: invention relates to a device and a method for analysing quality indicators of a natural gas product. Device has a sample loading unit and first, second, third, fourth and fifth column chromatographic analysis systems connected in parallel. First chromatographic column analysis system is configured to separate sulphides from natural gas. Second chromatographic column analysis system is configured to separate hydrocarbons having C₃ and higher from natural gas. Third chromatographic column analysis system is configured to separate oxygen, nitrogen, methane and carbon monoxide from natural gas. Fourth chromatographic column analysis system is configured to separate carbon dioxide and ethane from natural gas. Fifth chromatographic column analysis system is configured to separate helium and hydrogen from natural gas. Each chromatographic column analysis system is equipped with a quantitative tube, a tube for carrier gas and a chromatographic column. Quantitative tube is configured to store a natural gas sample. Carrier gas tube is configured to deliver the carrier gas to the chromatographic column analysis system in order to subject the natural gas sample in the quantitative tube to components inside the chromatographic column. Sample loading unit is connected to quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems with possibility of controlled connection/disconnection for supply of natural gas sample to quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems. Each chromatographic column analysis system is connected to the corresponding detector, respectively.

EFFECT: design of an analysis device and an analysis method, which simplify obtaining quality indicators of a natural gas product.

20 cl, 36 dwg, 30 tbl

Description

AREA OF TECHNOLOGY

[0001] The present invention relates to the field of natural gas testing technology and, in particular, to a device and method for analyzing quality indicators of a natural gas product and their use.

LEVEL OF TECHNOLOGY

[0002] According to China's mandatory national standard GB 17820-2018 "Natural Gas", commercial natural gas obtained by pre-treating natural gas produced from gas fields or oil fields and transported through pipelines shall meet the requirements for four quality indicators, i.e., gross calorific value, total sulfur content (expressed as sulfur), hydrogen sulfide content and carbon dioxide content.

[0003] The traditional test methods commonly used for the quality indicators of natural gas products are as follows. The gross calorific value is usually obtained by detecting the compositions by chromatography and then calculating the composition data; the total sulfur content is usually measured by coulometry, ultraviolet fluorescence or hydrogenolysis and ratiometric colorimetry; the hydrogen sulfide content is usually measured by iodometry, methylene blue method, laser method, chromatography or colorimetry; and the mole fraction of carbon dioxide is usually measured by chromatography. It can be seen that there are many principles for the test methods for the quality control indicators of natural gas, and a plurality of instruments and a plurality of sample loadings and analysis are needed to complete the tests, resulting in long test cycles. In addition, due to the need for multiple sample loadings, it is difficult to ensure the consistency of the samples; and the above problems are technical problems that urgently need to be solved in the present technical field.

DISCLOSURE OF THE ESSENCE OF THE INVENTION

[0004] The object of the present invention is to provide an analysis device and an analysis method that simplify obtaining quality indicators of a natural gas product.

[0005] In order to achieve the above-mentioned object, the present invention provides a device for analyzing the quality indicators of a natural gas product. The device comprises a sample loading unit and first, second, third, fourth and fifth chromatographic column analysis systems connected in parallel, wherein the first chromatographic column analysis system is configured to separate sulfides from the natural gas; the second chromatographic column analysis system is configured to separate hydrocarbons having C ₃ and higher from the natural gas; the third chromatographic column analysis system is configured to separate oxygen, nitrogen, methane and carbon monoxide from the natural gas; the fourth chromatographic column analysis system is configured to separate carbon dioxide and ethane from the natural gas; and the fifth chromatographic column analysis system is configured to separate helium and hydrogen from the natural gas; wherein

each chromatographic column analysis system is provided with a quantitative tube, a carrier gas tube and a chromatographic column, wherein the quantitative tube is configured to store a natural gas sample, and the carrier gas tube is configured to deliver a carrier gas to the chromatographic column analysis system to act on components of the natural gas sample in the quantitative tube that are subject to separation in the chromatographic column;

the sample loading unit is connected to the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems with the possibility of controlled connection/disconnection for feeding a natural gas sample into the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems; and

Column chromatographic analysis systems are connected to the corresponding detectors respectively.

[0006] The chromatographic column analysis systems are connected to the corresponding detectors in such a way that an analysis of the content of the components separated by the chromatographic column analysis systems can be performed. The first chromatographic column analysis system is connected to the corresponding detector for analyzing the content of sulfides in the natural gas. The second chromatographic column analysis system is connected to the corresponding detector for analyzing the content of hydrocarbons having C ₃ and higher in the natural gas. The third chromatographic column analysis system is connected to the corresponding detector for analyzing the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas. The fourth chromatographic column analysis system is connected to the corresponding detector for analyzing the content of carbon dioxide and ethane in the natural gas. The fifth chromatographic column analysis system is connected to the corresponding detector for analyzing the content of helium and hydrogen in the natural gas.

[0007] Using the device for analyzing the quality index of a natural gas product provided in the present invention, the components of the natural gas are divided into five parts for separating the components, the target analytes in each component separation are separated by a chromatographic column, and then the content of the target analytes in this part is obtained by an appropriate detector. The device has the following advantageous effects.

[0008] On the one hand, the product quality indices of natural gas, including the gross calorific value, the total sulfur content (in terms of sulfur, mg/ ^m3 ), the hydrogen sulfide content (mg/ ^m3 ) and the carbon dioxide content (molar percentage), can be easily determined based on the analytical results of the five parts.

[0009] On the other hand, this contributes to the realization of a higher degree of peak separation of the target analytes in the chromatograms obtained using the corresponding detectors and to obtaining a more accurate result, and thus the accuracy of the obtained quality indices of the natural gas product can be guaranteed more reliably.

[0010] In another aspect, the apparatus for analyzing the quality index of a natural gas product provided in the present invention is an integrated apparatus in which a sample loading unit is used to introduce a sample into each system, and then the analysis systems are respectively used to analyze various components, which simplifies the operation and helps shorten the test cycle time.

[0011] In the apparatus for analyzing quality indicators of a natural gas product as described above, preferably the first chromatographic column analysis system is configured to separate carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene from the natural gas.

[0012] In the device for analyzing quality indices of a natural gas product as described above, preferably the sample loading unit is connected to the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems in such a way that the quantitative tubes of the first, second, third, fourth and fifth chromatographic analysis systems are connected in series; wherein the sample loading unit comprises an inlet tube for natural gas, an outlet tube for natural gas and first, second, third and fourth connecting tubes for the quantitative tubes, wherein the first, second, third and fourth connecting tubes for the quantitative tubes are configured to connect the quantitative tubes in series, respectively, the inlet tube for natural gas is connected to the inlet end of the quantitative tubes connected in series, and the outlet tube for natural gas is connected to the outlet end of the quantitative tubes connected in series.

[0013] In this preferred embodiment, the series connection is more useful for the analysis systems to perform single sample loading, and the consistency of the samples can be better ensured. In addition, the systems can be used to analyze various components by single sample loading, which further contributes to reducing the test cycle time.

[0014] In a particular embodiment, the inlet tube for natural gas is connected to the inlet end of the quantitative tube of the first chromatographic column analysis system, and the first connecting tube for quantitative tubes is connected to the outlet end of the quantitative tube of the first chromatographic column analysis system and the inlet end of the quantitative tube of the second chromatographic column analysis system, respectively; the second connecting tube for quantitative tubes is connected to the outlet end of the quantitative tube of the second chromatographic column analysis system and the inlet end of the quantitative tube of the third chromatographic column analysis system, respectively; the third connecting tube for quantitative tubes is connected to the outlet end of the quantitative tube of the third chromatographic column analysis system and the inlet end of the quantitative tube of the fourth chromatographic column analysis system, respectively; the fourth connecting tube for quantitative tubes is connected to the outlet end of the quantitative tube of the fourth chromatographic column analysis system and the inlet end of the quantitative tube of the fifth chromatographic column analysis system, respectively; and the outlet pipe for natural gas is connected to the outlet end of the quantitative tube of the fifth chromatographic column analysis system.

[0015] In the apparatus for analyzing quality indicators of a natural gas product as described above, preferably the first chromatographic column analysis system is connected to a sulfur chemiluminescence detector (SCD), the second chromatographic column analysis system is connected to a flame ionization detector (FID), the third chromatographic column analysis system is connected to a thermal conductivity detector (TCD), the fourth chromatographic column analysis system is connected to a thermal conductivity detector (TCD), and/or the fifth chromatographic column analysis system is connected to a thermal conductivity detector (TCD).

[0016] More preferably, the device for analyzing quality indicators of a natural gas product further comprises a chemiluminescent sulfur detector that is connected to the first chromatographic column analysis system.

[0017] More preferably, the device for analyzing quality indicators of a natural gas product further comprises a flame ionization detector that is connected to a second chromatographic column analysis system.

[0018] More preferably, the device for analyzing quality indicators of a natural gas product further comprises a first thermal conductivity detector that is connected to a third chromatographic column analysis system and a fourth chromatographic column analysis system, respectively.

[0019] More preferably, the device for analyzing the quality indicators of a natural gas product further comprises a second thermal conductivity detector that is connected to a fifth chromatographic column analysis system.

[0020] In the apparatus for analyzing quality indices of a natural gas product as described above, preferably the chromatographic column of the chromatographic column analysis system comprises a sulfur detection column; in the chromatographic column analysis system, one end of the quantitative tube is connected to a carrier gas tube through a connection line with a controllable connection/disconnection, the other end of the quantitative tube is connected to an inlet end of the sulfur detection column through a connection line with a controllable connection/disconnection, and an outlet end of the sulfur detection column is connected to a chemiluminescence sulfur detector through a connection line with a controllable connection/disconnection;

The sulfur column provides separation of carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene.

[0021] More preferably, the column for determining sulfur is selected from one of a methyl silicone-based chromatographic column, a phthalate-based chromatographic column, a PLOT-based chromatographic column with bound silica, a high-permeability PLOT-based chromatographic column, and an optimized chromatographic column based on a non-polar stationary phase.

[0022] Furthermore, preferably the column for determining sulfur is selected from a GS-GasPro chromatographic column (referring to a chromatographic column based on PLOT with bound silica) and a DB-Sulfur SCD chromatographic column (referring to an optimized chromatographic column based on a non-polar stationary phase).

[0023] Furthermore, preferably the column for determining sulfur is a DB-Sulfur SCD chromatographic column. The DB-Sulfur SCD chromatographic column has a length of 50 m to 60 m. In a particular embodiment, the DB-Sulfur SCD chromatographic column has dimensions of 60 m in length and 0.32 mm in diameter with a liquid phase film thickness of 4.2 μm.

[0024] The DB-Sulfur SCD chromatography column has superior performance compared with other types of chromatography columns and can perform a complete sulfide analysis within a suitable period of time. Although the GS-GasPro chromatography column can perform a complete sulfide analysis, the complete analysis takes about 45 minutes, which is not suitable for production needs. In addition, the methyl silicone-based chromatography column, the phthalate-based chromatography column, and the PLOT-based chromatography column with bound silica cannot perform a complete analysis of sulfur compounds and even have a tailing phenomenon.

[0025] In the apparatus for analyzing quality indicators of a natural gas product as described above, preferably the chromatographic column of the second chromatographic column analysis system comprises a first pre-separation column and a first chromatographic analytical column; in the second chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube through a connection/disconnection controllable connection pipeline, the other end of the quantitative tube is connected to the inlet end of the first pre-separation column through a connection/disconnection controllable connection pipeline, the outlet end of the first pre-separation column is connected to the inlet end of the first chromatographic analytical column through a connection/disconnection controllable connection pipeline, the carrier gas tube is connected to the outlet end of the first pre-separation column and the inlet end of the first chromatographic analytical column respectively through a connection/disconnection controllable connection pipeline, and the inlet end of the first pre-separation column and the outlet end of the first chromatographic analytical column are connected to the flame ionization detector respectively through a connection/disconnection controllable connection pipeline;

wherein the first pre-separation column provides for the separation of C ₆ ⁺ hydrocarbon components (hydrocarbon components containing 6 or more carbon atoms) from C ₅ ^- hydrocarbon components (hydrocarbon components containing 5 or less carbon atoms); and

The first chromatographic analytical column provides separation of propane, isobutane, n-butane, neopentane, isopentane and n-pentane.

[0026] More preferably, the first pre-separation column is selected from one of the pre-separation column OV-1 and the capillary column DB-1. More preferably, the first pre-separation column is the pre-separation column OV-1. More preferably, the packing material of the pre-separation column OV-1 comprises Celite 545 of 80-100 mesh and OV-1 silicone, wherein the content of OV-1 silicone is 10%-20% based on the weight of celite 545 (OV-1 silicone 10% Celite 545 80/100 mesh). More preferably, the pre-separation column OV-1 has a length of from 1.0 m to 2.0 m. More preferably, the capillary column DB-1 has a length of from 3.0 m to 5.0 m. In a particular embodiment, the pre-separation column OV-1 has the dimensions: outer diameter 1.6 mm; inner diameter of 1.0 mm; and length of 1.0 m. In a specific embodiment, the DB-1 capillary column has the following dimensions: length of 5.0 m; diameter of 0.55 mm; liquid phase film thickness of 20 μm.

[0027] More preferably, the first chromatographic analytical column is selected from one of an HP-Al/S chromatographic column, an HP-PLOT Al ₂ O ₃ S capillary column, a PONA capillary column and a Plot Q capillary column. More preferably, the first chromatographic analytical column is an HP-Al/S chromatographic column. More preferably, the HP-Al/S chromatographic column has a length of 30 m to 50 m. More preferably, the HP-PLOT Al ₂ O ₃ S capillary column has a length of 25 m to 50 m. More preferably, the PONA capillary column has a length of 50 m to 100 m. More preferably, the Plot Q capillary column has a length of 25 m to 30 m. In a particular embodiment, the HP-Al/S chromatographic column has the dimensions: length 50 m; diameter 0.53 mm; liquid phase film thickness 15 µm.

[0028] In the apparatus for analyzing quality indices of a natural gas product as described above, preferably the chromatographic column of the third chromatographic column analysis system comprises a second pre-separation column and a second chromatographic analytical column; in the third chromatographic column analysis system, one end of the quantitative tube is connected to a carrier gas tube through a connecting pipeline with a controllable connection/disconnection, the other end of the quantitative tube is connected to an inlet end of the second pre-separation column through a connecting pipeline with a controllable connection/disconnection, an outlet end of the second pre-separation column is connected to an inlet end of the second chromatographic analytical column through a connecting pipeline with a controllable connection/disconnection, the carrier gas tube is connected to an outlet end of the second pre-separation column and an inlet end of the second chromatographic analytical column respectively through a connecting pipeline with a controllable connection/disconnection, and the outlet end of the second chromatographic analytical column is connected to a thermal conductivity detector through a connecting pipeline with a controllable connection/disconnection;

wherein the second pre-separation column provides for the separation of oxygen, nitrogen, methane and carbon monoxide from the natural gas; and the second chromatographic analytical column provides for the separation of oxygen, nitrogen, methane and carbon monoxide.

[0029] More preferably, the second pre-separation column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column. More preferably, the second pre-separation column is a Porapak N column. More preferably, the packing material of the Porapak N column has a sieve number from 80 to 100. More preferably, the Porapak N column has a length of from 3 m to 5 m. In a particular embodiment, the Porapak N column has the dimensions: length of 1.0 m; outer diameter of 3.2 mm; and inner diameter of 2.1 mm.

[0030] More preferably, the second chromatographic analytical column is selected from one of a 13X molecular sieve column and a 5A molecular sieve column. More preferably, the second chromatographic analytical column is an MS-13X molecular sieve column. More preferably, the MS-13X molecular sieve column has a length of 3.0 m to 5.0 m. In a particular embodiment, the MS-13X molecular sieve column has the dimensions: length 5.0 m; outer diameter 3.2 mm; and inner diameter 2.1 mm.

[0031] In the apparatus for analyzing quality indices of a natural gas product as described above, preferably the chromatographic column of the fourth chromatographic column analysis system comprises a third pre-separation column and a third chromatographic analytical column; in the fourth chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube through a connection/disconnection controllable connection pipeline, the other end of the quantitative tube is connected to the inlet end of the third pre-separation column through a connection/disconnection controllable connection pipeline, the outlet end of the third pre-separation column is connected to the inlet end of the third chromatographic analytical column through a connection/disconnection controllable connection pipeline, the carrier gas tube is connected to the outlet end of the third pre-separation column and the inlet end of the third chromatographic analytical column respectively through a connection/disconnection controllable connection pipeline, and the outlet end of the third chromatographic analytical column is connected to the thermal conductivity detector through a connection/disconnection controllable connection pipeline;

wherein the third pre-separation column provides for the separation of ethane and CO ₂ from the natural gas; and the third chromatographic analytical column provides for the separation of ethane and CO ₂ .

[0032] More preferably, the third pre-separation column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column. More preferably, the third pre-separation column is a Porapak N column. More preferably, the packing material of the Porapak N column has a sieve number from 80 to 100. More preferably, the Porapak N column has a length of from 1 m to 2 m. In a particular embodiment, the Porapak N column has the dimensions: length 1.0 m; outer diameter 3.2 mm and inner diameter 2.1 mm.

[0033] More preferably, the third chromatographic analytical column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column. More preferably, the third chromatographic analytical column is a Porapak N column. More preferably, the packing material of the Porapak N column has a sieve number from 80 to 100. More preferably, the Porapak N column has a length of 2 m to 3 m. In a particular embodiment, the Porapak N column has the dimensions: length 2.0 m; outer diameter 3.2 mm and inner diameter 2.1 mm.

[0034] In the apparatus for analyzing quality indices of a natural gas product as described above, preferably the chromatographic column of the fifth chromatographic column analysis system comprises a fourth pre-separation column and a fourth chromatographic analytical column; in the fifth chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube through a connection/disconnection controllable connection pipeline, the other end of the quantitative tube is connected to the inlet end of the fourth pre-separation column through a connection/disconnection controllable connection pipeline, the outlet end of the fourth pre-separation column is connected to the inlet end of the fourth chromatographic analytical column through a connection/disconnection controllable connection pipeline, the carrier gas tube is connected to the outlet end of the fourth pre-separation column and the inlet end of the fourth chromatographic analytical column respectively through a connection/disconnection controllable connection pipeline, and the outlet end of the fourth chromatographic analytical column is connected to the thermal conductivity detector through a connection/disconnection controllable connection pipeline;

wherein the fourth preliminary separation column provides for the separation of helium and hydrogen from the natural gas; and the fourth chromatographic analytical column provides for the separation of helium and hydrogen.

[0035] More preferably, the fourth pre-separation column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column. More preferably, the fourth pre-separation column is a Porapak N column. More preferably, the packing material of the Porapak N column has a sieve number from 80 to 100. More preferably, the Porapak N column has a length of from 1 m to 2 m. In a particular embodiment, the Porapak N column has the dimensions: length of 1.0 m; outer diameter of 3.2 mm and inner diameter of 2.1 mm.

[0036] More preferably, the fourth chromatographic analytical column is selected from one of a 13X molecular sieve column and a 5A molecular sieve column. More preferably, the fourth chromatographic analytical column is an MS-5A molecular sieve column. More preferably, the packing material of the MS-5A molecular sieve column has a sieve number of from 60 to 80. More preferably, the MS-5A molecular sieve column has a length of from 3.0 m to 5.0 m. In a particular embodiment, the MS-5A molecular sieve column has the dimensions: length 3.0 m; outer diameter 3.2 mm and inner diameter 2.1 mm 3.2 x 2.1 mm x 3.0 m.

[0037] In the apparatus for analyzing quality indices of a natural gas product as described above, the first chromatographic column analysis system preferably comprises a first sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the first chromatographic column analysis system, the first sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube and the chromatographic column, wherein the first sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the first chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the first chromatographic column analysis system;

when the first sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the first chromatographic column analysis system after passing through the quantitative tube; and when the first sample loading valve is switched to the second working position, introducing the gas flow in the carrier gas tube of the first chromatographic column analysis system into the chromatographic column of the first chromatographic column analysis system through the quantitative tube of the first chromatographic column analysis system.

[0038] More preferably, the first sample loading valve is a six-way valve having a first operating position and a second operating position, wherein the six-way valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port and a sixth valve port in clockwise sequence; when the six-way valve is in the first operating position, the sixth valve port is connected to the first valve port, the second valve port is connected to the third valve port, and the fourth valve port is connected to the fifth valve port; when the six-way valve is in the second operating position, the first valve port is connected to the second valve port, the third valve port is connected to the fourth valve port, and the fifth valve port is connected to the sixth valve port; and

each of the sixth hole and the fifth hole of the first sample loading valve is connected to the sample loading unit, the quantitative tube of the first chromatographic column analysis system has one end connected to the first hole of the first sample loading valve and the other end connected to the fourth hole of the first sample loading valve, the carrier gas tube of the first chromatographic column analysis system is connected to the second hole of the first sample loading valve, and the sulfur determination column is connected to the third hole of the first sample loading valve.

[0039] In the apparatus for analyzing quality indices of a natural gas product as described above, the second chromatographic column analysis system preferably comprises a second sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the second chromatographic column analysis system, the second sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube and the chromatographic column, and the second sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the second chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the second chromatographic column analysis system;

when the second sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the second chromatographic column analysis system after passing through the quantitative tube; and when the second sample loading valve is switched to the second working position, it is possible to introduce the gas in the carrier gas tube of the second chromatographic column analysis system into the chromatographic column of the second chromatographic column analysis system through the quantitative tube of the second chromatographic column analysis system.

[0040] More preferably, in the second chromatographic column analysis system, the second sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the first pre-separation column, an inlet end of the first chromatographic analytical column and a flame ionization detector, and the second sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the second chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the second chromatographic column analysis system;

when the second sample loading valve is switched to the first working position, it is possible to directly discharge gas in the sample loading unit from the second chromatographic column analysis system after passing through the quantitative tube, introduce gas in the carrier gas tube of the second chromatographic column analysis system into the first preliminary separation column from the side of its outlet end, discharge a flow from the inlet end of the first preliminary separation column, and then introduce the flow into the flame ionization detector, while it is possible to introduce gas in the carrier gas tube of the second chromatographic column analysis system into the first chromatographic analytical column through the inlet end of the first chromatographic analytical column; and when the second sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the second chromatographic column analysis system into the first column for preliminary separation through the quantitative tube of the second chromatographic column analysis system, introduce through the outlet end of the first preliminary separation column and withdraw the flow from the outlet end of the first preliminary separation column, and then introduce into the first chromatographic analytical column through the inlet end of the first chromatographic analytical column.

[0041] Furthermore, preferably, the second sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the second sample loading valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port, a sixth valve port, a seventh valve port, an eighth valve port, a ninth valve port and a tenth valve port in clockwise sequence; when the second sample loading valve is in the first operating position, the tenth valve port is connected to the first valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, and the eighth valve port is connected to the ninth valve port; when the second sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and

each of the tenth hole and the ninth hole of the second sample loading valve is connected to the sample loading unit, the quantitative tube of the second chromatographic column analysis system has one end connected to the first hole of the second sample loading valve and the other end connected to the eighth hole of the second sample loading valve, the carrier gas tube of the second chromatographic column analysis system is connected to each of the seventh hole and the fourth hole of the second sample loading valve, the first pre-separation column has an inlet end connected to the second hole of the second sample loading valve and an outlet end connected to the sixth hole of the second sample loading valve, the inlet end of the first chromatographic analytical column is connected to the fifth hole of the second sample loading valve, and the third hole of the second sample loading valve is connected to the flame ionization detector.

[0042] In the apparatus for analyzing quality indices of a natural gas product as described above, the third chromatographic column analysis system preferably comprises a third sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the third chromatographic column analysis system, the third sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube and the chromatographic column, wherein the third sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the third chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the third chromatographic column analysis system;

when the third sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the third chromatographic column analysis system after passing through the quantitative tube; and when the third sample loading valve is switched to the second working position, it is possible to introduce the gas flow in the carrier gas tube of the third chromatographic column analysis system into the chromatographic column of the third chromatographic column analysis system through the quantitative tube of the third chromatographic column analysis system.

[0043] More specifically, in the third chromatographic column analysis system, the third sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the second pre-separation column and the inlet end of the second chromatographic analytical column, and the third sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the third chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the third chromatographic column analysis system;

when the third sample loading valve is switched to the first working position, it is possible to directly discharge gas in the sample loading unit from the third chromatographic column analysis system after passing through the quantitative tube, introduce gas in the carrier gas tube of the third chromatographic column analysis system into the second preliminary separation column from the side of its outlet end and discharge a flow from the inlet end of the second preliminary separation column for discharge from the three analysis systems, while it is possible to introduce gas in the carrier gas tube of the third chromatographic column analysis system into the second chromatographic analytical column through the inlet end of the second chromatographic analytical column; and when the third sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the third chromatographic column analysis system into the second preliminary separation column through the quantitative tube of the third chromatographic column analysis system, introduce through the inlet end of the second preliminary separation column and remove the flow from the outlet end of the second preliminary separation column, and then introduce into the second chromatographic analytical column through the inlet end of the second chromatographic analytical column.

[0044] Furthermore, preferably, the third sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the third sample loading valve is provided with a first valve opening, a second valve opening, a third valve opening, a fourth valve opening, a fifth valve opening, a sixth valve opening, a seventh valve opening, an eighth valve opening, a ninth valve opening and a tenth valve opening in clockwise sequence; when the third sample loading valve is in the first operating position, the tenth valve opening is connected to the first valve opening, the second valve opening is connected to the third valve opening, the fourth valve opening is connected to the fifth valve opening, the sixth valve opening is connected to the seventh valve opening, and the eighth valve opening is connected to the ninth valve opening; when the third sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and

each of the tenth hole and the ninth hole of the third sample loading valve is connected to the sample loading unit, the quantitative tube of the third chromatographic column analysis system has one end connected to the first hole of the third sample loading valve and the other end connected to the eighth hole of the third sample loading valve, the carrier gas tube of the third chromatographic column analysis system is connected to the seventh hole and the fourth hole of the third sample loading valve, the second pre-separation column has an inlet end connected to the second hole of the third sample loading valve and an outlet end connected to the sixth hole of the third sample loading valve, and the inlet end of the second chromatographic analytical column is connected to the fifth hole of the third sample loading valve.

[0045] In the apparatus for analyzing quality indices of a natural gas product as described above, the fourth chromatographic column analysis system preferably comprises a fourth sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the fourth chromatographic column analysis system, the fourth sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube and the chromatographic column, wherein the fourth sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the fourth chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the fourth chromatographic column analysis system;

when the fourth sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the fourth chromatographic column analysis system after passing through the quantitative tube; and when the fourth sample loading valve is switched to the second working position, it is possible to introduce the gas flow in the carrier gas tube of the fourth chromatographic column analysis system into the chromatographic column of the fourth chromatographic column analysis system through the quantitative tube of the fourth chromatographic column analysis system.

[0046] More preferably, in the fourth chromatographic column analysis system, the fourth sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the third pre-separation column and an inlet end of the third chromatographic analytical column, and the fourth sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the fourth chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the fourth chromatographic column analysis system;

when the fourth sample loading valve is switched to the first working position, it is possible to directly discharge gas in the sample loading unit from the fourth chromatographic column analysis system after passing through the quantitative tube, it is possible to introduce gas in the carrier gas tube of the fourth chromatographic column analysis system into the third preliminary separation column from the side of its outlet end and to discharge a flow from the inlet end of the third preliminary separation column for discharge from the three analysis systems, while it is possible to introduce gas in the carrier gas tube of the fourth chromatographic column analysis system into the third chromatographic analytical column through the inlet end of the third chromatographic analytical column; and when the fourth sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the fourth chromatographic column analysis system into the third preliminary separation column through the quantitative tube of the fourth chromatographic column analysis system, introduce it through the inlet end of the third preliminary separation column and remove the flow from the outlet end of the third preliminary separation column, and then introduce it into the third chromatographic analytical column through the inlet end of the third chromatographic analytical column.

[0047] Furthermore, preferably the fourth sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the fourth sample loading valve is provided with a first valve opening, a second valve opening, a third valve opening, a fourth valve opening, a fifth valve opening, a sixth valve opening, a seventh valve opening, an eighth valve opening, a ninth valve opening and a tenth valve opening in clockwise sequence; when the fourth sample loading valve is in the first operating position, the tenth valve opening is connected to the first valve opening, the second valve opening is connected to the third valve opening, the fourth valve opening is connected to the fifth valve opening, the sixth valve opening is connected to the seventh valve opening, and the eighth valve opening is connected to the ninth valve opening; when the fourth sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and

each of the tenth port and the ninth port of the fourth sample loading valve is connected to the sample loading unit, the quantitative tube of the fourth chromatographic column analysis system has one end connected to the first port of the fourth sample loading valve and the other end connected to the eighth port of the fourth sample loading valve, the carrier gas tube of the fourth chromatographic column analysis system is connected to the seventh port and the fourth port of the fourth sample loading valve, the third pre-separation column has an inlet end connected to the second port of the fourth sample loading valve and an outlet end connected to the sixth port of the fourth sample loading valve, and the inlet end of the third chromatographic analytical column is connected to the fifth port of the fourth sample loading valve.

[0048] In the apparatus for analyzing quality indices of a natural gas product as described above, the fifth chromatographic column analysis system preferably comprises a fifth sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the fifth chromatographic column analysis system, the fifth sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube and the chromatographic column, wherein the fifth sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the fifth chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the fifth chromatographic column analysis system;

when the fifth sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the fifth chromatographic column analysis system after passing through the quantitative tube; and when the fifth sample loading valve is switched to the second working position, it is possible to introduce the gas flow in the carrier gas tube of the fifth chromatographic column analysis system into the chromatographic column of the fifth chromatographic column analysis system through the quantitative tube of the fifth chromatographic column analysis system.

[0049] More preferably, in the fifth chromatographic column analysis system, the fifth sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the fourth pre-separation column and an inlet end of the fourth chromatographic analytical column, wherein the fifth sample loading valve controls the connection/disconnection of the connecting pipeline between the components of the fifth chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the fifth chromatographic column analysis system;

when the fifth sample loading valve is switched to the first working position, it is possible to directly discharge gas in the sample loading unit from the fifth chromatographic column analysis system after passing through the quantitative tube, it is possible to introduce a gas flow in the carrier gas tube of the fifth chromatographic column analysis system into the fourth preliminary separation column from the side of its outlet end and to discharge a flow from the inlet end of the fourth preliminary separation column for discharge from the three analysis systems, while it is possible to introduce gas in the carrier gas tube of the fifth chromatographic column analysis system into the fourth chromatographic analytical column through the inlet end of the fourth chromatographic analytical column; and when the fifth sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the fifth chromatographic column analysis system into the fourth preliminary separation column through the quantitative tube of the fifth chromatographic column analysis system, introduce it through the inlet end of the fourth preliminary separation column and remove the flow from the outlet end of the fourth preliminary separation column, and then introduce it into the fourth chromatographic analytical column through the inlet end of the fourth chromatographic analytical column.

[0050] In addition, preferably the fifth sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the fifth sample loading valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port, a sixth valve port, a seventh valve port, an eighth valve port, a ninth valve port and a tenth valve port in clockwise sequence; when the fifth sample loading valve is in the first operating position, the tenth valve port is connected to the first valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, and the eighth valve port is connected to the ninth valve port; when the fifth sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and

each of the tenth port and the ninth port of the fifth sample loading valve is connected to the sample loading unit, the quantitative tube of the fifth chromatographic column analysis system has one end connected to the first port of the fifth sample loading valve and the other end connected to the eighth port of the fifth sample loading valve, the carrier gas tube of the fifth chromatographic column analysis system is connected to the seventh port and the fourth port of the fifth sample loading valve, the fourth pre-separation column has an inlet end connected to the second port of the fifth sample loading valve and an outlet end connected to the sixth port of the fifth sample loading valve, and the inlet end of the fourth chromatographic analytical column is connected to the fifth port of the fifth sample loading valve.

[0051] In a particular embodiment, the sample loading unit comprises an inlet tube for natural gas, an outlet tube for natural gas and first, second, third and fourth connecting tubes for quantity tubes, wherein the first, second, third and fourth connecting tubes for quantity tubes are configured to connect quantity tubes in series, respectively, the inlet tube for natural gas is connected to the inlet end of quantity tubes connected in series, and the outlet tube for natural gas is connected to the outlet end of quantity tubes connected in series.

[0052] In this case, the first, second, third, fourth and fifth sample loading valves are connected in series through the first, second, third and fourth connecting tubes for quantitative tubes, and the natural gas inlet tube and the natural gas outlet tube are respectively connected to the first and last sample loading valves of the first, second, third, fourth and fifth sample loading valves, which are connected in series.

[0053] In the device for analyzing the quality indicators of a natural gas product as described above, the device preferably also comprises an apparatus for programmable temperature change, in which a column for determining sulfur of the first chromatographic column analysis system and/or a first chromatographic analytical column of the second chromatographic column analysis system are located.

[0054] In the device for analyzing the quality indicators of a natural gas product as described above, the device preferably also comprises a thermostat in which a second chromatographic analytical column of a third chromatographic column analysis system, a third chromatographic analytical column of a fourth chromatographic column analysis system and/or a fourth chromatographic analytical column of a fifth chromatographic column analysis system are located.

[0055] In the apparatus for analyzing quality indicators of a natural gas product as described above, preferably the volume of the quantitative tube of the first chromatographic column analysis system is 1 ml.

[0056] In the apparatus for analyzing quality indicators of a natural gas product as described above, preferably the volume of the quantitative tube of the second chromatographic column analysis system is 100 μL.

[0057] In the apparatus for analyzing the quality indicators of a natural gas product as described above, preferably the volume of the quantitative tube of the third chromatographic column analysis system is 1 ml.

[0058] In the apparatus for analyzing the quality indicators of a natural gas product as described above, preferably the volume of the quantitative tube of the fourth chromatographic column analysis system is 1 ml.

[0059] In the apparatus for analyzing the quality indicators of a natural gas product as described above, preferably the volume of the quantitative tube of the fifth chromatographic column analysis system is 5 ml.

[0060] The present invention also provides a method for analyzing the quality indicators of a natural gas product. The method is carried out using a device for analyzing the quality indicators of a natural gas product, as described above. The method includes:

introducing a sample into the quantitative tubes of the first chromatographic column analysis system, the second chromatographic column analysis system, the third chromatographic column analysis system, the fourth chromatographic column analysis system and the fifth chromatographic column analysis system in such a way that each of the quantitative tubes is filled with a sample of natural gas;

in a first chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate sulfides from a natural gas sample in a quantitative tube under the action of the carrier gas, and feeding the separated components to a detection detector to obtain a first detection chromatogram; determining the sulfide content in the natural gas sample based on the obtained first detection chromatogram;

in a second chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate hydrocarbons having _C3 or higher from a natural gas sample in a quantitative tube under the action of the carrier gas, and delivering the separated components to a detection detector to obtain a second detection chromatogram; determining the content of hydrocarbons having _C3 or higher in the natural gas sample based on the obtained second detection chromatogram;

in a third chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate oxygen, nitrogen, methane and carbon monoxide from a natural gas sample in a quantitative tube under the action of the carrier gas, and supplying the separated components to a detector for detection to obtain a third detection chromatogram; determining the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample based on the obtained third detection chromatogram;

in a fourth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate carbon dioxide and ethane from a natural gas sample in a quantitative tube under the action of the carrier gas, and supplying the separated components to a detector for detection to obtain a fourth detection chromatogram; determining the content of carbon dioxide and ethane in the natural gas sample based on the obtained fourth detection chromatogram;

in a fifth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate helium and hydrogen from a natural gas sample in a quantitative tube under the action of the carrier gas, and delivering the separated components to a detection detector to obtain a fifth detection chromatogram; determining the content of helium and hydrogen in the natural gas sample based on the obtained fifth detection chromatogram; and

based on the obtained content of sulfides in a natural gas sample, hydrocarbons with _C3 and higher in a natural gas sample, oxygen, nitrogen, methane and carbon monoxide in a natural gas sample, carbon dioxide and ethane in a natural gas sample, as well as helium and hydrogen in a natural gas sample, the higher calorific value of natural gas, the total sulfur content (in terms of sulfur, in mg/ ^m3 ), the hydrogen sulfide content (in mg/ ^m3 ) and/or the carbon dioxide content (in mole percent) are determined.

[0061] Using the integrated device for analyzing natural gas product quality parameters disclosed in the present invention, together with the SCD, FID and TCD, 13 types of sulfur compounds and 15 types of common components in the natural gas product can be analyzed in one sample load, and the analysis cycle for detecting all the components in one sample load is less than 20 minutes.

[0062] In the method for analyzing the quality indices of a natural gas product as described above, based on the obtained first detection chromatogram, the sulfide content in the natural gas sample can be determined by a method generally accepted in the art, for example, by comparing the first detection chromatogram with standard curves of the sulfide content. Specifically, the response peak area data is obtained according to the first detection chromatogram, and then the sulfide content in the natural gas sample is determined according to the response peak data using the standard curves of the sulfide content. The standard curves of the sulfide content can be obtained by performing a standard test on the gas sample.

[0063] In the method for analyzing quality indices of a natural gas product as described above, based on the obtained second detection chromatogram, the content of hydrocarbons having C ₃ or higher in a natural gas sample can be determined by a method conventional in the art, for example, by comparing the second detection chromatogram with standard curves of the content of hydrocarbons having C ₃ or higher. Specifically, data on the area of the response peak is obtained according to the second detection chromatogram, and then the content of hydrocarbons having C ₃ or higher in the natural gas sample is determined according to the data on the response peak using the standard curves of the content of hydrocarbons having C ₃ or higher. The standard curves of the content of hydrocarbons having C ₃ or higher can be obtained by performing a standard test on the gas sample.

[0064] In the method for analyzing the quality indices of a natural gas product as described above, based on the obtained third detection chromatogram, the content of oxygen, nitrogen, methane and carbon monoxide in a natural gas sample can be determined by a method generally accepted in the art, for example, by comparing the third detection chromatogram with standard curves of the content of oxygen, nitrogen, methane and carbon monoxide. Specifically, the response peak area data is obtained according to the third detection chromatogram, and then the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample is determined according to the response peak data using the standard curves of the content of oxygen, nitrogen, methane and carbon monoxide. The standard curves of the content of oxygen, nitrogen, methane and carbon monoxide can be obtained by performing a standard test on the gas sample.

[0065] In the method for analyzing the quality indices of a natural gas product as described above, based on the obtained fourth detection chromatogram, the content of carbon dioxide and ethane in the natural gas sample can be determined by a method generally accepted in the art, for example, by comparing the fourth detection chromatogram with standard curves of the content of carbon dioxide and ethane. Specifically, data on the area of the response peak is obtained according to the fourth detection chromatogram, and then the content of carbon dioxide and ethane in the natural gas sample is determined according to the data on the response peak using the standard curves of the content of carbon dioxide and ethane. The standard curves of the content of carbon dioxide and ethane can be obtained by performing a standard test on the gas sample.

[0066] In the method for analyzing the quality indices of a natural gas product as described above, based on the obtained fifth detection chromatogram, the content of helium and hydrogen in a natural gas sample can be determined by a method generally accepted in the art, for example, by comparing the fifth detection chromatogram with standard curves of the content of helium and hydrogen. Specifically, data on the area of the response peak is obtained according to the fifth detection chromatogram, and then the content of helium and hydrogen in the natural gas sample is determined according to the data on the response peak using the standard curves of the content of helium and hydrogen. The standard curves of the content of helium and hydrogen can be obtained by performing a standard test on a gas sample.

[0067] In the method for analyzing the quality indices of a natural gas product as described above, the gross calorific value of the natural gas can be determined by a conventional method in the art, for example, by a method for obtaining a mole percentage of sulfur compounds and a mole percentage of hydrocarbons and non-hydrocarbons based on a content of sulfides in a natural gas sample, a content of hydrocarbons having _C3 or higher in a natural gas sample, a content of oxygen, nitrogen, methane and carbon monoxide in a natural gas sample, a content of carbon dioxide and ethane in a natural gas sample and a content of helium and hydrogen in a natural gas sample with a total percentage of 100%, and then the gross calorific value of the natural gas is determined using a gross calorific value calculation model.

[0068] In the method for analyzing the quality indicators of a natural gas product as described above, the total sulfur content of the natural gas can be determined by a method generally accepted in the art, for example, by a method of obtaining the sum of the sulfide content, i.e., the total sulfur content of the natural gas, based on the sulfide content in a natural gas sample.

[0069] In the method for analyzing the quality index of a natural gas product as described above, the hydrogen sulfide content in the natural gas can be determined by a method generally accepted in the art. For example, the hydrogen sulfide content in a natural gas sample is the hydrogen sulfide content in the natural gas.

[0070] In the method for analyzing the quality indices of a natural gas product as described above, the carbon dioxide content of the natural gas can be determined by a conventional method in the art, for example, by a method of obtaining the sum of the component contents based on the content of hydrocarbons having _C3 and above in a natural gas sample, the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample, the content of carbon dioxide and ethane in the natural gas sample and the content of helium and hydrogen in the natural gas sample, and then determining the proportion of the carbon dioxide content based on the sum of the component contents as the carbon dioxide content of the natural gas.

[0071] In the method for analyzing quality indices of a natural gas product as described above, preferably the step of using a carrier gas tube to deliver a carrier gas in a first chromatographic column analysis system, using a chromatographic column to separate sulfides from a natural gas sample in a quantitative tube under the action of the carrier gas, and feeding the separated components to a detection detector to obtain a first detection chromatogram, includes:

in a chromatographic column analysis system: using a carrier gas tube to supply a carrier gas, supplying a natural gas sample in a quantitative tube to a sulfur detection column under the action of the carrier gas to separate sulfides, and supplying the separated components to a chemiluminescence sulfur detector so that sulfides in the natural gas sample are detected so as to obtain a first detection chromatogram.

[0072] In this preferred technical solution, a natural gas sample is separated by a sulfur column under the action of a carrier gas, and carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene sulfides are sequentially withdrawn from the sulfur column to a chemiluminescence sulfur detector for detection.

[0073] More preferably, the sulfur determination column is maintained at 30-50°C until the carbonyl sulfur is released from the sulfur determination column, and then the sulfur determination column is heated at a rate of 10-20°C/min to 130°C-150°C and maintained at this temperature.

[0074] In a particular embodiment, the carrier gas flow rate is 3 ml/min.

[0075] In a particular embodiment, the sulfur chemiluminescence detector has a sample loading temperature of 200°C and a reaction temperature of 850°C, and the reaction gas flow rates in the sulfur chemiluminescence detector are 80 mL/min for hydrogen ( _H2 ), 40 mL/min for nitrogen ( _N2 ), 10 mL/min for oxygen ( _O2 ), and 25 mL/min for ozone ( _O3 ).

[0076] In the method for analyzing quality indices of a natural gas product as described above, preferably the step of using a carrier gas tube to deliver a carrier gas in the second chromatographic column analysis system, using a chromatographic column to separate hydrocarbons having _C3 and above from a natural gas sample in a quantitative tube under the action of the carrier gas, and feeding the separated components to a detector for detection to obtain a second detection chromatogram, includes:

in a second chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, and using a first pre-separation column and a first chromatographic analytical column sequentially to perform separation of a natural gas sample in a quantitative tube under the action of a carrier gas; when C ₅ ^- components in the natural gas sample exit from the first pre-separation column and enter the first chromatographic analytical column, transferring the carrier gas to an outlet end of the first pre-separation column, connecting an inlet end of the first pre-separation column to a flame ionization detector, and under the action of the carrier gas, backflush transferring C ₆ ⁺ hydrocarbon components from the first pre-separation column to the flame ionization detector for detection; and after completion of the backwash, transferring the carrier gas to the inlet end of the first chromatographic analytical column and, under the action of the carrier gas, sequentially introducing the C ₃ ^- hydrocarbon components separated by the first chromatographic analytical column into the flame ionization detector for detection so as to obtain a second detection chromatogram.

[0077] In this preferred technical solution, the first pre-separation column and the first chromatographic analytical column are sequentially used to separate a natural gas sample under the action of a carrier gas, wherein propane, isobutane, n-butane, neopentane, isopentane and n-pentane in the natural gas sample are output from the first pre-separation column to the first chromatographic analytical column for separation, so that the difference in the separation time of the components increases. When outputting the C ₅ ^- components from the first pre-separation column and inputting into the first chromatographic analytical column, the carrier gas is supplied to the outlet end of the first pre-separation column, the inlet end of the first pre-separation column is connected to a flame ionization detector, the C ₆ ⁺ hydrocarbon components in the first pre-separation column are first passed as a combined hexane peak through the flame ionization detector for detection by reversing the flow of the carrier gas. Then, the carrier gas is transferred to the inlet end of the first chromatographic analytical column, and under the action of the carrier gas, propane, isobutane, n-butane, neopentane, isopentane and n-pentane are sequentially discharged from the first chromatographic analytical column into the flame ionization detector for detection.

[0078] More preferably, the first chromatographic analytical column is maintained at 30-50°C until the flame ionization detector monitors peaks of C ₆ ⁺ hydrocarbon components, and then the first chromatographic analytical column is heated at a rate of 10-20°C/min to 130-150°C and maintained at that temperature.

[0079] In a particular embodiment, the carrier gas is pumped at a pressure of 500 kPa.

[0080] In a particular embodiment, the temperature of the flame ionization detector is 200°C, and the flow rates of the reaction gases of the flame ionization detector are 32 ml/min for hydrogen (H ₂ ), 200 ml/min for air, and 20 ml/min for make-up gas (make-up).

[0081] In the method for analyzing quality indices of a natural gas product as described above, preferably the step of using a carrier gas tube to deliver a carrier gas in a third chromatographic column analysis system, using a chromatographic column to separate oxygen, nitrogen, methane and carbon monoxide from a natural gas sample in a quantitative tube under the action of the carrier gas, and feeding the separated components to a detector for detection to obtain a third detection chromatogram, includes:

in a third chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, and using a second pre-separation column and a second chromatographic analytical column sequentially to perform separation of the natural gas sample in the quantitative tube under the action of the carrier gas; after the oxygen, nitrogen, methane and carbon monoxide components in the natural gas sample exit from the second pre-separation column and enter the second chromatographic analytical column, transferring the carrier gas to an outlet end of the second pre-separation column and removing by backwashing the remaining components in the second pre-separation column from the third chromatographic column analysis system under the action of the carrier gas; and after completing the backwashing, transferring the carrier gas to an inlet end of the second chromatographic analytical column and, under the action of the carrier gas, sequentially introducing the oxygen, nitrogen, methane and carbon monoxide components separated by the second chromatographic analytical column into a thermal conductivity detector for detection, so as to obtain a third detection chromatogram.

[0082] In this preferred technical solution, the second pre-separation column and the second chromatographic analytical column are used sequentially to separate the natural gas sample under the action of the carrier gas, and oxygen, nitrogen, methane and carbon monoxide in the natural gas sample are discharged from the second pre-separation column to the second chromatographic analytical column for separation, so that the time difference in separating the components increases. After the oxygen, nitrogen, methane and carbon monoxide components are discharged from the second pre-separation column and entered into the second chromatographic analytical column, the carrier gas is supplied to the outlet end of the second pre-separation column, and the remaining components in the second pre-separation column are washed out and removed by reversing the flow of the carrier gas. Then, the carrier gas is transferred to the inlet end of the second chromatographic analytical column, and under the action of the carrier gas, oxygen, nitrogen, methane and carbon monoxide are sequentially discharged from the second chromatographic analytical column to the thermal conductivity detector for detection.

[0083] More preferably, the temperature of the second chromatographic analytical column is 50-70°C.

[0084] In a particular embodiment, the carrier gas is pumped at a pressure of 295-500 kPa.

[0085] In a particular embodiment, the temperature of the thermal conductivity detector is 150°C, wherein the thermal conductivity detector has an operating current of 120 mA and is cathodic in polarity.

[0086] In the method for analyzing the quality indices of a natural gas product as described above, preferably the step of using a carrier gas tube to deliver a carrier gas in a fourth chromatographic column analysis system, using a chromatographic column to separate carbon dioxide and ethane from a natural gas sample in a quantitative tube under the action of the carrier gas, and feeding the separated components to a detector for detection to obtain a fourth detection chromatogram, includes:

in a fourth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, and using a third pre-separation column and a third chromatographic analytical column sequentially to separate the natural gas sample in the quantitative tube under the action of the carrier gas; after discharging the carbon dioxide and ethane components in the natural gas sample from the third pre-separation column and introducing into the third chromatographic analytical column: transferring the carrier gas to the outlet end of the third pre-separation column and removing by backwashing the remaining components in the third pre-separation column from the fourth chromatographic column analysis system under the action of the carrier gas; and after completing the backwashing, transferring the carrier gas to the inlet end of the third chromatographic analytical column and, under the action of the carrier gas, introducing sequentially the carbon dioxide and ethane components separated by the third chromatographic analytical column into a thermal conductivity detector for detection, so as to obtain a fourth detection chromatogram.

[0087] In this preferred technical solution, a third pre-separation column and a third chromatographic analytical column are sequentially used to separate a natural gas sample under the action of a carrier gas, and carbon dioxide and ethane in the natural gas sample are discharged from the third pre-separation column to the third chromatographic analytical column for separation, so that the time difference in separating the components increases. After the carbon dioxide and ethane components exit the third pre-separation column and enter the third chromatographic analytical column, the carrier gas is supplied to the outlet end of the third pre-separation column, and the remaining components in the third pre-separation column are washed and removed by reversing the flow of the carrier gas. Then, the carrier gas is transferred to the inlet end of the third chromatographic analytical column, and under the action of the carrier gas, carbon dioxide and ethane are sequentially discharged from the third chromatographic analytical column to a thermal conductivity detector for detection.

[0088] More preferably, the temperature of the third chromatographic analytical column is 50-70°C.

[0089] In a particular embodiment, the carrier gas is pumped under a pressure of 278-350 kPa.

[0090] In a particular embodiment, the temperature of the thermal conductivity detector is 150°C, wherein the thermal conductivity detector has an operating current of 120 mA and is cathodic in polarity.

[0091] In the method for analyzing the quality indices of a natural gas product as described above, preferably the step of using a carrier gas tube to deliver a carrier gas in the fifth chromatographic column analysis system, using the chromatographic column to separate helium and hydrogen from the natural gas sample in the quantitative tube under the action of the carrier gas, and feeding the separated components to a detector for detection to obtain a fifth detection chromatogram, includes:

in a fifth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, and using a fourth pre-separation column and a fourth chromatographic analytical column sequentially to perform separation of the natural gas sample in the quantitative tube under the action of the carrier gas; after the helium and hydrogen components in the natural gas sample exit from the fourth pre-separation column and enter the fourth chromatographic analytical column, transferring the carrier gas to an outlet end of the fourth pre-separation column and removing by backwashing the remaining components in the fourth pre-separation column from the fifth chromatographic column analysis system under the action of the carrier gas; and after the backwashing is completed, transferring the carrier gas to an inlet end of the fourth chromatographic analytical column and, under the action of the carrier gas, sequentially introducing the helium and hydrogen components separated by the fourth chromatographic analytical column into a thermal conductivity detector for detection, so as to obtain a fifth detection chromatogram.

[0092] In this preferred technical solution, a fourth pre-separation column and a fourth chromatographic analytical column are used sequentially to separate a natural gas sample under the action of a carrier gas, and helium and hydrogen in the natural gas sample are discharged from the fourth pre-separation column to the fourth chromatographic analytical column for separation, so that the time difference in separating the components increases. After the helium and hydrogen components exit the fourth pre-separation column and enter the fourth chromatographic analytical column, the carrier gas is supplied to the outlet end of the fourth pre-separation column, and the remaining components in the fourth pre-separation column are washed and removed by reversing the flow of the carrier gas. Then, the carrier gas is transferred to the inlet end of the fourth chromatographic analytical column, and under the action of the carrier gas, helium and hydrogen are sequentially discharged from the fourth chromatographic analytical column to a thermal conductivity detector for detection.

[0093] More preferably, the temperature of the fourth chromatographic analytical column is 50-70°C.

[0094] In a particular embodiment, the carrier gas is pumped at a pressure of 250 kPa.

[0095] In a particular embodiment, the temperature of the thermal conductivity detector is 150°C, wherein the thermal conductivity detector has an operating current of 70 mA and is anodic in polarity.

[0096] In the method for analyzing the quality indices of a natural gas product as described above, preferably the carrier gas used in the first chromatographic column analysis system is helium.

[0097] In the method for analyzing the quality indicators of a natural gas product as described above, preferably the carrier gas used in the second chromatographic column analysis system is helium.

[0098] In the method for analyzing the quality indicators of a natural gas product as described above, preferably the carrier gas used in the third chromatographic column analysis system is helium.

[0099] In the method for analyzing the quality indices of a natural gas product as described above, preferably the carrier gas used in the fourth chromatographic column analysis system is helium.

[0100] In the method for analyzing quality indicators of a natural gas product as described above, preferably the carrier gas used in the fifth chromatographic column analysis system is nitrogen.

[0101] The present invention also provides the use of a device for analyzing quality indicators of a natural gas product in analyzing a natural gas product.

BRIEF DESCRIPTION OF DRAWINGS

[0102] FIG. 1 shows a basic structural diagram of an apparatus for analyzing quality indicators of a natural gas product in Example 1 of the present invention.

[0103] FIG. 2 shows a schematic structural diagram of the first chromatographic column analysis system in Example 1 of the present invention.

[0104] FIG. 3 shows a schematic structural diagram of the second chromatographic column analysis system in Example 1 of the present invention.

[0105] FIG. 4 shows a schematic structural diagram of a third chromatographic column analysis system in Example 1 of the present invention.

[0106] FIG. 5 shows a schematic structural diagram of a fourth chromatographic column analysis system in Example 1 of the present invention.

[0107] FIG. 6 shows a schematic structural diagram of a fifth chromatographic column analysis system in Example 1 of the present invention.

[0108] FIG. 7 shows the first detection chromatogram in Example 2 of the present invention.

[0109] FIG. 8 shows a second detection chromatogram in Example 2 of the present invention.

[0110] FIG. 9 shows the third and fourth detection chromatograms in Example 2 of the present invention.

[0111] FIG. 10 shows a fifth detection chromatogram in Example 2 of the present invention.

[0112] FIG. 11 shows a hydrogen sulfide content reference curve.

[0113] FIG. 12 shows a reference curve for carbon oxysulfide content.

[0114] FIG. 13 shows a standard curve for methyl mercaptan content.

[0115] FIG. 14 shows a standard curve for ethyl mercaptan content.

[0116] FIG. 15 shows a standard curve of methyl sulfide content.

[0117] FIG. 16 shows a carbon disulfide content reference curve.

[0118] FIG. 17 shows a reference curve for isopropyl mercaptan content.

[0119] FIG. 18 shows a standard curve for tert-butyl mercaptan content.

[0120] FIG. 19 shows a standard curve of methyl ethyl sulfide content.

[0121] FIG. 20 shows a thiophene content reference curve.

[0122] FIG. 21 shows a standard curve of ethyl sulfide content.

[0123] FIG. 22 shows a reference curve for n-butyl mercaptan content.

[0124] FIG. 23 shows a standard curve of dimethyl disulfide content.

[0125] FIG. 24 shows a carbon dioxide content reference curve.

[0126] FIG. 25 shows a reference curve for ethane content.

[0127] FIG. 26 shows a nitrogen content reference curve.

[0128] FIG. 27 shows a helium content reference curve.

[0129] FIG. 28 shows a hydrogen content reference curve.

[0130] FIG. 29 shows a hexane content reference curve.

[0131] FIG. 30 shows a propane content reference curve.

[0132] FIG. 31 shows a carbon monoxide content reference curve.

[0133] FIG. 32 shows a reference curve for isobutane content.

[0134] FIG. 33 shows a reference curve for n-butane content.

[0135] FIG. 34 shows a neopentane content reference curve.

[0136] FIG. 35 shows a reference curve for isopentane content.

[0137] FIG. 36 shows a reference curve for n-pentane content.

[0138] Description of the main reference symbols:

1 - sample loading unit; 11 - inlet tube for natural gas; 12 - outlet tube for natural gas; 13 - first connecting tube for quantitative tubes; 14 - second connecting tube for quantitative tubes; 15 - third connecting tube for quantitative tubes; 16 - fourth connecting tube for quantitative tubes;

21 - first chromatographic column analysis system; 211 - first sample loading valve; 212 - first quantitative tube; 213 - first carrier gas tube; 214 - sulfur determination column; 215 - split/splitless inlet;

22 - second chromatographic column analysis system; 221 - second sample loading valve; 222 - second quantitative tube; 223 - second tube for carrier gas; 224 - first preliminary separation column; 225 - first chromatographic analytical column;

23 - third chromatographic column analysis system; 231 - third sample loading valve; 232 - third quantitative tube; 233 - third tube for carrier gas; 234 - second preliminary separation column; 235 - second chromatographic analytical column;

24 - fourth chromatographic column analysis system; 241 - fourth sample loading valve; 242 - fourth quantitative tube; 243 - fourth tube for carrier gas; 244 - third preliminary separation column; 245 - third chromatographic analytical column;

25 - fifth chromatographic column analysis system; 251 - fifth sample loading valve; 252 - fifth quantitative tube; 253 - fifth tube for carrier gas; 254 - fourth preliminary separation column; 255 - fourth chromatographic analytical column;

31 - chemiluminescent detector for sulfur; 32 - flame ionization detector; 33 - first thermal conductivity detector; 34 - second thermal conductivity detector.

IMPLEMENTATION OF THE INVENTION

[0139] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is obvious that the described examples are some, not all, examples of the present invention. Any other embodiments obtained by persons skilled in the art based on the embodiments of the present invention without any creative efforts fall within the scope of protection of the present invention. The principles and essences of the present invention will be described in detail below with reference to several typical embodiments.

Example 1

[0140] As shown in FIG. 1-6, in this example, a device for analyzing quality indicators of a natural gas product is proposed. The system comprises: a sample loading unit 1, a first chromatographic column analysis system 21, a second chromatographic column analysis system 22, a third chromatographic column analysis system 23, a fourth chromatographic column analysis system 24, a fifth chromatographic column analysis system 25, a chemiluminescence detector 31 for sulfur, a flame ionization detector 32, a first thermal conductivity detector 33 and a second thermal conductivity detector 34.

[0141] The sample loading unit 1 comprises an inlet pipe 11 for natural gas, an outlet pipe 12 for natural gas, a first connecting pipe 13 for quantity pipes, a second connecting pipe 14 for quantity pipes, a third connecting pipe 15 for quantity pipes and a fourth connecting pipe 16 for quantity pipes.

[0142] Each chromatographic column analysis system comprises a sample loading valve and a quantitative tube, and a carrier gas tube and a chromatographic column that are connected to the sample loading valve. In particular, the first chromatographic column analysis system 21 comprises a first sample loading valve 211, a first quantitative tube 212, a first carrier gas tube 213, a sulfur detection column 214, and a split/splitless inlet 215. The first sample loading valve 211 is a six-way valve having a first operating position and a second operating position, and is provided with a first valve opening a1, a second valve opening a2, a third valve opening a3, a fourth valve opening a4, a fifth valve opening a5, and a sixth valve opening a6 in clockwise sequence; when the first sample loading valve 211 is in the first operating position, the sixth valve opening a6 is connected to the first valve opening a1, the second valve opening a2 is connected to the third valve opening a3, and the fourth valve opening a4 is connected to the fifth valve opening a5; when the first sample loading valve 211 is in the second operating position, the first valve opening a1 is connected to the second valve opening a2, the third valve opening a3 is connected to the fourth valve opening a4, and the fifth valve opening a5 is connected to the sixth valve opening a6; the first quantitative tube 212 has one end connected to the first valve opening a1 and the other end connected to the fourth valve opening a4, the first carrier gas tube 213 is connected to the second valve opening a2, and the sulfur detection column 214 is connected to the third valve opening a3; and a split/splitless inlet 215 is located in the connecting pipeline between the sulfur column 214 and the third port a3 of the valve. The sulfur column 214 provides separation of carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene. The first tube 213 for the carrier gas is provided with a flow meter 2131.

[0143] The second system 22 for chromatographic column analysis comprises a second valve 221 for loading a sample, a second quantitative tube 222, a second tube 223 for a carrier gas, a first column 224 for preliminary separation and a first chromatographic analytical column 225. The second valve 221 for loading a sample is a ten-way valve having a first operating position and a second operating position, and is provided with a first valve hole b1, a second valve hole b2, a third valve hole b3, a fourth valve hole b4, a fifth valve hole b5, a sixth valve hole b6, a seventh valve hole b7, an eighth valve hole b8, a ninth valve hole b9 and a tenth valve hole b10 in clockwise sequence; when the second sample loading valve 221 is in the first working position, the tenth valve opening b10 is connected to the first valve opening b1, the second valve opening b2 is connected to the third valve opening b3, the fourth valve opening b4 is connected to the fifth valve opening b5, the sixth valve opening b6 is connected to the seventh valve opening b7, and the eighth valve opening b8 is connected to the ninth valve opening b9; when the second sample loading valve 221 is in the second working position, the first valve opening b1 is connected to the second valve opening b2, the third valve opening b3 is connected to the fourth valve opening b4, the fifth valve opening b5 is connected to the sixth valve opening b6, the seventh valve opening b7 is connected to the eighth valve opening b8, and the ninth valve opening b9 is connected to the tenth valve opening b10; and the second quantitative tube 222 has one end connected to the first opening b1 of the valve and the other end connected to the eighth opening b8 of the valve, the second tube 223 for the carrier gas is connected to each of the seventh opening b7 of the valve and the fourth opening b4 of the valve, the first pre-separation column 224 has an inlet end connected to the second opening b2 of the valve and an outlet end connected to the sixth opening b6 of the valve, and the inlet end of the first chromatographic analytical column 225 is connected to the fifth opening b5 of the valve. The first pre-separation column 224 allows separating ^C ₆₊ hydrocarbon components (including hydrocarbon components containing 6 or more carbon atoms) from ^C _5- hydrocarbon components (including hydrocarbon components containing 5 or less carbon atoms); and the first chromatographic analytical column 225 ensures the separation of propane, isobutane, n-butane, neopentane, isopentane and n-pentane. The second tube 223 for the carrier gas is provided with a flow meter 2231; the damping tube 227 is located in the connecting pipeline between the second tube 223 for the carrier gas and the fourth opening b4 of the valve; and the diverter valve 229 is located in the connecting pipeline between the inlet end of the first chromatographic analytical column 225 and the fifth opening b5 of the valve.

[0144] The third chromatographic column analysis system 23 comprises a third sample loading valve 231, a third quantitative tube 232, a third tube 233 for a carrier gas, a second pre-separation column 234 and a second chromatographic analytical column 235. The third sample loading valve 231 is a ten-way valve having a first operating position and a second operating position, and is provided with a first valve opening c1, a second valve opening c2, a third valve opening c3, a fourth valve opening c4, a fifth valve opening c5, a sixth valve opening c6, a seventh valve opening c7, an eighth valve opening c8, a ninth valve opening c9 and a tenth valve opening c10 in clockwise sequence; when the third sample loading valve 231 is in the first working position, the tenth valve opening c10 is connected to the first valve opening c1, the second valve opening c2 is connected to the third valve opening c3, the fourth valve opening c4 is connected to the fifth valve opening c5, the sixth valve opening c6 is connected to the seventh valve opening c7, and the eighth valve opening c8 is connected to the ninth valve opening c9; when the third sample loading valve 231 is in the second working position, the first valve opening c1 is connected to the second valve opening c2, the third valve opening c3 is connected to the fourth valve opening c4, the fifth valve opening c5 is connected to the sixth valve opening c6, the seventh valve opening c7 is connected to the eighth valve opening c8, and the ninth valve opening c9 is connected to the tenth valve opening c10; the third quantitative tube 232 has one end connected to the first opening c1 of the valve and the other end connected to the eighth opening c8 of the valve, the third tube 233 for the carrier gas is connected to each of the seventh opening c7 of the valve and the fourth opening c4 of the valve, the second pre-separation column 234 has an inlet end connected to the second opening c2 of the valve and an outlet end connected to the sixth opening c6 of the valve, and the inlet end of the second chromatographic analytical column 235 is connected to the fifth opening c5 of the valve; wherein the third opening c3 of the valve is used as an outlet for backwashing the second pre-separation column 234. The second preliminary separation column 234 provides for the separation of oxygen, nitrogen, methane and carbon monoxide from the natural gas (other hydrocarbon components in the natural gas can be removed by backwashing), and the second chromatographic analytical column 235 provides for the separation of oxygen, nitrogen, methane and carbon monoxide; the third tube 233 for the carrier gas is provided with a flow meter 2331, and the damping tube 237 is located in the connecting pipeline between the third tube 233 for the carrier gas and the fourth opening c4 of the valve; wherein the damping tube 236 is located on the external outlet pipeline connected to the third opening c3 of the valve.

[0145] The fourth chromatographic column analysis system 24 comprises a fourth sample loading valve 241, a fourth quantitative tube 242, a fourth tube 243 for a carrier gas, a third pre-separation column 244 and a third chromatographic analytical column 245. The fourth sample loading valve 241 is a ten-way valve having a first operating position and a second operating position, and is provided with a first valve opening d1, a second valve opening d2, a third valve opening d3, a fourth valve opening d4, a fifth valve opening d5, a sixth valve opening d6, a seventh valve opening d7, an eighth valve opening d8, a ninth valve opening d9 and a tenth valve opening d10 in clockwise sequence; when the fourth valve 241 for loading a sample is in the first working position, the tenth hole d10 of the valve is connected to the first hole d1 of the valve, the second hole d2 of the valve is connected to the third hole d3 of the valve, the fourth hole d4 of the valve is connected to the fifth hole d5 of the valve, the sixth hole d6 of the valve is connected to the seventh hole d7 of the valve, and the eighth hole d8 of the valve is connected to the ninth hole d9 of the valve; when the fourth valve 241 for loading a sample is in the second working position, the first opening d1 of the valve is connected to the second opening d2 of the valve, the third opening d3 of the valve is connected to the fourth opening d4 of the valve, the fifth opening d5 of the valve is connected to the sixth opening d6 of the valve, the seventh opening d7 of the valve is connected to the eighth opening d8 of the valve, and the ninth opening d9 of the valve is connected to the tenth opening d10 of the valve; the fourth quantitative tube 242 has one end connected to the first opening d1 of the valve and the other end connected to the eighth opening d8 of the valve, the fourth tube 243 for carrier gas is connected to each of the seventh opening d7 of the valve and the fourth opening d4 of the valve, the third pre-separation column 244 has an inlet end connected to the second opening d2 of the valve and an outlet end connected to the sixth opening d6 of the valve, and the inlet end of the third chromatographic analytical column 245 is connected to the fifth opening d5 of the valve; wherein the third opening d3 of the valve is used as an outlet for backwashing the third pre-separation column 244. The third pre-separation column 244 provides for the separation of ethane and CO ₂ from the natural gas, and the third chromatographic analytical column 245 provides for the separation of ethane and CO ₂ ; the fourth tube 243 for the carrier gas is provided with a flow meter 2431; the damping tube 247 is located in the connecting pipeline between the fourth tube 243 for the carrier gas and the fourth opening d4 of the valve; while the damping tube 246 is located on the outer outlet pipeline connected to the third opening d3 of the valve.

[0146] The fifth chromatographic column analysis system 25 comprises a fifth sample loading valve 251, a fifth quantitative tube 252, a fifth tube 253 for carrier gas, a fourth pre-separation column 254 and a fourth chromatographic analytical column 255. The fifth sample loading valve 251 is a ten-way valve having a first operating position and a second operating position, and is provided with a first valve opening e1, a second valve opening e2, a third valve opening e3, a fourth valve opening e4, a fifth valve opening e5, a sixth valve opening e6, a seventh valve opening e7, an eighth valve opening e8, a ninth valve opening e9 and a tenth valve opening e10 in clockwise sequence; when the fifth sample loading valve 251 is in the first working position, the tenth valve opening e10 is connected to the first valve opening e1, the second valve opening e2 is connected to the third valve opening e3, the fourth valve opening e4 is connected to the fifth valve opening e5, the sixth valve opening e6 is connected to the seventh valve opening e7, and the eighth valve opening e8 is connected to the ninth valve opening e9; when the fifth sample loading valve 251 is in the second working position, the first valve opening e1 is connected to the second valve opening e2, the third valve opening e3 is connected to the fourth valve opening e4, the fifth valve opening e5 is connected to the sixth valve opening e6, the seventh valve opening e7 is connected to the eighth valve opening e8, and the ninth valve opening e9 is connected to the tenth valve opening e10; a fifth quantitative tube 252 has one end connected to a first port e1 of the valve and the other end connected to an eighth port e8 of the valve, a fifth tube 253 for carrier gas is connected to each of the seventh port e7 of the valve and the fourth port e4 of the valve, a fourth pre-separation column 254 has an inlet end connected to a second port e2 of the valve and an outlet end connected to a sixth port e6 of the valve, and an inlet end of a fourth chromatographic analytical column 255 is connected to the fifth port e5 of the valve; wherein the third port e3 of the valve is used as an outlet port for backwashing the fourth pre-separation column 254. The fourth pre-separation column 254 provides for the separation of helium and hydrogen from the natural gas (other hydrocarbon components in the natural gas can be removed by backwashing), and the fourth chromatographic analytical column 255 provides for the separation of helium and hydrogen; the fifth tube 253 for the carrier gas is provided with a flow meter 2531; the damping tube 257 is located on the connecting pipeline between the fifth tube 253 for the carrier gas and the fourth opening e4 of the valve; while the damping tube 256 is located on the external outlet pipeline connected to the third opening e3 of the valve. The first sample loading valve 211, the second sample loading valve 221, the third sample loading valve 231, the fourth sample loading valve 241 and the fifth sample loading valve 251 are connected in series through the first connecting pipe 13 for quantitative pipes, the second connecting pipe 14 for quantitative pipes, the third connecting pipe 15 for quantitative pipes and the fourth connecting pipe 16 for quantitative pipes, and the inlet pipe 11 for natural gas and the outlet pipe 12 for natural gas are connected to the first and last sample loading valves of the first sample loading valve 211, the second sample loading valve 221, the third sample loading valve 231, the fourth sample loading valve 241 and the fifth sample loading valve 251, which are connected in series, thereby connecting the quantitative pipes in series. In particular, the sixth port a6 of the first sample loading valve 211 is connected to the inlet pipe 11 for natural gas, the fifth port a5 of the first sample loading valve 211 is connected to the first connecting pipe 13 for quantitative pipes, the tenth port b10 of the second sample loading valve 221 is connected to the first connecting pipe 13 for quantitative pipes, the ninth port b9 of the second sample loading valve 221 is connected to the second connecting pipe 14 for quantitative pipes, the tenth port c10 of the third sample loading valve 231 is connected to the second connecting pipe 14 for quantitative pipes, the ninth port c9 of the third sample loading valve 231 is connected to the third connecting pipe 15 for quantitative pipes, the tenth port d10 of the fourth sample loading valve 241 is connected to the third connecting pipe 15 for quantitative pipes tubes, the ninth opening d9 of the fourth valve 241 for loading a sample is connected to the fourth connecting tube 16 for quantitative tubes, the tenth opening e10 of the fifth valve 251 for loading a sample is connected to the fourth connecting tube 16 for quantitative tubes, and the ninth opening e9 of the fifth valve 251 for loading a sample is connected to the outlet tube 12 for natural gas. The inlet tube 11 for natural gas is provided with a regulating valve 111; the second connecting tube 14 for quantitative tubes is provided with a regulating valve 141; the third connecting tube 15 for quantitative tubes is provided with a regulating valve 151; and the chromatographic column analysis systems are connected to the corresponding detectors, respectively. In particular, the chemiluminescent detector 31 for sulfur is connected to the outlet end of the column 214 for determining sulfur, the third opening b3 of the second valve 221 for loading the sample and the first chromatographic analytical column 225 are connected to the flame ionization detector 32, the second chromatographic analytical column 235 is connected to the first thermal conductivity detector 33, the third chromatographic analytical column 245 is connected to the first thermal conductivity detector 33, and each of the fourth chromatographic analytical column 255 and the fifth tube 253 for the carrier gas is connected to the second thermal conductivity detector 34. The diverter valve 228 and the damping tube 226 are located on the connecting pipeline between the third opening b3 of the second valve 221 for loading the sample and the flame ionization detector 32; and the damping tube 258 is located in the connecting pipeline between the fifth tube 253 for the carrier gas and the second thermal conductivity detector 34.

[0147] The first chromatographic column analysis system 21 is configured to separate carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene from the natural gas, wherein the first chromatographic column analysis system 21 is connected to a chemiluminescent detector 31 for sulfur for analyzing the content of carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene in the natural gas.

[0148] The second chromatographic column analysis system 22 is configured to separate hydrocarbons having C ₃ and above from the natural gas, wherein the second chromatographic column analysis system 22 is connected to a flame ionization detector 32 for analyzing the content of hydrocarbons having C ₃ and above in the natural gas.

[0149] The third chromatographic column analysis system 23 is configured to separate oxygen, nitrogen, methane and carbon monoxide from the natural gas, wherein the third chromatographic column analysis system 23 is connected to the first thermal conductivity detector 33 for analyzing the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas.

[0150] The fourth chromatographic column analysis system 24 is configured to separate carbon dioxide and ethane from the natural gas, wherein the fourth chromatographic column analysis system 24 is connected to the first thermal conductivity detector 33 for analyzing the content of carbon dioxide and ethane in the natural gas.

[0151] The fifth chromatographic column analysis system 25 is configured to separate helium and hydrogen from the natural gas, wherein the fifth chromatographic column analysis system 25 is connected to a second thermal conductivity detector 34 for analyzing the content of helium and hydrogen in the natural gas.

[0152] In particular, the column 214 for determining sulfur is a DB-Sulfur SCD chromatographic column. The column 214 for determining sulfur has the following dimensions: length 60 m; diameter 0.32 mm; film thickness of the liquid phase in the capillary column 4.2 μm.

[0153] The volume of the first quantitative tube 212 is 1 ml.

[0154] In particular, the first pre-separation column 224 is an OV-1 pre-separation column; the packing material of the first pre-separation column 224 comprises 80-100 mesh celite 545 and OV-1 silicone, wherein the OV-1 silicone content is 10% based on the weight of celite 545 (10% OV-1 silicone on 80/100 mesh celite 545); and the first pre-separation column 224 has dimensions of: an outer diameter of 1.6 mm; an inner diameter of 1.0 mm; and a length of 1.0 m.

[0155] The first chromatographic analytical column 225 is an HP-Al/S chromatographic column. The first chromatographic analytical column 225 has the following dimensions: length 50 m; diameter 0.53 mm; liquid phase film thickness 15 μm.

[0156] The volume of the second quantitative tube 222 is 0.1 ml.

[0157] In particular, the second pre-separation column 234 is a Porapak N column; the packing material of the second pre-separation column 234 has a sieve number of 80-100; and the second pre-separation column 234 has dimensions of: an outer diameter of 3.2 mm; an inner diameter of 2.1 mm; and a length of 1.0 m.

[0158] The second chromatographic analytical column 235 is a column with a molecular sieve MS-13X. The second chromatographic analytical column 235 has dimensions: an outer diameter of 3.2 mm; an inner diameter of 2.1 mm; and a length of 5.0 m.

[0159] The volume of the third quantitative tube 232 is 1 ml.

[0160] In particular, the third pre-separation column 244 is a Porapak N column; the packing material of the third pre-separation column 244 has a sieve number of 80-100; and the third pre-separation column 244 has dimensions: an outer diameter of 3.2 mm; an inner diameter of 2.1 mm; and a length of 1.0 m.

[0161] The third chromatographic analytical column 245 is a Porapak N column; the packing material of the third chromatographic analytical column 245 has a sieve number of 80-100; wherein the third chromatographic analytical column 245 has dimensions: an outer diameter of 3.2 mm; an inner diameter of 2.1 mm; and a length of 2.0 m.

[0162] The volume of the fourth quantitative tube 242 is 1 ml.

[0163] In particular, the fourth pre-separation column 254 is a Porapak N column; the packing material of the fourth pre-separation column 254 has a sieve number of 80-100; and the fourth pre-separation column 254 has dimensions: an outer diameter of 3.2 mm; an inner diameter of 2.1 mm; and a length of 1.0 m.

[0164] The fourth chromatographic analytical column 255 is a column with a molecular sieve MS-5A, and the packing material of the fourth chromatographic analytical column 255 has a sieve number of 60-80. The fourth chromatographic analytical column 255 has dimensions: an outer diameter of 3.2 mm; an inner diameter of 2.1 mm; and a length of 3.0 m.

[0165] The volume of the fifth quantitative tube 252 is 5 ml.

[0166] In particular, the device further comprises an apparatus for programmable temperature change, in which a column 214 for determining sulfur and a first chromatographic analytical column 225 are located.

[0167] In particular, this device further comprises a thermostat in which a second chromatographic analytical column 235, a third chromatographic analytical column 245 and a fourth chromatographic analytical column 255 are located.

Example 2

[0168] Further, in this example, a method for analyzing the quality indicators of a natural gas product is proposed. The method is carried out using a device for analyzing the quality indicators of a natural gas product according to example 1. The method includes the following steps.

[0169] In step S1, a sample is introduced into the quantitative tubes of the first chromatographic column analysis system 21, the second chromatographic column analysis system 22, the third chromatographic column analysis system 23, the fourth chromatographic column analysis system 24 and the fifth chromatographic column analysis system 25 such that each of the quantitative tubes is filled with a sample of natural gas. In particular, each of the first sample loading valve 211, the second sample loading valve 221, the third sample loading valve 231, the fourth sample loading valve 241 and the fifth sample loading valve 251 is moved to the first working position, the natural gas product is introduced from the natural gas inlet pipe 11 into the first sample loading valve 211, wherein the natural gas product passes through the first quantity pipe 212, the second quantity pipe 222, the third quantity pipe 232, the fourth quantity pipe 242 and the fifth quantity pipe 252, and then exits from the natural gas outlet pipe 12; wherein the first quantity pipe 212, the second quantity pipe 222, the third quantity pipe 232, the fourth quantity pipe 242 and the fifth quantity pipe 252 capture a part of the natural gas product as a natural gas sample.

[0170] In step S2, in the first chromatographic column analysis system 21, the first carrier gas tube 213 is used to deliver the carrier gas, the natural gas sample in the first quantitative tube 212 is fed to the sulfur detection column 214 under the action of the carrier gas to separate the sulfides, and the separated components are fed to the chemiluminescence detector 31 for sulfur, so that the sulfides in the natural gas sample are detected so that the first detection chromatogram is obtained. In particular, the first sample loading valve 211 in the first chromatographic column analysis system 21 is switched to the second operating position, the carrier gas is introduced into the first chromatographic column analysis system 21 from the first carrier gas tube 213 at a flow rate of 3 ml/min, the carrier gas enters the first quantitative tube 212 through the second valve opening a2 and the first valve opening a1 sequentially and forces the natural gas sample in the first quantitative tube 212 to flow into the sulfur determination column 214 after passing through the fourth valve opening a4, the third valve opening a3 and the split/splitless inlet opening 215 sequentially to split it in the sulfur determination column 214; wherein carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene sequentially exit from the sulfur column 214 into the chemiluminescent sulfur detector 31 for detection so as to obtain a first detection chromatogram. FIG. 7 shows the first detection chromatogram.

[0171] The carrier gas is helium.

[0172] The sulfur column 214 is held (in this example for 3 min) at 40°C until carbonyl sulfur has exited the sulfur column, and then the sulfur column is heated at 15°C/min to 130°C and held (in this example for 6 min) at this temperature until the first detection chromatogram is obtained.

[0173] The sulfur chemiluminescence detector 31 has a sample loading temperature of 200°C and a reaction temperature of 850°C, wherein the sulfur chemiluminescence detector 31 has a split ratio of 10:1, and the reaction gas flow rates in the sulfur chemiluminescence detector 31 are 80 ml/min for hydrogen (H ₂ ), 40 ml/min for nitrogen (N ₂ ), 10 ml/min for oxygen (O ₂ ) and 25 ml/min for ozone (O ₃ ).

[0174] In step S3, in the second chromatographic column analysis system 22, the second carrier gas tube 223 is used to deliver a carrier gas, and the first pre-separation column 224 and the first chromatographic analytical column 225 are used sequentially to perform separation of the natural gas sample in the second quantitative tube 222 under the action of the carrier gas; when the C ₅ ^- components in the natural gas sample exit the first pre-separation column 224 and enter the first chromatographic analytical column 225, the carrier gas moves to the outlet end of the first pre-separation column 224, wherein the inlet end of the first pre-separation column 225 is connected to the flame ionization detector 32, and under the action of the carrier gas, the C ₆ ⁺ hydrocarbon components in the first pre-separation column 224 are backflushed into the flame ionization detector 32 for detection; after completion of the backwash, the carrier gas moves to the inlet end of the first chromatographic analytical column 224, and under the action of the carrier gas, the C ₃ ^- hydrocarbon components separated by the first chromatographic analytical column 225 are sequentially supplied to the flame ionization detector 32 for detection so as to obtain a second detection chromatogram. In particular, the second sample loading valve 221 in the second chromatographic column analysis system 22 is switched to the second operating position, wherein the carrier gas is introduced into the second chromatographic column analysis system 22 from the second carrier gas tube 223 under a pressure of 500 kPa, enters the second quantitative tube 222 through the seventh valve opening b7 and the eighth valve opening b8 sequentially, and forces the natural gas sample in the second quantitative tube 222 to flow into the first pre-separation column 224 after passing through the first valve opening b1 and the second valve opening b2 sequentially for pre-separation in the first pre-separation column 224; wherein propane, isobutane, n-butane, neopentane, isopentane and n-pentane sequentially exit from the first pre-separation column 224 and then enter the first chromatographic analytical column 225 for further separation after passing through the sixth valve opening b6 and the fifth valve opening b5 sequentially under the action of the carrier gas, so that the time difference in separating the components increases. After the C ₅ ^- components exit from the first pre-separation column 224 and enter the first chromatographic analytical column 225, the second valve 221 for loading a sample of the second system 22 for chromatographic column analysis is switched to the first working position. The carrier gas is introduced from the second carrier gas tube 223 under a pressure of 500 kPa and supplied to the first pre-separation column 224 from the outlet end side of the first pre-separation column 224 through the seventh valve opening b7 and the sixth valve opening b6 sequentially, wherein the C ₆ ⁺ hydrocarbon components in the first pre-separation column 224 are washed out from the first pre-separation column 224 and supplied to the flame ionization detector 32 through the second valve opening b2 and the third valve opening b3 for detection. After the flame ionization detector 32 monitors the combined hexane peak, the flow direction of the carrier gas is adjusted. The carrier gas is introduced from the second carrier gas tube 223 under a pressure of 500 kPa and supplied to the first chromatographic analytical column 225 after sequentially passing through the fourth valve opening b4 and the fifth valve opening b5. Under the influence of the carrier gas, propane, isobutane, n-butane, neopentane, isopentane and n-pentane sequentially exit from the first chromatographic analytical column 225 and enter the flame ionization detector 32 for detection so as to obtain a second detection chromatogram. FIG. 8 shows the second detection chromatogram.

[0175] The carrier gas is helium.

[0176] The first chromatographic analytical column 225 is held (in this example for 3 min) at 40°C until the combined hexane peak is monitored, and then the first chromatographic analytical column is heated at a rate of 15°C/min to 130°C and held (in this example for 6 min) at this temperature until the second detection chromatogram is obtained.

[0177] The temperature of the flame ionization detector 32 is 200°C, and the flow rates of the reaction gases of the flame ionization detector 32 are 32 ml/min for hydrogen (H ₂ ), 200 ml/min for air, and 20 ml/min for make-up gas (make-up).

[0178] In step S4, in the third chromatographic column analysis system 23, the third carrier gas tube 233 is used to supply a carrier gas, and the second pre-separation column 234 and the second chromatographic analytical column 235 are used to perform separation of the natural gas sample in the third quantitative tube 232 under the action of the carrier gas; after the components of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample are discharged from the second pre-separation column 234 and supplied to the second chromatographic analytical column 235, the carrier gas is supplied to the outlet end of the second pre-separation column 234, wherein the remaining components in the second pre-separation column 235 are backwashed from the third chromatographic analysis system 23 under the action of the carrier gas; and after completion of the backwash, the carrier gas is supplied to the inlet end of the second chromatographic analytical column 235, and under the action of the driving force of the carrier gas, the components of oxygen, nitrogen, methane and carbon monoxide separated by the second chromatographic analytical column 235 are sequentially introduced into the first thermal conductivity detector 33 for detection so as to obtain a third detection chromatogram. Specifically, the third sample loading valve 231 in the third chromatographic column analysis system 23 is switched to the second operating position, wherein the carrier gas enters the third chromatographic column analysis system 23 from the third carrier gas tube 233 under a pressure of 500 kPa, passes into the third quantitative tube 232 through the seventh valve opening c7 and the eighth valve opening c8 sequentially, and forces the natural gas sample in the third quantitative tube 232 to flow into the second pre-separation column 234 after passing through the first valve opening c1 and the second valve opening c2 sequentially for pre-separation in the second pre-separation column 234; wherein oxygen, nitrogen, methane and carbon monoxide are sequentially discharged from the second pre-separation column 234 and then entered into the second chromatographic analytical column 235 for further separation after passing through the sixth valve port c6 and the fifth valve port c5 sequentially under the action of the carrier gas, so that the time difference in separating the components increases. After the oxygen, nitrogen, methane and carbon monoxide components are discharged from the second pre-separation column 234 and entered into the second chromatographic analytical column 235, the third sample loading valve 231 of the third chromatographic column analysis system 23 is switched to the first operating position. The carrier gas is introduced from the third carrier gas tube 233 under a pressure of 500 kPa and supplied to the second pre-separation column 234 from the outlet end of the second pre-separation column 234 through the seventh valve opening c7 and the sixth valve opening c6 sequentially, wherein the remaining components in the second pre-separation column 234 are washed out from the third chromatographic column analysis system 23. Then, the flow direction of the carrier gas is adjusted. The carrier gas is introduced from the third carrier gas tube 233 under a pressure of 500 kPa and supplied to the second chromatographic analytical column 235 after sequentially passing through the fourth valve opening c4 and the fifth valve opening c5, wherein oxygen, nitrogen, methane and carbon monoxide sequentially exit from the second chromatographic analytical column 235 under the influence of the carrier gas and enter the first thermal conductivity detector 33 for detection so as to obtain a third detection chromatogram. The third detection chromatogram is shown in FIG. 9 (the third detection chromatogram and the fourth detection chromatogram are combined into one detection chromatogram).

[0179] The carrier gas is helium.

[0180] The temperature of the second chromatographic analytical column is 60°C.

[0181] The temperature of the first thermal conductivity detector 33 is 150°C, and the first thermal conductivity detector 33 has an operating current of 120 mA and is cathodic in polarity.

[0182] In step S5, in the fourth chromatographic column analysis system 24, the fourth carrier gas tube 243 is used to supply the carrier gas, and the third pre-separation column 244 and the third chromatographic analytical column 245 are used to perform separation of the natural gas sample in the fourth quantitative tube 242 under the action of the carrier gas; after the carbon dioxide and ethane components in the natural gas sample exit the third pre-separation column 244 and enter the third chromatographic analytical column 245, the carrier gas is supplied to the outlet end of the third pre-separation column 244, wherein the remaining components in the third pre-separation column 245 are backwashed from the fourth chromatographic column analysis system 24 under the action of the carrier gas; and after completion of the backwash, the carrier gas is supplied to the inlet end of the third chromatographic analytical column 245, and under the action of the carrier gas, the carbon dioxide and ethane components separated by the third chromatographic analytical column 245 sequentially enter the first thermal conductivity detector 33 for detection so as to obtain a fourth detection chromatogram. Specifically, the fourth sample loading valve 241 in the fourth chromatographic column analysis system 24 is switched to the second operating position, wherein the carrier gas is introduced into the fourth chromatographic column analysis system 24 from the fourth carrier gas tube 243 under a pressure of 350 kPa, sequentially enters the fourth quantitative tube 242 through the seventh valve opening d7 and the eighth valve opening d8, and forces the natural gas sample in the fourth quantitative tube 242 to flow into the third pre-separation column 244 after passing through the first valve opening d1 and the second valve opening d2 sequentially for pre-separation in the third pre-separation column 244; wherein carbon dioxide and ethane are successively discharged from the third pre-separation column 244 and then entered into the third chromatographic analytical column 245 for further separation after passing through the sixth valve opening d6 and the fifth valve opening d5 successively under the action of the carrier gas, so that the time difference in separating the components increases. After the carbon dioxide and ethane components are discharged from the third pre-separation column 244 and entered into the third chromatographic analytical column 245, the fourth sample loading valve 241 of the third chromatographic column analysis system 23 is switched to the first working position. The carrier gas is introduced from the fourth carrier gas tube 243 under a pressure of 350 kPa into the third pre-separation column 244 from the outlet end side of the third pre-separation column 244 through the seventh valve opening d7 and the sixth valve opening d6 sequentially, wherein the remaining components in the third pre-separation column 244 are washed out from the third chromatographic column analysis system 23. Then, the flow direction of the carrier gas is adjusted. The carrier gas is introduced from the fourth carrier gas tube 243 under a pressure of 350 kPa into the third chromatographic analytical column 245 after passing sequentially through the fourth valve opening d4 and the fifth valve opening d5, wherein carbon dioxide and ethane sequentially exit from the third chromatographic analytical column 245 under the action of the carrier gas and enter the first thermal conductivity detector 33 for detection so as to obtain a fourth detection chromatogram. In FIG. 9 shows the fourth detection chromatogram (the third detection chromatogram and the fourth detection chromatogram are combined into one detection chromatogram)

[0183] The carrier gas is helium.

[0184] The temperature of the second chromatographic analytical column is 60°C.

[0185] The temperature of the first thermal conductivity detector 33 is 150°C, and the first thermal conductivity detector 33 has an operating current of 120 mA and is cathodic in polarity.

[0186] In step S6, in the fifth chromatographic column analysis system 25, the fifth carrier gas tube 253 is used to supply the carrier gas, and the fourth pre-separation column 254 and the fourth chromatographic analytical column 255 are used to perform separation of the natural gas sample in the fifth quantitative tube 252 under the action of the carrier gas; after the carbon dioxide and ethane components in the natural gas sample exit the fourth pre-separation column 254 and enter the fourth chromatographic analytical column 255, the carrier gas is supplied to the outlet end of the fourth pre-separation column 254, and the remaining components in the third pre-separation column 245 are backwashed from the fifth chromatographic column analysis system 25 under the action of the carrier gas; and after completion of the backwash, the carrier gas is supplied to the inlet end of the fourth chromatographic analytical column 255, and under the action of the carrier gas, the carbon dioxide and ethane components separated by the fourth chromatographic analytical column 255 are sequentially introduced into the second thermal conductivity detector 34 for detection so as to obtain a fifth detection chromatogram. Specifically, the fifth sample loading valve 251 in the fifth chromatographic column analysis system 25 is switched to the second working position, the carrier gas enters the fifth chromatographic column analysis system 25 from the fifth carrier gas tube 253 under a pressure of 250 kPa, sequentially enters the fifth quantitative tube 252 through the seventh valve opening e7 and the eighth valve opening e8, and forces the natural gas sample in the fifth quantitative tube 252 to flow into the fourth pre-separation column 254 after passing through the first valve opening e1 and the second valve opening e2 sequentially for pre-separation in the fourth pre-separation column 254; wherein carbon dioxide and ethane are successively discharged from the fourth pre-separation column 254 and then entered into the fourth chromatographic analytical column 255 for further separation after passing through the sixth valve port e6 and the fifth valve port e5 successively under the action of the carrier gas, so that the time difference in separating the components increases. After the carbon dioxide and ethane components are discharged from the fourth pre-separation column 254 and entered into the fourth chromatographic analytical column 255, the fifth sample loading valve 251 of the third chromatographic column analysis system 23 is switched to the first working position. The carrier gas is supplied from the fifth carrier gas tube 253 under a pressure of 250 kPa to the fourth pre-separation column 254 from the outlet end side of the fourth pre-separation column 254 through the seventh valve opening e7 and the sixth valve opening e6 sequentially, wherein the remaining components in the fourth pre-separation column 254 are washed out from the third chromatographic column analysis system 23. Then, the flow direction of the carrier gas is adjusted. The carrier gas is introduced from the fifth carrier gas tube 253 under a pressure of 250 kPa and supplied to the fourth chromatographic analytical column 255 after sequentially passing through the fourth valve opening e4 and the fifth valve opening e5, and carbon dioxide and ethane sequentially exit from the fourth chromatographic analytical column 255 under the action of the carrier gas and enter the second thermal conductivity detector 34 for detection so as to obtain a fifth detection chromatogram. In FIG. 10 shows the fifth detection chromatogram.

[0187] The carrier gas is nitrogen.

[0188] The temperature of the second chromatographic analytical column is 60°C.

[0189] The temperature of the second thermal conductivity detector 34 is 150°C, and the second thermal conductivity detector 34 has an operating current of 70 mA and is anodic in polarity.

[0190] In step S7, the sulfide content in the natural gas sample is determined based on the obtained first detection chromatogram. Specifically, based on the obtained first detection chromatogram, the content of carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene in the natural gas sample is determined using standard sulfide content curves, and the results are shown in Table 1.

[0191] Based on the obtained second detection chromatogram, the content of hydrocarbons having C ₃ and above in the natural gas sample is determined. In particular, based on the obtained second detection chromatogram, the content of hydrocarbon components of propane, isobutane, n-butane, neopentane, isopentane, n-pentane and C ₆ ⁺ in the natural gas sample is determined using standard curves of the content of hydrocarbons having C ₃ and above, and the results are shown in Table 2.

[0192] Based on the obtained third detection chromatogram, the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample is determined. In particular, based on the obtained third detection chromatogram, the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample is determined using standard curves of the content of oxygen, nitrogen, methane and carbon monoxide, and the results are given in Table 3.

[0193] Based on the obtained fourth detection chromatogram, the content of carbon dioxide and ethane in the natural gas sample is determined. In particular, based on the obtained fourth detection chromatogram, the content of carbon dioxide and ethane in the natural gas samples is determined using standard curves of the content of carbon dioxide and ethane, and the results are given in Table 3.

[0194] Based on the obtained fifth detection chromatogram, the content of helium and hydrogen in the natural gas sample is determined. In particular, based on the obtained fifth detection chromatogram, the content of helium and hydrogen in the natural gas sample is determined using standard curves of the content of helium and hydrogen, and the results are presented in Table 4.

[0195] Standard curves of sulfide content are obtained by inserting 7 vials of standard substances of 4 types of sulfur compounds and 13 types of sulfur compounds at different concentration points into an analytical instrument, reanalyzing each vial of standard substance 11 or more times, collecting effective peak area data of the component from 11 injections, plotting the average value of the peak areas of the component during the 11 injections against the corresponding content, and checking the concentration profile of each component depending on the response value. The calibration curves of the 13 types of sulfur compounds are shown in the following Tables 5-17 and in FIGS. 11-23.

[0196] Standard curves of hydrocarbons having _C3 and above, standard curves of oxygen, nitrogen, methane and carbon monoxide, and standard curves of helium and hydrogen are obtained by the same method, and the results are shown in Tables 18-30 and FIGS. 24-36.

Table 1

Content (ppm) Signal/Noise PO (S/N = 3) (ppm) _H2S 5.03 4167,315329 0.004107 COS 5.02 6224,611520 0.002739 Methyl mercaptan 5.01 6566,940805 0.002607 Ethyl mercaptan 5.02 5970,898393 0.002854 Methyl sulfide 4.98 6374,534079 0.002667 CS ₂ 4.99 14033,098416 0.001214 Isopropyl mercaptan 4.97 5456,459935 0.003098 Tert-butyl mercaptan 4.98 4907,412677 0.003449 Methyl ethyl sulfide 5.09 6540,707642 0.002655 Thiophene 5.12 7051,172391 0.002478 Ethyl sulfide 4.98 6265,610865 0.002668 n-butyl mercaptan 5.01 5403,188018 0.003151 Dimethyl disulfide 5.04 10803,035573 0.001581

Table 2

Content (%) Signal/Noise PO (S/N = 3) (%) nC ₆ H ₁₄ 0.201 17658,493960 0.000038 CH ₄ 97,207 2272939,090391 0,000141 _{C2H6 ​} 0.197 10094,716574 0.000064 _{C3H8 ​} 0.199 10645,721892 0.000062 iC ₄ H ₁₀ 0.2 10281,417050 0.000064 _{nC4H10 ​} 0.2 10644,095409 0.000062 neo-C ₅ H ₁₂ 0.197 8484,621906 0,000077 iC ₅ H ₁₂ 0.2 9580,508528 0.000069 nC ₅ H ₁₂ 0.202 9284,511168 0,000072

Table 3

Content (%) Signal/Noise PO (S/N = 3) (%) _CO2 0.199 3808,073 0.000172 _{C2H6 ​} 0.197 2833,088 0.000229 O ₂ 0.2 4977,471 0,000133 N ₂ 0.2 3799,549 0,000174 CH ₄ 97,207 411381,3 0,000780 CO 0.199 1504,117 0,000437

Table 4

Content (%) Signal/Noise PO (S/N = 3) (%) He 0.199 11306,401497 0.000058 H ₂ 0.2 17661,056323 0.000037

Table 5 Corresponding table of hydrogen sulfide component concentration values and response values

No. Peak area Content, mg/ ^m3 1 7755 0.995 2 23123 3.01 3 35894 4.93 4 61473 7.05 5 77139 10.1 6 113568 15 7 145374 20.1 8 175204 25.2 9 223374 29.9 10 257488 35 11 293867 40.1 12 318306 44.5 13 362401 49.9

Table 6 Corresponding table of carbon oxysulfide component concentration values and response values

No. Peak area Content, mg/ ^m3 1 8603 0.996 2 24695 3.01 3 37690 4.92 4 48431 7.06 5 80341 10.1 6 109724 15 7 148874 20.1 8 184133 27.7 9 234731 29.9 10 271912 35.1 11 311048 40.2 12 337337 44.5 13 378141 49.9

Table 7 Corresponding table of methyl mercaptan component concentration values and response values

No. Peak area Content, mg/ ^m3 1 8364 0.992 2 24219 3 3 38070 4.92 4 49528 7.03 5 81729 10.1 6 110957 15.1 7 144832 20.1 8 179477 25.3 9 228265 29.8 10 262857 34.9 11 300462 40 12 325956 44.4 13 365652 49.7

Table 8 Corresponding table of ethyl mercaptan component concentration values and response values

No. Peak area Content, mg/ ^m3 1 8539 0.994 2 24343 3 3 37681 4.92 4 49182 7.04 5 80886 10.1 6 111031 15 7 145870 20.1 8 180016 25.2 9 229900 29.8 10 263783 35 11 302057 40.1 12 327803 44.4 13 368402 49.8

Table 9 Corresponding table of methyl sulfide component concentration values and response values

No. 1 2 3 4 Peak area 39105 81791 110268 137852 Content, mg/ ^m3 5.1 10.2 15.2 20.2

Table 10 Corresponding table of carbon disulfide component concentration values and response values

No. 1 2 3 4 Peak area 40022 84178 113526 141749 Content, mg/ ^m3 5.17 10.3 15.3 20.5

Table 11 Corresponding table of isopropyl mercaptan component concentration values and response values

No. 1 2 3 4 Peak area 38399 80736 108164 135258 Content, mg/ ^m3 5.07 10.1 15 20.1

Table 12 Corresponding table of tert-butyl mercaptan component concentration values and response values

No. 1 2 3 4 Peak area 38543 80962 108250 135598 Content, mg/ ^m3 5.05 10.1 15.0 20.0

Table 13 Corresponding table of methyl ethyl sulfide component concentration values and response values

No. 1 2 3 4 Peak area 37895 79999 107262 134436 Content, mg/ ^m3 5.14 10.3 15.3 20.3

Table 14 Corresponding table of thiophene component concentration values and response values

No. 1 2 3 4 Peak area 38278 80734 108777 136348 Content, mg/ ^m3 5.06 10.1 15.0 20.0

Table 15 Corresponding table of ethyl sulfide component concentration values and response values

No. 1 2 3 4 Peak area 38654 81228 108819 136410 Content, mg/ ^m3 5.04 10.1 15.0 20.0

Table 16 Corresponding table of n-butyl mercaptan component concentration values and response values

No. 1 2 3 4 Peak area 36725 77902 104555 131298 Content, mg/ ^m3 5.04 10.1 15.0 20.0

Table 17 Corresponding table of dimethyl disulfide component concentration values and response values

No. 1 2 3 4 Peak area 37989 79919 107123 134151 Content, mg/ ^m3 4.99 10.0 15.0 20.0

Table 18 Corresponding table of carbon dioxide component concentration values and response values

No. 1 2 3 4 5 6 Peak area 276 2688 50784 90583 131274 183647 Reference value of standard substance, y, % 0.0105 0.105 1.93 3.46 5.02 7.01

Table 19 Corresponding table of ethane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 277 2688 52359 97512 138525 189990 Reference value of standard substance, y, % 0.0105 0.106 1.83 3.4 4.85 6.63

Table 20 Corresponding table of nitrogen component concentration values and response values

No. 1 2 3 4 5 6 Peak area 867 5710 65424 122862 207039 288884 Reference value of standard substance, y, % 0.0281 0.189 1.73 3.49 5.32 7.39

Table 21 Corresponding table of helium component concentration values and response values

No. 1 2 3 4 Peak area 1517 7540 41303 72947 Content, mg/ ^m3 0.0105 0.088 0.513 0.93

Table 22 Corresponding table of hydrogen component concentration values and response values

No. 1 2 3 4 Peak area 1424 12544 190478 370350 Content, mg/ ^m3 0,0114 0.09 1.36 2.67

Table 23 Corresponding table of hexane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 162737 1181843 1834728 2267348 3199737 3292007 Reference value of standard substance, y, % 0,013 0.0923 0.131 0.201 0.262 0.282

Table 24 Corresponding table of propane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 74514 840546 6689402 12540797 18536241 25084340 Reference value of standard substance, y, % 0.0105 0.114 0.883 1.85 2.39 3.24

Table 25 Corresponding table of carbon monoxide component concentration values and response values

No. 1 2 3 4 5 6 Peak area 3242 8645 13585 22539 27093 120340 Reference value of standard substance, y, % 0.084 0.224 0.352 0.584 0.702 3.24

Table 26 Corresponding table of isobutane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 197855 1022004 3058375 4649287 7216474 9990056 Reference value of standard substance, y, % 0,0209 0.105 0.306 0.522 0.704 0.977

Table 27 Corresponding table of n-butane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 247785 1151669 2974204 4510332 7051530 9831076 Reference value of standard substance, y, % 0.0264 0.119 0.299 0.507 0.688 0.960

Table 28 Corresponding table of neopentane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 315140 1512452 2875956 3466614 5151799 6773936 Reference value of standard substance, y, % 0.0265 0.124 0.23 0.311 0.4 0.526

Table 29 Corresponding table of isopentane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 299733 1332670 2654538 3339374 4684940 6288516 Reference value of standard substance, y, % 0.0261 0.113 0.218 0.307 0.372 0.498

Table 30 Corresponding table of n-pentane component concentration values and response values

No. 1 2 3 4 5 6 Peak area 303535 1270585 2616985 3370006 5092523 6586821 Reference value of standard substance, y, % 0.0264 0.107 0.213 0.31 0.401 0.52

[0197] In step S8, based on the obtained content of sulfides in the natural gas sample, hydrocarbons having _C3 and above in the natural gas sample, oxygen, nitrogen, methane and carbon monoxide in the natural gas sample, carbon dioxide and ethane in the natural gas sample, as well as helium and hydrogen in the natural gas sample, the higher calorific value of the natural gas, the total sulfur content (in terms of sulfur, in mg/ ^m3 ), the hydrogen sulfide content (in mg/ ^m3 ) and the carbon dioxide content (in mole percent) are determined.

[0198] In the analysis method, as shown in FIG. 7-10, the separation degree of each target component is high, with OD (S/N = 3) < 50 ppm. All the separation degrees are greater than 1, wherein: the separation degrees of iC ₄ H ₁ and nC ₄ H ₁₀ can reach 4.45; the separation degrees of CH ₄ and CO can reach 5.245; and the separation degrees of H ₂ S and COS can reach 2.701.

[0199] Although the principle and embodiments of the present invention are described herein using specific embodiments, the above description of the embodiments is intended only to facilitate an understanding of the methods and the basic concept of the present invention. In addition, changes can be made to the specific embodiments and the scope of application by those skilled in the art in accordance with the concept of the present invention. Finally, the contents of the description should not be construed as limiting the present invention.

Claims (75)

1. A device for analyzing quality indicators of a natural gas product, comprising a sample loading unit and first, second, third, fourth and fifth chromatographic column analysis systems connected in parallel, wherein the first chromatographic column analysis system is configured to separate sulfides from the natural gas; the second chromatographic column analysis system is configured to separate hydrocarbons having _C3 and higher from the natural gas; the third chromatographic column analysis system is configured to separate oxygen, nitrogen, methane and carbon monoxide from the natural gas; the fourth chromatographic column analysis system is configured to separate carbon dioxide and ethane from the natural gas; and the fifth chromatographic column analysis system is configured to separate helium and hydrogen from the natural gas; wherein each chromatographic column analysis system is provided with a quantitative tube, a carrier gas tube and a chromatographic column, wherein the quantitative tube is configured to store a sample of natural gas, and the carrier gas tube is configured to deliver the carrier gas to the chromatographic column analysis system so as to subject the sample of natural gas in the quantitative tube to separation into components inside the chromatographic column; the sample loading unit is connected to the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems with the possibility of controlled connection/disconnection for feeding a natural gas sample into the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems; and Each chromatographic column analysis system is connected to the corresponding detector respectively. 2. The device according to claim 1, wherein the sample loading unit is connected to the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems in such a way that the quantitative tubes of the first, second, third, fourth and fifth chromatographic column analysis systems are connected in series; wherein the sample loading unit comprises an inlet tube for natural gas, an outlet tube for natural gas and first, second, third and fourth connecting tubes for quantitative tubes, wherein the first, second, third and fourth connecting tubes for quantitative tubes are configured to connect quantitative tubes in series, respectively, the inlet tube for natural gas is connected to the inlet end of the quantitative tubes connected in series, and the outlet tube for natural gas is connected to the outlet end of the quantitative tubes connected in series. 3. The device according to item 1, in which the chromatographic column of the first chromatographic column analysis system comprises a sulfur detection column; in the first chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube via a connection line with a controllable connection/disconnection, the other end of the quantitative tube is connected to the inlet end of the sulfur detection column via a connection line with a controllable connection/disconnection, and the outlet end of the sulfur detection column is connected to the chemiluminescence detector for sulfur via a connection line with a controllable connection/disconnection, wherein the sulfur detection column ensures separation of carbon oxysulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, methyl sulfide, methyl ethyl sulfide, dimethyl disulfide, ethyl sulfide, carbon disulfide, n-butyl mercaptan, tert-butyl mercaptan, isopropyl mercaptan and thiophene; the chromatographic column of the second chromatographic column analysis system comprises a first pre-separation column and a first chromatographic analytical column; in the second chromatographic column analysis system, one end of the quantitative tube is connected to a carrier gas tube via a connecting pipeline with a controllable connection/disconnection, the other end of the quantitative tube is connected to an inlet end of the first pre-separation column via a connecting pipeline with a controllable connection/disconnection, an outlet end of the first pre-separation column is connected to an inlet end of the first chromatographic analytical column via a connecting pipeline with a controllable connection/disconnection, the carrier gas tube is connected to an outlet end of the first pre-separation column and an inlet end of the first chromatographic analytical column, respectively, via a connecting pipeline with a controllable connection/disconnection, and the inlet end of the first pre-separation column and the outlet end of the first chromatographic analytical column are connected to a hydrogen flame ionization detector, respectively, via a connecting pipeline with a controllable connection/disconnection; wherein the first preliminary separation column ensures the separation of C ₆ ⁺ hydrocarbon components from C ₅ ^- hydrocarbon components; and the first chromatographic analytical column ensures the separation of propane, isobutane, n-butane, neopentane, isopentane and n-pentane; the chromatographic column of the third chromatographic column analysis system comprises a second preliminary separation column and a second chromatographic analytical column; in the third chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube through a connection/disconnection controllable connection pipeline, the other end of the quantitative tube is connected to the inlet end of the second pre-separation column through a connection/disconnection controllable connection pipeline, the outlet end of the second pre-separation column is connected to the inlet end of the second chromatographic analytical column through a connection/disconnection controllable connection pipeline, the carrier gas tube is connected to the outlet end of the second pre-separation column and the inlet end of the second chromatographic analytical column respectively through a connection/disconnection controllable connection pipeline, and the outlet end of the second chromatographic analytical column is connected to a detector with thermal conductivity cells through a connection/disconnection controllable connection pipeline, wherein the second pre-separation column provides separation of oxygen, nitrogen, methane and carbon monoxide from natural gas; and the second chromatographic analytical column provides separation of oxygen, nitrogen, methane and carbon monoxide; the chromatographic column of the fourth chromatographic column analysis system comprises a third pre-separation column and a third chromatographic analytical column; in the fourth chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube via a connecting pipeline with a controllable connection/disconnection, the other end of the quantitative tube is connected to the inlet end of the third pre-separation column via a connecting pipeline with a controllable connection/disconnection, the outlet end of the third pre-separation column is connected to the inlet end of the third chromatographic analytical column via a connecting pipeline with a controllable connection/disconnection, the carrier gas tube is connected to the outlet end of the third pre-separation column and the inlet end of the third chromatographic analytical column respectively via a connecting pipeline with a controllable connection/disconnection, and the outlet end of the third chromatographic analytical column is connected to a detector with thermal conductivity cells via a connecting pipeline with a controllable connection/disconnection; wherein the third preliminary separation column provides for the separation of ethane and carbon dioxide from the natural gas; and the third chromatographic analytical column provides for the separation of ethane and carbon dioxide; the chromatographic column of the fifth chromatographic column analysis system comprises a fourth pre-separation column and a fourth chromatographic analytical column; in the fifth chromatographic column analysis system, one end of the quantitative tube is connected to the carrier gas tube through a connecting pipeline with a controllable connection/disconnection, and the other end of the quantitative tube is connected to the inlet end of the fourth pre-separation column through a connecting pipeline with a controllable connection/disconnection, the outlet end of the fourth pre-separation column is connected to the inlet end of the fourth chromatographic analytical column through a connecting pipeline with a controllable connection/disconnection, the carrier gas tube is connected to the outlet end of the fourth pre-separation column and the inlet end of the fourth chromatographic analytical column respectively through a connecting pipeline with a controllable connection/disconnection, and the outlet end of the fourth chromatographic analytical column is connected to a detector with thermal conductivity cells through a connecting pipeline with a controllable connection/disconnection; wherein the fourth preliminary separation column ensures the separation of helium and hydrogen from natural gas; and the fourth chromatographic analytical column ensures the separation of helium and hydrogen. 4. The device according to item 3, in which The column for sulfur determination is a DB-Sulfur SCD chromatographic column; the DB-Sulfur SCD chromatographic column has a length of 50 to 60 m; the first pre-separation column is selected from one of the pre-separation column OV-1 and the capillary column DB-1; the pre-separation column OV-1 has a length of 1.0 to 2.0 m; the capillary column DB-1 has a length of 3.0 to 5.0 m; the first chromatographic analytical column is selected from one of an HP-Al/S chromatographic column, an HP-PLOT Al ₂ O ₃ S capillary column, a PONA capillary column and a Plot Q capillary column; the HP-Al/S chromatographic column has a length of 30 to 50 m; the HP-PLOT Al ₂ O ₃ S capillary column has a length of 25 to 50 m; the PONA capillary column has a length of 50 to 100 m; the Plot Q capillary column has a length of 25 to 30 m; the second pre-separation column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column; the Porapak N column has a length of 3 to 5 m; the second chromatographic analytical column is a MS-13X molecular sieve column; the MS-13X molecular sieve column has a length of 3.0 to 5.0 m; the third pre-separation column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column; the Porapak N column has a length of 1 to 2 m; the third chromatographic analytical column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column; the Porapak N column has a length of 2 to 3 m; the fourth pre-separation column is selected from one of a Porapak N column, a Porapak Q column and a Porapak QS column; the Porapak N column has a length of 1 to 2 m; The fourth chromatographic analytical column is an MS-5A molecular sieve column; the MS-5A molecular sieve column has a length of 3.0 to 5.0 m. 5. The device according to item 3, in which the first chromatographic column analysis system comprises a first sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the first chromatographic column analysis system, the first sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube and the chromatographic column, respectively, wherein the first sample loading valve is used to control the connection/disconnection of the connecting pipeline between parts of the first chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the first chromatographic column analysis system; when the first sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the first chromatographic column analysis system after passing through the quantitative tube; and when the first sample loading valve is switched to the second working position, it is possible to introduce the gas flow in the carrier gas tube of the first chromatographic column analysis system into the chromatographic column of the first chromatographic column analysis system through the quantitative tube of the first chromatographic column analysis system. 6. The device according to item 5, in which the first sample loading valve is a six-way valve having a first operating position and a second operating position, wherein the six-way valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port and a sixth valve port in clockwise sequence; when the six-way valve is in the first operating position, the sixth valve port is connected to the first valve port, the second valve port is connected to the third valve port, and the fourth valve port is connected to the fifth valve port; when the six-way valve is in the second operating position, the first valve port is connected to the second valve port, the third valve port is connected to the fourth valve port, and the fifth valve port is connected to the sixth valve port; and each of the sixth hole and the fifth hole of the first sample loading valve is connected to the sample loading unit, the quantitative tube of the first chromatographic column analysis system has one end connected to the first hole of the first sample loading valve and the other end connected to the fourth hole of the first sample loading valve, the carrier gas tube of the first chromatographic column analysis system is connected to the second hole of the first sample loading valve, and the sulfur determination column is connected to the third hole of the first sample loading valve. 7. The device according to item 3, in which the second chromatographic column analysis system comprises a second sample loading valve, which is a multi-port valve having a first operating position and a second operating position; in the second chromatographic column analysis system, the second sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the first pre-separation column, the inlet end of the first chromatographic analytical column and the hydrogen flame ionization detector, respectively, wherein the second sample loading valve is used to control the connection/disconnection of the connecting pipeline between parts of the second chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the second chromatographic column analysis system; when the second sample loading valve is switched to the first working position, it is possible to directly discharge gas in the sample loading unit from the second chromatographic column analysis system after passing through the quantitative tube, introduce gas in the carrier gas tube of the second chromatographic column analysis system into the outlet end of the first pre-separation column, discharge a flow from the inlet end of the first pre-separation column, and then introduce the flow into the hydrogen flame ionization detector, while it is possible to introduce gas in the carrier gas tube of the second chromatographic column analysis system into the first chromatographic analytical column through the inlet end of the first chromatographic analytical column; and when the second sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the second chromatographic column analysis system into the first preliminary separation column through the quantitative tube of the second chromatographic column analysis system, introduce it into the inlet end of the first preliminary separation column and remove the flow from the outlet end of the first preliminary separation column, and then introduce it into the first chromatographic analytical column through the inlet end of the first chromatographic analytical column. 8. The device according to item 7, in which the second sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the second sample loading valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port, a sixth valve port, a seventh valve port, an eighth valve port, a ninth valve port and a tenth valve port in clockwise sequence; when the second sample loading valve is in the first operating position, the tenth valve port is connected to the first valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, and the eighth valve port is connected to the ninth valve port; when the second sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and the tenth hole and the ninth hole of the second sample loading valve are connected to the sample loading unit, the quantitative tube of the second chromatographic column analysis system has one end connected to the first hole of the second sample loading valve and the other end connected to the eighth hole of the second sample loading valve, the carrier gas tube of the second chromatographic column analysis system is connected to each of the seventh hole and the fourth hole of the second sample loading valve, the first pre-separation column has an inlet end connected to the second hole of the second sample loading valve and an outlet end connected to the sixth hole of the second sample loading valve, the inlet end of the first chromatographic analytical column is connected to the fifth hole of the second sample loading valve, and the third hole of the second sample loading valve is connected to the hydrogen flame ionization detector. 9. The device according to item 3, in which the third chromatographic column analysis system comprises a third sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the third chromatographic column analysis system, the third sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the second pre-separation column and the inlet end of the second chromatographic analytical column, respectively, wherein the third sample loading valve is used to control the connection/disconnection of the connecting pipeline between parts of the third chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the third chromatographic column analysis system; when the third sample loading valve is switched to the first working position, it is possible to directly discharge gas in the sample loading unit from the third chromatographic column analysis system after passing through the quantitative tube, introduce gas in the carrier gas tube of the third chromatographic column analysis system into the outlet end of the second pre-separation column and discharge a flow from the inlet end of the second pre-separation column to discharge from the three analysis systems, while it is possible to introduce gas in the carrier gas tube of the third chromatographic column analysis system into the second chromatographic analytical column through the inlet end of the second chromatographic analytical column; and when the third sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the third chromatographic column analysis system into the second preliminary separation column through the quantitative tube of the third chromatographic column analysis system, introduce it into the inlet end of the second preliminary separation column and remove the flow from the outlet end of the second preliminary separation column, and then introduce it into the second chromatographic analytical column through the inlet end of the second chromatographic analytical column. 10. The device according to item 9, in which the third sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the third sample loading valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port, a sixth valve port, a seventh valve port, an eighth valve port, a ninth valve port and a tenth valve port in clockwise sequence; when the third sample loading valve is in the first operating position, the tenth valve port is connected to the first valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, and the eighth valve port is connected to the ninth valve port; when the third sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and each of the tenth hole and the ninth hole of the third sample loading valve is connected to the sample loading unit, the quantitative tube of the third chromatographic column analysis system has one end connected to the first hole of the third sample loading valve and the other end connected to the eighth hole of the third sample loading valve, the carrier gas tube of the third chromatographic column analysis system is connected to the seventh hole and the fourth hole of the third sample loading valve, the second pre-separation column has an inlet end connected to the second hole of the third sample loading valve and an outlet end connected to the sixth hole of the third sample loading valve, and the inlet end of the second chromatographic analytical column is connected to the fifth hole of the third sample loading valve. 11. The device according to item 3, in which the fourth chromatographic column analysis system comprises a fourth sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the fourth chromatographic column analysis system, the fourth sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the third pre-separation column and an inlet end of the third chromatographic analytical column, respectively, wherein the fourth sample loading valve is used to control the connection/disconnection of the connecting pipeline between parts of the fourth chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the fourth chromatographic column analysis system; when the fourth sample loading valve is switched to the first working position, it is possible to directly discharge the gas in the sample loading unit from the fourth chromatographic column analysis system after passing through the quantitative tube, introduce the gas in the carrier gas tube of the fourth chromatographic column analysis system into the outlet end of the third pre-separation column and discharge a flow from the inlet end of the third pre-separation column to discharge from the three analysis systems, while it is possible to introduce the gas in the carrier gas tube of the fourth chromatographic column analysis system into the third chromatographic analytical column through the inlet end of the third chromatographic analytical column; and when the fourth sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the fourth chromatographic column analysis system into the third preliminary separation column through the quantitative tube of the fourth chromatographic column analysis system, introduce it into the inlet end of the third preliminary separation column and remove the flow from the outlet end of the third preliminary separation column, and then introduce it into the third chromatographic analytical column through the inlet end of the third chromatographic analytical column. 12. The device according to item 11, in which the fourth sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the fourth sample loading valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port, a sixth valve port, a seventh valve port, an eighth valve port, a ninth valve port and a tenth valve port in clockwise sequence; when the fourth sample loading valve is in the first operating position, the tenth valve port is connected to the first valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, and the eighth valve port is connected to the ninth valve port; when the fourth sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and each of the tenth hole and the ninth hole of the fourth sample loading valve is connected to the sample loading unit, the quantitative tube of the fourth chromatographic column analysis system has one end connected to the first hole of the fourth sample loading valve and the other end connected to the eighth hole of the fourth sample loading valve, the carrier gas tube of the fourth chromatographic column analysis system is connected to the seventh hole and the fourth hole of the fourth sample loading valve, the third pre-separation column has an inlet end connected to the second hole of the fourth sample loading valve and an outlet end connected to the sixth hole of the fourth sample loading valve, and the inlet end of the third chromatographic analytical column is connected to the fifth hole of the fourth sample loading valve. 13. The device according to item 3, in which the fifth chromatographic column analysis system comprises a fifth sample loading valve, which is a multi-way valve having a first operating position and a second operating position; in the fifth chromatographic column analysis system, the fifth sample loading valve is connected to two ends of the quantitative tube, the carrier gas tube, two ends of the fourth pre-separation column and the inlet end of the fourth chromatographic analytical column, respectively, wherein the fifth sample loading valve is used to control the connection/disconnection of the connecting pipeline between parts of the fifth chromatographic column analysis system and the connection/disconnection of the connecting pipeline between the sample loading unit and the fifth chromatographic column analysis system; when the fifth sample loading valve is switched to the first working position, it is possible to directly discharge the gas flow in the sample loading unit from the fifth chromatographic column analysis system after passing through the quantitative tube, it is possible to introduce the gas in the carrier gas tube of the fifth chromatographic column analysis system into the outlet end of the fourth pre-separation column and discharge the flow from the inlet end of the fourth pre-separation column to discharge from the three analysis systems, and it is possible to introduce the gas in the carrier gas tube of the fifth chromatographic column analysis system into the fourth chromatographic analytical column through the inlet end of the fourth chromatographic analytical column; and when the fifth sample loading valve is switched to the second working position, it is possible to introduce a gas flow in the carrier gas tube of the fifth chromatographic column analysis system into the fourth preliminary separation column through the quantitative tube of the fifth chromatographic column analysis system, introduce it into the inlet end of the fourth preliminary separation column and remove the flow from the outlet end of the fourth preliminary separation column, and then introduce it into the fourth chromatographic analytical column through the inlet end of the fourth chromatographic analytical column. 14. The device according to item 13, in which the fifth sample loading valve is a ten-way valve having a first operating position and a second operating position, wherein the fifth sample loading valve is provided with a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port, a sixth valve port, a seventh valve port, an eighth valve port, a ninth valve port and a tenth valve port in clockwise sequence; when the fifth sample loading valve is in the first operating position, the tenth valve port is connected to the first valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, and the eighth valve port is connected to the ninth valve port; when the fifth sample loading valve is in the second working position, the first valve opening is connected to the second valve opening, the third valve opening is connected to the fourth valve opening, the fifth valve opening is connected to the sixth valve opening, the seventh valve opening is connected to the eighth valve opening, and the ninth valve opening is connected to the tenth valve opening; and each of the tenth port and the ninth port of the fifth sample loading valve is connected to the sample loading unit, the quantitative tube of the fifth chromatographic column analysis system has one end connected to the first port of the fifth sample loading valve and the other end connected to the eighth port of the fifth sample loading valve, the carrier gas tube of the fifth chromatographic column analysis system is connected to the seventh port and the fourth port of the fifth sample loading valve, the fourth pre-separation column has an inlet end connected to the second port of the fifth sample loading valve and an outlet end connected to the sixth port of the fifth sample loading valve, and the inlet end of the fourth chromatographic analytical column is connected to the fifth port of the fifth sample loading valve. 15. A method for analyzing the quality indicators of a natural gas product, implemented using a device for analyzing the quality indicators of a natural gas product according to any of paragraphs 1-14, including: loading the sample into the quantitative tubes of the first chromatographic column analysis system, the second chromatographic column analysis system, the third chromatographic column analysis system, the fourth chromatographic column analysis system and the fifth chromatographic column analysis system such that each of the quantitative tubes is filled with a sample of natural gas; in a first chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate sulfides from a natural gas sample in a quantitative tube under the action of the carrier gas, and feeding the separated components to a detection detector to obtain a first detection chromatogram; determining the sulfide content in the natural gas sample based on the obtained first detection chromatogram; in a second chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate hydrocarbons having _C3 or higher from a natural gas sample in a quantitative tube under the action of the carrier gas, and delivering the separated components to a detection detector to obtain a second detection chromatogram; determining the content of hydrocarbons having _C3 or higher in the natural gas sample based on the obtained second detection chromatogram; in a third chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate oxygen, nitrogen, methane and carbon monoxide from a natural gas sample in a quantitative tube under the action of the carrier gas, and supplying the separated components to a detector for detection to obtain a third detection chromatogram; determining the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample based on the obtained third detection chromatogram; in a fourth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate carbon dioxide and ethane from a natural gas sample in a quantitative tube under the action of the carrier gas, and supplying the separated components to a detection detector to obtain a fourth detection chromatogram; determining the content of carbon dioxide and ethane in the natural gas sample based on the obtained fourth detection chromatogram; in a fifth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, using a chromatographic column to separate helium and hydrogen from a natural gas sample in a quantitative tube under the action of the carrier gas, and delivering the separated components to a detection detector to obtain a fifth detection chromatogram; determining the content of helium and hydrogen in the natural gas sample based on the obtained fifth detection chromatogram; and based on the obtained content of sulfides in the natural gas sample, the content of hydrocarbons having _C3 and higher in the natural gas sample, the content of oxygen, nitrogen, methane and carbon monoxide in the natural gas sample, the content of carbon dioxide and ethane in the natural gas sample and the content of helium and hydrogen in the natural gas sample, the higher calorific value, total sulfur content, hydrogen sulfide content and/or carbon dioxide content for natural gas are determined. 16. The method according to claim 15, implemented using a device for analyzing the quality indicators of a natural gas product according to any of claims 3-14, according to which the step of using a carrier gas tube in a first chromatographic column analysis system for delivering a carrier gas using a chromatographic column for separating sulfides from a natural gas sample in a quantitative tube under the influence of the carrier gas and with the supply of separated components to a detector for detection with obtaining a first detection chromatogram includes: in a first chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas, feeding a natural gas sample in a quantitative tube into a sulfur column under the action of the carrier gas to separate sulfides, and feeding the separated components into a chemiluminescence sulfur detector to detect sulfides in the natural gas sample to obtain a first detection chromatogram; the sulfur column is maintained at 30-50°C until the carbonyl sulfur is released from the sulfur column, and then the temperature of the sulfur column is increased at a rate of 10-20°C/min to 130°C and maintained at this level. 17. The method according to claim 15, implemented using a device for analyzing the quality indicators of a natural gas product according to any of claims 3-14, according to which the step of using a carrier gas tube in a second chromatographic column analysis system for delivering a carrier gas using a chromatographic column for separating hydrocarbons having _C3 and above from a natural gas sample in a quantitative tube under the influence of a carrier gas and with the supply of separated components to a detector for detection with the production of a second detection chromatogram includes: in a second chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas and subjecting a natural gas sample in a quantitative tube under the action of the carrier gas to separation operations using a first pre-separation column and a first chromatographic analytical column sequentially; moving the carrier gas to an outlet end of the ^first pre-separation column after _C5- components in the natural gas sample exit from the first pre-separation column and enter the first chromatographic analytical column, connecting an inlet end of the first pre-separation column to a hydrogen flame ionization detector, and backflush transferring _C6 ⁺ hydrocarbon components under the action of the carrier gas from the first pre-separation column to the hydrogen flame ionization detector for detection; and after completion of the backwash, transferring the carrier gas to the inlet end of the first chromatographic analytical column and sequentially introducing, under the influence of the carrier gas, individual _C3 hydrocarbon components separated by the first chromatographic analytical column into a hydrogen flame ionization detector for detection to obtain a second detection chromatogram; the first chromatographic analytical column is maintained at 30-50°C until the hydrogen flame ionization detector detects peaks of C ₆ ⁺ hydrocarbon components, and then the temperature of the first chromatographic analytical column is increased at a rate of 10-20°C/min to 130°C and maintained at this level. 18. The method of claim 15, implemented using a device for analyzing the quality indicators of a natural gas product according to any one of claims 3-14, according to which the step of using a carrier gas tube in a third chromatographic column analysis system to deliver a carrier gas, using a chromatographic column to separate oxygen, nitrogen, methane and carbon monoxide from a natural gas sample in a quantitative tube under the influence of the carrier gas and feeding the separated components to a detector for detection to obtain a third detection chromatogram includes: in a third chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas and subjecting a natural gas sample in a quantitative tube, under the action of the carrier gas, to separation operations using a second pre-separation column and a second chromatographic analytical column sequentially; after the oxygen, nitrogen, methane and carbon monoxide components in the natural gas sample exit from the second pre-separation column and enter the second chromatographic analytical column, transferring the carrier gas to an outlet end of the second pre-separation column and removing by backwashing the remaining components in the second pre-separation column from the third chromatographic column analysis system under the action of the carrier gas; and after completing the backwashing, transferring the carrier gas to an inlet end of the second chromatographic analytical column and, under the action of the carrier gas, sequentially introducing the oxygen, nitrogen, methane and carbon monoxide components separated by the second chromatographic analytical column into a detector with thermal conductivity cells for detection to obtain a third detection chromatogram; the temperature of the second chromatographic analytical column is 50-70°C. 19. The method of claim 15, implemented using a device for analyzing the quality indicators of a natural gas product according to any one of claims 3-14, according to which the step of using a carrier gas tube in a fourth chromatographic column analysis system to deliver a carrier gas, using a chromatographic column to separate carbon dioxide and ethane from a natural gas sample in a quantitative tube under the influence of the carrier gas and feeding the separated components to a detector for detection to obtain a fourth detection chromatogram includes: in a fourth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas and subjecting a natural gas sample in a quantitative tube, under the action of the carrier gas, to separation operations by sequentially using a third pre-separation column and a third chromatographic analytical column; transferring the carrier gas to an outlet end of the third pre-separation column after the carbon dioxide and ethane components in the natural gas sample exit from the third pre-separation column and enter the third chromatographic analytical column, and removing by backwashing the remaining components in the third pre-separation column from the fourth chromatographic column analysis system under the action of the carrier gas; and transferring the carrier gas to an inlet end of the third chromatographic analytical column after completing the backwashing and, under the action of the carrier gas, sequentially introducing the carbon dioxide and ethane components separated by the third chromatographic analytical column into a detector with thermal conductivity cells for detection to obtain a fourth detection chromatogram; Preferably, the temperature of the third chromatographic analytical column is 50-70°C. 20. The method of claim 15, implemented using a device for analyzing the quality indicators of a natural gas product according to any one of claims 3-14, according to which the step of using a carrier gas tube in a fifth chromatographic column analysis system to deliver a carrier gas, using a chromatographic column to separate helium and hydrogen from a natural gas sample in a quantitative tube under the influence of the carrier gas and feeding the separated components to a detector for detection to obtain a fifth detection chromatogram includes: in a fifth chromatographic column analysis system: using a carrier gas tube to deliver a carrier gas and subjecting a natural gas sample in a quantitative tube, under the action of the carrier gas, to separation operations by sequentially using a fourth pre-separation column and a fourth chromatographic analytical column; transferring the carrier gas to an outlet end of the fourth pre-separation column after helium and hydrogen components in the natural gas sample exit the fourth pre-separation column and enter the fourth chromatographic analytical column, and removing by backwashing the remaining components in the fourth pre-separation column from the fifth chromatographic column analysis system under the action of the carrier gas; and transferring the carrier gas to an inlet end of the fourth chromatographic analytical column after completing the backwash, and under the action of the carrier gas sequentially introducing the helium and hydrogen components separated by the fourth chromatographic analytical column into a detector with thermal conductivity cells for detection to obtain a fifth detection chromatogram; Preferably, the temperature of the fourth chromatographic analytical column is 50-70°C.