RU2835089C2 - Method of reducing content of hydrogen sulphide and mercaptans in associated petroleum gas - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry and can be used to reduce the amount of hydrogen sulphide and mercaptans in associated petroleum gas. Method of reducing content of hydrogen sulphide and mercaptans in associated petroleum gas consists in neutralizing hydrogen sulphide and mercaptans by feeding a liquid neutralizing reagent with a reagent dosing unit through a spraying unit into a gas pipeline-reactor. Reactor gas line is configured to collect reacted neutralizer reagent. Also, the gas pipeline-reactor is made with the possibility of cleaning the inner cavity of the gas pipeline-reactor by starting the cleaning devices.

EFFECT: invention simplifies the composition of the equipment used, increases efficiency of the process of neutralizing hydrogen sulphide and mercaptans, and also prevents clogging of pipelines and equipment with reaction products.

1 cl, 1 dwg

Description

The invention relates to the oil and gas industry and can be used to reduce the amount of hydrogen sulfide and mercaptans in associated petroleum gas.

There are known methods for cleaning hydrogen sulfide-containing gases with the absorption of hydrogen sulfide by alkanolamine solutions - MEA, DEA, TEA (Kole A.L., Rezenfeld F.S. Gas Cleaning. - M., 1962. - Pp. 21-49), where neutralization is carried out by physicochemical absorption, and sorbent regeneration is carried out by high-temperature desorption. The basic scheme of gas cleaning processes with alkanolamine solutions consists of a column-type absorber, heat exchangers, a stripping column and refrigerators. These methods have a number of disadvantages: they are energy-intensive, metal-intensive, cleaning units are complex, in addition, a large consumption of sorbents is required, and for cleaning acid gases with the production of elemental sulfur it is necessary to build a Claus unit, the tail gases of which must also be additionally purified from hydrogen sulfide. With small volumes of the gas being cleaned, the methods become uneconomical.

A method for cleaning associated petroleum gas (APG) from H2S is known, which consists of passing the petroleum gas through a layer of hydrogen sulfide neutralizer in a bubbling reactor (Scheme for cleaning hydrogen sulfide-containing oil. / Safin R.R., Gaidukevich V.V., Ismagilova Z.F. et al. // Environmental protection in the oil and gas complex. - 2003. - No. 4. - P. 17-19). To implement the method, capacitive equipment and constant monitoring of the presence of the neutralizer in the reactor are required.

A method is known for removing hydrogen sulfide from gas mixtures by an oxidative method using electrolysis, in which the oxidation of hydrogen sulfide is carried out by a solution formed in the near-anode space of the electrolyzer as a result of the electrolytic decomposition of water (see Russian patent No. 2160152, IPC B01D 53/52). To implement the method, an electrolyzer with electrical equipment and capacitive equipment are required.

The closest to the claimed invention is the "Method for purifying gas from hydrogen sulfide and an installation for implementing it" (patent for invention No. 2116121 C1, cl. B01D 53/14 (1995.01); B01D 53/18 (1995.01); B01D 53/52 (1995.01), published on 27.07.1998), which consists of neutralizing hydrogen sulfide by mixing a hydrogen sulfide-containing gas with a liquid absorption solution containing trivalent iron compounds as an oxidizer, and then regenerating the spent solution by mixing it with air. The installation for implementing the above-described method contains an absorber, a regenerator and separators, wherein each absorber contains a jet ejector with a dispersant and a pipeline coil-shaped reactor connected to them in series. The disadvantages of this method and device include the inability to separate condensate during the cleaning process, the tendency for the grey contact surface of the reactor to become clogged, and the method requires capacitive equipment.

The technological problem solved by the invention consists of simplifying the composition of the equipment used, increasing the efficiency of the process of neutralizing hydrogen sulfide and mercaptans, and preventing clogging of pipelines and equipment with reaction products.

The set task is achieved by the fact that standard equipment is used to implement the method - a gas pipeline reactor, a reagent dosing unit, nozzles for dispersing the reagent, condensate collectors, a cleaning device for the pipeline, which do not require capital expenditures and construction.

A distinctive feature of the proposed method is the use of a gas pipeline section as a reactor, together with a reagent dosing unit, a spray unit, condensate collectors and cleaning devices.

The necessity and expediency of using a section of a gas pipeline as a reactor, together with the listed equipment, is due to the possibility of organizing an effective supply of reagent and cleaning the gas pipeline from reaction products using the existing equipment with minimal costs for re-equipping the facility.

Depending on the content of sulfur compounds and the geometric parameters of the gas pipeline, before implementing the invention, it is necessary to focus on the method of contact of the APG with the neutralizer. When using a relatively short section of the gas pipeline as a reactor, the highest reaction rate and cleaning efficiency are achieved in the process of spraying the reagent and during further contact on the wall of the pipeline. In such conditions, it will be necessary to ensure maximum spraying by selecting the pressure drop, the number of nozzles and their optimal location.

When using a long gas pipeline, the contact of the APG with the neutralizer will be achieved both at the spraying unit and at the lower points of the relief by bubbling the APG through the neutralizer. This implementation ensures the most lenient requirements for reagent spraying.

With a significant length of the gas pipeline, a large contact spot is formed along its length, and multiple bubbling is ensured at the lower points of the gas pipeline, allowing the quality of spraying to be neglected.

An example of the implementation of the method with a full set of equipment and methods is illustrated in the figure.

The installation includes a gas pipeline reactor 1 (a section of an operating gas pipeline in which the neutralization process takes place), a spraying unit 2, a reagent dosing unit 3, a condensate collector 4, a cleaning device launch chamber 5, and a cleaning device receiving chamber 6.

The following symbols are also used on the figure:

IG - source gas,

OG - purified gas,

NPN - direction of supply of hydrogen sulfide and mercaptan neutralizer.

The initial gas (line IG), containing hydrogen sulfide and mercaptans, enters the gas pipeline-reactor 1, where the flow of the purified gas is mixed with a reagent-neutralizer of hydrogen sulfide and mercaptans, which is supplied by the reagent dosing unit 3 through the spraying unit 2. The neutralizer is supplied under pressure, higher than the pressure in the gas pipeline-reactor by an amount sufficient for effective spraying.

Partially reacted neutralizer 7 is deposited in the gas pipeline and continues to react during further movement of the gas flow, accumulating at the lower points of the gas pipeline 8. When the neutralizer completely fills the pipeline cross-section, bubbling occurs at its lower points, which supplements the spraying effect and ensures full interaction of the neutralizer with the APG. The removal of chemical reaction products is carried out periodically by squeezing out liquid and deposits by cleaning devices into a condensate collector 4, which is emptied into motor transport for further disposal. The launch/reception of cleaning devices is carried out through standard launch chambers 5 and reception 6 of cleaning devices. All the described processes occur without additional measures using existing equipment and do not require the use of energy-intensive and metal-intensive heating, blowing, electrolysis installations, etc.

Claims (1)

A method for reducing the content of hydrogen sulfide and mercaptans in associated petroleum gas, consisting of neutralizing hydrogen sulfide and mercaptans by feeding a liquid neutralizing reagent by a reagent dosing unit through a spraying unit into a gas pipeline-reactor, designed with the ability to collect the reacted neutralizing reagent, as well as the ability to clean the internal cavity of the gas pipeline-reactor by starting cleaning devices.

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