RU2264430C1 - Crude oil distillation process and installation - Google Patents

Abstract

FIELD: petroleum processing.

SUBSTANCE: invention relates to primary petroleum processing on atmospheric and atmospheric vacuum distillation installations. Preheated crude oil is fed into first distillation column separated in its median part with tight plate, from the top of which gaseous low-boiling hydrocarbons are picked and, as side-cut distillate from the tight plate, hydrocarbon condensate is withdrawn, which is routed into second column as top feed. Bottom residue from the first column is also fed into second column. Distillation is continued according to consecutive scheme while picking as distillate from 2^nd column fraction boiling up to 85°C, from 3^rd column gasoline, from 4^th column kerosene, and from 5^th column diesel fuel. From the bottom of 5^th column, mazut-type distillation residue is obtained. Installation may comprise five or more in series connected columns each having 7 to 12 plates. Each column produces one distillate from the top condenser. Number of columns is equal to number of picked commercial distillate fractions. Two first columns are separated in two with tight plates to create temperatures 35-45°C at reduced pressures in their top condensers. Feed is heated only in lower column heaters except last steam column.

EFFECT: reduced production expenses and increased recovery of light clearly separated petroleum products.

2 cl, 3 dwg, 3 tbl

Description

The invention relates to a method and installation for the processing of crude oils and can be used in installations AT and ABT with a two-column oil distillation scheme at atmospheric or close to it pressure.

A known method for the distillation of crude oils in two sequentially operating columns (US Pat. US No. 4274944), in which the original heated oil is soaked into the lower section of the first two-section atmospheric column R-1. Gases and unstable gasoline are taken from the top of the R-1 column, commercial gasoline is taken from the middle, and distillate from the pallet. Part of the unstable gasoline from the top condenser is returned to R-1 for irrigation.

In the upper section R-1 serves the second power from the upper condenser of the second atmospheric column R-2. After heating, R-1 is filtered into the lower section of the R-2 column, which produces light oil products, gasoline fractions in the upper condenser and fuel oil in the distillation in lateral selections.

Lateral withdrawals of R-2 are cleaned of light hydrocarbons in lateral stripping columns. To the bottom of R-2 serves sharp steam, the condensate of which is removed from the upper condenser.

The disadvantages of this method are as follows:

- inefficient use of separation power of both columns, as a consequence of this, the need for stripping columns, side irrigation, excess heat;

- non-optimal choice of the number of selections and their total value from each of the columns;

- non-optimal modes of heating oil and the point of its supply to the columns;

- high pressure in the columns.

Known closer in technical essence and the achieved results "Method for the primary distillation of oil" (US Pat. RU No. 2140957), presented in figure 1. According to figure 1, in the first of two successive atmospheric columns R-1, R-2, gases and the NK-85 fraction, as well as the gasoline-kerosene fraction from the half-blank plate installed in the upper section of R-1, are taken from the upper condenser. The distillation of R-1 after heating in the furnace is filtered by lower feeding into the second atmospheric column R-2. Top food R-2 - lateral selection from a half-deaf plate R-1.

The R-2 column delivers light oil products and fuel oil in the distillation in the selections. Its side extraction is cleaned of light hydrocarbons in stripping columns. The steam R-2 is fed with hot steam, the condensate of which is removed from the upper condenser.

The installation of primary oil refining AT, ABT (US Pat. RU No. 2205055) is also known, the scheme of which is presented in figure 2. It can be seen from it that the installation is composed of two series-connected two and three (four) sectional atmospheric distillation columns (R-1, R-2), in which

- both columns have upper condensers, oil heaters installed in front of the columns have one, two feeds and several selections with light oil products;

- the R-1 column has a lower heater, and the R-2 column has a stream of sharp steam in the pan and side stripping columns.

This method has lower heat consumption with the same volume of products compared to the above US patent No. 4274944. However, its shortcomings are the same:

- non-optimal choice of the number of selections and their total value from each column;

- suboptimal heating modes of oil and the points of its supply to the columns, which is accompanied by the loss of part of the heat in the upper condenser and lateral irrigation;

- high pressures used in the columns lead to an increase in the heat consumption of the columns.

The disadvantages of the known distillation plant are as follows:

- the use of ineffective 2-4 sectional columns operating at atmospheric or slightly higher pressure; it is difficult to organize optimal hydraulics and separation in them with minimal heat consumption;

- the location of the oil heaters in front of the columns is not optimal, because leads to useless loss of part of the heat in the upper condenser and side irrigation.

The main objectives of the proposed method and device are to eliminate the disadvantages of the known distillation method and to constructively improve the AT, ABT plants in order to better use their separation power with minimal heat consumption.

Regarding the method of distillation, the problem is solved in that in the known method (US Pat. RU No. 2140957), including:

- supply to the first atmospheric column R-1 of compressed and heated crude oil with the selection of gases from its upper condenser, NK-85 fraction and gasoline-kerosene fraction in a side chase;

- supply of a hot stream to the R-1 pan from its lower heater and heated R-1 distillate to the R-2 column with lower power;

- supply of side extraction R-1 without changing its temperature to the second atmospheric steam column R-2 by top feed with the selection of light oil products and fuel oil from it in distillation;

- in the new method, the original oil is fed into the lower part of the first single-section column R-1, divided in the middle by a blank plate; in the lower part of R-1 the pressure is atmospheric, in the upper - above atmospheric;

- the vapor phase from the lower part of R-1 is compressed in a compressor and is sucked into the upper part of R-1, removing gases with a temperature of 35-40 ° С from its upper condenser, and from the blank plate - hydrocarbon condensate, which is absorbed by the first feed into the lower a second atmospheric column R-2;

- the heated distillation R-1 is also screened in the lower part of R-2, the column R-2 is divided in two by a blank plate; in its lower part - atmospheric pressure, in the upper - above atmospheric pressure;

- vapors from the lower part of R-2 are compressed in a compressor and fed to the upper part of R-2, where they produce the NK-85 fraction in the upper condenser with a temperature of 35-45 ° С and hydrocarbon condensate on a blank plate;

- the latter is fed with the upper feed into the third atmospheric column R-3 or slightly lower, the distillation of R-2 is fed into R-3 by its lower feed; the R-3 column delivers commercial gasoline at the top, heated topped oil below;

- R-3 distillation is soaked into the fourth atmospheric or slightly lower R-4 column to obtain commercial kerosene from it at the top and heated distillation below;

- distillation of R-4 is tested in the fifth steam column with a pressure below atmospheric, in it the oil is divided into diesel fuel at the top of the column and fuel oil at the bottom.

Regarding the installation for implementing the method of distillation, the problems are solved in that in the known installation of the primary oil distillation AT, ABT (US Pat. RU No. 2205055), including:

- two series-connected two- and three (four) sectional atmospheric columns (R-1, R-2) with upper condensers, a lower heater in the first and a stream of sharp steam in the second, preliminary oil heaters installed in front of each column, having several selections with light petroleum products in each column;

- a new installation AT, ABT (see figure 3) is composed of five or more series-connected 7-12 plate atmospheric or close to it columns with upper condensers and lower heaters in the first four (or more) columns and a stream of sharp steam in the last fifth (or more) column;

- the first atmospheric 7-plate column (R-1) with a blank plate in the middle is connected by its lower half to the pipe 1 supplying crude oil, the pan R-1 is connected by a pipe 5 to the heater H1, from which the hot stream is returned to the pan through the pipe 6 R-1, and its heated distillation is led through a pipe 7 to the bottom of the column R-2;

- the lower half of R-1 is connected through the K-1 compressor by a pipe 2 to the upper half of R-1, from which gases are removed from the pipe 3 from the top, and hydrocarbon condensate is supplied from the blank plate by a pipe 4 to the lower part of the R-2 column;

- the second atmospheric 9-plate column R-2 is also divided in two by a blank plate, pipe 8 through the K-2 compressor connects the lower part of R-2 to its upper part, where the NK-85 fraction is removed from the upper condenser cond2 by pipe 12, and by pipe 13 from a blank plate, condensate is filtered onto the upper plates of atmospheric or slightly lower than the 9-plate column R-3;

- oil from the sump R-2 through the pipe 9 is fed to the heater H2 and then through the pipe 10 part of it is returned to R-2, and distillation through the pipe 11 is fed to the lower plates of the gasoline column R-3;

- gasoline from the upper condenser cond3 through the pipe 17 is removed from R-3, and its heated distillate through the pipe 16 is fed into the fourth atmospheric or lower column (R-4);

- the fourth 12-plate column gives out commodity kerosene from the upper condenser cond4 through the pipe 19, and the heated distillation R-4 is fed through the pipe 18 to the lower plates of the fifth steam column under reduced pressure;

- in the fifth 9-plate steam column, diesel fuel is discharged from its condenser cond5 through a pipe 21, water condensate through a pipe 22, and fuel oil from a pallet through a pipe 20; steam is fed through a pipe 23.

The claimed distillation unit AT, ABT operates as follows. The original crude oil with atmospheric pressure and a temperature of 20 ° C through pipe 1 enters the lower part of the 7-plate column R-1, divided in half by a blank plate. In R-1, oil is heated in the lower heater H1 by a "hot stream" supplied through pipe 6, and the heated stripping from H1 through pipe 7 is fed to the lower plates of R-2. The vapor phase from the lower part of R-1 after its compression in the compressor K-1 is absorbed into the upper part of R-1 at elevated pressure. Here, gases with a temperature of 35-40 ° C are removed from the upper condenser cond1 through the pipe 3, and condensate is removed from the blank plate R-1 through the pipe 4 by the second feed R-2 to its lower part.

This 9-plate column is also divided in two by a blank plate. At the bottom of R-2, the pressure is atmospheric, above it is above atmospheric. Its value is determined by the condensation temperature in the condenser cond2. The oil fed down R-2 is divided into the vapor phase discharged through pipe 8 through the K-2 compressor to the upper part of R-2, and the liquid phase, which through pipe 9 enters the H2 heater and then part of it in the form of a “hot stream” "through the pipe 10 is returned back to R-2, and the rest (distillation R-2) through the pipe 11 is fed into the lower plates of the column R-3 by its lower power supply.

In the upper part of R-2, the power that came with stream 8 is divided into the NK-85 fraction in the upper condenser cond2 and the condensate from the blank plate supplied by the pipe 13 with the second, upper power of R-3.

The R-3 gasoline column divides the oil into commercial gasoline (stream 17) and heated topped oil (stream 16), which is sieved into the fourth 12-plate kerosene column R-4. Column R-4 operates near atmospheric or slightly lower pressure. It produces commodity kerosene from the upper condenser cond4, and below it is heated distillate, which is filtered into the fifth R-5 steam column operating at a pressure slightly lower than atmospheric.

The diesel 9-plate column R-5 divides the incoming oil (stream 18) into diesel fuel (stream 21) and fuel oil (stream 20). Steam is supplied to the pallet R-5 through the pipe 23, and water condensate is removed from the upper condenser cond5 through the pipe 22.

From the presented materials it can be seen that in the inventive distillation plant

- the number of columns is equal to the number of samples taken from it,

- blank plates were used on the first two columns, which allowed to increase the pressure only in the upper part of the columns R-1, R-2 to organize the temperatures necessary for the technology in their upper condensers (35-45 ° С),

- the number of plates in the columns of the installation varies from 7 to 12 and is determined by the volatility of the separated fractions and the size of the selection of columns.

The following is a comparison of the operational efficiency of the known and claimed installations for the distillation of Permian crude oil. All calculations were performed using the Hysys Plant program.

Example

The heat consumption of two methods and installations for the distillation of crude oil is compared: (option 1) the known and (option 2) the claimed. The known method and installation are shown in figures 1 and 2, the claimed - in figure 3. Both plants process 940.5 kgmol / h Perm oil of known fractional composition. From it, in both variants, products of the same fractional composition in the same amount are obtained.

Table 1 below shows the enlarged composition of marketable products and the magnitude of the flows taken from the installation. They are the same for both options. The following tables 2 and 3 show the heat consumption of two options.

Table 1 The boiling point of the fractions, ° C Fraction Designation Fractional compositions of selected products Gases NK-85 Petrol Kerosene Diesel fuel Fuel oil % mol. % mol. % mol. % mol. % mol. % mol. - G 94.16 48.19 6.04 43-85 Nk 5.82 51.51 56.16 1,07 85-120 IN 0.02 0.3 35.02 9.34 120-240 TO 2.78 86.79 11.98 240-360 Dt 2.80 84.17 12.12 360-836 M 3.85 87.88 Sample Values Kgmol / hour 67 132 133 255 160 193.5

table 2
The heat consumption of the known method and installation (option 1) Heat source Unit H1 H2 H3 H4 H5 H6 Total Heat flow

12,945 9,434 15,831 1,231 1,342 0.410 41,193 Tempera tour source ° C 140 222.7 222.7 380 350 380 Table 3
The heat consumption of the proposed method and installation (option 2) Heat source Unit K1 H1 K2 H2 H3 H4 H5 Total Heat flow

0,085 5,964 0,084 6,825 4,814 14,214 2,399 34,385 Source temperature ° C 80.9 140.6 173.7 301.9 360

The reduction in heat consumption of the proposed method and installation amounted to

The decrease in pressure in the inventive installation in columns R-4, R-5 from 0.8 atm to 0.5 atm allows to reduce its heat consumption by ~ 20.7%.

Claims (2)

1. The method of distillation of crude oils, including supplying the first atmospheric column R-1 of compressed and heated crude oil with the selection of gases from its upper condenser, NK-85 fraction and gasoline-kerosene fraction in a side stream; the supply of a hot stream to the pallet R-1 from its lower heater and heated distillation R-1 to the column R-2 with lower power; lateral extraction of R-1 without changing its temperature to the second atmospheric steam column R-2 by top feed, with the selection of light oil products and fuel oil from it in distillation; characterized in that the original oil is fed into the lower part of the first single-section column R-1, divided in the middle by a blank plate; in the lower part of R-1 the pressure is atmospheric, in the upper - above atmospheric; the vapor phase from the lower part of R-1 is compressed in a compressor and is sucked into the upper part of R-1, extracting gases with a temperature of 35-40 ° С from its upper condenser, and from the blank plate - hydrocarbon condensate, which is absorbed by the first feed into the lower part of the second atmospheric column R-2; heated distillation of R-1 is also tested in the lower part of R-2, the column R-2 is divided in two by a blank plate, in its lower part the pressure is atmospheric, in the upper - above atmospheric; the vapors from the lower part of R-2 are compressed in a compressor and fed to the upper part of R-2, where they produce the NK-85 fraction in the upper condenser with a temperature of 35-45 ° C and hydrocarbon condensate on a blank plate; the latter is fed with the upper feed into the third atmospheric column R-3 or slightly lower, the distillation R-2 is fed into R-3 with its lower feed, the R-3 column gives out commodity gas at the top, and heated topped oil at the bottom; R-3 distillation is soaked into the fourth atmospheric or slightly lower R-4 column to obtain commercial kerosene from above and heated distillation below; distillation of R-4 is tested in a fifth steam column with a pressure below atmospheric, in which oil is divided into diesel fuel at the top of the column and fuel oil at the bottom. 2. Installation for implementing the method of primary distillation of crude oils AT, ABT, including two series-connected two and three (four) sectional atmospheric columns (R-1, R-2) with upper condensers, a lower heater in the first and a stream of sharp steam in the second , preliminary oil heaters installed in front of each column, and having several selections with light oil products in each column, characterized in that the new installation AT, ABT (see Fig. 3) is composed of five (or more) series-connected 7-12 atmospheric or nearby columns with upper condensers and lower heaters in the first four (or more) columns and a stream of sharp steam in the last fifth (or more) column; the first atmospheric 7-plate column (R-1) with a blank plate in the middle is connected by its lower half to the pipe 1 supplying crude oil, the pan R-1 is connected by a pipe 5 to the heater HI, from which the pipe is returned to the R- pan through a hot stream 1, and its heated distillation is led through a pipe 7 to the lower part of the column R-2; the lower half of R-1 is connected through the K-1 compressor by pipe 2 to the upper half of R-1, from the upper condenser of which cond1 gases are removed through pipe 3, and from the blank plate, hydrocarbon condensate is supplied by pipe 4 to the lower part of column R-2; the second atmospheric 9-plate column R-2 is also divided in two by a blank plate, pipe 8 through the K-2 compressor connects the lower part of R-2 to its upper part, where the NK-85 fraction is removed from the upper condenser cond2 by pipe 12, and 13 s blank plates condensate is filtered on the upper plates of atmospheric or slightly lower than 9 - plate columns R-3; the oil from the sump R-2 through the pipe 9 is fed to the heater H2 and then through the pipe 10 part of it is returned to R-2, and the distillation through the pipe 11 is fed to the lower plates of the gasoline column R-3; gasoline from the upper condenser cond3 through the pipe 17 is removed from R-3, and its heated distillate through the pipe 16 is fed to the fourth atmospheric or lower column R-4; the fourth 12-plate column delivers commodity kerosene from the upper condenser cond4 through the pipe 19, and the heated distillation R-4 is fed through the pipe 18 to the lower plates of the fifth steam column under reduced pressure; in the fifth 9-plate steam column, diesel is discharged from its condenser cond5 through a pipe 21, water condensate through a pipe 22, and fuel oil from its pan through a pipe 20; steam is fed through a pipe 23.

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