RU23874U1 - INSTALLATION FOR ORTHOXYLENE - Google Patents

Abstract

1. Installation for the production of continuous orthoxylene, comprising a feed pump, an orthoxylene separation unit, consisting of a first distillation column for separating ethylbenzene, para- and methaxylene from orthoxylene and C aromatic hydrocarbons above and a second distillation column for separating orthoxylene from C aromatic hydrocarbons above, isomerization unit , a stabilization column for separating light hydrocarbons CC, a refrigerator connected by pipelines, characterized in that the orthoxylene separation unit is arranged before isomerization unit, wherein the distillate xylene fractionator via line input izomerizatsii.2 block. Installation according to claim 1, characterized in that the distillation and stabilization columns contain distillate and feed heaters, distillate condensers, tanks and pumps that supply power. Installation according to claim 1, characterized in that the isomerization unit contains a heat exchanger, a tubular furnace, a reactor, a refrigerator, a separator connected in series with each other by pipelines, a compressor that circulates the hydrogen-containing gas, and the heat exchanger is arranged in such a way that the mixture is supplied isomerization due to the heat of the products leaving the reactor. 4. Installation according to claim 1, characterized in that the installation further comprises a distillation column for separating ethylbenzene from the xylene mixture located in front of the xylene distillation column of the orthoxylene separation unit.

Description

INSTALLATION FOR ORTHOXYLENE

A useful model refers to the production of orthoxylene from petroleum xylenes and can be used in the petrochemical, oil refining, oil shale and coke and chemical industries.

The prior art. There is no known plant for producing orthoxylene containing rectification columns for the separation of orthoxylene, air-cooled condensers, refrigerators, a steam heater, irrigation tanks, furnaces for heating refluxing reflux pumps. (Emelyanov V.E., Zhukov S.S. Xylene separation processes. M: Chemistry, 1975, p. 49).

However, in this installation, at a significant energy cost, the yield of orthoxylene is quite low.

A known installation for producing para- and orthoxylene, consisting of an orthoxylene separation unit, a cristagrator, a tube furnace, a heat exchanger, a reactor, a stabilization column for the isolation of hydrogenation products, benzene, a refrigerator, a compressor for circulating a hydrogen-containing gas, and a high-pressure gas separator. (Sulimov A.D. Production of aromatic hydrocarbons from petroleum feedstocks. M: Chemistry, 1975, SL93). This installation is taken as a prototype.

However, when using this installation, high energy and material costs per unit output of the product are required.

S07C15 / 08

The essence of the utility model. The utility model is aimed at creating an installation for producing cheap orthoxylene with its increased output per unit of raw material.

The technical result, which mediates the solution of this problem, is to reduce energy costs by eliminating the stages of adsorption or crystallization of paraxylene at a temperature, utilizing secondary energy resources, as well as increasing the yield of orthoxylene per unit of feedstock by increasing the amount of isomerization feedstock and increasing the proportion of paraxylene , which contributes to an increase in the rate of formation of orthoxylene.

The specified technical result is achieved by the fact that the distillate of the xylene distillation column is piped to the isomerization unit, bypassing the stage of adsorption or crystallization of paraxylene, and the heat exchanger in the isomerization unit is located in such a way that it heats the mixture supplied to the isomerization due to the heat of the products leaving the reactor . The installation may further comprise a distillation column for separating ethylbenzene from the xylene mixture located in front of the xylene distillation column of the orthoxylene separation unit.

The drawing (figL) shows a schematic diagram of a plant for the production of continuous orthoxylene.

The orthoxylene production unit includes a pipe 1, through which raw materials are supplied, it is pumped into a pipe 3, passed through a heater 4, and through a pipe 5 to a xylene distillation column 6, from where an orthoxylene concentrate flows through a pipe 7 to an orthoxylene distillation column 8, via a pipeline 9

orthoxylol enters the refrigerator 10 and goes through the pipe 11 to the park, through the pipe 12 the aromatic hydrocarbons Cd get into the refrigerator 13 and above where they go to the park through the pipe 14, the xylene column distillate goes through the pipes 15 and 16 to the heat exchanger 17, from where it goes through the pipe 18 enters the tube furnace 19 and through the pipe 20 to the isomerization reactor 21, through the pipelines 22 and 23 the isomerization products enter the refrigerator 24, from where they enter the separator 26 through the pipe 25, the gas phase from the separator 26 enters the compressor 28 through a pipe 27, through which it is again fed into a reaction zone through a pipe 29, the liquid phase from the separator 26 enters a stabilization column 31 through a pipe 30, the distillate of which is sent to a refrigerator 33 through a pipe 32 and then discharged through a pipe 34 to the park, and still residue through pipeline 35 is sent to pipeline 3.

Installation works as follows.

The feedstock, petroleum xylene, is pumped from pipeline 2 to pipeline 3, passed through a heater 4, and fed through pipeline 5 to xylene distillation column 6. An orthoxyl concentrate containing orthoxylene and aromatic hydrocarbons Сд and higher is formed in the bottom residue of distillation column 6 which through pipeline 7 enters the orthoxylol distillation column 8, where the separation of orthoxylene and aromatic hydrocarbons Cd and higher occurs. From the top of the orthoxylol distillation column 8, orthoxylene is released, which through pipe 9 enters the refrigerator 10, where it is cooled, and then sent through pipe 11 to the park. From the bottom of the orthoxylol distillation column 8 are separated aromatic

hydrocarbons Сд and higher, which are piped through 12 for cooling to the refrigerator 13 and then sent through piping 14 to the park.

The distillate from the top of the xylene distillation column 6, containing ethylbenzene, meta- and paraxylene, is mixed through a pipe 15 after mixing in a pipe 16 with hydrogen-containing gas through a heat exchanger 17 through a pipe 18 to a tube furnace 19, is heated to a temperature of 500 ° C and then fed through a pipe 20 into the reactor 21, where the isomerization process is carried out. Isomerization Products Pipeline

22B heat exchanger 17, where the heat is transferred to the mixture entering the furnace 19. Further isomerization products are piped

23 to the refrigerator 24, where they are cooled and fed through a pipe 25 to a separator 26. In the separator 26, the products are separated into liquid and gas phases. The gas phase containing the circulating hydrogen-containing gas from the top of the separator 26 through the pipeline 27 enters the compressor 28, which is again fed through the pipeline 29 to the mixture with the distillate of the xylene distillation column 6 supplied through the pipeline 15. The diagram shows: I supply of fresh hydrogen-containing gas, II - discharge of hydrogen-containing gas. The liquid phase from the bottom of the separator 26 through the pipeline 30 enters the stabilization column 31, in which the light hydrocarbons C-C-j, which are the products of degradation and hydrogenation of aromatic hydrocarbons Cg, are separated at the top, and a mixture of xylenes and aromatic hydrocarbons Cd and higher is discharged through the cube. The distillate, consisting of light hydrocarbons СрСу, from the top of the stabilization column 31 through the pipe 32 enters the refrigerator 33, where it is cooled, and then through the pipe 34 is sent to the park. VAT residue.

comprising a mixture of xylenes and aromatic hydrocarbons of Сd and higher, from the bottom of the stabilization column 31 through pipeline 35 it is sent to pipeline 3, where it is mixed with fresh raw materials and mixed with it through a heat exchanger 4 through pipeline 5 to xylene distillation column 6. The technological cycle is repeated.

Example. The raw material, the composition of which is shown in table 1, was supplied to the xylene distillation column in an amount of 2110 kg / h.

Table 1 Raw Material Composition

The orthoxylene concentrate formed in the bottom residue of the xylene distillation column containing orthoxylene and heavy aromatic hydrocarbons C and higher was sent to the orthoxylene distillation column, where the separation of orthoxylene and hydrocarbons Cd and higher took place. The upper product of the xylene distillation column mixed with hydrogen-containing gas (molar ratio of feed: hydrogen 1: 8) was heated in a tube furnace to a temperature of -3 ° C and entered the isomerization reactor. To carry out the isomerization reaction, a platinum-containing rate of 10 hours was used.

Full material balance (kg / h)

Raw materials

petroleum xylene 2110

1455

590 57

Flow rate for individual process flow units

xylene column 6

orthoxylol column 8

isomerization reactor 21

stabilization column 31

The reaction products after cooling in a refrigerator were separated into liquid and gas phases in a separator. The gas phase, the circulating hydrogen-containing gas was again fed into the reaction zone by the compressor, and the liquid phase was sent to the stabilization column. Light hydrocarbons were removed from the top of the stabilization column, which are products of the degradation and hydrogenation of aromatic hydrocarbons Cg. The bottom residue of the stabilization column was mixed with fresh raw materials and sent to the beginning of the process. catalyst 1-300, volumetric table 2

orthoxylene, are presented in table 2. From these data it is seen that the flow to the isomerization unit increases significantly, and, therefore, the amount of isomerizate increases and the yield of orthoxylene increases. Upon receipt of orthoxylene according to the above scheme, its yield is 69% of the feedstock.

Claims (4)

1. Installation for the production of continuous orthoxylene, containing a feed pump, an orthoxylene separation unit, consisting of a first distillation column for separating ethylbenzene, para- and methaxylene from orthoxylene and aromatic hydrocarbons C ₉ and higher, and a second distillation column for separating orthoxylene from aromatic hydrocarbons C ₉ and above block isomerization stabilizer column to separate light hydrocarbons C ₁ -C _7, a refrigerator connected conduits, characterized in that the selection unit of orthoxylene races olozhen before isomerization unit, wherein the distillate xylene fractionator via line input to the isomerization unit.  2. The installation according to claim 1, characterized in that the distillation and stabilization columns contain heaters of distillation liquid and power, distillate condensers, tanks and pumps that provide power.  3. The installation according to claim 1, characterized in that the isomerization unit contains a heat exchanger, a tube furnace, a reactor, a refrigerator, a separator connected in series with each other by pipelines, a compressor that circulates the hydrogen-containing gas, and the heat exchanger is arranged in such a way that the mixture is heated, fed to isomerization due to the heat of the products leaving the reactor. 4. Installation according to claim 1, characterized in that the installation further comprises a distillation column for separating ethylbenzene from the xylene mixture, located in front of the xylene distillation column of the orthoxylene separation unit.