SU1296557A1 - Method for producing styrene - Google Patents

Abstract

The invention relates to the field of styrene production by catalytic dehydrogenation of ethylbeneol and can be used in the production of styrene and other vinyl aromatic hydrocarbons. The goal is to reduce energy consumption through the use of heat from ethylbenzene dehydrogenation products. The goal was achieved by the method of producing styrene by catalytic dehydrogenation of ethylbenzene in the presence of water vapor at. The condensation of the reaction products is cooled by indirect heat exchange with the steam condensate up to 150-180 ° C, followed by compression to a pressure of 3-8 atm. After that, the product is condensed using indirect heat exchange with steam condensate. The method involves the use of catalytic heat to preheat the starting reagents, and the condensation heat is used to draw up low-pressure water vapor of 0.7-0.91 atm. Thus, by increasing the pressure at the stage of condensation, 306 kcal / kg (versus 14.0 kcal / kg) of heat are utilized, and 198 when it is cooled, 198 kcal / kg (against 140 kcal / kg). 1 il. (L to CD O) 01 ate

Description

one

The invention relates to methods for producing styrene by catalytic dehydrogenation of ethyl benzene and can be used in the production of styrene and other vinyl aromatic hydrocarbons.

The purpose of the invention is to reduce energy consumption by using the body of ethyl benzene dehydrogenation products.

The drawing shows the implementation of the proposed method

Ethylbenzene is fed to the dehydrogenation reactor 1 through line 2, and water vapor along the line 3. The reaction products (catalyzate), preheated, from reactor 1 through line 4 are fed to reactor 5, from which catalyzed by line 6 are diverted to waste-heat boiler 7 to produce steam with a pressure of 4.0-6.0 atm. Water vapor is obtained from steam condensate, according to. stepping into the apparatus 7 through line 8, heat exchange with catalyzate through the wall. Steam from the waste heat boiler 7 is led through line 9 to the process and transferred to the side. The cooled catalytic acid from the apparatus 7 through line 10 enters the separator bunker 11, in which the separation of catalyst dust particles from catacchate occurs.

The catalyst dust from the separator bunker 11 through line 12 periodically, as it accumulates, is shipped

dumping and catalyzed from the line 13 is fed to compression into compressor 14. Compressed catalyst from apparatus 14 through line 15 is fed to the boiler utilizer 16 for almost complete condensation of the reaction products at elevated pressure. The steam is obtained from the steam condensate entering the waste heat boiler 16 from line 17 by heat exchange with the catalyst through the wall. The resultant steam is discharged via line 18 and directed to the process, and the excess is transferred to the side.

Condensed and partially non-condensed products from apparatus 16 through line 19 are fed for rapid cooling to heat exchanger 20, from which uncondensed hydrocarbons through line 21 enter the process and are used as fuel. Liquid reaction products from heat exchanger 20 through line 22 are diverted to separator 23, in which

five

0

0

Hydrocarbons are separated from steam condensate. Hydrocarbons from the separator 23 through line 24 serves for fractionation, and steam condensate through line 25 serves for cleaning and subsequent use in the process.

Example 1. Styrene is obtained according to a known method. The dehydrogenation is carried out on a catalyst that has in its composition,%: Fe O 68-72; 4--6; 19-21, and

also other additives up to 4 wt.%, at a temperature of 600 ° C and a pressure at the inlet of the reactor 1.8 at. The volumetric feed rate of 0.5 hours

100 kg / h of ethylbenzene is fed to the dehydrogenation. The ratio of ethylbenzene - water vapor is kept equal to 1: 3 by weight. The temperature of the catalyst at the outlet of the reactor is 574 ° C. The heat of catalyzate is used to preheat the starting reagents. When this catalyzate is cooled with

5 574 to. The catalyzate is then rapidly cooled to and condensed at this temperature. Heat condensable reaction products are used to produce low pressure water vapor (0.7-0.91 ata). To maintain a condensation temperature of equal, it is necessary to maintain a condensation pressure of 1, 2 atm, respectively, the inlet pressure to the reactor

must be at least 1.8 ata.

The proportion of condensed products from the supplied condensation at a pressure of 1.2 at and a condensation temperature of 104 ° C is 0.333.

During condensation, 55,940 kcal / h of heat is released.

For 1 kg of catalysis, 140 kcal / kg of heat is utilized during condensation during cooling, and 174 kcal / kg of heat is utilized during cooling from 574 to 1 kg of catalyzate.

Example 2, Styrene receive according to the proposed method. The dehydrogenation is carried out on a catalyst whose composition is similar to that shown in Example 1 at 600 ° C and a 1.0 at pressure at the inlet to the reactor. The volumetric feed rate of the raw material is 0.5 h. 100 kg / h of ethylbenzene is fed to the dehydrogenation. The ratio of ethylbenzene - water vapor is kept equal to 1: 3 by weight. The product temperature at the outlet of the reactor is 574 ° C. Heat catalyzate exiting

from the reactor, is used to produce steam pressure of 4.0 to 6.0 atm in the recovery boiler. When this catalyzate is cooled from 574 to 180 ° C. After separation from the catalyst, the catalyst will be compressed to a pressure of 3.0 atm and condensed at this pressure. Heat condensable products are used to produce water vapor at a pressure of 2.0 atm. The proportion of condensed products from condensation data is 0.751,

During the condensation of catalyzate at a pressure of 3.0 atm and 130 ° C, 122560 kcal / kg of heat is released.

For 1 kg of catalyzate, 306 kcal / kg of heat are utilized during condensation. During cooling from 574 to 180 ° C per 1 k of catalyzate 198 kcal / kg of heat is utilized.

Due to the pressure increase at the stage of catalyzing catalysate up to 3.0 atm, the amount of utilized heat increases by a factor of 2.2 in comparison with the known method to obtain water vapor at a pressure of 2.0 atm.

It also increases by 14%.

the amount of heat utilized at I

cooling catalyzate in the steam generator.

Example 3, Styrene receive according to the proposed method. The dehydrogenation is carried out on a catalyst, whose composition is similar to that shown in example 1, at 600 ° C and

the pressure at the inlet to the reactor is 1.0 atm. The volumetric feed rate of the raw material is 0.5 h. 100 kg / h of ethylbenzene are fed to the dehydrogenation. The ratio of ethylbenzene to water vapor is kept equal to 1: 3 by weight. The temperature of the reaction products at the outlet of the reactor is 574 ° C. The heat of catalysate leaving the reactor is used to produce steam at a pressure of 4.0–6.0 atm in the recovery boiler. In this case, the catalyst is cooled from 574 to 150 ° C. After separation from the catalyst bed, the catalyst is compressed to a pressure of 6.0 atm and condenses at this pressure. Heat condensable products are used to produce water vapor at a pressure of 3.6 at. The proportion of condensed products from the condensation feeds is 0.862,

to

15

m -

20

25

thirty

35

40

45

2965574

During the condensation of catalyzate at a pressure of 6.0 atm and 152400 kcal / 4 heat is released,

381 kcal / kg of heat is utilized for 1 kg of tcatalysate during condensation. When cooled from 574 to 150 ° C per 1 kg of the catalcate, 212 kcal / kg of heat is utilized.

By increasing the pressure at the stage of catalyzing catalysis to 6.0 atm, the amount of heat utilized increases by 2.7 times as compared with the known method to produce water vapor at a pressure of 3.6 at.

In addition, the amount of heat utilized increases by 22% when the catalyzate is cooled in a steam generator.

Example 4, Styrene receive according to the proposed method. The dehydrogenation is carried out on a catalyst whose composition is similar to that shown in Example 1 at 600 ° C and a pressure of 1.0 at the inlet to the reactor. The volumetric feed rate of the raw material is about 5h. 100 kg / h of ethyl benzene is fed to the dehydrogenation. The ratio of ethylbenzene - water vapor is kept equal to 1: 3 by weight. The temperature of the reaction products at the outlet of the reactor is, The heat of catalyzate leaving the reactor is used to produce water vapor at a pressure of 4.0-6.0 atm in the recovery boiler. In this case, the catalyzate is cooled from 574 to 180 ° C. After separation from the catalyst dust, the catalyzate is compressed to a pressure of 8.0 atm and condenses at this pressure. Heat condensable products are used to produce water vapor at a pressure of 5.0 atm. The proportion of condensed products from the supplied condensation is 0.938,

Upon condensation of the catalyzate at a pressure of 8.0 atm and 165840 kcal / kg of heat are released.

For 1 kg of catalyzate, 415 kcal / kg of heat is utilized during condensation. Upon cooling from 574 to 180 ° C, 198 kcal / kg of heat are utilized per kg of catalyzate.

Due to the increase in pressure at the stage of catalyzing catalysis to 8.0 atm, the amount of heat utilized increases by 2.9 times as compared with the limestone method to produce water vapor at a pressure of 5.0 atm.

In addition, the amount of heat utilized increases by 14% when catalyzate is cooled in a steam generator-5 motor.

According to the proposed method, the pressure of catalyzate after cooling 55 to ISO-ISO C is 0.4-0.5 at,

Catalysate cooling to 150-180 ° C fO is necessary to obtain secondary steam with a pressure of 4-6 at. The resulting steam is used in this process, and its pressure is determined by the hydraulic resistance of the con- struction devices of the device; U1 the heat is carried out in two stages; when cooled from 574 to 150-180 ° C and obtaining secondary water vapor at a pressure of 4-6 atm; during the condensation of catalyzate at a pressure of 3–8 at and 130–150 ° C with the formation of secondary water vapor at a pressure of at. The indicated pressure and temperature intervals are inexpedient, since this leads to an increase in the energy consumption for compression; In addition, there is no need to get secondary steam with a pressure higher than 2-5 atm,

Therefore, the relationship between the temperature to which the catalyzate is cooled and the pressure range during its condensate does not exist.

Thus, the use of the proposed method for the production of styrene with condensation of reaction products at a pressure of 3.0–8.0 atm allows a 2.2–2.9 times increase in the amount of heat utilized.

Claims (1)

Invention Formula A method for producing styrene by catalytic dehydrogenation of ethylbenzene in the presence of water vapor, including the condensation of reaction products by cooling by indirect heat exchange with steam condensate, the preferred method for condensation of the catalyzate is 25 electricity and the use of the resulting secondary steam in the process. So, at 130 ° C and P 2 at, the catalyzate does not condense. Increasing the condensation pressure of catalyzate over 8 ATA is inexpedient, since it leads to an increase in energy consumption for compression; In addition, there is no need to get secondary steam with a pressure higher than 2-5 atm, Therefore, the relationship between the temperature to which the catalyzate is cooled and the pressure range during its condensate does not exist. Thus, the use of the proposed method for the production of styrene with condensation of reaction products at a pressure of 3.0–8.0 atm allows a 2.2–2.9 times increase in the amount of heat utilized. Invention Formula A method of producing styrene by the catalytic dehydrogenation of ethylbenzene in the presence of water vapor, comprising the condensation of reaction products by cooling by indirect heat exchange with steam condensate, from 30 In order to reduce energy consumption, the cooling is carried out to 150-180 ° C, the cooled product is compressed to a pressure of 3-8 atm and fed to a condenser of condensation, which is carried out by indirect heat exchange with steam condensate. & Editor A, 0gar Compiled by E. Gorlov Tehred A. Kravchuk Order 715/27 Tirazk 372Subscription VNI.SH1I USSR State Committee on matters of inventions and discoveries 113035, Moscow, 1-35, Raushsk nab ", d. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader A. Obruchar