SU1490140A1 - Method of separating catalytic cracking products - Google Patents

Abstract

The invention relates to the production of fuels, in particular to a method for the separation of catalytic cracking products, and can be used in refining. The goal is to increase the efficiency of the process. It is carried out by four-stage condensation of the initial products of catalytic cracking with the formation of vapor and liquid phases at each stage. The condensation in the first stage is carried out by mixing the starting products with the cooled residue of vacuum distillation of the liquid phase in the first stage of condensation. The suspension formed at this stage is divided into condensed sludge and clarified part. The thickened sludge is sent to the stripper of the catalytic cracking reactor. The vapor condensation in the second, third and fourth steps is carried out by indirect heat exchange with the liquid products obtained in the subsequent steps. The liquid phases of these stages are mixed and heated by indirect heat exchange with the clarified part obtained in the first condensation stage. The heated mixture of liquid phases is subjected to atmospheric distillation to obtain the desired products. The method makes it possible to increase the overhaul mileage of the steam distillation heat exchangers from 3000 hours to 12000 hours. 1 Il., Table 1.

Description

one

(21) 4314467 / 23-04

(22) 10/08/87

(46) 06/30/89. Bul 24

(71) Grozny Oil Institute. Acad. Mdmillionaschikova

(72) A.K. Manov and G., V. Tarakanov

(53) 665.644.4 (088.8)

(56) USSR Copyright Certificate 732360, cl. From 10 G 7/00, 1980.

USSR author's certificate 1273378. cl. With 10 G 7/00. 1986

(54) METHOD FOR SEPARATING CATALYTIC CRACKING PRODUCTS

(57) The invention relates to the production of fuels, in particular to a method for the separation of catalytic cracking products, and can be used in refining. The purpose of the invention is to increase the efficiency of the process. It is carried out by four-stage condensation of the initial products of catalytic cracking with obtaining steam and liquid at each stage.

phases. The condensation in the first stage is carried out by mixing the starting products with the cooled residue of vacuum distillation of the liquid phase in the first stage of condensation. The suspension formed at this stage is divided into condensed sludge and clarified part. The thickened sludge is sent to the stripper of the catalytic cracking reactor. The vapor condensation in the second, third and fourth steps is carried out by indirect heat exchange with the liquid products obtained in the subsequent steps. The liquid phases of these stages are mixed and heated by indirect heat exchange with the clarified part, nojry at the first stage of co-condensation. The heated mixture of liquid phases is subjected to atmospheric distillation to obtain the desired products. The method makes it possible to increase the run between repairs of the steam distillation heat exchangers from 3000 to 12000 hours. 1 Il., 1 tab.

S

(L

four;

with

The invention relates to a process for the separation of products of catalytic cracking and can be used in the oil refining industry.

The purpose of the invention is to increase the efficiency of the process of sectioning 1t of catalytic cracking products by reducing pollution and extending the life of the heat exchanging equipment.

The drawing shows a schematic of the process.

Catalytic cracking via line 1 is fed to the catalytic cracking reactor 2, equipped with a stripping zone, from which the mixture of process vapors and water vapor through line 3 is sent to the partial mixing condenser 4, which is the first step of condensation of catalytic vapors. In the upper part of the condenser 4, a vacuum residue 420-500C cooled in a heat exchanger 5 is discharged through line 6 from the vacuum column 7. A liquid product boiling away condensed and separated from the sludge in the partial condenser 4 is mixed above 340-350 ° C, cooled in a heat exchanger 8 and sent via line 9 to a vacuum column 7. In the latter, it is divided into a vacuum residue A20-500 ° C, which is diverted along line 6, directed part to a partial condenser A, and the excess removed from the unit via line 10, and vacuum distillate 350-420 ° C, discharged via line 11 and partially after cooling in refrigerator 12, returned via line 13 to the vacuum column 7 as the upper circulating spray. From the top of the vacuum column 7, the vapor is removed via line 14 by means of an evacuating system 15. The condensed spam through line 16 is returned from the mixing condenser 4 to the stripping zone of the reactor 2.

33 remove rectified vapors via line 34, which condense and cool in condenser-cooler 35 and transfer to gas separator 36. From the latter, hydrocarbon gas is removed via line 37, which is mixed with hydrocarbon gas discharged through lines 26 from the water separator 25 and this mixture is removed from the plant by line 39 by the co-pressor 38. Gasoline condensed in the separator 36 from rectified vapors is partially returned to atmospheric irrigation: columns 33, and the rest of the line 40 is removed from the plant. Side straps from the atmospheric column derive kerosene through line 41 and gasoil through line 42, and from the bottom of this column

Catalyst vapors mixed with water

steam from condenser 4 is directed along line 20 to line 43 — the residue, which is mixed 17, is heated into vapor-distillation heat with exchanger 18 with vacuum distillate 350, and then into hot sepa-420 0 discharged from a vacuum condenser 19 of the second condensation stage. on line 11. The resulting mixture A mixture of catalyzed catalyzed vapor and water vapor-highly aromatic gas oil from a hot separator 19 partially draws 25 from the installation on line 44.

is condensed in a steam distillation heat exchanger 20 and fed via line 21 to the third stage condensation hot separator 22, from where the mixture of catalyzed vapors and water vapor is sent through line 23 to the condenser / cooler 24, where it is cooled to 35-40 ° C and introduced into gas separator-water separator 25 fourth condensation stage. From the top of the separator / water separator 25, hydrocarbon gas is withdrawn through line 26, and from the bottom through line 27 - condensate of water vapor. The liquid product from the separator / water separator 25 is fed through line 28 to the steam distillation heat exchanger 20, where it is heated by the heat of the vapor supplied through line 21 and mixed with the liquid product, which is filled with water.

29 from the hot separator 22. These carbon blacks, as well as mixtures along line 30, are sent to a steam distillation heat exchanger 18, where they are heated by the heat of the vapors discharged through line 17 from the partial condenser 4, and mixed with a liquid product supplied via line 31 from a hot separator 19.

The resulting mixture is sent via line 32 to heat exchanger 8, where it is heated with heat from a liquid product with a boiling point of 340-350 ° C, moving along line 9 from a partial condenser 4 and fed to atmospheric column 33. From the top of the atmospheric column

50

55

Tatka - boiler fuel.

The vapor phase from the partial mixing condenser is fed to a second-stage vapor-heat exchanger, where it is cooled to 200 ° C, and sent to a second stage hot separator.

The vapor phase from this separator is fed to a third-stage vapor-distillation heat sink, where it is cooled to 125 ° C, and sent to a third-stage hot steam generator. The vapor phase formed is cooled in a condensate cooler to 35 ° C and served

15

90140

33 remove rectified vapors via line 34, which condense and cool in condenser-cooler 35 and transfer to gas separator 36. From the latter, hydrocarbon gas is removed via line 37, which is mixed with hydrocarbon gas discharged through lines 26 from the water separator 25 and this mixture is removed from the plant by line 39 by the co-pressor 38. Gasoline condensed in the separator 36 from rectified vapors is partially returned to atmospheric irrigation: columns 33, and the rest of the line 40 is removed from the plant. Side straps from the atmospheric column derive kerosene through line 41 and gasoil through line 42, and from the bottom of this column

to

0 o

five

Example. At a catalytic cracking unit with a capacity of 2 mnp / year (250 t / h), a pair of catalytic cracking products mixed with steam from a reactor with a temperature of 5 DO C is sent to a partial mixing condenser, where they are cooled to 300–310 ° C directly heat exchange with vacuum residue 420-500 0 from a vacuum column. Liquid products boiling above 340-350 ° C from the partial mixing condenser after their use to heat the mixture of liquid products of the second, third and fourth stages of separation are sent to a vacuum column operating under a residual pressure of 8 kPa. As a vacuum distillate from this column, raw materials were produced for production

five

Tatka - boiler fuel.

The vapor phase from the partial mixing condenser is fed to a second-stage vapor distillation heat exchanger, where it is cooled to 200 ° C, and sent to a second-stage hot separator.

The vapor phase from this separator is fed to a third-stage vapor-distillation heat exchanger, where it is cooled to 125 ° C, and sent to a third-stage hot separator. The resulting vapor phase is cooled in a condenser-cooler to 35 ° C and served n

in the gas separator-water separator (the fourth stage of condensation).

Hydrocarbon gas from the gas separator / water separator is supplied by KONmpeccor for gas fractionation, condensate of water vapor for reuse, and the liquid product is heated in a third-stage vapor-heat exchanger until it is discharged with a liquid product from the third-stage separator and heated this mixture into a vapor-distillate tnom heat exchanger of the second stage to 220 C.

After the second stage parodistillation heat exchanger, the mixture of the fourth and third stage liquid products is mixed with the second stage liquid product and after heating in the heat exchanger liquid products from the partial mixing condenser up to 300 ° C is directed to separation into an atmospheric column.

Unstable gasoline is removed from the top of the atmospheric column, from which the remaining amount of hydrocarbon gas is separated in the separator. The latter is mixed with the hydrocarbon gas from the gas separator-water separator and serves as a co-pressor for gas fractionation.

BoKOBbtMH removed kerosene and gas oil from atmospheric columns, and the remainder - raw materials for the production of carbon black, which is usually mixed with raw materials for the production of carbon black from a vacuum column.

The main indicators of the operation of separation units for catalytic cracking products according to the proposed and known methods are given in the table.

From the table it follows that the proposed method allows to increase the performance of the installation

catalytic cracking

feedstock, t / h

Pressure, kPa:

in the reactor

in the partial capacitor

mix

in hot separators:

first stage second stage

The overhaul mileage of the steam-exchanger heat exchangers is due to a decrease in the catalyst load from 40 to 0.1 kg / h due to contamination.

Claims (1)

Invention Formula The method of separation of catalytic cracking products by four-stage condensation with obtaining the vapor and liquid phases at each stage, heating the fourth phase liquid phase by indirect heat exchange with the second stage vapor phase, mixing it with the third cry- liquid phase. fines, heating this mixture by indirect heat exchange with the first-stage vapor phase, mixing the resulting mixture with the second-phase liquid phase, heating the liquid phase mixture by indirect heat exchange with the cracking products and their atmospheric distillation, and obtaining the desired products, vacuum distillation of the first-stage liquid phase five 0 denominations, which are fractions above 340–350 ° C, which produce a vacuum distillate and a residue, characterized in that, in order to increase the efficiency of the process through the mind of the equipment, contamination in the first stage is carried out by mixing the precursors with a pre-cooled vacuum residue with separating the resulting suspension into condensed sludge and clarified part with directing the thickened sludge into the stripping zone of the catalytic cracking reactor, and the clarified part before vacuum onkoy as cracking products - by indirect heat exchange with a mixture of liquid phases. Indicators third stage in the separator-water separator in a vacuum column in an atmospheric column, temperature, С: the vapor at the outlet of the reactor in the partial condenser, displacement: top bottom in hot separators: the first stage of the second stage of the third stage in the gas separator-water separator liquid phase four. stages at the exit from the distillation heat exchanger of the third stage of the mixture of liquid phases of the third and fourth stages at the “entrance to the second-stage vapor distillation heat exchanger  the liquid phase at the outlet of the second-stage steam distillation heat exchanger of the mixture of the liquid phases of the second, third and fourth stages at the entrance to the first-stage steam distillation heat exchanger of the liquid phase at the entrance to the heat exchanger of the clarified liquid products from the partial mixing condenser at the entrance to the atmospheric column vacuum residue in the partial condenser mix in the atmospheric column: top bottom in the vacuum column: top bottom Amount, t / h: Product Catalytic Vapor Method Known d Proposed 250 240 eight 120 500 300 420 200 125 35 100 100 115 115 220 220 205 205 300 80 133 306 198 298 cracking from the first stage vapor phase reactor 225 (from a parodistilled heat exchanger, mixing) 198.0 first stage liquid product from a partial mixing condenser (without circulating vacuum residue) 17.0 sludge 10.0 second phase vapor phase 148.0 liquid product of the second stage of 50.0 vapor phase of the third stage of 92.0 liquid product of the third stage of 56.0 hydrocarbon gas from the gas separator-water separator of water vapor with vapors of products of catalytic cracking from the reactor 12.5 liquid product from the gas separator-water a vacuum column separator 52.0 cf of a vacuum 17.0 vacuum distillate 9.1 of a vacuum residue 7.9 of a circulating vacuum residue into a partial mixing condenser — unstable gasoline 94.5 kerosene 24.8 gas oil 22.5 cf for the production of carbon black 20.3 fuel oil 7.9 Heat transfer surface, m: steam distillation heat exchangers: first stage680 second stage690 the third stage 2AO of the heat exchanger of liquid products from the partial mixing condenser - total 1610 diameter of partial mixing condenser, m 149014010 Table continuation 225.0 198.0 17.0 10.0 148.0 50.0 92.0 56.0 12.5 52.0 354.6 9.1 7.9 337.5 94.5 24.8 22.5 . 20.3 7.9 690,240 980 1910 2.8 eleven The height of the partial mixing condenser, m Gasoline; boiling point end of boiling Kerosene: boiling point end of boiling Gas oil boiling point end of boiling Raw materials for the production of carbon boiling point end of boiling Boiler fuel: boiling point Content of catalyst dust in vapors of catalytic cracking products, kg / h from the reactor at the exit from the partial condenser mix exit first go parody distillation indirect heat exchanger  heat exchange The overhaul mileage parodistiltnyh heat exchangers, h G739 d- I a} S k ,, / Л, -. /. I / V m and . 149014012 Table continuation .ci jt-