SU1084286A1 - Method for producing coke from heavy-weight hydrocarbon feedstock - Google Patents

Abstract

METHOD FOR COKE FROM HEAVY UGLEVODOROdaOGO feed comprising heating the feed in its coking chamber of the coke is withdrawn steam and gas products, their separation into fractions vscheleniem high-boiling fraction with a boiling point above 350®S, characterized in that, in order to increase coke output, gas, gasoline and light gas oil, the high boiling fraction is heated to. 480-520 C at 1-8 MPa and the obtained products are sent to the coke oven chamber.

Description

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The invention relates to the oil refining industry, in particular, to the method for delayed coking. . There is a known method for producing coke from petroleum hydrocarbon feedstock by continuously heating the feedstock, giving a portion for the time needed to form the coke, venting the gaseous portion of the feedstock and dividing e into two fractions; high boiling with a boiling point above and low boiling with a boiling point below 250 ° C 3. The disadvantage of this method is high coking during the heating of the raw material. A known method for producing coke from heavy hydrocarbon feedstocks. The feedstock is heated in a tubular furnace to ZZO-AOO C, introduced into a distillation column, in which it is mixed with heavy fractions of coking products with heavy gas. Then, the resulting mixture is heated in a reaction furnace to 470-500 ° C and in unheated chambers, vapor-gas products are withdrawn, they are divided into fractions with high boiling fractions with a keel temperature above 350fc C2 |. This method gives low yields of coke gas, gasoline and light gas oil. . The aim of the invention is to increase the yield of coke, gas, gasoline and light gas oil. This goal is achieved by the fact that, according to the method for producing coke from heavy hydrocarbon syr, coke feedstock is heated, coked it in a coke oven chamber, steam-gas products are removed, they are divided into fractions with release of high-boiling fractions with a boiling point higher, they heat high boiling fractions up to 480-520 0 at 1-8 MPa and the obtained products are directed into the coke oven chamber. Allocation of a narrower fraction with a boiling range of 350-525C makes it possible to reduce the energy consumption associated with the transfer and heating of a wider fraction. Heating the lined gas oil fraction in a furnace at a pressure of 1-8 MPa allows it to be cracked maximum or completely to form gas, gasoline, light gas oil, and cracking residue, which serves as an additional source for coke production. At the same time, in general, the yield of the fractions, up to coke, and coke increases. The method is carried out as follows. Pre-heated to 4755tO ° C, the raw coke feedstock is fed to the coking chamber, where the liquid part of the feedstock is kept for a time sufficient for the formation of coke, and the gaseous product is taken to a distillation column, where it is divided into fractions with release of high boiling temperature. boiling above 350; C, which is fed to the furnace, where it is heated to a temperature of 480-520 ° C, and the heating product of the high-boiling fraction is sent directly to the coking chamber or returned to the distillation column. Example 1 (the proposed method). The West Siberian oil tar (density at 1,000 g / cm, Condrason coking ability is t4%) is processed at a pilot delayed coking unit. The tar in the amount of 21.4 kg / h from the raw material tank is sent to the first tube furnace, where it is heated to 38 ° C, after which it enters the lower part of the distillation column. The mixture formed in the bottom of the distillation column, as a result of contact with products that also entered the bottom of the distillation column from the top of the coking chamber, coking feedstock is heated to the second furnace, then sent to the lower part of the chamber to coking. The liquid part of the coking feedstock is kept in the coke oven for 7 hours, and the gaseous product is directed through the top of the coke oven to the bottom of the distillation column. In the form of a side stream from a distillation column, a high-boiling fraction (heavy gas oil with a boiling range of 350-525 C), which in the amount of 8.6 kg / h after heating in the third furnace to 520 ° C under pressure at the outlet of the furnace,

2 MPa and the residence time of the raw material in the coil for 3 minutes are directed to the stream entering the coke oven chamber. Gas, gasoline, light gas oil are removed from the top of the distillation column.

Other process parameters: pressure in the coking chamber 0.4 MPa, pressure in the distillation column Ou38 MPa, product pressure at the outlet of the furnace for heating tar 0.4 MPa, pressure of the product at the exit of the oven for heating the coking feed (mixture of tar and distillation ) 0.76 MPa. The temperature of the product at the entrance to the furnace for heating the high boiling fraction (heavy gas oil with a boiling range of 250-525 0),. the flow temperature at the inlet to the coking chamber, the temperature of the bottom of the distillation column 400 C.

The material balance of the pilot plant, wt.%:

But then: tar too, Oh. Received: gas at -C 11.6

gasoline (Fr.Ss - 200 ° C

14.4

light gas oil (fr.200350 C) 25.3

heavy gas oil (fr.

350-KK) 22.1

coke 24,8

loss 1.8

PRI m 2 p (the proposed method). The experiment was carried out under the conditions of Example 1, but the product of heating the high boiling fraction (heavy gas oil with boiling range 350-523®С) after -. the furnace is sent to a distillation column; In this case, the temperature of the bottom of the distillation column, the temperature of the product at the entrance to the coke oven chamber. The material balance of the installation coincides with the balance in example 1.

Example 3 (proposed method j. Under the conditions of example 1, but at the temperature and pressure of the product at the exit of the furnace for heating the high boiling fraction (heavy gas oil with boiling range 325-525 ° C) and 8 MPa, respectively, the temperature of the product at the entrance to the chamber coking, the temperature of the bottom of the distillation column is 401 ° C, the pressure at the outlet of the furnace for heating the coking feed is 0.7 MPa.

Received, wt.%, In the calculation of tar:

Gas at C4 1-1.2

Gasoline (fr. Cj 200®С) 12,8

Light gas oil (FR. 200-350 C)

24.5. T yellow gas oil (FR. 350-C-KK)

25.1

Coke 24.6

Loss of 1.8

Example 4 (the proposed method). Under the conditions of Example 1, but at the exit temperature of the furnace for heating the high boiling fraction (heavy gas oil with a boiling range of 350-525 ° C), the residence time of the product in the furnace is 6 minutes, the pressure at the exit of the furnace for heating the coking feed 0,76 MPa, the temperature of the product on the inside into the coking chamber 482С, the temperature of the bottom of the distillation column 401 C.

From tar obtained, wt.%:

Gas at C4 13.2

Gasoline (fr. Cj 200 ° C) 14.6

Light gas oil (fr. 200-35 (f C) 28.1

T yellow gas oil (FR. 350-C-KK)

17.1

Coke 25.2

Losses 1.8.

Example 5 (proposed method). Under the conditions of example 1, but at the exit temperature of the furnace, the high-boiling fraction heating temperature (heavy gas oil with boiling range 350-525 0, product residence time in the furnace 10 min, pressure at the exit from the furnace to heat the coking feed 0, 72 MPa, the flow temperature at the inlet to the coking chamber, the temperature of the bottom of the distillation column.

From tar obtained, wt.%:

Gas 16, C

Bbnzin (fr. C5200 C) 18.9

Light gas oil (FR 200-350 CJ)

35.9

T gas oil (FR. 350-C-KK)

Coke 27.4

Loss of 1.8

Example 6 (prototype). The experiment was conducted under the conditions of Example 1, but gas oil with a boiling range of 250-525 ° C was used as the raw material of the furnace for heating the high boiling fraction, and heating the gas oil after the furnace once: 5: - divided into additional column a. two fractions: boiling up to 400 ° C and higher, the latter being completely directed to the loading of SF coking (mixture of tar and recirculated). The product temperature at the entrance to the coking chamber A82 ° C.

When this was obtained, wt.%:

Gas at C4 10.2

Gasoline (FR.SZ200 about 11.5

Light gas oil (fr. 200-350 ° С)

24.2 I T yellow gas oil (Fr. 350-KK)

29.5

Coke 22.8

Loss of 1.8

The application of the proposed method (examples 1-5) in comparison with the prototype (example 6) allows increasing the gas yield (by 3%), gasoline (by 7%), light gas oil (by 11.7%), coke (by 4, 6%), i.e. the process contributes to a more in-depth processing of raw materials. The method also makes it possible to limit or completely eliminate the output from the plant of the fraction boiling above, the further hydrogenation processing of which is difficult due to coke deposits on the catalyst. Usually, this fraction is used as a component of boiler fuel, which does not correspond to the current direction in oil refining, which requires maximum utilization of oil and oil products in order to increase light output.

In addition, in the proposed method, the cracking products of heavy gas oil are sent directly to the coking process, in contrast to the prototype, which provides for subsequent separation into fractions, as a result of which there is no need to install an additional distillation column.

Claims (1)

METHOD FOR PRODUCING COX 'FROM HEAVY-HYDROCARBON RAW MATERIALS, including heating the raw material, coking it in a coke oven, removing steam and gas products, separating them into fractions with the release of a high-boiling fraction with a boiling point above 350 ° C, characterized in that, in order to increase the yield of coke, gas, gasoline and light gas oil, the high-boiling fraction is heated to · 480-520 ° C at 1-8 MPa and the resulting products are sent to the coke oven.