RU2719849C1 - Method of producing petroleum coke (embodiments) - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industries.SUBSTANCE: invention relates to oil refining industry, particularly, to methods of producing petroleum coke by delayed coking oil stock with different content of volatile substances. Method involves heating of the coking raw material, its supply to the additional column with formation of secondary raw material with its further heating to 475 °C, supply to the coke chamber and fractionation of gas-vapour coking products in the rectification column. At that, according to the first embodiment of coke production with increased content of volatile substances, heat carrier - mixture of heavy and bottom-gas coke gasoil is heated in furnace to temperature of 510 °C, Then, it is supplied into reaction chamber and then through reduction valve with pressure of 0.1 MPa higher than in coke chamber, and temperature not lower than that of coking feed is supplied to bottom of coke chamber. According to the second embodiment, to produce coke with low content of volatile substances, a heat carrier with temperature of 510 °C is introduced into a hot feed stream with temperature of 505 °C, and then is fed into a coke chamber.EFFECT: technical result is higher output of components of motor fuel and higher efficiency of coking plant.6 cl, 1 tbl, 1 dwg

Description

The invention relates to the oil refining industry, in particular, to methods for producing petroleum coke by delayed coking of crude oil with different volatile substances.

A known method of producing petroleum coke by delayed coking of oil residues, including heating the coking chamber with water vapor and coking vapors, heating the feed and supplying it down to the coking chamber together with a heat carrier - heavy coking gas oil (fr. 200-500 ° C), which before feeding into the chamber coking is heated to a temperature of 50-60 ° C above the temperature of the coking feed. In addition, the specified coolant is also used for additional heating of the chamber after the supply of water vapor and coking vapor. (Pat. RF №2162876, IPC СВВ 55/00, op. 02.10.2001).

The disadvantage of this method is the supply of a coolant heated to a temperature above 50-60 ° C of the temperature of the coking feed (490-500 ° C) together with the coking feed, which does not allow to obtain coke with an increased yield of volatile substances.

Closest to the claimed object is a method for producing petroleum coke by delayed coking of oil residues, including preheating the coking chamber with water vapor and coking vapors, additional heating of the coking chamber with a heat carrier - heavy coking gas oil, heating of coking feedstock and secondary raw materials, heating a heat carrier - heavy coking gas oil and the supply of secondary raw materials and coolant to the lower part of the coking chamber, while the coolant is a heavy coking gas oil heated to a temperature of 400-420 ° C and served with secondary raw materials in the lower part of the coking chamber in separate streams with the supply of the latter through an additional column, and the aforementioned coolant is also fed into the middle and upper parts of the coking chamber when filling the coking chamber 1/3 and 2/3, respectively its height, as well as additional heating of the coking chamber after water vapor is supplied, is carried out jointly by the heat transfer medium and coking vapors, and the heating medium is supplied to the middle part of the coking chamber during heating. After distillation, the liquid part in the distillation column flows down to form bottoms gas oil, which is collected at the bottom of the distillation column and is withdrawn as a component of boiler fuel. [RF patent No. 2433159, IPC 10B 55/00, publ. November 10, 2001, BI No. 31].

The disadvantage of this method is the heating of the coolant - heavy coking gas oil in the furnace to a temperature of 400-420 ° C, which leads to an increase in recirculate (coolant - heavy coking gas oil) in the coking process, and as a result, the installation productivity and yield of light distillate coking products are reduced - raw materials for the production of motor fuel: gasoline and light gas oil. In addition, the known method is aimed at obtaining only coke with a high content of volatile substances.

The present invention is aimed at producing coke with a different content of volatiles, the first option with a high content of volatiles, the second option with a low content of volatiles with the same technical result - reducing the amount of coolant-recycle with a simultaneous increase in the yield of motor components fuels - gasoline and light gas oil and plant performance.

The specified technical result is achieved by the method of producing petroleum coke, including heating the initial and secondary coking feeds, heating the heat carrier, feeding the raw materials through an additional column with the output of vaporous products into the distillation column, supplying secondary raw materials and coolant to the coke chamber with the formation of coke and vapor-liquid coking products, fractionation the latter in a distillation column to produce gas, gasoline, light, heavy and bottoms gas oil, in which, according to the invention, in as a heat carrier, a mixture of heavy and bottoms gas oil is used, which is heated in a furnace to a temperature of at least 510 ° C, then it is fed to the lower part of the coke chamber at the stage of filling it with coking feed through a reaction chamber equipped with a pressure reducing valve with a pressure of 0.1 MPa higher, than in the coke oven, and at a temperature not lower than the temperature of the coking feed.

The specified technical result is also achieved by the method of producing petroleum coke, including heating the initial and secondary coking raw materials, heating the heat carrier, feeding the raw material through an additional column with the output of vaporous products into the distillation column, supplying the secondary raw materials and coolant to the coke chamber with the formation of coke and vapor-liquid coking products, fractionation of the latter in a distillation column to produce gas, gasoline, light, heavy and bottoms gas oil, in which, according to the invention As a heat carrier, a mixture of heavy and bottoms gas oil is used, which is heated in an oven to a temperature of at least 510 ° C, and then fed into a hot feed stream with a temperature of at least 505 ° C entering the coking chamber.

It is advisable to use a mixture of heavy and bottoms gas oil in a ratio of 1: 1 as a heat carrier.

The temperature in the reaction chamber may be 480 ° C.

The residence time of the raw material in the reaction chamber may be 2-4 minutes.

To obtain coke with a high content of volatile substances, secondary raw materials and coolant are fed into the coke chamber by various flows.

Heating the coolant-mixture of heavy and still gas oil in the furnace to a temperature of 510 ° C provides high conversion (decomposition) of the coolant, and as a result, reducing its amount.

The flow of coolant into the coke chamber through the reaction chamber with a pressure reducing valve according to the first embodiment allows prolonging the conversion process of the latter and lowering its temperature and pressure to 480 ° C and 0.3 MPa, respectively, i.e., to carry out the coking process in mild temperature conditions to obtain coke with an increased volatile matter content.

The supply of heat from the furnace with a temperature of at least 510 ° C to the hot feed stream, with a temperature of at least 505 ° C entering the coking chamber, creates severe coking conditions in which coke with a low content of volatile substances is formed

The drawing shows a diagram of a plant for producing petroleum coke with a different output of volatile substances by delayed coking of petroleum feed by the proposed method.

The method is as follows.

The coking feedstock is pumped through heat exchangers 1, 2 and 3, where it is heated by light and heavy coking gas oils to a temperature of 220 ÷ 260 ° C and enters the convection coil 4 of furnace 5, where it is heated to a temperature of 340 ÷ 380 ° C. The raw material heated in the furnace 5 enters the additional column 6. Vapors from the additional column 6 are sent to a distillation column 7. The heavier raw materials from the bottom of the additional column 6 — secondary raw materials are taken by pump 8 and pumped through radiant coils 9 of furnace 5, where it is heated to 475 ° C, and then enters through a four-way valve 10 into one of the coke oven chambers 11 or 12.

In coke oven chambers 11, 12, due to the accumulated heat, the process of delayed coking of raw materials takes place. Coke cake is expanded in coke ovens 11 or 12 to a predetermined level, steam-gas coking products with a temperature of 410-420 ° C are taken to the bottom of distillation column 7. At the end of the filling cycle of coke ovens 11, 12 with coke (in the last 2-3 hours) on the top of the coke mass serves with a pump 13 from a container 14 a solution of antifoam additives.

From the bottom of the distillation column 7, the coolant — heavy gas oil — combined with bottoms coking gas oil (in a 1: 1 ratio) is pumped by pump 15 through the coil of furnace 16, where it is heated to a temperature of 510 ° C. The vapor-liquid coolant products from the tube furnace 16 enter the upper part of the reaction chamber 17, equipped with a pressure reducing valve 18. Passing through the pressure reducing valve 18, the vapor-liquid coolant products with a pressure above 0.1 MPa and a temperature of 480 ° C (not lower than the coking feed temperature) arrive launch line to the bottom of one of the coke oven chambers Pili 12, which is at the stage of coking. The vapor phase of the coolant products introduced into the lower part of the coke oven chamber 11 or 12 along the start-up line with a temperature not lower than the temperature of the coking raw material provides accelerated heating of the upper part of the coke oven chambers, avoiding foaming of the reaction mass, and, as a result, its transfer to the distillation column.

From the bottom of the distillation column 7, vaporous products rise upward - to the strengthening part of the column, equipped with plates 19, where the distillate is separated into components: gas, gasoline, water condensate, light and heavy gas oils. A heavy gas oil is withdrawn from the battery 20 by the pump 21, which is used as a coolant or is sent outside the installation. To ensure distillation, part of the heavy gas oil to remove excess heat after the heat exchanger 3 is returned to the distillation column 7. Part of the hot stream of heavy gas oil is fed to the washing nozzle 22 located in the lower part of the column 7 and maintain (control) the level in the cube of the distillation column 7. Easy gas oil is removed from the distillation column 7 through a stripping column 23, where light hydrocarbons are stripped with water vapor, which are returned to the distillation column 7. From the bottom of the stripping column s 23, light gas oil 24 is pumped with a pump installation. From the top of the distillation column 7, gas, gasoline and water vapors through an air condenser — a refrigerator 25 and a water refrigerator 26 — enter the separator 27 for separation. From the separator 27, water is directed to a sulphide-containing effluent stripping unit. Unstable gasoline pump 28 is sent to stabilization. Part of the unstable gasoline is supplied as acute irrigation to control the temperature of the top of the distillation column 7. Fatty gas from the top of the separator 27 is removed for further purification.

In order to prevent coke particles from entering the bottoms gas oil entering the furnace 16, part of the bottoms gas oil is returned by the pump 29 through self-cleaning filters 30 to the bottom of the distillation column 7 as a circulating stream. According to the above scheme (first option) receive coke with a high content of volatile substances - 16-18%,

According to the second option, to obtain coke with a low content of volatile substances (not more than 8%), the heat carrier - a mixture of heavy and bottoms gas oils in a ratio of 1: 1 is heated in a furnace 16 to a temperature of at least 510 ° C and sent through the coolant supply line to the hot feed stream (transfer line) with a temperature of 505 ° C, leaving the radiant coils of the main furnace 5 in front of the four-way valve 10. This results in a high conversion (decomposition) of the coolant, and as a result, a significant reduction in the amount of heavy and still gas oil by installation. The residual amount of heavy and bottoms gas oil at the installation is used as a coolant and is not removed from the installation.

The following are specific examples of the implementation of the proposed method. Sulfur oil tar was used as raw material:

- density at 20 ° C - 1016 kg / m ³ ;

- coking ability - 20%;

- sulfur content - 2.9%.

Example 1 - obtaining coke with a high content of volatile substances, example 2 - with a low content of volatile substances, example 3 - prototype.

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As can be seen from the data presented, the use of the proposed variants of the method for producing petroleum coke allows one to obtain cokes differing in the yield of volatile substances by varying the heating mode of the coolant and the hot coolant supply point. The first option is in a moderate temperature range of 475-480 ° C using a furnace and a reaction chamber with a pressure reducer and supplying hot coolant to the lower part of the coke oven chamber through the start line when receiving coke with a high content of volatile substances, the second option - in case of a harsh temperature regime 510 ° C using a furnace with a coolant supply together with a stream of hot raw materials leaving the radiant coils of the main furnace to a four-way valve. Moreover, in both versions, the heating temperature of the coolant - a mixture of heavy and bottoms gas oil in the furnace is 510 ° C, providing high conversion (decomposition) of the coolant, and as a result, reducing its amount.

Thus, the proposed method options allows you to get coke with a different content of volatile substances, while the productivity of the installation increases by 10-15%, the output of the components of motor fuels - gasoline and light gas oil increases: upon receipt of coke with a high content of volatile substances by 1.2 and 4%, respectively, upon receipt of coke with a low content of volatiles at 6.2 and 7.1%, respectively.

Claims (6)

1. A method of producing petroleum coke, including heating the initial and secondary coking feeds, heating the coolant, feeding the feed through an additional column, supplying the secondary feed and coolant to the coke oven to form coke and vapor-liquid coking products, fractionating the latter in a distillation column to produce gas, gasoline , light, heavy and distillation gas oil, characterized in that as a heat carrier use a mixture of heavy and distillation gas oil, which is heated in an oven to a temperature not lower e 510 ° C, then fed to the lower part of the coke oven chamber at the stage of filling it with coking feed through a reaction chamber equipped with a pressure reducing valve with a pressure of 0.1 MPa higher than in the coke oven and at a temperature not lower than the temperature of the coking feedstock. 2. A method of producing petroleum coke, including heating the initial and secondary coking feeds, heating the coolant, supplying the feed through an additional column with the output of vaporous products into the distillation column, supplying the secondary raw materials and coolant to the coke oven with the formation of coke and vapor-liquid coking products, fractionating the latter into distillation column to produce gas, gasoline, light, heavy and still gas oil, characterized in that a mixture of heavy and cube is used as a heat carrier Vågå gasoils, which is heated in a furnace to a temperature not lower than 510 ° C and then fed into a heated feed stream temperature not lower than 505 ° C, entering into the coking chamber. 3. The method of producing petroleum coke in paragraphs. 1 and 2, characterized in that the ratio of heavy and bottoms gas oil in the coolant is 1: 1. 4. The method of producing petroleum coke under item 1, characterized in that the temperature in the reaction chamber is 480 ° C. 5. A method of producing petroleum coke according to claim 1, characterized in that the residence time of the raw material in the reaction chamber is 2-4 minutes. 6. A method of producing petroleum coke according to claim 1, characterized in that the secondary raw materials and coolant are supplied to the coke chamber by various flows.

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