RU2565715C1 - Method of decelerated coking of oil residues - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes the input feed stock heating, its supply to the bottom or top part of the evaporator (1). Heavy gasoil of coking from the accumulator (5) of the rectification column (4) is partially supplied for the quenching cooling, and balance is supplied to its bottom part and is mixed with bottom products. The mixture of the bottom products and heavy gasoil of coking from the bottom of the rectification column (4) is subjected to thermal cracking in the furnace (6) with the rectification chamber (7). After the quenching cooling of the thermal cracking products by the heavy gasoil of coking they are supplied to the evaporator (1) for mixing with the input coking feed stock. The obtained feed stock mixture is divided to light fractions and secondary coking feed stock, which through the coking furnace (2) is supplied to operating alternatively coking chambers (3). The produced vapour-liquid coking products are supplied to the rectification column (4) for rectification with production of gas, gasoline, light and heavy gasoils of coking and bottom products.

EFFECT: increased output of components of the engine fuels upon keeping the run between repairs of the unit.

4 cl, 1 dwg, 1 tbl

Description

The invention relates to the field of oil refining and can be used to obtain delayed coking of petroleum coke and gas oil fractions - raw materials for the production of motor fuel.

A known method of delayed coking of oil residues, including heating the feedstock, separating it into light fractions and a heavy residue in the evaporator, fractionation of light fractions in a distillation column together with vapor-liquid coking products, mixing the heavy residue from the evaporator with bottom residue obtained by fractionation in a distillation column , followed by coking of the preheated mixture, while the quantity and quality of the bottom residue is controlled by the dosed hearth the amount of cooling gas oil to the mass transfer devices in the lower part of the distillation column, and the bottom residue is fed to the upper part of the evaporator equipped with mass transfer devices. [RF patent No. 2209826, IPC C10B 55/00, publ. 08/10/2003].

The disadvantage of this method is the low yield of gasoline and light gas oil - components of the feedstock for producing high-octane gasoline and diesel fuel.

Closest to the claimed object is a method of delayed coking of oil residues, including heating the feedstock with the subsequent formation of secondary feedstock, heating the secondary feedstock in the reaction furnace and feeding it into the coking chamber to form coke and vapor-liquid coking products, fractionating the latter in a distillation column to produce gas , gasoline, light and heavy gas oil and bottoms coking residue, thermal cracking of heavy gas oil, while the formation of secondary raw materials is carried out It is carried out in an evaporator connected in pairs with a distillation column by mixing the feedstock with a portion of the heavy gas oil supplied from the distillation column to the evaporator as recirculate, and the resulting thermal cracking products of the remaining part of the heavy gas oil are mixed with the bottom residue of coking and the resulting mixture is introduced into the secondary raw materials before feeding into the coking chamber. [RF patent No. 2451711, IPC C10B 55/00, publ. May 27, 2012].

The disadvantage of this method is the involvement of the bottom residue from the bottom of the distillation column into the secondary raw materials supplied to the coking chamber, which leads to an increase in recycle (heavy coking gas oil) in the latter, and, as a result, to a decrease in the yield of light distilled coking products - raw materials for production motor top liv.

The invention is aimed at increasing the yield of components of motor fuels: gasoline and light gas oil.

This is achieved by the fact that in the method of delayed coking of oil residues, including heating the feedstock with the subsequent formation of secondary feedstock by mixing the feedstock with part of the heavy gas oil supplied from the distillation column to the evaporator as recirculate, heating the secondary feedstock in the reaction furnace and feeding it into coking chamber to produce coke and vapor-liquid coking products, fractionation of the latter in a distillation column to produce gas, gasoline, light and heavy gas oils and bottom residue, thermal cracking of the obtained heavy coking gas oil and involving thermal cracking products in the secondary raw materials according to the invention, the mixture of the bottom residue and heavy coking gas oil is subjected to thermal cracking, while the thermal crack products after quenching are cooled by recirculated heavy coking gas oil, mixed with feedstock in the evaporator.

It is advisable to thermally crack a mixture of the bottom residue and heavy coking gas oil in the reaction chamber at a temperature of 440-450 ° C.

It is advisable to introduce into the secondary raw materials, before feeding to the coking oven, a light coking gas oil in a ratio of 1:10 per feedstock.

It is advisable to feed the coking feed to the bottom or top of the evaporator.

The drawing shows a diagram of the installation delayed coking of oil residues by the proposed method.

The delayed coking unit according to the proposed method comprises an evaporator 1, a coking oven 2, a coking chamber 3, a distillation column 4 with a battery 5, a furnace 6, a reaction chamber 7.

The method is as follows.

Coking feedstock, for example tar, preheated in heat exchangers to a temperature of 280-290 ° C, enters the lower or upper part of the evaporator 1. The heavy coking gas oil (THC) from the battery 5 of the distillation column 4 is partially brought to quenching cooling (~ 10%) , and the balance amount (~ 90%) is involved in its lower (bottom) part and mixes with the bottom residue. A mixture of the bottom residue with a heavy coking gas oil from the bottom of the distillation column 4 is subjected to thermal cracking in a furnace 6 with a reaction chamber 7 at a temperature of 440-450 ° C. After quenching cooling of thermal cracking products with heavy coking gas oil in an amount of 10% to coking feedstock (recycling), they are fed to evaporator 1 with a temperature of 340-360 ° C, where they are mixed with coking feedstock and the resulting feed mixture is separated into light fractions and secondary feedstock coking. Secondary coking feedstock from evaporator 1 with a temperature of 320-330 ° C, enriched with light coking gas oil in a ratio of 1:10 to the feedstock, enters through coking ovens 2 with a temperature of 485-495 ° C into alternating coking chambers 3, and the resulting vapor-liquid products the coking through the helmet tube is fed to distillation column 4 for fractionation to produce gas, gasoline, light and heavy coking gas oils and bottoms.

The proposed method is illustrated by the following examples, which are given in the table. These tables were obtained experimentally in a pilot plant for delayed coking at a pressure of 0.25 MPa and a temperature of 480 ° C at the outlet of the furnace.

In our experiments, tar was used with the following quality indicators: density 1.025 kg / m ³ , coking ability 24.0%, sulfur content 2.21%.

As can be seen from the table, thermal cracking of the mixture of bottoms and heavy coking gas oil with subsequent quenching of the thermal cracking products by introducing 10% recycled coking gas oil into the coking feedstock, mixing the newly obtained mixture in the evaporator with coking feedstock allows increase the output of motor fuels: gasoline and light gas oil.

The use of thermal cracking with a reaction chamber allows, by softening its temperature regime, to minimize the amount of heavy coking gas oil introduced into thermal cracking products during their quenching cooling, and, as a result, to keep recycling - heavy coking gas oil at a level of 10% for the feedstock.

The use of light coking gas oil in an amount of 10% for the feedstock as a recycle by feeding it at the entrance to the coking oven will allow maintaining the overhaul run of the latter and the yield of distillate coking products.

The supply of coking feedstock to the lower or upper part of the evaporator will allow further control of the amount of recirculate involved in the coking secondary feedstock and, therefore, the output of petroleum coke to the feedstock.

Thus, the proposed method allows to increase the yield of components of motor fuels while maintaining the turnaround path of the installation and thereby increase the profitability of the process of delayed coking of oil residues.

Claims (4)

1. A method of delayed coking of oil residues, including heating the feedstock with the subsequent formation of secondary feedstock by mixing the feedstock with a portion of the heavy gas oil supplied from the distillation column to the evaporator as recirculate, heating the secondary feedstock in the reaction furnace and feeding it into the coking chamber to form coke and vapor-liquid coking products, fractionation of the latter in a distillation column to produce gas, gasoline, light and heavy gas oil and bottoms, ter the chemical cracking of the obtained heavy coking gas oil and the involvement of thermal cracking products in secondary raw materials, characterized in that the mixture is subjected to thermal cracking of the bottom residue and heavy coking gas oil, while the thermal crack products after they are quenched by recirculated heavy coking gas oil are mixed with the feedstock in the evaporator . 2. The method of delayed coking of oil residues according to claim 1, characterized in that the thermal cracking of a mixture of bottoms and heavy coking gas oil is carried out in a reaction chamber at a temperature of 440-450 ° C. 3. The method of delayed coking of oil residues according to claim 1, characterized in that a light coking gas oil in a ratio of 1:10 of the coking feedstock is introduced into the secondary raw materials before being fed to the coking oven. 4. The method of delayed coking of oil residues according to claim 1. characterized in that the coking feedstock is fed to the lower or upper part of the evaporator.