RU2282656C1 - Delayed petroleum feedstock coking process - Google Patents

Abstract

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: process comprises: heating petroleum feedstock; coking it in coking chamber while simultaneously withdrawing vapor-gas products and separating them on rectification column; cooling and separating resulting gas-liquid mixture into gas, gasoline, and water; draining water condensate; mixing gasoline with gas followed by separating them; and performing processing to produce coking gas and coking gasoline. Mixing of gas and gasoline is conducted in gas-liquid contactor by tangentially feeding stream of compressed gas preliminarily purified of liquid drop phase into injector-atomized gasoline. Gasoline-atomization injector is constructed in the form of perforated tube provided with bumper disk and mounted along axis of gas-liquid contactor.

EFFECT: increased yield of coking gasoline and improved quality of coking gasoline.

2 dwg, 3 tbl

Description

The invention relates to the refining industry, in particular to a method for delayed coking of crude oil.

A known method of delayed coking of petroleum feedstock, including heating the feedstock, coking it in a coke oven, removing steam and gas products, separating them in fractions, fractioning gasoline and water vapor for cooling, followed by separating gasoline from water condensate and gas by settling and their subsequent separate processing (Benderov D.I., Pokhodenko N.T., Bronds B.I. Process of delayed coking in unheated chambers. M: Chemistry, 1976, p. 32-34).

The disadvantage of this method is the low yield of gasoline.

The closest in technical essence and the achieved result to the claimed object is a method of delayed coking of crude oil, including heating the feed, coking it in a coke oven, removing steam and gas products, separating them into fractions, fractionating gasoline and water vapor for cooling, with further separation gasoline from water condensate and gas by sludge, draining water condensate, mixing gasoline and gas in an absorber-deethanizer and their subsequent separation and processing (Benderov D.I. , Pokhodenko N.T., Bronds B.I. Process of delayed coking in unheated chambers (Moscow: Chemistry, 1976, p. 34-37).

However, due to the weak heat and mass transfer during the mixing of gasoline and gas in the absorber-deethanizer, a slowed-down process of gasoline fractions separation from the fatty gas occurs, which leads to a low gasoline yield and a deterioration in gas quality.

The invention is aimed at solving the problem of increasing the yield of gasoline while improving gas quality.

The solution to the problem is mediated by a new technical result. This technical result consists in intensification of heat and mass transfer between the liquid and gaseous phases due to the process of mixing gasoline with gas previously purified from the liquid droplet phase in a gas-liquid contactor by tangentially supplying a stream of compressed gas to gasoline sprayed by the nozzle, while the nozzle is made in the form of perforated pipe equipped with a fender at the end of the disk and installed along the axis of the gas-liquid contactor. This embodiment of a gas-liquid contactor makes it possible to contact the atomized liquid and the tangentially directed stream of compressed gas in the annular space at its entire depth and create a high rate of impact of the gas-liquid stream formed against the disk chipper, which ensures high heat and mass transfer of the mixed media, effective separation of gasoline from water condensate and gas upon repeated cooling and sludge and, as a result, leads to an increase in the yield of coking gasoline with simultaneous th improvement of quality coking gas.

The essential features of the proposed technical solution: a delayed coking method, including heating the raw material, coking it in a coke oven, removing steam and gas products, separating them into fractions in a distillation column, removing gasoline and water vapor for cooling, with further separation of gasoline from water condensate and gas by settling , draining water condensate, mixing gasoline and gas and their subsequent separation and processing.

Distinctive features: mixing gasoline and gas is carried out in a gas-liquid contactor by tangentially supplying a stream of compressed gas previously purified from the liquid droplet phase into gasoline sprayed by the nozzle, while the gasoline spray nozzle is made in the form of a perforated pipe equipped at the end with a baffle disk and installed along the gas-liquid axis contactor.

In the drawing (Figure 1) shows a diagram of an installation for implementing the method. In the drawing (Figure 2) - contactor gasoline and fatty gas.

The installation comprises coking chambers 1, a distillation column 2, a raw material heating furnace 3, a primary separator 4, a droplet collector 5, a compressor 6, air coolers 7, 9, a gas-liquid contactor 8 with a nozzle 10 coaxially mounted inside a nozzle made in the form of a perforated pipe, a water cooler 11, a secondary separator 12, pumps 13, 14, 15, 16.

The method is as follows. The preheated coking feed is fed to the bottom of the distillation column 2, where it is mixed with heavy fractions of coking products. The resulting mixture of secondary coking feedstock is pumped through a furnace 3 into a coking chamber 1 through a furnace 3, where it is kept for a sufficient time for coke formation, and gas-vapor products are taken for fractionation into a distillation column 2. From the top of the distillation column 2 through an air-cooling unit 9, the primary separator 4 exhaust gas, water and gasoline vapors. From the primary separator 4, gasoline pump 14 is sprayed through a nozzle 10 made in the form of a perforated pipe into the annular space of the gas-liquid contactor 8. Into the annular space of the gas-liquid contactor 8 into the gas spray zone, the compressor 6 tangentially through the drop collector 5, the air cooling apparatus 7 is supplied with a stream of compressed gas by establishing a uniform and continuous circulation of the mixed streams. A swirling two-phase gas-liquid flow, striking at a high speed against a disk-chipper, provides effective gas saturation of the liquid phase with finely dispersed bubbles of the gas phase. Gasoline from the droplet collector 5 is returned to the bottom of the primary separator 4 by pump 15. From the gas-liquid contactor 8, the reaction gas-liquid mixture through the refrigerator 11 in the form of fog and drops enters the secondary separator 12. From the secondary separator 12, coking gas is separated by settling from condensate and gas , is allocated by pump 16 for further processing to hydrotreatment, catalytic reforming, and then to the freight fleet. The purified gas is transferred as a raw material to the gas processing plant, and the water condensate for further treatment to the sour effluent stripping unit.

The proposed method of delayed coking of crude oil was tested on the installation of delayed coking of the enterprise. These tests are shown in tables 1, 2, 3.

Table 1 presents the data on the selection of the products of the delayed coking unit before the introduction of the gas-liquid contactor - according to the prototype and the selection when supplying gasoline from the primary separator (4) and mixing gasoline and gas in the gas-liquid contactor (8) - according to the invention.

Table 1 Product selection,% prototype selection,% according to the invention RAW MATERIALS one hundred one hundred Fatty gas 10.1 8.2 Petrol fifteen 16,4 Light gas oil 22 21.5 Heavy gas oil 26.3 26.3 Coke total 25.7 27 Losses 0.9 0.6

From table 1 we see that when the balance amount of gasoline (absorbent) is supplied from the primary separator to the nozzle and mixed with gas in a gas-liquid contactor (8), a gas-liquid mixture is formed, which, passing through the refrigerator (11), comes in the form of fog and drops into the secondary separator (12), where after settling from water condensate and gas, gasoline is sent from the installation in an amount increased by 1.4%.

Table 2 presents data on the fractional composition of gasoline.

table 2 Fractional composition,% According to the prototype T ° According to the invention, T ° nk (start of boiling) 37 33 5 48-49 63.5 10 56 76 twenty 63 91 thirty 70 104 40 77 115.5 fifty 85-86 128 60 94 138 70 105 148 80 129-130 158 kk (end of boil) 152 185 Exit % % 87.8 95 Density (d ₄ ²⁰ under normal conditions) kg / m ³ kg / m ³ 682 729

From table 2 we see according to the invention: a decrease in the boiling point of the gasoline fraction and an increase in the temperature of the end of boiling of the gasoline fraction, an increase in the density and yield of gasoline fractions.

Table 3 presents data on the composition of the fatty gas when mixing gasoline and gas according to the prototype and mixing gasoline and gas in a gas-liquid contactor (8) according to the invention.

Table 3 Parameter Gas inlet Gas outlet Petrol prototype according to the invention prototype according to the invention Beats weight relates. air 0.8974 0.8855 0.8302 - - Density, g / l 1.1618 1.1464 1,1374 682 740.9 Like the weight 26,0244 25.6801 25.0548 - - Methane 33,20 35.35 37.36 - - Ethane 27.26 29.02 36.26 0.29 0.01 Propane 15.21 16.01 17.43 1.93 0.28 Propene 4.98 5.35 - 0.63 Isobutane 1.33 1.77 4.88 0.73 1.48 n-butane 5.37 5.98 2.87 4,56 0.48 Butene 1 1,03 1.78 - 2.18 - Butene-2-cis 0.93 1.86 - 0.65 - Butene-2-trans 0.32 0.31 - 0.46 - Isopentane 0.95 0.78 0.45 2.43 0.52 n-pentane 1.40 1.34 0.72 6.22 3.05 C ₆ and up 0.79 - 0,03 79.92 94.18

From table 3 we see that with an increase in the yield of gasoline (increase in the density of gasoline), the quality of the fatty gas according to the invention increases, due to a decrease in the content of hydrocarbons C ₅ and above.

The results obtained allow us to conclude that the use of this invention allows to increase the yield of coking gasoline and at the same time improve the quality of coking gas.

Claims (1)

A method for delayed coking of petroleum feedstock, including heating the feedstock, coking it in a coke oven, removing steam and gas products, separating them into fractions in a distillation column, removing gasoline and water vapor for cooling, and further separating gasoline from water condensate and gas by settling, draining water condensate mixing gasoline and gas, their subsequent separation and processing, characterized in that the mixing of gasoline and gas is carried out in a gas-liquid contactor by tangential supply of a stream of compressed gas, primarily itelno purified from the liquid drop phase in the atomized fuel injector, wherein the injector is formed as a perforated tube, provided at the end of the baffle disc, and installed on the gas-liquid contactor axis.

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