RU2720809C2 - Apparatus for producing ultra-low-sulfur diesel fuel - Google Patents

Abstract

FIELD: chemical or physical processes; oil refining industry.

SUBSTANCE: invention relates to a device for hydroprocessing hydrocarbon material in the presence of a fixed catalyst bed and can be used in oil refining industry. Invention relates to an apparatus for producing ultra-low-sulfur diesel fuel, comprising an inlet separator with a hydrogen outlet line, at least one reactor with a phase interface with at least one catalyst layer each, and a hydrogenation unit. Device includes reactors with radial supply of homogeneous feed mixture through catalyst layer, in each catalyst layer there is at least one heat exchange unit, equipped with cooling agent inlet/outlet lines, hydrogenisate circulation unit is made in form of ejector with raw mixture as working medium, and in axial region of central header of reactor there is a nozzle device for hydrogen sulphide blowing, equipped with axial hydrogen supply pipeline from inlet separator below nozzle and hydrogenation device distributor arranged at phase interface surface and above nozzle, as well as the desulphurised hydrogenated product discharge line, besides, the reactor is equipped with a circulating hydrogenation unit supply line located below the phase interface and above the catalyst layer, on which the absorber is installed, connected to the reactor above the phase separation level by the hydrogen supply line, and to the ejector with the hydrogen saturated hydrogen circulating hydrogenation feed line, also equipped with the offgas discharge line.

EFFECT: technical result is higher reliability of device, elimination of temperature rise in reactor, low power consumption and prevention of secondary hydrogenation of hydrogenated.

1 cl, 1 dwg

Description

The invention relates to a device for the hydro-processing of hydrocarbons in the presence of a fixed catalyst bed and may find application in the oil refining industry.

During deep hydrotreatment of diesel fuel, the separation of hydrogenate with a sequential decrease in temperature in the absence of hydrogen is accompanied by secondary sulfurization of the hydrogenate due to sulfidation of hydrocarbons with labile hydrogen atoms, in addition, the process is accompanied by heat generation, which requires equipment for the hydroprocessing with systems for removing heat from the catalyst layer and preventing secondary sulfurization.

Hydrotreating units for middle distillates are known and widely used [N.L. Solodova, N.A. Terentyev. Hydrotreating fuels. Kazan: Kazan Publishing House. Gos. technol. University, 2008, with. 33], including devices for mixing raw materials with fresh and circulating hydrogen-containing gas (hydrogen), a recuperative heat exchanger, a furnace, a reactor with an axial feed of raw materials into the catalyst bed, a hydrogen purification and circulation system, and a commodity product separation system from hydrogenate.

The disadvantages of the known plants are the high energy consumption for hydrogen circulation, increased gas and coke formation due to a rise in temperature in the reactor due to the heat released during hydrotreatment, as well as secondary hydrogenation of the hydrogenate.

Closest to the claimed invention, the control system, method and device for continuous liquid-phase hydroprocessing [RU 2411285, publ. 02/10/2011, IPC C10G 47/00, C10G 45/02], which consists of a raw material mixture preparation system, a hydroprocessing system for a heated raw material mixture as part of an inlet separator with exhaust gas (insoluble hydrogen) discharge lines, and a homogeneous raw material mixture at least one reactor with an axial feed of the feed mixture into at least one catalyst bed, with a phase interface separating the gas space and the space with the hydrogenate and the catalyst, and a hydrogenate unit with a circulation pump, and a hydrogenate separation system.

The disadvantages of this system for hydroprocessing are: low reliability due to the presence of a pump, temperature rise in the reactor due to the lack of a heat removal system from the reactor, high energy consumption for the circulation of the hydrogenated product due to the high hydraulic resistance of the reactor with an axial feed of a homogeneous feed mixture, and secondary sulfurization of the hydrogenate due to the high concentration of hydrogen sulfide in the hydrogenate supplied to the separation system.

The objective of the invention is to increase the reliability of the device, eliminating the rise in temperature in the reactor, reducing energy consumption and secondary sulfurization of hydrogenate.

The technical result is to increase the reliability of the device due to the exclusion of dynamic equipment, reduce energy consumption due to the use of a reactor with a radial feed of a homogeneous raw material mixture through the catalyst bed, and also reduce the secondary sulfurization of hydrogenate due to the installation of a device for blowing hydrogen sulfide.

The specified technical result is achieved by the fact that in the known device comprising an inlet separator with a hydrogen output line, at least one reactor with a phase interface with at least one catalyst layer each, and a hydrogenation unit circulation unit, the feature is that the device includes reactors with a radial feed of a homogeneous feed mixture through the catalyst bed, at least one heat exchanger unit equipped with refrigerant input / output lines is placed in each catalyst bed, the hydrogenate unit is made in the form of an ejector with the feed mixture as a working fluid, and in the axial region of the central collector the reactor is equipped with a nozzle device for blowing hydrogen sulfide, equipped with an axial pipeline for supplying hydrogen from the inlet separator below the nozzle and a hydrogenation distributor located at the interface and above the nozzle, as well as a withdrawal line of desulfurized hydrogenate , the reactor is equipped with a supply line of circulating hydrogenate, located below the phase interface and above the catalyst bed, on which an absorber is connected, connected to the reactor above the level of phase separation by a supply line of hydrogen, and with an ejector, a supply line of circulating hydrogenated, saturated with hydrogen, also equipped with a discharge line gas.

A reactor with a radial feed of the feed mixture through the catalyst bed, a nozzle for gas stripping, a separator, an absorber and an ejector are known from the prior art.

The use of reactors with a radial feed of the raw material mixture through the catalyst bed allows to reduce the hydraulic resistance of the reactor and to reduce the energy consumption for the circulation of the hydrogenate. Placing the heat-exchange units in the catalyst bed eliminates the temperature rise in the reactor by removing the heat of reaction. Equipping the reactor with a nozzle device for blowing hydrogen sulfide makes it possible to obtain desulfurized hydrogenate and prevent its secondary sulfurization during separation, and the installation of an absorber in the supply line of the circulating hydrogenate allows saturating the circulating hydrogenate with hydrogen, which ensures the effective operation of the ejector due to the large gas factor of the raw material mixture both at the input and at the exit of the ejector.

The device includes an ejector 1, an inlet separator 2, a reactor 3 with a radial feed mixture (conventionally shown is one reactor with one catalyst layer 4, in which one heat transfer unit 5 is placed) with a phase separation surface 6, a device for blowing hydrogen sulfide 7 with nozzle 8 and a hydrogen supply line 9, and an absorber 10.

When the device is operating, the hydrogen-containing raw material mixture is fed through line 11 as a working fluid to the ejector 1, into which circulating hydrogenated hydrogen saturated with hydrogen is fed via line 12, the resulting mixture in separator 2 is separated into hydrogen supplied via line 13 to pipeline 9, and a homogeneous raw material the mixture sent through line 14 to reactor 3, where it contacts the catalyst, moving through its layer to the central manifold 15 and then to the liquid layer 16. The circulating hydrogenate is fed through line 17 to the absorber 10, into the lower part of which hydrogen is fed via line 18 , circulating hydrogenate saturated with hydrogen is removed from the bottom, and off-gas from the top through line 19. The balance part of the hydrogenate through the distribution device 20 is fed to the nozzle 8, flowing down through which it is purged with hydrogen supplied through the pipe 9, the obtained desulphurized hydrogenate through line 21 is led to separation. The catalyst layer 4 is cooled by a refrigerant supplied to the block of heat exchange elements 5 along lines 22.

Thus, the proposed device is reliable, eliminates the temperature rise in the reactor, allows to reduce energy consumption and prevent secondary sulfurization of the hydrogenate, and can find application in industry.

Claims (1)

A device for producing ultrafine sulfur diesel fuel, comprising an inlet separator with a hydrogen output line, at least one reactor with a phase interface with at least one catalyst layer each, and a hydrogenation unit circulation unit, characterized in that the device includes reactors with a radial feed of homogeneous feed mixture through the catalyst bed, at least one heat transfer unit is placed in each catalyst bed, equipped with coolant input / output lines, the hydrogenate circulation unit is made in the form of an ejector with a raw mixture as a working fluid, and a nozzle device is located in the axial region of the central reactor manifold hydrogen sulphide stripping, equipped with an axial hydrogen supply line from the inlet separator below the nozzle and a hydrogenate distributor located at the level of the interface and above the nozzle, as well as an outlet line for the desulfurized hydrogenate, in addition, the reactor is equipped with a circulating hydrogenate feed line located below the phase interface and above the catalyst bed, on which an absorber is installed, connected to the reactor above the phase separation line with a hydrogen supply line, and with an ejector, a hydrogen-rich circulating hydrogenate feed line, also equipped with an exhaust gas discharge line.

Images