WO2018177401A1

WO2018177401A1 - Method for increasing hydrogen partial pressure in hydrogenation reaction system, design method therefor and use thereof

Info

Publication number: WO2018177401A1
Application number: PCT/CN2018/081271
Authority: WO
Inventors: 李苏安; 邓清宇; 王坤朋
Original assignee: 北京中科诚毅科技发展有限公司
Priority date: 2017-03-31
Filing date: 2018-03-30
Publication date: 2018-10-04
Also published as: CN106957681A

Abstract

Disclosed are a method for increasing hydrogen partial pressure in a hydrogenation reaction system, a design method therefor and the use thereof. The hydrogenation reaction system comprises at least two reactors, wherein a discharged material from the previous stage of reactor first enters a separation system, which increases the hydrogen partial pressure, for separation, a non-hydrogen component is separated and discharged, and a hydrogen component and liquid and solid phases enter the next stage of reactor. By using this method, the hydrogen partial pressure in the next stage of reactor can be increased, deepening the depth of reaction, improving the rate of conversion of raw materials and the yield of light oils, improving the space velocity, and reducing energy consumption.

Description

Method for improving hydrogen partial pressure of hydrogenation reaction system, design method and use thereof

Technical field

The invention relates to a method for increasing hydrogen partial pressure, in particular to a method for improving hydrogen partial pressure of a hydrogenation reaction system, a design method thereof and a use thereof, and belongs to the fields of petrochemical industry and coal chemical industry.

Background technique

In recent years, with the continuous increase of crude oil extraction and the continuous reduction of conventional crude oil reserves, the trend of deteriorating crude oil is becoming more and more serious. The middle distillate obtained by direct distillation of crude oil and the middle distillate obtained by secondary processing such as coking and catalytic cracking are among the middle distillates. The S and N contents also increase accordingly. At the same time, the market demand for light oil continues to increase and people's awareness of environmental protection continues to increase. Environmental laws and regulations impose stricter requirements on engine exhaust emissions. Various fuel standards require S and N to be more demanding. How to process middle distillates with high levels of impurities such as sulfur and nitrogen into products that meet environmental protection requirements is an important issue faced by various refineries. At present, heavy oil hydrogenation, direct coal liquefaction technology and oil-coal co-refining technology are receiving more and more attention. The core of these technologies are hydrogenation processes.

In order to increase the conversion of raw materials and the yield of light oil, it is necessary to deepen the reaction depth. In the case where the reaction temperature, the reaction pressure, and the type and amount of the catalyst are determined, the hydrogen partial pressure becomes a key factor affecting the reaction depth. The most common way to increase the partial pressure of hydrogen is to replenish the reactors at various stages to increase the proportion of hydrogen in the gas phase components. However, for the hydrogenation process in which the multi-stage reactor is set, the other gases generated in the upper-stage reactor occupy the gas phase partial pressure, which is disadvantageous for the hydrogenation reaction to proceed in the positive direction, which limits the depth of the hydrogenation reaction.

Summary of the invention

In order to solve the problems in the prior art, the present invention provides a method for increasing the hydrogen partial pressure of a hydrogenation reaction system, which can separate the non-hydrogen components in the upper reaction product in time to ensure the next-stage reactor. The hydrogen partial pressure is kept at a high level. The invention also proposes its design method and use.

The technical solution of the invention:

A method for increasing hydrogen partial pressure of a hydrogenation reaction system, the hydrogenation reaction system comprising at least two reactors, characterized in that the discharge of the upper-stage reactor is first separated into a separation system for increasing hydrogen partial pressure, and then The non-hydrogen component is separated and discharged, and the hydrogen component and the liquid solid phase enter the next-stage reactor, respectively.

Preferably, the separation system comprises a separator and a gas phase separation device, the feed of the separator being the discharge of the upper stage reactor, the discharge of the separator being a gas phase and a liquid solid phase, the gas phase The feed to the separation unit is the vapor phase discharge of the separator, and the discharge is a hydrogen component and a non-hydrogen component.

Preferably, the non-hydrogen component is fed to a separation system of the hydrogenation system.

Preferably, the gas phase separation device is mainly composed of a hydrogen separation membrane.

The number of said separation systems is preferably: 1 ≤ the number of said separation systems ≤ the number of reactors -1.

Preferably, the discharge of the upper-stage reactor has a residence time in the separator of 0.5-59 minutes, an operating temperature of 350-480 ° C, and an operating pressure not lower than the operating pressure of the next-stage reactor. .

Preferably, the separator has a conduit inlet for cold hydrogen and/or cold oil.

Preferably, the lower end of the separator is a liquid solid phase outlet, and the outlet is a tapered structure.

The foregoing method is used for a heavy oil hydrogenation process or a petrochemical hydrostatic slurry bed hydrogenation process, wherein the heavy oil hydrogenation process refers to using one or more combinations of residual oil, catalytic oil slurry, deoiled asphalt, and coal tar as raw materials. Processing; the oil coal slurry bed hydrogenation process refers to combination of one or more of crude oil, residual oil, catalytic oil slurry, deoiled asphalt and coal tar with one or more of lignite and bituminous coal. For the processing of raw materials, the ratio of the ratio of oil to coal is 30-97:70-3.

The foregoing design method for increasing the partial pressure of hydrogen in a hydrogenation reaction system, the hydrogenation reaction system comprising at least two reactors, characterized in that the discharge of the design of the first-stage reactor is first introduced into a separation system for increasing the partial pressure of hydrogen. Separation, the non-hydrogen component is separated and discharged, and the hydrogen component and the liquid solid phase enter the next-stage reactor.

Technical effects of the present invention:

The invention discloses a method for increasing the partial pressure of hydrogen in a hydrogenation system, by separating a separation system for increasing the partial pressure of hydrogen between the reactors, effectively separating the outlet materials of the upper-stage reactor, and the liquid-solid phase enters the next stage. In the reactor, the gas phase is separated again to raise the concentration of hydrogen in the gas phase and then enter the next-stage reactor. The method can increase the hydrogen partial pressure of the next-stage reactor, effectively deepen the reaction depth, increase the conversion rate of the raw materials and the light oil yield, and at the same time, can improve the space velocity of the next-stage reactor and reduce the energy consumption.

The separation system for increasing the partial pressure of hydrogen firstly performs gas/liquid-solid separation of the outlet material of the upper-stage reactor through a separator, and then separates the gas phase by a gas phase separation device to increase the concentration of hydrogen in the gas phase.

The separation system in which the non-hydrogen component enters the hydrogenation system is further separated into an oil phase, a gas phase, and an aqueous phase.

The hydrogen separation membrane can effectively separate the hydrogen component, and the purity after separation can reach 90 vol% or more.

The number of separation systems provided between the reactors for increasing the partial pressure of hydrogen may be set according to the number of reactors and the partial pressure of hydrogen of the next-stage reactor.

In order to stabilize the operating temperature of the separator, the temperature is controlled by means of cold hydrogen and/or cold oil.

The outlet at the lower end of the separator is tapered to prevent clogging.

The method can effectively increase the partial pressure of hydrogen in the next-stage reactor, which is particularly important in the process of heavy oil slurry bed hydrogenation and oil coal slurry bed hydrogenation. For the first stage hydrogenation reaction, a sufficient hydrogen partial pressure can be maintained by supplementing the hydrogen gas. As the gas phase product is formed, the hydrogen partial pressure in the subsequent stage reactor is "diluted", and the hydrogen is added by the method of supplementing hydrogen. Pressure does not work and can cause hydrogen loss. The invention separates the non-hydrogen component in the discharge of the upper-stage reactor in time, so that the hydrogen partial pressure of the next-stage reaction system is maintained at a high level, thereby improving the utilization efficiency of hydrogen and deepening the slurry-bed hydrogenation of heavy oil. And the depth of hydrogenation reaction in the coal-fired slurry bed hydrogenation process. At the same time, the light component formed by the reaction of the previous stage is separated, and it is also prevented from being cracked into a gas in the next-stage reactor to increase the light oil yield.

DRAWINGS

Figure 1 is a schematic view of a reactor of Example 1 of the present invention;

Figure 2 is a schematic view of a reactor of Example 2 of the present invention.

LIST OF REFERENCE NUMERALS 1 - primary reactor; 2-second reactor; 3-stage separator; 4-gas phase separation unit; 5-stage reaction product; 6-stage separator gas phase; Stage separator liquid solid phase; 8-hydrogen component; 9-non-hydrogen component; 10-second reaction product; 11-three-stage reactor; 12-second separator; 13-second separator liquid-solid Phase; 14-stage separator gas phase; 15-hydrogen component; 16-tertiary reaction product.

detailed description

In order to further explain the contents of the present invention, the following will be described in detail by way of specific embodiments with reference to the accompanying drawings.

Example 1

This embodiment is a coal-fired co-refining slurry bed hydrogenation process. As shown in FIG. 1 , the oil coal mixed slurry bed hydrogenation system comprises a two-stage reactor, that is, a primary reactor 1 and a secondary reactor 2, and between the primary reactor 1 and the secondary reactor 2 The separation system for increasing the partial pressure of hydrogen is composed of a primary separator 3 and a gas phase separation device 4, wherein the lower end of the primary separator 3 can have a tapered structure, which facilitates the smooth outflow of the liquid solid phase in the separated product.

The process flow is as follows: the first-stage reaction product 5 obtained after the reaction of the oil coal mixture in the first-stage reactor 1 enters the primary separator 3 for separation, the residence time is 10 minutes, and the operating temperature and the operating pressure are both combined with the primary reactor. 1 is consistent, 450 ° C and 19 MPa, respectively. The primary separator liquid-solid phase 7 separated from the primary separator 3 is sent out from the lower end to the secondary reactor 2 for further hydrocracking; the primary separator gas phase 6 flows from the upper end to the gas phase separation device 4, in the hydrogen gas The hydrogen component 8 is separated from the non-hydrogen component 9 by the separation membrane, wherein the non-hydrogen component 9 is sent to the separation system for further separation into an oil phase, a gas phase and water, and the hydrogen component 8 is sent to the secondary reactor. 2, participate in the hydrogenation reaction. The finally obtained secondary reaction product 10 enters the separation system to further separate different fractions of light oil, calculate the yield, and determine the partial pressure of hydrogen in each reactor. The specific data is shown in Table 1.

For comparison, a two-stage reactor having the same conditions as in the above-described scheme was employed, but a separation system for increasing the hydrogen partial pressure was not provided between the reactors, and the light oil yield and the hydrogen partial pressure were also measured. The specific data are shown in Table 1.

Table 1. Data comparison of oil-coal co-smelting hydrogenation system

It can be seen from Table 1 that the oil-coal co-smelting hydrogenation system using a separation system that increases the partial pressure of hydrogen is used in a coal-coal co-refining hydrogenation system using a separation system that increases the hydrogen partial pressure, and the secondary reactor The partial pressure of hydrogen increased by 1.4 MPa, the conversion of coal powder increased by 2.6%, the yield of distillate oil of 370 °C or less increased by 3.3%, and the depth of hydrogenation reaction was greatly improved.

Example 2

This embodiment is a vacuum residue slurry bed reaction process. As shown in FIG. 2, the vacuum residue slurry bed hydrogenation system includes a three-stage reactor, that is, a primary reactor 1, a secondary reactor 2, and a tertiary reactor 11, and two disposed between the reactors. A separation system for increasing the hydrogen partial pressure: a primary separator 3 and a gas phase separation device 4 disposed between the primary reactor 1 and the secondary reactor 2, and a secondary reactor 2 and a tertiary reactor 11 The secondary separator 12 and the gas phase separation device 4 are interposed. In order to save the device, the two separation systems share a gas phase separation device 4, although it is of course also possible to use different gas phase separation devices. In addition, the lower ends of the primary separator 3 and the secondary separator 12 have a tapered structure to facilitate smooth outflow of the liquid solid phase in the separated product.

The process flow of this embodiment is as follows: the first-stage reaction product 5 obtained after the reaction of the residue mixture in the first-stage reactor 1 enters the primary separator 3 for gas-solid liquid separation, and the residence time is 8 minutes, the operation temperature and the operation. The pressures were all consistent with the first reactor 1, 430 ° C and 17 MPa, respectively. The primary separator 3 separates the first-stage separator liquid-solid phase 7 and the primary separator gas phase 6, and the primary separator gas phase 6 flows out from the upper end to the gas phase separation device 4, and the hydrogen component is formed under the action of the hydrogen separation membrane. Separated from the non-hydrogen component 9, wherein the non-hydrogen component 9 is sent to the separation system for further separation into an oil phase, a gas phase and water; a portion of the hydrogen component 8 obtained by the gas phase separation device 4 and the lower end of the primary separator 3 are discharged. The primary separator liquid solid phase 7 is sent together to the secondary reactor 2 for further hydrocracking. The secondary reaction product 10 of the secondary reactor 2 enters the secondary separator 12 for a residence time of 8 minutes, and the operating temperature and operating pressure are the same as those of the secondary reactor 2, which are 430 ° C and 17 MPa, respectively. The second separator 12 separates the second separator liquid solid phase 13 and the second separator gas phase 14, wherein the second separator gas phase 14 flows out from the upper end and is sent to the gas phase separation device 4 for further separation, and a portion obtained by the gas phase separation device 4 The hydrogen component 15 is sent to the tertiary reactor 11 together with the second-stage separator liquid-solid phase 13 to further hydrocrack, and the obtained tertiary reactor product 16 is separated into a separation system to further separate different fractions of light oil, and calculation Yield, specific data are shown in Table 2.

For comparison, a two-stage reactor having the same conditions as in the above-described scheme was employed, but a separation system for increasing the hydrogen partial pressure was not provided between the reactors, and the light oil yield and the hydrogen partial pressure were also measured. The specific data are shown in Table 2.

Table 2. Data comparison of hydrogenation systems

It can be seen from Table 2 that the oil-coal co-synthesis hydrogenation system using a separation system that increases the partial pressure of hydrogen is used in the oil-coal co-smelting hydrogenation system, the secondary reactor and The hydrogen partial pressure of the three-stage reactor was increased by 0.8 MPa and 1.6 MPa, the conversion of vacuum residue was increased by 8.8%, the yield of distillate oil by 370 °C was increased by 7.4%, and the depth of hydrogenation reaction was greatly improved.

In summary, the method for improving the partial pressure of hydrogen in a hydrogenation reaction system is simple and practical, and can effectively increase the partial pressure of hydrogen in the reactor, deepen the depth of reaction, and improve the conversion rate of oil and coal and light oil. rate.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any reactor skilled in the art can easily conceive the reactor and the technical scope disclosed in the present invention. Variations in the number of separators or replacement of the separation system are intended to be encompassed within the scope of the invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

A method for increasing hydrogen partial pressure of a hydrogenation reaction system, the hydrogenation reaction system comprising at least two reactors, characterized in that the discharge of the upper-stage reactor is first separated into a separation system for increasing hydrogen partial pressure, and then The non-hydrogen component is separated and discharged, and the hydrogen component and the liquid solid phase enter the next-stage reactor, respectively.
The method of claim 1 wherein said separation system comprises a separator and a gas phase separation unit, said separator being fed to said upper stage reactor, said separator being discharged The gas phase and liquid solid phase, the feed to the gas phase separation unit is the gas phase discharge of the separator, and the discharge is a hydrogen component and a non-hydrogen component.
The method of claim 2 wherein said non-hydrogen component is fed to a separation system of the hydrogenation system.
The method of claim 2 wherein said vapor phase separation means consists essentially of a hydrogen separation membrane.
A method according to any one of claims 1-4, characterized in that the number of said separation systems is: 1 ≤ the number of said separation systems ≤ the number of reactors -1.
A method according to any one of claims 1 to 4, characterized in that the residence time of the discharge of the upper stage reactor in the separator is from 0.5 to 59 minutes, the operating temperature is from 350 to 480 ° C, and the operating pressure Not lower than the operating pressure of the next-stage reactor.
A method according to any one of claims 1-4, characterized in that said separator has a conduit inlet for cold hydrogen and/or cold oil.
A method according to any one of claims 1 to 4, characterized in that the lower end of the separator is a liquid-solid phase outlet and the outlet is of a tapered structure.
The use of the method according to any one of claims 1-8, characterized in that it is used in a heavy oil hydrogenation process or a petrochemical hydrogenation slurry bed hydrogenation process, and the heavy oil hydrogenation process refers to a residue oil, a catalytic oil slurry, and a desulfurization process. One or more combinations of oil pitch and coal tar are processed as raw materials; the oil coal slurry bed hydrogenation process refers to one or more of crude oil, residual oil, catalytic oil slurry, deoiled asphalt and coal tar The combination is processed with one or more of lignite and bituminous coal as raw materials, and the weight ratio of oil to coal ranges from 30 to 97:70-3.
A design method for increasing hydrogen partial pressure of a hydrogenation reaction system, the hydrogenation reaction system comprising at least two reactors, characterized in that the discharge of the design first-stage reactor first enters a separation system for increasing hydrogen partial pressure for separation Then, the non-hydrogen component is separated and discharged, and the hydrogen component and the liquid solid phase enter the next-stage reactor.