阅读说明：本技术 一种异构化碳八芳烃的方法 (Method for isomerizing carbon octa-arene ) 是由 张方方 刘凯祥 张旭 张耀辉 杨雁 于 2019-11-21 设计创作，主要内容包括：本发明属于炼油化工技术领域,具体涉及一种异构化碳八芳烃的方法。该方法包括以下步骤：(1)将碳八芳烃和氢气进行混合,得到混氢碳八芳烃；氢气与碳八芳烃的摩尔比为0.5:99.5-30:70；(2)使混氢碳八芳烃升温,形成气液混合态的反应进料；(3)将反应进料送入反应器,反应进料经过反应器中的气液分布器后,进入催化剂床层进行异构化反应,生成含有对二甲苯的产物,产物经过位于催化剂床层上方的气液分离组件进行气液分离后,得到气相产物和液相产物。本发明的异构化碳八芳烃的方法所需的设备少,并且能耗低,投资成本和生产成本均低。(The invention belongs to the technical field of oil refining chemical industry, and particularly relates to a method for isomerizing carbon octa-arene. The method comprises the following steps: (1) mixing the carbon octaarene and hydrogen to obtain mixed hydrogen carbon octaarene; the molar ratio of the hydrogen to the carbon octaarene is 0.5:99.5-30: 70; (2) heating the mixed hydrocarbon and the carbon eight aromatic hydrocarbon to form reaction feed in a gas-liquid mixed state; (3) feeding reaction feed into a reactor, feeding the reaction feed into a catalyst bed layer for isomerization reaction after the reaction feed passes through a gas-liquid distributor in the reactor to generate a product containing p-xylene, and performing gas-liquid separation on the product through a gas-liquid separation component positioned above the catalyst bed layer to obtain a gas-phase product and a liquid-phase product. The method for isomerizing the carbon octa-arene needs less equipment, has low energy consumption and low investment cost and production cost.)

1. A process for isomerizing a carbaoctaaromatic hydrocarbon, comprising the steps of:

(1) mixing the carbon octaarene and hydrogen to obtain mixed hydrogen carbon octaarene; the molar ratio of the hydrogen to the carbon octaarene is 0.5:99.5-30: 70;

(2) heating the mixed hydrogen carbon octa-aromatic hydrocarbon to form a gas-liquid mixed reaction feed;

(3) and feeding the reaction feed into a reactor, feeding the reaction feed into a catalyst bed layer for isomerization reaction after the reaction feed passes through a gas-liquid distributor in the reactor, and generating a product containing p-xylene, wherein the product is subjected to gas-liquid separation through a gas-liquid separation component positioned above the catalyst bed layer to obtain a gas-phase product and a liquid-phase product.

2. The process according to claim 1, characterized in that the isomerization reaction is carried out at a reaction temperature of 150-.

3. The method of claim 1The method is characterized in that the liquid space velocity of the reaction feed is 0.3-65h^-1Preferably 3 to 45h^-1。

4. The process according to claim 1, characterized in that the molar ratio of hydrogen to the carbon octaarene is from 0.8:99.2 to 20:80, preferably from 3:97 to 10: 90.

5. The method of claim 1, further comprising: (4) and cooling the gas-phase product, and then carrying out gas-liquid separation, wherein a first gas-phase separator and a first liquid-phase separator obtained by gas-liquid separation are respectively sent to downstream processing.

6. The method of claim 1, wherein said warming said mixed hydrogen carbon octaarene comprises sequentially preheating and heating said mixed hydrogen carbon octaarene, wherein said mixed hydrogen carbon octaarene is preheated with said liquid phase product as a heat exchange medium.

7. The method of claim 6, further comprising: and carrying out gas-liquid separation on the liquid phase product after heat exchange, and respectively sending a second gas phase separator and a second liquid phase separator obtained by gas-liquid separation to downstream processing.

8. The method of claim 1, wherein the reactor is an upflow reaction separation complex reactor;

preferably, the number of the reactors is two or more, and the two or more reactors are arranged in series or in parallel.

9. The method according to any one of claims 1-8, wherein the reactor comprises a shell (101), the gas-liquid distributor (102) arranged from bottom to top inside the shell (101), the catalyst bed (103), and the gas-liquid separation assembly (104);

the reactor being in communication with a feed line (W), a liquid phase outlet line (X), and a gas phase outlet line (Y);

the gas-liquid separation assembly (104) includes: the device comprises an annular liquid accumulating plate (1041) and a cylinder (1042) connected with the inner edge of the liquid accumulating plate (1041);

the gas-liquid separation assembly (104) and the shell (101) positioned above the liquid accumulation plate (1041) enclose a gas-liquid separation space (A); a gas-liquid separation channel (B) is formed inside the cylinder (1042);

the feed line (W) communicates with the bottom of the housing (101);

the liquid phase outlet line (X) communicates with the housing (101) above the liquid trap (1041);

one end of the gas phase outlet line (Y) is communicated with the top of the shell (101);

preferably, the other end of the gas phase outlet line (Y) is communicated with a first gas-liquid separation tank (4); a cooler (3) for cooling the gas-phase product in the gas-phase outlet line (Y);

preferably, the reactor further comprises: a liquid level detecting element (105) for detecting a liquid level in the gas-liquid separation space, a liquid level control valve (F1) provided on the liquid phase outlet line (X), a pressure detecting element (106) and a pressure control valve (F2) provided on the gas phase outlet line (Y);

preferably, a cover plate is disposed on the catalyst bed.

10. Method according to claim 9, characterized in that the liquid phase outlet line (X) communicates with a second gas-liquid separation tank (5).

Technical Field

The invention belongs to the technical field of oil refining chemical industry, and particularly relates to a method for isomerizing carbon octa-arene.

Background

C8A is one of the products of naphtha reforming, cracking. C8A contains 10-30% Ethylbenzene (EB) in addition to ortho-xylene (MX), meta-xylene (OX) and para-xylene (PX). The main components of reformate are benzene, toluene and xylene, which are abbreviated as BTX. The main components of BTX are benzene and xylene. PX in xylene is an important raw material for producing resins, polyesters, detergents and medical products, and its demand is large, and it is considered as one of important products in petrochemical industry.

In the prior art, BTX is separated from reformate and left with C8A. The C8 aromatic hydrocarbons are then sent to an isomerization reactor to convert MX, OX into a thermodynamically balanced xylene mixture through a specific catalytic reaction to produce a PX-containing product. Xylene isomerization converts PX-lean carbon octa-aromatics over a catalyst into C8A of near equilibrium composition; ethylbenzene dealkylation also occurs in the isomerization reaction. Xylene isomerization can be combined with a PX separation process, OX, MX and EB are all converted into PX step by step through circulation operation, and the purpose of improving the PX yield is achieved.

The general process for the isomerization of xylenes to PX is now: firstly, the gasified PX-poor C8 aromatic hydrocarbon is heated to above 400 ℃ for gasification, then is mixed with hydrogen pressurized by a compressor, and then is introduced into a reactor for isomerization reaction, the reaction temperature is usually 380-420 ℃, the mixed gas containing the generated product is cooled for gas-liquid separation, the redundant hydrogen is subjected to gas-liquid separation and is circularly compressed for use, and the generated product is sent to downstream processing.

In the process of implementing the present invention, the inventors found that, in the existing process of isomerizing xylene to generate PX, more energy is consumed for gasifying PX-lean carbon octaarene, the use of a compressor to compress hydrogen not only consumes more energy, but also the compressor occupies a larger space, and more capacity is consumed for compressing hydrogen, and the isomerization reaction temperature is also high, and more energy is consumed. In a word, the conventional method for generating PX by xylene isomerization has high energy consumption and high production cost, and is not beneficial to industrial production of xylene isomerization.

Disclosure of Invention

The invention aims to provide a method for isomerizing carbon octaarene, which has low energy consumption and low cost.

In order to achieve the above object, the present invention provides a method for isomerizing a carbaoctaarene, comprising the steps of:

(1) mixing the carbon octaarene and hydrogen to obtain mixed hydrogen carbon octaarene; the molar ratio of the hydrogen to the carbon octaarene is 0.5:99.5-30: 70;

(2) heating the mixed hydrogen carbon octa-aromatic hydrocarbon to form a gas-liquid mixed reaction feed;

(3) and feeding the reaction feed into a reactor, feeding the reaction feed into a catalyst bed layer for isomerization reaction after the reaction feed passes through a gas-liquid distributor in the reactor, and generating a product containing p-xylene, wherein the product is subjected to gas-liquid separation through a gas-liquid separation component positioned above the catalyst bed layer to obtain a gas-phase product and a liquid-phase product.

During the reaction, the carbon octaarene is a gas-liquid mixed phase, and the reaction temperature and pressure of the isomerization reaction can be set by a person skilled in the art. In view of the energy consumption and reaction efficiency of the reaction, in a preferred embodiment of the present invention, the isomerization reaction is carried out at a reaction temperature of 150 ℃ to 300 ℃ and a reaction pressure of 0.5 to 4.0 MPaG. More preferably, the isomerization reaction is carried out at a reaction temperature of 200 ℃ and 250 ℃ and a reaction pressure of 0.9 to 2.0 MPaG.

In a preferred embodiment of the invention, the liquid space velocity of the reaction feed as it is fed to the reactor is in the range of from 0.3 to 65h^-1Preferably 3 to 45h^-1。

In the present invention, hydrogen does not need to be recycled, and therefore, the amount of hydrogen used is not large, and the molar ratio of the hydrogen to the carbon octaarene is 0.8:99.2-20:80, preferably 3:97-10:90, so as to promote the reaction equilibrium to progress to generate PX.

In a preferred embodiment of the present invention, the method further comprises: (4) and cooling the gas-phase product, and then carrying out gas-liquid separation, wherein a first gas-phase separator and a first liquid-phase separator obtained by gas-liquid separation are respectively sent to downstream processing.

In order to save energy consumption and be beneficial to gas-liquid separation of subsequent liquid phase products, the heating of the mixed hydrogen carbon octaarene comprises the steps of sequentially preheating and heating the mixed hydrogen carbon octaarene, wherein the liquid phase product is used as a heat exchange medium to preheat the mixed hydrogen carbon octaarene. The temperature of the gas-liquid mixed reaction feed formed after the temperature rise can be 150-300 ℃.

The equipment used for preheating may be a heat exchanger. The device used for heating may be a heater.

In a specific embodiment of the present invention, the method further comprises: and carrying out gas-liquid separation on the liquid phase product after heat exchange, and respectively sending a second gas phase separator and a second liquid phase separator obtained by gas-liquid separation to downstream processing.

The reactor used in the method for isomerizing the carbon octaarene is preferably an upflow reaction separation composite reactor.

In the invention, the number of the reactors is two or more, and the two or more reactors are arranged in series or in parallel.

The specific structure of the reactor used in the method for isomerizing the carbon octaarene provided by the invention is as follows: the reactor comprises: the gas-liquid distributor, the catalyst bed layer and the gas-liquid separation component are arranged in the shell from bottom to top;

the reactor and feed line, liquid phase outlet line, and gas phase outlet line;

the gas-liquid separation module includes: the device comprises an annular liquid accumulating plate and a cylinder body connected with the inner edge of the liquid accumulating plate;

the gas-liquid separation assembly and the shell positioned above the liquid accumulation plate enclose a gas-liquid separation space; a gas-liquid separation channel is formed inside the cylinder body;

the feed line is in communication with the bottom of the housing;

the liquid phase outlet pipeline is communicated with the shell positioned above the liquid accumulating plate;

one end of the gas phase outlet line communicates with the top of the housing.

Preferably, the other end of the gas phase outlet pipeline is communicated with a first gas-liquid separation tank; a cooler is used to cool the gas phase product in the gas phase outlet line.

In one embodiment of the present invention, the reactor further comprises: a liquid level detecting element for detecting the liquid level in the gas-liquid separation space, a liquid level control valve arranged on the liquid phase outlet pipeline, a pressure detecting element and a pressure control valve arranged on the gas phase outlet pipeline.

In order to prevent the catalyst from being carried out of the reactor by the product fluid, a cover plate is preferably arranged on the catalyst bed.

In the present invention, the liquid phase outlet line is communicated with the second gas-liquid separation tank.

The method for isomerizing the C-octaarene reduces the energy consumption for generating PX by using a liquid phase hydrogenation mode for the C-octaarene through the molar ratio of hydrogen to the C-octaarene of 0.5:99.5-30:70, reduces the using amount of hydrogen, ensures that the reaction feeding is in a gas-liquid mixed state, reduces the energy consumption for generating the PX, realizes the full mixing of the C-octaarene and the hydrogen by arranging a gas-liquid distributor in a reactor, improves the yield of the PX under the action of a catalyst, and realizes the primary gas-liquid separation of a product by a gas-liquid separation component, so the method for isomerizing the C-octaarene needs less equipment, has low energy consumption, and has low investment cost and production cost.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.

FIG. 1 shows a schematic diagram of a reactor in a process for isomerizing a C-eight aromatic hydrocarbon according to the present invention.

FIG. 2 shows a schematic diagram of another reactor in a process for isomerizing a C-octaaromatic hydrocarbon according to the present invention.

FIG. 3 shows a schematic diagram of yet another reactor in a process for isomerizing a C-octaaromatic hydrocarbon according to the present invention.

FIG. 4 shows a schematic diagram of yet another reactor in a process for isomerizing a C-octaaromatic hydrocarbon according to the present invention.

Reference numerals:

101. a housing;

102. a gas-liquid distributor;

103. a catalyst bed layer;

104. a gas-liquid separation assembly;

1041. an annular effusion plate; 1042. a barrel;

w, a feed line;

x, a liquid phase outlet line;

y, a gas phase outlet line;

105. a liquid level detection element;

106. a pressure detecting element;

f1, a liquid level control valve;

f2, a pressure control valve;

1. a heat exchanger;

2. a heater;

3. a cooler;

4. a first gas-liquid separation tank;

5. a second knock-out pot;

10. a reactor.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

The invention provides a method for isomerizing carbon octa-arene. The method comprises the following steps:

(1) mixing the carbon octaarene and hydrogen to obtain mixed hydrogen carbon octaarene; the molar ratio of the hydrogen to the carbon octaarene is 0.5:99.5-30: 70.

(2) And heating the mixed hydrogen carbon octa-aromatic hydrocarbon to form a gas-liquid mixed reaction feed.

(3) And feeding the reaction feed into a reactor, feeding the reaction feed into a catalyst bed layer for isomerization reaction after the reaction feed passes through a gas-liquid distributor in the reactor, and generating a product containing p-xylene, wherein the product is subjected to gas-liquid separation through a gas-liquid separation component positioned above the catalyst bed layer to obtain a gas-phase product and a liquid-phase product.

The method for isomerizing the C-octaarene reduces the energy consumption for generating PX by using a liquid phase hydrogenation mode for the C-octaarene through the molar ratio of hydrogen to the C-octaarene of 0.5:99.5-30:70, reduces the using amount of hydrogen, ensures that the reaction feeding is in a gas-liquid mixed state, reduces the energy consumption for generating the PX, realizes the full mixing of the C-octaarene and the hydrogen by arranging a gas-liquid distributor in a reactor, improves the yield of the PX under the action of a catalyst, and realizes the primary gas-liquid separation of a product by a gas-liquid separation component, so the method for isomerizing the C-octaarene needs less equipment, has low energy consumption, and has low investment cost and production cost.

During the reaction, the carbon octaarene is a gas-liquid mixed phase, and the reaction temperature and pressure of the isomerization reaction can be set by a person skilled in the art. In view of the energy consumed by the reaction and the reaction efficiency, in a preferred embodiment of the present invention, the isomerization reaction is carried out at a reaction temperature of 150-.

In a preferred embodiment of the invention, the liquid space velocity of the reaction feed as it is fed to the reactor is in the range of from 0.3 to 65h^-1Preferably 3 to 45h^-1。

The temperature of the mixed hydrocarbon and the octaarene after being heated can be set by a person skilled in the art according to actual needs, and the invention is not particularly limited. It will be understood that the elevated temperature of the mixed hydrocarbon carbon octaaromatic hydrocarbon, i.e. the temperature of the reaction feed, is suitably slightly less than or equal to the reaction temperature in the reactor. For example, the temperature of the reaction feed is 150 ℃ to 300 ℃, preferably 200 ℃ to 250 ℃.

In the invention, hydrogen does not need to be recycled, so that the using amount of the hydrogen is not large, the molar ratio of the hydrogen to the carbon octaarene is 0.8:99.2-20:80, preferably 1.0:99-10:90, the reaction balance can be promoted to be developed to the process of generating PX, and the hydrogen does not need to be compressed for recycling.

The method for isomerizing the carbon octaarene further comprises the following steps: (4) and cooling the gas-phase product, and then carrying out gas-liquid separation, wherein a first gas-phase separator and a first liquid-phase separator obtained by gas-liquid separation are respectively sent to downstream processing.

In order to save energy consumption and facilitate gas-liquid separation of subsequent liquid phase products, the heating of the mixed hydrogen carbon octaarene comprises the steps of sequentially preheating and heating the mixed hydrogen carbon octaarene, wherein the liquid phase product is used as a heat exchange medium to preheat the mixed hydrogen carbon octaarene. The temperature of the reaction feed formed after the temperature rise may be 150-300 ℃. The equipment used for preheating may be a heat exchanger. The device used for heating may be a heater.

In the invention, the liquid phase product output by the reactor can be directly sent to downstream processing, or the gas phase product and the liquid phase product obtained by gas-liquid separation are sent to downstream processing, or sent to downstream processing after exchanging heat with the reaction feed, and the gas phase product and the liquid phase product obtained by gas-liquid separation are sent to downstream processing. Therefore, after the liquid-phase product is subjected to heat exchange and temperature reduction, the method further comprises the following steps: and carrying out gas-liquid separation on the liquid phase product after heat exchange, and respectively sending a second gas phase separator and a second liquid phase separator obtained by gas-liquid separation to downstream processing. The gas-liquid separation can be achieved using a gas-liquid separation tank.

The reactor used in the method for isomerizing the carbon octaarene can be an upflow reaction separation composite reactor.

Referring to fig. 1, fig. 1 shows a schematic diagram of a reactor in a method for isomerizing a C-octaaromatic hydrocarbon according to the present invention. As shown in fig. 1, the reactor includes a shell 101, the gas-liquid distributor 102 disposed inside the shell 101 from bottom to top, the catalyst bed 103, and the gas-liquid separation assembly 104; the method comprises the following steps: a feed line W, a liquid phase outlet line X, and a gas phase outlet line Y; the gas-liquid separation module 104 includes: an annular liquid accumulation plate 1041, and a cylinder 1042 connected with the inner edge of the liquid accumulation plate 1041; the gas-liquid separation assembly 104 and the shell 101 above the liquid accumulation plate 1041 enclose a gas-liquid separation space a; a gas-liquid separation channel B is formed inside the cylinder 1042; the feed line W communicates with the bottom of the housing 101; the liquid phase outlet pipeline X is communicated with the casing 101 above the liquid loading plate 1041; one end of the gas phase outlet pipeline Y is communicated with the top of the shell 101, and the other end of the gas phase outlet pipeline Y is communicated with the first gas-liquid separation tank 4; the cooler 3 serves to cool the gas-phase product in the gas-phase outlet line Y. The reactor adopts an up-flow and separation combined type reactor, has reaction and separation functions, and reduces the energy consumption, the operation cost and the investment cost of isomerizing the carbon octaarene.

Further, referring to fig. 2, fig. 2 shows a schematic diagram of another reactor in the method for isomerizing a C-octaarene provided by the invention. As shown in fig. 2, the other end of the gas phase outlet line Y communicates with the first gas-liquid separation tank 4; the cooler 3 serves to cool the gas-phase product in the gas-phase outlet line Y.

Further, with continued reference to fig. 1, the reactor further comprises: a liquid level detecting element 105 for detecting a liquid level in the gas-liquid separation space, a liquid level control valve F1 provided in the liquid phase outlet line X, a pressure detecting element 106 provided in the gas phase outlet line Y, and a pressure control valve F2.

Further, a cover plate (not shown in fig. 1) is provided on the catalyst bed 103. The cover plate may be a grid plate. In the process that gas-liquid materials flow from bottom to top, the catalyst is prevented from moving up and down, and smooth flow of gas-liquid materials in the reactor can be guaranteed.

Referring to fig. 3, fig. 3 is a schematic diagram of another reactor in the method for isomerizing a C-octaaromatic hydrocarbon according to the present invention. As shown in fig. 3, the liquid phase outlet line X communicates with the second knock-out pot 5. And the second gas-liquid separation tank 5 is used for realizing gas-liquid separation of the liquid-phase product, and the obtained second gas-phase separator and the second liquid-phase separator are respectively sent to downstream processing.

In the invention, the number of the reactors is two or more, and the two or more reactors are arranged in series or in parallel. Referring to fig. 4, fig. 4 is a schematic diagram of another reactor in the method for isomerizing a C-octaarene according to the present invention. As shown in fig. 4, two reactors 10 are arranged in parallel, communicating with a feed line W, a liquid phase outlet line X and a gas phase outlet line Y, respectively.

Further, the method further comprises: the liquid level detecting element detects the liquid level in the gas-liquid separation tank (the first gas-liquid separation tank and the second gas-liquid separation tank), and the liquid level control valve controls the discharge of the liquid in the gas-liquid separation tank.

Example 1

This example provides a process for isomerizing a carbaoctaarene. Referring to fig. 1, the method includes the following steps:

(1) the hydrogen and the C-eight aromatic hydrocarbon are mixed in a molar ratio of 0.03 (namely, hydrogen-oil ratio) in a feed line W as shown by an arrow to obtain the mixed hydrogen C-eight aromatic hydrocarbon.

(2) The mixed hydrogen carbon octaarene is preheated by a heat exchanger 1 by taking a liquid phase product as a heat exchange medium, and then heated by a heater 2 until the temperature of the mixed hydrogen carbon octaarene is 220 ℃, so that a gas-liquid mixed reaction feed is formed.

(3) Feeding a reaction feed to the reactor, the liquid space velocity of the reaction feed being 10h^-1After being fully mixed and distributed by the gas-liquid distributor 102, the mixture enters the catalyst bed layer 103 for isomerization reaction at the reaction temperature of 230 ℃ and the reaction pressure of 1.6MPaG to generate a product containing paraxylene, and the product is subjected to gas-liquid separation by a gas-liquid separation component 104 positioned above the catalyst bed layer 103After that, a gas phase product and a liquid phase product are obtained.

Through detection, the conversion rate of EB is 75%, and the mass ratio of PX/X is 23.8%; the xylene (single pass) loss rate is less than 0.5%.

Examples 2 and 3

This example provides a process for isomerizing a carbaoctaarene. Examples 2 and 3 differ from example 1 only in the reaction conditions, which are specified in table 1.

Table 1 reaction conditions of examples 2 and 3

Therefore, the method for isomerizing the carbon octaarene is suitable for the raw material with high ethylbenzene content or high ethylbenzene content in C8A.

Comparative example

Compressing hydrogen to 1.5MPaG by a compressor, mixing the hydrogen with the C-eight aromatic hydrocarbon according to the mol ratio of 1.0-4.0, and heating the mixed hydrogen and C-eight aromatic hydrocarbon to 400 ℃ by a heating furnace to form gaseous reaction feed.

Feeding reaction feed into a reactor, feeding the reaction feed into a catalyst bed layer for isomerization reaction, wherein the reaction temperature is 400 ℃, the reaction pressure is 1.1MPaG, and the liquid space velocity of the reaction feed is 10h^-1To produce a product containing p-xylene; the outlet product of the reactor contains a large amount of unreacted hydrogen and unconverted carbon-eight aromatic hydrocarbon, and reaction byproducts of benzene, toluene, o-xylene, m-xylene and the like.

Through detection, the conversion rate of Ethylbenzene (EB) is 65%, and the mass ratio of PX/X (dimethylbenzene) is 23.0%; the xylene (per pass) loss was 1.50%.

Therefore, the method for isomerizing the carbon octaarene provided by the invention has low energy consumption, correspondingly, the production cost and the investment cost are low, and the conversion rate of the ethylbenzene and the content of the generated PX are higher than those of the comparative example 1.

Example 4

This example provides a process for isomerizing a carbaoctaarene. Referring to fig. 3, the present embodiment further includes, based on the method provided in embodiment 1:

(4) and after being cooled by the cooler 3, the gas-phase product is sent to the first gas-liquid separation tank 4 for gas-liquid separation, and a first gas-phase separator and a first liquid-phase separator obtained by gas-liquid separation are respectively sent to downstream processing.

(5) The liquid phase product after heat exchange is subjected to gas-liquid separation through the second gas-liquid separation tank 5, the separated second gas phase separated matter and the first gas phase separated matter from the first gas-liquid separation tank 4 are combined and sent to the downstream, and the liquid phase product is sent to the downstream for treatment.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.