Apparatus and method for removing residual olefins from a refined solvent

Abstract

The application discloses a device for removing residual olefins in refined solvent, which comprises a hydrogen membrane assembly, a catalyst-loaded catalytic module and a low-pressure separation tank. The hydrogen membrane assembly has a high-pressure side flow channel and a low-pressure side flow channel separated by a permeation membrane. The high-pressure side flow channel is provided with a hydrogen inlet connector and a hydrogen outlet connector for hydrogen gas to enter and exit. The low-pressure side flow channel is provided with a solvent inlet connector and a solvent outlet connector for solvent to enter and exit. The permeation membrane is arranged to allow hydrogen gas in the high-pressure side flow channel to pass through. The catalyst-loaded catalytic module is arranged in the low-pressure side flow channel. The low-pressure separation tank is connected with the solvent outlet connector of the hydrogen membrane assembly. The bottom of the low-pressure separation tank is provided with a liquid outlet for outputting solvent, and the top of the low-pressure separation tank is provided with an exhaust port. The application also discloses a method for removing residual olefins in refined solvent by using the device. Compared with the prior art, the application can remove residual olefins in solvent and reduce the loss of solvent.

Description

Technical Field

[0001] This invention belongs to the field of polymer preparation technology, specifically relating to an apparatus and method for removing residual olefins from purified solvents. Background Technology

[0002] Solution polymerization is a polymerization reaction in which monomers and comonomers are dissolved in a solvent and an initiator (catalyst) is added, and the reaction proceeds in solution. In this process, the solvent does not participate in the reaction but acts as a heat transfer medium, making the reaction temperature easy to control. The monomers, comonomers, and the polymer produced by the reaction are uniformly dispersed in the solvent, allowing the polymer to react in a low-concentration environment, making it easy to control the molecular weight distribution and structural state of the polymer.

[0003] However, the introduction of solvents also increases the costs of polymer purification, recovery of unreacted monomers, and solvent separation. In industry, methods such as flash distillation are commonly used to separate monomers, comonomers, solvents, and polymers. After multi-stage distillation, refined solvents are obtained and recycled.

[0004] However, because monomers or comonomers are very soluble in solvents, it is impossible to completely separate the solvent, monomers and comonomers by distillation. Trace amounts of monomers or comonomers will dissolve in the solvent and will follow the circulating solvent into the entire solvent system.

[0005] Once the monomers and comonomers enter the catalyst preparation unit along with the circulating solvent, they will react prematurely to form polymers under the action of the catalyst. This can clog the pipelines of the catalyst preparation system or adhere to the inner wall of the catalyst preparation tank. In severe cases, it can cause catalyst metering imbalance and polymer quality degradation.

[0006] like Figure 1 As shown, in the petrochemical industry, the separation of residual monomers (olefins) from solvents often employs a combination of a hydrogenation reactor 1' and a condensation degassing device 2' (tank, tower, etc.). Hydrogen and olefins undergo an addition reaction in the hydrogenation reactor 1' to produce low-boiling-point alkanes, which then enter the degassing device 2' (tank, tower, etc.). Under the influence of an inert gas (such as nitrogen), unreacted hydrogen and the alkanes produced by the reaction are carried away by the solvent and removed through the exhaust system.

[0007] Pressurization promotes the forward hydrogenation reaction, and high temperature enhances the catalyst activity within the hydrogenation reactor. The hydrogenation reactor is a crucial piece of equipment in oil refining processes, operating under high temperature, high pressure, and hydrogen-containing media conditions. Its operating conditions are extremely demanding, and accidents can cause severe losses. Furthermore, hydrogenation reactors are relatively expensive and have long manufacturing cycles.

[0008] In order to completely remove the olefins in the solvent, the hydrogenation reaction can as much as possible increase the hydrogen pressure in the hydrogenation reactor, and the high-pressure hydrogen is usually used for the reaction, but the flow of the high-pressure hydrogen is difficult to control, and the excessive hydrogen is easily caused by the fluctuation, and the waste of the hydrogen is caused, and when the waste gas is discharged, the excessive hydrogen is also discharged together with the solvent, that is, the environment is polluted, and the energy is wasted. Therefore, how to obtain the refined solvent while reducing the loss of the solvent is very important in the solution polymerization. SUMMARY

[0009] The first technical problem to be solved by the present application is to provide a device for removing residual olefins in refined solvent in order to reduce the loss of solvent in view of the current situation of the prior art.

[0010] The second technical problem to be solved by the present application is to provide a method for removing residual olefins by using the above-mentioned device.

[0011] The technical scheme adopted by the present application to solve the above-mentioned first technical problem is as follows: a device for removing residual olefins in refined solvent, characterized by comprising:

[0012] a hydrogen membrane assembly having a high-pressure side flow channel and a low-pressure side flow channel in the inside, the two being separated by a permeation membrane, and the high-pressure side flow channel having a hydrogen inlet connector and a hydrogen outlet connector for the hydrogen to enter and exit, and the low-pressure side flow channel having a solvent inlet connector and a solvent outlet connector for the solvent to enter and exit, and the permeation membrane being arranged to allow only the hydrogen in the high-pressure side flow channel to pass through;

[0013] a catalytic module loaded with a catalyst, arranged in the low-pressure side flow channel;

[0014] a low-pressure separation tank, the inlet of which is connected to the solvent outlet connector of the hydrogen membrane assembly, and the bottom of the low-pressure separation tank having a liquid outlet for the solvent to output, and the top of the low-pressure separation tank having a gas outlet.

[0015] The material of the permeation membrane is at least one of polyimide, polysulfone, polyvinyl trimethylsilane, polyphenyl ether and polyamide.

[0016] The principle of the hydrogen membrane assembly is as follows:

[0017] F=A*k*(piH-piL)

[0018] F is the permeation amount, in kmol / h;

[0019] A is the permeation membrane area, in m 2 ;

[0020] k is the permeation factor, in kmol / (m 2 ·h·bar);

[0021] piH—high pressure side component partial pressure, unit: bar;

[0022] piL—low pressure side component partial pressure, unit: bar;

[0023] The hydrogen membrane assembly increases the hydrogen permeation amount by increasing the flow channel and the membrane area, and ensures that the turbulent hydrogen can be mixed uniformly with the solvent and react completely under the action of the catalyst within a specified Reynolds number range.

[0024] The hydrogen membrane assembly can be one or two or more, and when there are two or more, the hydrogen membrane assemblies can be connected in series or in parallel or both in series and in parallel, and the specific design is based on the actual working conditions.

[0025] Preferably, the hydrogen membrane assembly comprises a shell, the inside of which is hollow to form the high-pressure side flow channel; and the permeation membrane is arranged in the shell and has a tubular body, and the inside space of the tubular body is the low-pressure side flow channel.

[0026] In addition, the permeation membrane can also be in the form of a sheet, which divides the space in the shell into at least two spaces, which are the high-pressure side flow channel and the low-pressure side flow channel.

[0027] To improve the reaction efficiency, preferably, the tubular body has a plurality of tubular bodies arranged side by side and spaced apart, and each tubular body is provided with the catalytic module. In this way, the plurality of tubular bodies can increase the membrane area and thus increase the hydrogen permeation amount, so that the hydrogen can be mixed uniformly with the olefins in the solvent and react under the action of the catalyst.

[0028] Further, the catalytic module in each tubular body has a plurality of catalytic modules arranged along the length direction of the tubular body.

[0029] To further promote the gas-liquid mixing reaction, preferably, a mixing module is further arranged in the tubular body for the mixed gas-liquid to pass through, and the mixing module has a plurality of mixing modules arranged alternately with the catalytic modules in the length direction of the tubular body. The mixing module is a conventional mixer to enable the hydrogen to be mixed and reacted with the olefins in the solvent sufficiently.

[0030] Preferably, the solvent inlet connector and the solvent outlet connector are arranged respectively at the two ends of the tubular body, the hydrogen inlet connector is arranged at the bottom of the shell and close to the solvent inlet connector, and the hydrogen outlet connector is arranged at the bottom of the shell and close to the solvent outlet connector. In this way, the low-pressure side flow channel can be long enough to enable the hydrogen to enter the low-pressure side flow channel and react with the olefins in the solvent sufficiently.

[0031] In the above-mentioned schemes, preferably, a compressor is further included, the output end of the compressor is connected with the hydrogen inlet pipe of the hydrogen membrane module, the input end of the compressor is connected with a hydrogen pipeline for conveying hydrogen and the hydrogen outlet pipe of the hydrogen membrane module, and the hydrogen pipeline is provided with a flow control valve and a pressure control valve. Thus, the hydrogen can be recycled and supplied, and the pressure of the hydrogen entering the hydrogen membrane module can be ensured.

[0032] The technical scheme adopted by the present application to solve the second technical problem is: a method for removing residual olefins in a solvent by using the device described above, characterized by the following steps:

[0033] I. The solvent to be treated is input into the low-pressure side flow channel of the hydrogen membrane module through the solvent inlet pipe, and hydrogen is input into the high-pressure side flow channel of the hydrogen membrane module through the hydrogen inlet pipe. At least part of the hydrogen in the high-pressure side flow channel permeates through the permeation membrane into the low-pressure side flow channel, and the olefins in the solvent to be treated react with the hydrogen at a temperature of 30-200 ℃. After the reaction, the solvent is output from the solvent outlet pipe, and the hydrogen that does not permeate through the permeation membrane in the high-pressure side flow channel is output from the hydrogen outlet pipe. The solvent to be treated is an inert solvent and is at least one of an alkane and a cycloalkane. The olefins in the solvent to be treated are at least one of ethylene, propylene, butylene, pentene, hexene and their isomers. The concentration of the double bonds of the olefins in the solvent to be treated is 1-200 mol / m 3 The ratio between the molar flow of the hydrogen input into the hydrogen membrane module and the molar flow of the double bonds of the olefins in the solvent to be treated is 1-1.2, and the pressure of the hydrogen input into the hydrogen membrane module is 0.3-1.2 MPaG.

[0034] II. The solvent after the reaction is output from the solvent outlet pipe and enters the low-pressure separation tank for gas-liquid separation. The gas phase after the separation is discharged from the gas outlet of the low-pressure separation tank, and the liquid phase after the separation is discharged from the liquid outlet of the low-pressure separation tank. The pressure in the low-pressure separation tank is denoted as P1, the pressure of the hydrogen input into the hydrogen membrane module is denoted as P2, and 1.2 MPaG≥P2≥3P1.

[0035] The "inert" in the above-mentioned inert solvent means that the solvent does not interfere with the progress of the hydrogenation reaction as a principle, that is, the hydrocarbon solvent cannot react with the reactants and reaction products, and cannot negatively affect the activation performance of the catalyst.

[0036] The hydrogenation method in the present application can be continuous operation or intermittent operation. The present method has more advantages when it is continuously operated. When it is intermittently operated, the solvent and the catalyst are intermittently fed, and the hydrogen is continuously fed. When the hydrogenation reaction reaches the required residence time, the hydrogenated material is discharged to the low-pressure separation tank.

[0037] The refined solvent from which the olefins are removed by the method of the present application can be used not only for catalyst arrangement but also for other purposes of the solvent in solution polymerization such as polymerization temperature arrangement, reaction flushing, reaction monomer dilution, etc.

[0038] Preferably, the solvent to be treated is at least one of cyclohexane, n-heptane, n-hexane and 1-octane; the concentration of double bonds of the olefins in the solvent to be treated is 5-100 mol / m 3 The ratio between the molar flow of hydrogen input into the hydrogen membrane assembly and the molar flow of double bonds of the olefins in the solvent to be treated is 1-1.05.

[0039] Compared with the prior art, the present application has the following advantages:

[0040] By arranging the hydrogen membrane assembly, the catalytic module and the low-pressure separation tank, the high-pressure hydrogen in the high-pressure side flow channel of the hydrogen membrane assembly can controllably permeate into the low-pressure side flow channel, and the olefins in the solvent in the low-pressure side flow channel react under the action of the catalyst. In this process, the double bonds of the olefins in the reaction system are nearly equimolar with the hydrogen, which avoids the loss of hydrogen and the environmental pollution caused by the excess hydrogen, and improves the utilization rate of hydrogen.

[0041] The principle of the method for removing the residual olefins in the refined solvent is the addition reaction of the olefins. The addition reaction of the olefins in the present application occurs in the hydrogen membrane assembly. The present application uses the hydrogen membrane assembly instead of the high-temperature and high-pressure hydrogenation equipment such as hydrogenation reactor, which avoids the harsh operating conditions.

[0042] The low-pressure separation tank of the present application does not need to be additionally provided with a condensing device and a degassing device. The gas can be smoothly discharged, and the inert gas does not need to be introduced from the bottom as a power gas to carry out the residual gas. The inert gas can be avoided to carry out the solvent, which causes the loss of the solvent.

[0043] The exhaust gas discharged from the exhaust port of the low-pressure separation tank of the present application almost has no residual hydrogen, and the hydrogen content is less than 500 ppm. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a structural schematic view of the device for removing the residual olefins in the refined solvent in the prior art;

[0045] Figure 2 It is a structural schematic view of the device for removing the residual olefins in the refined solvent in Example 1 of the present application;

[0046] Figure 3 It is a longitudinal sectional view of the hydrogen membrane assembly in Example 1 of the present application;

[0047] Figure 4 It is a transverse sectional view of the hydrogen membrane assembly in Example 1 of the present application. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0049] Example 1:

[0050] like Figures 2 to 4 The image shows a preferred embodiment 1 of an apparatus and method for removing residual olefins from a refined solvent according to the present invention. The apparatus includes a hydrogen membrane assembly 1, a catalyst-supported catalytic module 2, a low-pressure separation tank 3, a mixing module 4, and a compressor 5.

[0051] The hydrogen membrane assembly 1 includes a high-pressure side flow channel 11 and a low-pressure side flow channel 12, separated by a permeation membrane 13. The high-pressure side flow channel 11 has a hydrogen inlet pipe 11a and a hydrogen outlet pipe 11b for hydrogen gas to enter and exit, while the low-pressure side flow channel 12 has a solvent inlet pipe 12a and a solvent outlet pipe 12b for solvent to enter and exit. The permeation membrane 13 is arranged to allow only hydrogen gas from the high-pressure side flow channel 11 to pass through. In this embodiment, the hydrogen membrane assembly 1 includes a housing 10, which is hollow to form the aforementioned high-pressure side flow channel 11. The permeation membrane 13 is disposed within the housing 10 and is tubular in shape, with the internal space of the tubular body serving as the low-pressure side flow channel 12. Multiple tubular bodies are arranged side-by-side at intervals. The solvent inlet pipe 12a and solvent outlet pipe 12b are respectively provided at both ends of each tubular body. The hydrogen inlet pipe 11a is located at the bottom of the shell 10 and is located close to the solvent inlet pipe 12a. The hydrogen outlet pipe 11b is located at the bottom of the shell 10 and is located close to the solvent outlet pipe 12b.

[0052] Each tubular body is equipped with multiple catalytic modules 2 and multiple mixing modules 4 as described above, arranged alternately along the length of the tubular body. The catalysts on the catalytic modules are existing catalysts used for hydrogenation reactions, and the mixing modules 4 are existing mixers for supplying gas-liquid mixtures.

[0053] The inlet 31 of the aforementioned low-pressure separator 3 is connected to the solvent outlet pipe 12b of the hydrogen membrane module 1. The bottom of the low-pressure separator 3 has a drain port 32 for solvent output, and the top has an exhaust port 33. At the same time, a nitrogen sealing pressure valve group and an exhaust control valve group are also provided at the exhaust port 33 at the top of the low-pressure separator 3. Both are existing technologies and serve to isolate air, improve safety, and control the pressure on the low-pressure side of the solvent, thereby controlling the osmotic pressure difference.

[0054] In order to recycle hydrogen, the output end of the compressor 5 is connected to the hydrogen inlet pipe 11a of the hydrogen membrane module 1, and the input end is connected to the hydrogen pipeline 50 for transporting hydrogen and the hydrogen outlet pipe 11b of the hydrogen membrane module 1; the hydrogen pipeline 50 is equipped with a flow control valve 51 and a pressure control valve 52.

[0055] The ethylene / 1-butene copolymer elastomer is prepared by solution polymerization process with n-hexane as solvent. After the preparation, the steps of removing residual olefins in the solvent by the method of the device of the embodiment are as follows:

[0056] I. The solvent to be treated is input into the low-pressure side flow channel 12 of the hydrogen membrane assembly 1 through the solvent inlet connecting pipe 12a, and hydrogen is input into the high-pressure side flow channel 11 of the hydrogen membrane assembly 1 through the hydrogen inlet connecting pipe 11a. At least part of the hydrogen in the high-pressure side flow channel 11 permeates through the permeation membrane 13 into the low-pressure side flow channel 12, and reacts with the olefins in the solvent to be treated at a temperature of 60°C to generate low-boiling-point alkanes. After the reaction, the solvent is output from the solvent outlet connecting pipe 12b, and the hydrogen in the high-pressure side flow channel 11 that does not permeate through the permeation membrane 13 is output from the hydrogen outlet connecting pipe 11b. The concentration of double bonds of the olefins in the solvent to be treated is 5 mol / m 3 , the ratio between the molar flow of the hydrogen input into the hydrogen membrane assembly 1 and the molar flow of the double bonds of the olefins in the solvent to be treated is 1.02, the pressure of the hydrogen input into the hydrogen membrane assembly 1 is 500 KPaG, and the molar flow of the hydrogen entering the low-pressure side flow channel 12 (i.e. the consumption of the hydrogen in the hydrogen membrane assembly 1) is 10.02 mol / h.

[0057] II. The solvent after the reaction output from the solvent outlet connecting pipe 12b enters the low-pressure separation tank 3 for gas-liquid separation. The gas phase after the separation is discharged from the gas outlet 33 of the low-pressure separation tank 3, and the liquid phase after the separation is discharged from the liquid outlet 32 of the low-pressure separation tank 3. The pressure in the low-pressure separation tank 3 is 50 KPaG, the discharge amount of the gas phase from the gas outlet 33 of the low-pressure separation tank 3 is 10.02 mol / h, and the discharge amount of the hydrogen in the gas phase is 0.02 mol / h.

[0058] Example 2:

[0059] The same as example 1, the difference is that the parameters in the method are different. In this embodiment, the concentration of double bonds of the olefins in the solvent to be treated in step I is 10 mol / m 3 , and the consumption of the hydrogen in the hydrogen membrane assembly 1 is 20.06 mol / h. In step II, the discharge amount of the gas phase from the gas outlet 33 of the low-pressure separation tank 3 is 20.06 mol / h, and the discharge amount of the hydrogen in the gas phase is 0.06 mol / h.

[0060] Example 3:

[0061] The process is basically the same as that of Example 1, except that the parameters in the process are different. In this example, the pressure of the hydrogen gas input into the hydrogen membrane assembly 1 in step one is 600 KPaG, and the consumption of the hydrogen gas in the hydrogen membrane assembly 1 is 10.03 mol / h; in step two, the discharge amount of the gas phase from the exhaust port 33 of the low-pressure separation tank 3 is 10.03 mol / h, and the discharge amount of the hydrogen gas in the gas phase is 0.03 mol / h.

[0062] Example 4:

[0063] The process is basically the same as that of Example 1, except that the parameters in the process are different. In this example, the double bond concentration of the olefin in the solvent to be treated in step one is 10 mol / m 3 , the pressure of the hydrogen gas input into the hydrogen membrane assembly 1 is 600 KPaG, and the consumption of the hydrogen gas in the hydrogen membrane assembly 1 is 20.08 mol / h; in step two, the discharge amount of the gas phase from the exhaust port 33 of the low-pressure separation tank 3 is 20.08 mol / h, and the discharge amount of the hydrogen gas in the gas phase is 0.08 mol / h.

[0064] Example 5:

[0065] The process is basically the same as that of Example 1, except that the parameters in the process are different. In this example, the pressure of the hydrogen gas input into the hydrogen membrane assembly 1 in step one is 700 KPaG, and the consumption of the hydrogen gas in the hydrogen membrane assembly 1 is 10.04 mol / h; in step two, the discharge amount of the gas phase from the exhaust port 33 of the low-pressure separation tank 3 is 10.04 mol / h, and the discharge amount of the hydrogen gas in the gas phase is 0.04 mol / h.

[0066] Example 6:

[0067] The process is basically the same as that of Example 1, except that the parameters in the process are different. In this example, the double bond concentration of the olefin in the solvent to be treated in step one is 10 mol / m 3 , the pressure of the hydrogen gas input into the hydrogen membrane assembly 1 is 700 KPaG, and the consumption of the hydrogen gas in the hydrogen membrane assembly 1 is 20.1 mol / h; in step two, the discharge amount of the gas phase from the exhaust port 33 of the low-pressure separation tank 3 is 20.1 mol / h, and the discharge amount of the hydrogen gas in the gas phase is 0.1 mol / h.

[0068] Comparative Example 1:

[0069] An ethylene / 1-butene copolymer elastomer was prepared by a solution polymerization process using n-hexane as a solvent. After the preparation was completed, the hydrogen membrane assembly 1 was removed, and the hydrogen gas in the hydrogen membrane assembly 1 was replaced with nitrogen gas. Figure 1The device in the method removes residual olefins in the refined solvent, and hydrogen and the olefins in the solvent to be treated are subjected to hydrogenation reaction in the hydrogenation reactor 1' (reaction temperature 200°C, pressure 1.5 MPaG) to generate low-boiling-point alkanes, which are then introduced into the degassing device 2'. Under the driving of inert gas, unreacted hydrogen and the alkanes generated in the reaction are entrained with the solvent and removed through the exhaust system. In the method, the flow rate of the solvent to be treated introduced into the hydrogenation reactor 1' is 2 m 3 / h, the double bond concentration of the olefins in the solvent to be treated is 5 mol / m 3 , the pressure of the hydrogen introduced into the hydrogenation reactor 1' is 1.5 MPaG, the consumption of hydrogen is 41.9 mol / h, the emission of the exhaust gas removed through the exhaust system is 82.1 mol / h, and the emission of hydrogen in the exhaust gas is 31.9 mol / h.

[0070] Comparative Example 2:

[0071] The method is basically the same as that in Comparative Example 1, except that the parameters in the method are different. In the method, the double bond concentration of the olefins in the solvent to be treated is 10 mol / m 3 , the consumption of hydrogen is 52.04 mol / h, the emission of the exhaust gas removed through the exhaust system is 92.7 mol / h, and the emission of hydrogen in the exhaust gas is 32.04 mol / h.

[0072] Comparative Example 3:

[0073] The method is basically the same as that in Comparative Example 1, except that the parameters in the method are different. In the method, the pressure of the hydrogen introduced into the hydrogenation reactor 1' is 2 MPaG, the consumption of hydrogen is 43.2 mol / h, the emission of the exhaust gas removed through the exhaust system is 85.3 mol / h, and the emission of hydrogen in the exhaust gas is 33.2 mol / h.

[0074] Comparative Example 4:

[0075] The method is basically the same as that in Comparative Example 1, except that the parameters in the method are different. In the method, the double bond concentration of the olefins in the solvent to be treated is 10 mol / m 3 , the pressure of the hydrogen introduced into the hydrogenation reactor 1' is 2 MPaG, the consumption of hydrogen is 54.8 mol / h, the emission of the exhaust gas removed through the exhaust system is 95.8 mol / h, and the emission of hydrogen in the exhaust gas is 34.8 mol / h.

[0076] Comparative Example 5:

[0077] The parameters in the method are different from those in Comparative Example 1. In this comparative example, the pressure of hydrogen gas input into the hydrogenation reactor 1' is 3 MPaG, the consumption of hydrogen gas is 50.7 mol / h, the discharge of waste gas removed through the exhaust system is 97.7 mol / h, and the discharge of hydrogen gas in the waste gas is 40.7 mol / h.

[0078] Comparative Example 6:

[0079] The parameters in the method are different from those in Comparative Example 1. In this comparative example, the concentration of double bonds of olefins in the solvent to be treated is 10 mol / m 3 , the pressure of hydrogen gas input into the hydrogenation reactor 1' is 3 MPaG, the consumption of hydrogen gas is 62.1 mol / h, the discharge of waste gas removed through the exhaust system is 112.1 mol / h, and the discharge of hydrogen gas in the waste gas is 42.1 mol / h.

[0080] The parameters and results of Examples 1-6 and Comparative Examples 1-6 above are shown in Table 1 below:

[0081]

[0082]

[0083] Comparing the results of the examples and comparative examples of the present application, it can be seen that the present application uses a hydrogen membrane assembly combined with a hydrogen gas pressurization circulation device to replace the traditional "hydrogenation reactor + degassing condensing equipment" process, and the hydrogen gas flow is controllable, thereby reducing the discharge of hydrogen gas and waste gas in the subsequent unit, having excellent environmental protection performance; the normal pressure and normal temperature hydrogenation operating conditions replace the traditional high temperature and high pressure conditions, avoiding the harsh operating conditions of the hydrogenation reactor, reducing the risk of accidents, and improving the safety of hydrogenation operation.

Claims

1. An apparatus for removing residual olefins from a refined solvent, characterized by The application relates to a hydrogen membrane assembly (1) with a high-pressure side flow channel (11) and a low-pressure side flow channel (12) separated by a permeation membrane (13), wherein the high-pressure side flow channel (11) is provided with a hydrogen inlet pipe (11a) and a hydrogen outlet pipe (11b) for hydrogen gas, the low-pressure side flow channel (12) is provided with a solvent inlet pipe (12a) and a solvent outlet pipe (12b) for solvent, and the permeation membrane (13) is arranged to allow hydrogen gas in the high-pressure side flow channel (11) to pass through only; a catalytic module (2) loaded with a catalyst is arranged in the low-pressure side flow channel (12); a low-pressure separation tank (3) is connected to the solvent outlet pipe (12b) of the hydrogen membrane assembly (1) and is provided with a liquid outlet (32) at the bottom and a gas outlet (33) at the top; the permeation membrane (13) is made of at least one of polyimide, polysulfone, polyvinyltrimethylsilane, polyphenylene ether and polyamide. The hydrogen membrane assembly (1) comprises a shell (10) with a hollow interior forming the high-pressure side flow channel (11); the permeation membrane (13) is arranged in the shell (10) and is in the form of a tubular body, and the interior space of the tubular body is the low-pressure side flow channel (12). The tubular body has a plurality of tubular bodies arranged side by side and spaced apart, and each tubular body is provided with the catalytic module (2). The catalytic module (2) in each tubular body has a plurality of catalytic modules (2) arranged along the length direction of the tubular body. The mixing module (4) arranged in the tubular body for passing the mixed gas and liquid has a plurality of mixing modules (4) arranged alternately with the catalytic module (2) along the length direction of the tubular body.

2. The apparatus of claim 1, wherein: The solvent inlet pipe (12a) and the solvent outlet pipe (12b) are respectively arranged at the two ends of the tubular body, the hydrogen inlet pipe (11a) is arranged at the bottom of the shell (10) and close to the solvent inlet pipe (12a), and the hydrogen outlet pipe (11b) is arranged at the bottom of the shell (10) and close to the solvent outlet pipe (12b).

3. The apparatus of claim 2, wherein: The compressor (5) is connected to the hydrogen inlet pipe (11a) of the hydrogen membrane assembly (1) at the output end, is connected to the hydrogen pipeline (50) for conveying hydrogen gas and the hydrogen outlet pipe (11b) of the hydrogen membrane assembly (1) at the input end, and is provided with a flow control valve (51) and a pressure control valve (52) on the hydrogen pipeline (50).

4. The apparatus of claim 3, wherein: The steps are as follows:

5. The apparatus of claim 4, wherein: The reaction solvent output from the solvent outlet pipe (12b) is separated into gas phase and liquid phase in the low-pressure separation tank (3), the gas phase is discharged from the gas outlet (33) of the low-pressure separation tank (3), the liquid phase is discharged from the liquid outlet (32) of the low-pressure separation tank (3), the pressure in the low-pressure separation tank (3) is P1, the pressure of the hydrogen gas input into the hydrogen membrane assembly (1) is P2, and 1.2 MPaG >= P2 >= 3P1.

6. The apparatus of claim 2, wherein: ​ 7. The apparatus of any one of claims 1-6, wherein: ​ 8. A method for removing residual olefins from a solvent using the apparatus according to any one of claims 1 to 7, characterized in that ​ I. The solvent to be treated is input into the low-pressure side flow channel (12) of the hydrogen membrane assembly (1) through the solvent inlet connector (12a), and hydrogen is input into the high-pressure side flow channel (11) of the hydrogen membrane assembly (1) through the hydrogen inlet connector (11a), at least part of the hydrogen in the high-pressure side flow channel (11) permeates into the low-pressure side flow channel (12) through the permeation membrane (13), and reacts with the olefin in the solvent to be treated under the condition that the temperature is 30-200 ℃, after the reaction, the solvent is output from the solvent outlet connector (12b), and the hydrogen in the high-pressure side flow channel (11) that does not permeate through the permeation membrane (13) is output from the hydrogen outlet connector (11b); wherein the solvent to be treated is an inert solvent, and is at least one of an alkane and a cycloalkane, the olefin in the solvent to be treated is at least one of ethylene, propylene, butene, pentene, hexene and isomers thereof; the double bond concentration of the olefin in the solvent to be treated is 1-200 mol / m 3 3, the ratio between the molar flow of the hydrogen input into the hydrogen membrane assembly (1) and the molar flow of the double bond of the olefin in the solvent to be treated is 1-1.2, and the pressure of the hydrogen input into the hydrogen membrane assembly (1) is 0.3-1.2 MPaG. ​ 9. The method of claim 8, wherein: The solvent to be treated is at least one of cyclohexane, n-heptane, n-hexane, 1-octane; the concentration of double bonds of olefins in the solvent to be treated is 5-100 mol / m 3 ; the ratio between the molar flow of hydrogen fed to the hydrogen membrane module (1) and the molar flow of double bonds of olefins in the solvent to be treated is 1-1.05.

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