Utilization process of heavy component waste liquid after refining and heavy component removal of methyl acetate

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly relates to a utilization process of heavy component waste liquid after refining and heavy component removal of methyl acetate. The method comprises the following steps: carrying out hydrogenation reaction on the heavy component waste liquid after refining and heavy component removal of methyl acetate and hydrogen to generate fusel oil, and then separating the fusel oil through a nanofiltration membrane to obtain the high-purity fusel oil. According to the method, ethyl acetate in the waste liquid is converted into fusel, the obtained fusel is subjected to membrane purification treatment to obtain high-purity fusel, and resource utilization of the waste liquid is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular provides a process for utilizing heavy component waste liquid after refining and de-weighting of methyl acetate. Background Art

[0002] The carbonylation of methyl ether to synthesize methyl acetate, which is then hydrogenated to produce ethanol, is a new process for producing ethanol. When the market conditions for methyl acetate are good, the intermediate product methyl acetate can be sold. However, the content of methyl acetate produced by the carbonylation of dimethyl ether does not meet the requirements of industrial methyl acetate products, and it needs to be distilled and refined again to remove the heavy components. The heavy components are taken out and put into the heavy component tank for sale. Since the vast majority of the heavy components are still methyl acetate, it only contains a small amount of heavy components. If it is sold only as a heavy component, its economic value is greatly reduced. In addition, it is difficult to find a domestic buyer who recycles heavy components containing a large amount of methyl acetate, which increases the difficulty of processing. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a process for utilizing the heavy component waste liquid after the refining and de-weighting of methyl acetate. The present invention converts ethyl acetate in the waste liquid into fusel alcohol, and the obtained fusel alcohol is subjected to membrane purification treatment to obtain high-purity fusel alcohol, thereby realizing the resource utilization of the waste liquid.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: A process for utilizing heavy component waste liquid after refining and de-weighting of methyl acetate comprises the following steps: 1) The heavy component waste liquid after refining and de-weighting of methyl acetate is subjected to hydrogenation reaction with hydrogen to generate fusel oil; 2) The fusel oil is separated by nanofiltration membrane to obtain high-purity fusel oil.

[0005] The main components of the heavy components after methyl acetate refining and weight removal are methyl acetate and a small amount of fusel alcohols. If they are only sold as heavy components, their economic value is greatly reduced, and there are no domestic buyers who can recycle heavy components containing a large amount of methyl acetate. In order to solve the above technical problems, the present invention firstly performs hydrogenation treatment on the heavy components to convert most of the methyl acetate into fusel alcohols, and the remaining small amount of methyl acetate is separated and removed by nanofiltration membrane to obtain high-purity fusel alcohols, thereby improving the economic value of the heavy components.

[0006] Preferably, in step 2), the method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride into n-hexane solution, heating and stirring to dissolve, to obtain trimesoyl chloride solution; b) adding polyethyleneimine to water, stirring to dissolve, then adding bentonite, and dispersing it evenly by ultrasonic vibration to obtain an aqueous solution; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction to obtain a primary nanofiltration membrane; d) placing the nascent nanofiltration membrane in an oven for heat curing to obtain a nanofiltration membrane.

[0007] The nanofiltration membrane of the present invention uses polyethyleneimine and trimesoyl chloride to undergo interfacial polymerization reaction on the surface of a polyethersulfone-based membrane, thereby covering a layer of a polyamide separation layer with a separation effect on the surface of the polyethersulfone, and the surface of the separation layer has a large number of hydrophilic amino groups, which have hydrogen bonding forces with the fusel alcohol molecules, thereby allowing the fusel alcohol to pass through the nanofiltration membrane, intercepting methyl acetate, and realizing the separation of methyl acetate and fusel alcohol. However, the technical problem faced further is that the nanofiltration membrane has a smaller pore size and a lower membrane flux, and its application in industrial production has a lower filtering and separation efficiency, which affects production efficiency. The present invention mixes hydrophilic bentonite into an aqueous phase solution, and the bentonite is doped in the separation layer of the nanofiltration membrane to improve the hydrophilicity of the membrane, thereby improving the water flux of the nanofiltration membrane, and then improving the separation efficiency of the nanofiltration membrane to methyl acetate and fusel alcohol.

[0008] Preferably, in step a), the concentration of the trimesoyl chloride solution is 0.5-2.0 wt %.

[0009] Preferably, in step c), the interfacial polymerization reaction time is 8-10 min.

[0010] Preferably, in step d), the heat curing treatment temperature is 50-70° C., and the heat curing treatment time is 15-30 min.

[0011] Preferably, in step b), the bentonite is subjected to modification treatment, comprising the following steps: Add γ-(2,3-epoxypropoxy)propyltrimethoxysilane to a mixed solution of ethanol and water, stir and hydrolyze to obtain a hydrolyzate; add bentonite to the hydrolyzate, stir and react, and obtain coupling agent modified bentonite through centrifugal separation, washing and drying; add triethylenetetramine to water, stir and dissolve, then add coupling agent modified bentonite, heat and stir to react for 2 hours, and obtain modified bentonite through centrifugal separation, washing and drying.

[0012] In the technical solution of the present invention, the hydrophilicity of the membrane is improved by adding bentonite, thereby improving the water flux of the membrane. However, in the step of preparing the thermal curing cross-linking treatment of the nanofiltration membrane, the bentonite on the surface of the nanofiltration membrane separation layer falls off in large quantities, affecting the improvement of the hydrophilicity of the nanofiltration membrane by the bentonite, which may be because the volume of the bentonite shrinks during the drying process of the nanofiltration membrane, and the bentonite is separated from the nanofiltration membrane separation layer under the action of the shrinkage force. In order to solve the above-mentioned technical problems, the present invention further modifies the bentonite, and through the bridging effect of the epoxy silane coupling agent, triethylenetetramine is grafted on the surface of the bentonite, so that the surface of the bentonite is loaded with amino groups, and in the process of interfacial polymerization reaction between polyethyleneimine and trimesoyl chloride, the amino groups on the surface of the bentonite participate in the interfacial polymerization reaction, that is, the amino groups on the surface of the bentonite react with the acyl chloride groups, thereby bonding the bentonite to the nanofiltration membrane separation layer through chemical bonds, improving the binding force between the bentonite and the nanofiltration membrane separation layer, and avoiding the bentonite from falling off the surface of the nanofiltration membrane separation layer in the thermal curing cross-linking step.

[0013] Preferably, the volume ratio of ethanol to water is 10:1.

[0014] Preferably, the mass ratio of the coupling agent-modified bentonite to triethylenetetramine is 1:0.5-0.8.

[0015] In order to make the bentonite and the nanofiltration membrane separation layer have good bonding force, the bentonite surface must be grafted with a sufficient amount of amino groups, that is, the mass ratio of the coupling agent-modified bentonite and triethylenetetramine is controlled to be less than 1:0.5, so that a sufficient amount of triethylenetetramine is grafted on the bentonite surface. However, during the experiment, it was found that although the bonding force between the bentonite and the nanofiltration membrane was improved, the water pressure resistance of some nanofiltration membranes decreased, resulting in the rupture of the membrane body, which affected the separation of methyl acetate and fusel alcohol. According to research and analysis by the invention team, this is because excessive triethylenetetramine is grafted onto the surface of bentonite, and a large number of amino groups on triethylenetetramine participate in the reaction with trimesoyl chloride, affecting the reaction of polyethyleneimine with trimesoyl chloride, resulting in the inability to fully undergo cross-linking reaction between the amino groups on polyethyleneimine and the acyl chloride groups on trimesoyl chloride. The formed three-dimensional network cross-linking structure has weak strength, which causes the separation layer of the nanofiltration membrane to easily rupture under water pressure. The present invention has found through experiments that when the mass ratio of modified bentonite to triethylenetetramine is less than 1:0.8, the compressive strength of the membrane begins to drop significantly. Therefore, the present invention simultaneously controls the mass ratio of modified bentonite to triethylenetetramine to be greater than 1:0.8.

[0016] Compared with the prior art, the advantages of the present invention are: 1) The heavy components are first subjected to hydrogenation treatment to convert most of the methyl acetate into fusel alcohols, and the remaining small amount of methyl acetate is separated and removed using a nanofiltration membrane to obtain high-purity fusel alcohols, thereby increasing the economic value of the heavy components; 2) By mixing hydrophilic bentonite into the aqueous phase solution, the bentonite is doped into the separation layer of the nanofiltration membrane to improve the hydrophilicity of the membrane, thereby increasing the water flux of the nanofiltration membrane, and further improving the separation efficiency of the nanofiltration membrane for methyl acetate and fusel alcohol; 3) The bentonite is modified by grafting triethylenetetramine onto the surface of the bentonite through the bridging effect of the epoxy silane coupling agent, so that the surface of the bentonite is loaded with amino groups. During the interfacial polymerization reaction between polyethyleneimine and trimesoyl chloride, the amino groups on the surface of the bentonite participate in the interfacial polymerization reaction, that is, the amino groups on the surface of the bentonite react with the acyl chloride groups, thereby bonding the bentonite to the nanofiltration membrane separation layer through chemical bonds, thereby improving the bonding force between the bentonite and the nanofiltration membrane separation layer and preventing the bentonite from falling off the surface of the nanofiltration membrane separation layer during the thermal curing cross-linking step. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] Embodiment 1: A process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate, comprising the following steps: 1) 0.5 g Cu-ZnO nanocatalyst was added to 300 mL of the heavy component waste liquid after methyl acetate refining and de-weighting, and then 2 mol of hydrogen was introduced for hydrogenation reaction for 8 h. The reaction temperature was controlled at 250 ° C and the pressure was controlled at 3 MPa to generate fusel oil with a mass concentration of 92%; 2) The fusel oil is separated by a nanofiltration membrane, the operating pressure is controlled at 1.5 MPa, the temperature is controlled at 30°C, and the filtrate is collected to obtain high-purity fusel oil with a fusel oil mass concentration of 99.3%.

[0019] The method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride to n-hexane solution, heating to 50°C and stirring to dissolve, to prepare a trimesoyl chloride solution with a concentration of 1.5wt%; b) adding polyethyleneimine to water at a mass volume ratio of 1 g / 100 mL, stirring to dissolve, then adding bentonite, the mass ratio of polyethyleneimine to bentonite being 1:0.2, and uniformly dispersing by ultrasonic oscillation to obtain an aqueous solution; Bentonite is modified by the following steps: 1 g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added to a mixed solution of 100 mL of ethanol and 10 mL of water, and the mixture was stirred for hydrolysis to obtain a hydrolyzate; 2 g of bentonite was added to the hydrolyzate, and the mixture was stirred for reaction. After centrifugal separation, washing and drying, a coupling agent-modified bentonite was obtained; 0.5 g of triethylenetetramine was added to 200 mL of water, and the mixture was stirred for dissolution. Then, the coupling agent-modified bentonite was added, and the mass ratio of the coupling agent-modified bentonite to the triethylenetetramine was 1:0.7. The mixture was heated and stirred for reaction for 2 h, and the modified bentonite was obtained after centrifugal separation, washing and drying; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution for 10 seconds, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction for 9 minutes to obtain a primary nanofiltration membrane; d) placing the nascent nanofiltration membrane in an oven for heat curing treatment at a temperature of 60° C. for 20 min to obtain a nanofiltration membrane.

[0020] Embodiment 2: A process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate, comprising the following steps: 1) 0.5 g Cu-ZnO nanocatalyst was added to 300 mL of the heavy component waste liquid after methyl acetate refining and de-weighting, and then 2 mol of hydrogen was introduced for hydrogenation reaction for 8 h. The reaction temperature was controlled at 250 ° C and the pressure was controlled at 3 MPa to generate fusel oil with a mass concentration of 92%; 2) The fusel oil is separated by a nanofiltration membrane, the operating pressure is controlled at 1.5 MPa, the temperature is controlled at 30°C, and the filtrate is collected to obtain high-purity fusel oil with a fusel oil mass concentration of 99.5%.

[0021] The method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride into n-hexane solution, heating to 50°C and stirring to dissolve, to prepare a trimesoyl chloride solution with a concentration of 1.0 wt%; b) adding polyethyleneimine to water at a mass volume ratio of 1 g / 100 mL, stirring to dissolve, then adding bentonite, the mass ratio of polyethyleneimine to bentonite being 1:0.2, and uniformly dispersing by ultrasonic oscillation to obtain an aqueous solution; Bentonite is modified by the following steps: 1 g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added to a mixed solution of 100 mL of ethanol and 10 mL of water, and the mixture was stirred for hydrolysis to obtain a hydrolyzate; 2 g of bentonite was added to the hydrolyzate, and the mixture was stirred for reaction. After centrifugal separation, washing and drying, a coupling agent-modified bentonite was obtained; 0.5 g of triethylenetetramine was added to 200 mL of water, and the mixture was stirred for dissolution. Then, the coupling agent-modified bentonite was added, and the mass ratio of the coupling agent-modified bentonite to the triethylenetetramine was 1:0.6. The mixture was heated and stirred for reaction for 2 h, and the modified bentonite was obtained after centrifugal separation, washing and drying; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution for 10 seconds, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction for 9 minutes to obtain a primary nanofiltration membrane; d) placing the nascent nanofiltration membrane in an oven for heat curing treatment at a temperature of 60° C. for 20 min to obtain a nanofiltration membrane.

[0022] Embodiment 3: A process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate, comprising the following steps: 1) 0.5 g Cu-ZnO nanocatalyst was added to 300 mL of the heavy component waste liquid after methyl acetate refining and de-weighting, and then 2 mol of hydrogen was introduced for hydrogenation reaction for 8 h. The reaction temperature was controlled at 250 ° C and the pressure was controlled at 3 MPa to generate fusel oil with a mass concentration of 92%; 2) The fusel oil is separated by a nanofiltration membrane, the operating pressure is controlled at 1.5 MPa, the temperature is controlled at 30°C, and the filtrate is collected to obtain high-purity fusel oil with a fusel oil mass concentration of 99.2%.

[0023] The method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride into n-hexane solution, heating to 50°C and stirring to dissolve, to prepare a trimesoyl chloride solution with a concentration of 1.0 wt%; b) adding polyethyleneimine to water at a mass volume ratio of 1 g / 100 mL, stirring to dissolve, then adding bentonite, the mass ratio of polyethyleneimine to bentonite being 1:0.2, and uniformly dispersing by ultrasonic oscillation to obtain an aqueous solution; Bentonite is modified by the following steps: 1 g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added to a mixed solution of 100 mL of ethanol and 10 mL of water, and the mixture was stirred for hydrolysis to obtain a hydrolyzate; 2 g of bentonite was added to the hydrolyzate, and the mixture was stirred for reaction. After centrifugal separation, washing and drying, a coupling agent-modified bentonite was obtained; 0.5 g of triethylenetetramine was added to 200 mL of water, and the mixture was stirred for dissolution. Then, the coupling agent-modified bentonite was added, and the mass ratio of the coupling agent-modified bentonite to the triethylenetetramine was 1:0.65. The mixture was heated and stirred for reaction for 2 h, and the modified bentonite was obtained after centrifugal separation, washing and drying; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution for 10 seconds, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction for 9 minutes to obtain a primary nanofiltration membrane; d) placing the nascent nanofiltration membrane in an oven for heat curing treatment at a temperature of 60° C. for 20 min to obtain a nanofiltration membrane.

[0024] Embodiment 4: A process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate, comprising the following steps: 1) 0.5 g Cu-ZnO nanocatalyst was added to 300 mL of the heavy component waste liquid after methyl acetate refining and de-weighting, and then 2 mol of hydrogen was introduced for hydrogenation reaction for 8 h. The reaction temperature was controlled at 250 ° C and the pressure was controlled at 3 MPa to generate fusel oil with a mass concentration of 92%; 2) The fusel oil is separated by a nanofiltration membrane, the operating pressure is controlled at 1.5 MPa, the temperature is controlled at 30°C, and the filtrate is collected to obtain high-purity fusel oil with a fusel oil mass concentration of 99.7%.

[0025] The method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride to a n-hexane solution, heating to 50°C and stirring to dissolve, to prepare a trimesoyl chloride solution with a concentration of 2.0 wt%; b) adding polyethyleneimine to water at a mass volume ratio of 1 g / 100 mL, stirring to dissolve, then adding bentonite, the mass ratio of polyethyleneimine to bentonite being 1:0.2, and uniformly dispersing by ultrasonic oscillation to obtain an aqueous solution; Bentonite is modified by the following steps: 1 g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added to a mixed solution of 100 mL of ethanol and 10 mL of water, and the mixture was stirred for hydrolysis to obtain a hydrolyzate; 2 g of bentonite was added to the hydrolyzate, and the mixture was stirred for reaction. After centrifugal separation, washing and drying, a coupling agent-modified bentonite was obtained; 0.5 g of triethylenetetramine was added to 200 mL of water, and the mixture was stirred for dissolution. Then, the coupling agent-modified bentonite was added, and the mass ratio of the coupling agent-modified bentonite to the triethylenetetramine was 1:0.8. The mixture was heated and stirred for reaction for 2 h, and the modified bentonite was obtained after centrifugal separation, washing and drying; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution for 10 seconds, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction for 10 minutes to obtain a primary nanofiltration membrane; d) placing the nascent nanofiltration membrane in an oven for heat curing treatment at a temperature of 70° C. for 15 min to obtain a nanofiltration membrane.

[0026] Embodiment 5: A process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate, comprising the following steps: 1) 0.5 g Cu-ZnO nanocatalyst was added to 300 mL of the heavy component waste liquid after methyl acetate refining and de-weighting, and then 2 mol of hydrogen was introduced for hydrogenation reaction for 8 h. The reaction temperature was controlled at 250 ° C and the pressure was controlled at 3 MPa to generate fusel oil with a mass concentration of 92%; 2) The fusel oil is separated by a nanofiltration membrane, the operating pressure is controlled at 1.5 MPa, the temperature is controlled at 30°C, and the filtrate is collected to obtain high-purity fusel oil with a fusel oil mass concentration of 99.4%.

[0027] The method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride into n-hexane solution, heating to 50°C and stirring to dissolve, to prepare a trimesoyl chloride solution with a concentration of 0.5wt%; b) adding polyethyleneimine to water at a mass volume ratio of 1 g / 100 mL, stirring to dissolve, then adding bentonite, the mass ratio of polyethyleneimine to bentonite being 1:0.2, and uniformly dispersing by ultrasonic oscillation to obtain an aqueous solution; Bentonite is modified by the following steps: 1 g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added to a mixed solution of 100 mL of ethanol and 10 mL of water, and the mixture was stirred for hydrolysis to obtain a hydrolyzate; 2 g of bentonite was added to the hydrolyzate, and the mixture was stirred for reaction. After centrifugal separation, washing and drying, a coupling agent-modified bentonite was obtained; 0.5 g of triethylenetetramine was added to 200 mL of water, and the mixture was stirred for dissolution. Then, the coupling agent-modified bentonite was added, and the mass ratio of the coupling agent-modified bentonite to the triethylenetetramine was 1:0.5. The mixture was heated and stirred for reaction for 2 h, and the modified bentonite was obtained after centrifugal separation, washing and drying; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution for 10 seconds, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction for 8 minutes to obtain a primary nanofiltration membrane; d) placing the primary eco-nanofiltration membrane in an oven for heat curing treatment at a temperature of 50° C. for 30 min to obtain a nanofiltration membrane.

[0028] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that: No bentonite was added to the aqueous solution during the preparation of the nanofiltration membrane. The remaining steps are the same as those in Example 1.

[0029] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is: Bentonite is not modified. The remaining steps are the same as those in Example 1.

[0030] Comparative Example 3 The difference between Comparative Example 3 and Example 5 is that: During the bentonite modification process, The mass ratio of coupling agent modified bentonite to triethylenetetramine is 1:0.4. The remaining steps are the same as those in Example 5.

[0031] Comparative Example 4 The difference between Comparative Example 4 and Example 4 is that: During the bentonite modification process, The mass ratio of coupling agent modified bentonite to triethylenetetramine is 1:0.9. The remaining steps are the same as those in Example 4.

[0032] Comparative Example 5 The difference between Comparative Example 5 and Example 4 is that: During the bentonite modification process, The mass ratio of coupling agent modified bentonite to triethylenetetramine is 1:1. The remaining steps are the same as those in Example 4.

[0033] Performance Testing The cross-flow experimental device was used to test the water flux of the membrane and evaluate the hydrophilicity of the nanofiltration membrane. The test conditions were: temperature 30°C, test pressure 1.5MPa. The nanofiltration membrane was operated at a high pressure of 4MPa for 24h, and then the nanofiltration membrane was tested for its retention effect on methyl acetate in a 5% mass concentration methyl acetate solution. The higher the methyl acetate retention rate, the better the separation effect of methyl acetate and fusel alcohols.

[0034]

[0035] The embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate, characterized in that: The following steps are involved: 1) The heavy component waste liquid after refining and de-weighting of methyl acetate is subjected to hydrogenation reaction with hydrogen to generate fusel oil; 2) The fusel oil is separated by nanofiltration membrane to obtain high-purity fusel oil.

2. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 1, characterized in that: In the step 2), the method for preparing the nanofiltration membrane comprises the following steps: a) adding trimesoyl chloride into n-hexane solution, heating and stirring to dissolve, to obtain trimesoyl chloride solution; b) adding polyethyleneimine to water, stirring to dissolve, then adding bentonite, and dispersing it evenly by ultrasonic vibration to obtain an aqueous solution; c) immersing the polyethersulfone-based membrane in a trimesoyl chloride solution, taking it out and immersing it in an aqueous solution to perform an interfacial polymerization reaction to obtain a primary nanofiltration membrane; d) placing the nascent nanofiltration membrane in an oven for heat curing to obtain a nanofiltration membrane.

3. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 2, characterized in that: In the step a), the concentration of the trimesoyl chloride solution is 0.5-2.0 wt %.

4. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 2, characterized in that: In the step c), the interfacial polymerization reaction time is 8-10 minutes.

5. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 2, characterized in that: In the step d), the heat curing treatment temperature is 50-70° C., and the heat curing treatment time is 15-30 minutes.

6. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 2, characterized in that: In the step b), the bentonite is subjected to a modification treatment, comprising the following steps: Add γ-(2,3-epoxypropoxy)propyltrimethoxysilane to a mixed solution of ethanol and water, stir and hydrolyze to obtain a hydrolyzate; add bentonite to the hydrolyzate, stir and react, and obtain coupling agent modified bentonite through centrifugal separation, washing and drying; add triethylenetetramine to water, stir and dissolve, then add coupling agent modified bentonite, heat and stir to react for 2 hours, and obtain modified bentonite through centrifugal separation, washing and drying.

7. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 6, characterized in that: The volume ratio of ethanol to water is 10:

1.

8. The process for utilizing the heavy component waste liquid after refining and de-weighting of methyl acetate according to claim 6, characterized in that: The mass ratio of the coupling agent modified bentonite to triethylenetetramine is 1:0.5-0.8.

Images