Production method of bio-based methyl acetate
By combining biomass thermal fractionation and biochar gasification, the problems of high cost and low resource utilization in the production of bio-based methyl acetate have been solved, achieving an efficient and stable green production process that reduces energy consumption and carbon emissions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGTZE DELTA REGION INST OF TSINGHUA UNIV ZHEJIANG
- Filing Date
- 2026-03-12
- Publication Date
- 2026-04-14
AI Technical Summary
Existing bio-based methyl acetate production methods suffer from high costs, unstable processes, and low resource utilization.
The process employs a combined approach of biomass thermal fractionation and biochar gasification. Thermal fractionation enables the deoxygenation and initial separation of volatiles from biomass, while the gasification unit generates hydrogen-rich biogas to supply the overall thermal energy needs. Furthermore, precise carbon monoxide separation and a material recycling system optimize the synthesis and carbonylation reactions, resulting in a highly efficient and green production process.
It significantly improves the continuity and stability of the production process, reduces energy consumption and production costs, and achieves efficient utilization of biomass resources, which is in line with green chemical industry and "dual carbon" goals.
Smart Images
Figure CN121850865A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of biomass energy chemical technology, specifically to a method for producing bio-based methyl acetate. Background Technology
[0002] Methyl acetate, as an important low-carbon oxygen-containing organic chemical, possesses excellent properties such as low toxicity, high solubility, and adaptability to volatility. It is widely used in coating solvents, adhesives, pharmaceutical intermediate synthesis, and fragrance preparation. It also holds significant potential as a green gasoline additive and a solvent for lithium-ion battery electrolytes. Currently, global industrial production of methyl acetate still relies on fossil resources such as coal and natural gas as core raw materials. These resources are non-renewable and generate substantial carbon emissions, contradicting the "dual-carbon" development philosophy, thus necessitating urgent industry transformation and upgrading.
[0003] However, existing technologies for preparing bio-based methyl acetate face numerous bottlenecks. On one hand, the traditional route requires microbial fermentation of grains to produce acetic acid. This method is not only inefficient and complex in its separation process, but also carries the risk of competing with humans for grain, impacting food security. On the other hand, the route of directly gasifying biomass to produce methanol and then further synthesizing methyl acetate faces severe challenges in practical applications: biomass contains approximately 45% oxygen, resulting in low utilization and carbon conversion rates during direct biomass gasification. This process also generates large amounts of tar and moisture, easily causing pipeline blockages and equipment corrosion, leading to unstable processes and frequent malfunctions. Simultaneously, the high moisture and low density of biomass raw materials result in extremely high pretreatment energy consumption, significantly increasing the overall process cost. Furthermore, in existing technologies, to meet the hydrogen-to-carbon ratio required for methanol synthesis, complex water-gas shift conversion adjustments are often necessary. This process not only increases equipment investment and energy consumption but also results in carbon loss, reducing the utilization rate of biomass resources.
[0004] In summary, the industry urgently needs a green preparation method for bio-based methyl acetate that can avoid the drawbacks of direct biomass gasification, achieve efficient utilization of biomass components in stages, and has stable and controllable costs. Summary of the Invention
[0005] The purpose of this invention is to provide a method for producing bio-based methyl acetate, thereby solving the following technical problems:
[0006] Existing methods for producing methyl acetate suffer from high costs, unstable processes, and low resource utilization.
[0007] The objective of this invention can be achieved through the following technical solutions:
[0008] A method for producing bio-based methyl acetate includes at least the following steps:
[0009] The pretreated non-grain biomass raw materials are added to the thermal fractionation unit, and after pyrolysis and fractionation, biochar and biocombustible gas are obtained.
[0010] The biochar is added to the gasification unit, and after the gasification reaction, crude syngas is obtained.
[0011] The crude syngas is added to a separation unit to separate a first part of carbon monoxide and a second part to obtain syngas.
[0012] The syngas is added to the synthesis unit, and after the synthesis reaction, it is purified to obtain methanol.
[0013] The methanol is added to the dehydration unit, and after the dehydration reaction, dimethyl ether is obtained;
[0014] The first portion of carbon monoxide and the dimethyl ether are added to the carbonyl insertion unit, and after the carbonyl insertion reaction, the mixture is purified to obtain methyl acetate.
[0015] The non-grain biomass raw materials include at least straw, agricultural and forestry waste, fermentation residue or kitchen waste, the moisture content of the pretreated non-grain biomass raw materials is ≤20%, and the pyrolysis fractionation pressure is atmospheric pressure and the temperature is 400-700℃.
[0016] As a further aspect of the present invention: the biocombustible gas contains at least carbon monoxide, hydrogen and methane, the calorific value of the biocombustible gas is 2800-4000 Kcal / Nm3, and the calorific value of the biochar is 4500-6500 Kcal / Kg.
[0017] As a further aspect of the present invention: the temperature of the gasification reaction is 800-1200℃, and the gasification medium is a mixture of water vapor and oxygen.
[0018] As a further aspect of the present invention: the volume ratio of hydrogen to carbon monoxide in the synthesis gas is 2:1, the purity of the first portion of carbon monoxide is ≥98%, and the volume ratio of the first portion of carbon monoxide to the carbon monoxide in the synthesis gas is 1:2.
[0019] As a further aspect of the present invention: the temperature of the synthesis reaction is 220-280℃ and the pressure is 5-10MPa.
[0020] As a further aspect of the present invention: the purity of the methanol is ≥99.5%, the temperature of the dehydration reaction is 130-170℃, the pressure is 0.5-2MPa, the catalyst is a solid acid catalyst, and the purity of the dimethyl ether is ≥99%.
[0021] As a further aspect of the present invention: the molar ratio of the first portion of carbon monoxide to the dimethyl ether is 1:1, the temperature of the carbonyl insertion reaction is 240-300℃, the pressure is 3-8MPa, the catalyst is a molecular sieve catalyst, and the purity of the methyl acetate is ≥99.8%.
[0022] As a further aspect of the present invention, the production method further includes:
[0023] The second part of carbon monoxide and biogas are added to the energy utilization unit to obtain energy to meet the energy requirements of the production method.
[0024] As a further aspect of the present invention: the carbonyl insertion unit is further provided with a circulation system, which separates the mixed products obtained from the carbonyl insertion reaction to obtain crude methyl acetate, unreacted carbon monoxide and unreacted dimethyl ether;
[0025] In this process, the unreacted carbon monoxide and the unreacted dimethyl ether are returned to the carbonylation unit to participate in the carbonylation reaction again, and the crude methyl acetate is purified.
[0026] The beneficial effects of this invention are:
[0027] This invention provides a method for producing bio-based methyl acetate, employing a combined approach of biomass thermal fractionation and biochar gasification. The thermal fractionation process achieves deoxygenation and preliminary separation of volatiles from the biomass, fundamentally solving the persistent problems of tar clogging pipes and corroding equipment in traditional direct gasification processes, significantly improving the continuity and stability of the production process. Simultaneously, the biochar produced by thermal fractionation has a regular structure and uniform properties, requiring no stringent drying pretreatment before direct gasification, reducing pretreatment requirements and energy consumption. Furthermore, the hydrogen-rich biogas produced during thermal fractionation is directly recovered to supply the heat energy needs of the entire process, effectively replacing purchased fossil fuels. This achieves a highly efficient coupling of energy and material utilization from biomass resources, significantly reducing external energy consumption and production costs.
[0028] The separation unit of this invention can separate a portion of carbon monoxide. Through precise carbon monoxide separation, high-purity carbon monoxide feedstock required for methanol synthesis and carbonylation reactions can be obtained in one step, avoiding complex water-gas shift adjustment and the resulting carbon loss and equipment investment. Simultaneously, the carbonylation unit is equipped with a material recycling system to recover and reuse unreacted carbon monoxide and dimethyl ether, greatly improving feedstock conversion rate, reducing resource waste, and forming a green production process with high atom economy.
[0029] This invention uses renewable non-grain biomass such as straw and agricultural and forestry waste as raw materials, completely eliminating dependence on fossil resources and reducing carbon emissions from the source. The entire process is free of highly corrosive and toxic additives such as iodine, making it environmentally friendly and in line with the development direction of green chemical industry and the "dual carbon" goal. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 This is a process flow diagram of a method for producing bio-based methyl acetate in one embodiment. Detailed Implementation
[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0033] Please see Figure 1 As shown, this invention provides a method for producing bio-based methyl acetate, comprising at least a thermal fractionation unit, a gasification unit, a separation unit, a synthesis unit, a dehydration unit, and a carbonylation unit. The specific steps of the method for producing bio-based methyl acetate are as follows:
[0034] Please see Figure 1As shown, non-grain biomass raw materials undergo pretreatment. In one embodiment of the invention, the non-grain biomass raw materials include at least straw, agricultural and forestry waste, fermentation residue, or kitchen waste. Pretreatment includes, for example, at least impurity removal, crushing, and dehydration, with crushing to a particle size of less than 50 mm and dehydration to a moisture content of less than 20%. After pretreatment, the raw materials are sent to a thermal fractionation unit for pyrolysis fractionation. After deoxygenation and volatile matter removal, biochar and biocombustible gas are generated. In one embodiment of the invention, the pressure of pyrolysis fractionation is, for example, atmospheric pressure (0.1 MPa), and the temperature is, for example, 400-600°C. The biocombustible gas is directly used to supply the energy demand of the entire process. If the supply of biocombustible gas is insufficient, energy is supplemented from outside the boundary to ensure stable operation of the process. The biochar is then transported to the next production unit. In one embodiment of the present invention, the main components of the biogas are, for example, carbon monoxide, hydrogen, and methane, and the content of carbon monoxide (by volume) is, for example, 20-30%, the content of hydrogen (by volume) is, for example, 5-20%, and the content of methane (by volume) is, for example, 5-15%. The calorific value of the biogas is, for example, 2800-4000 Kcal / Nm³. 3 The calorific value of biochar is, for example, 4500-6500 kcal / kg.
[0035] Please see Figure 1 As shown, the biochar obtained from the thermal fractionation unit is directly fed into the gasification unit for gasification to obtain crude syngas. In one embodiment of the invention, the gasification temperature is, for example, 800-1200°C, the gasification medium is, for example, a mixture of oxygen and water vapor, and the main components of the generated crude syngas are carbon monoxide, hydrogen, and a small amount of carbon dioxide. In one embodiment of the invention, the carbon monoxide content (by volume) is, for example, 30-40%, the hydrogen content (by volume) is, for example, 30-40%, and the methane content (by volume) is, for example, 10-20%.
[0036] Please see Figure 1 As shown, the crude syngas is fed into a separation unit to separate a first portion of carbon monoxide and a second portion of carbon monoxide, yielding syngas with a hydrogen to carbon monoxide volume ratio of 2:1. In one embodiment of the invention, for example, a pressure swing adsorption (PSA) process is used for separation and purification. Trace impurities and carbon dioxide are first removed, and then two portions of carbon monoxide are precisely separated. The first portion of carbon monoxide has a volume ratio of 1:2 to the carbon monoxide in the syngas, with a purity ≥98%, and is used for the subsequent dimethyl ether carbonylation reaction. The second portion of carbon monoxide is mixed with biogas and fed into an energy utilization unit to supply the energy requirements of the process.
[0037] Please see Figure 1As shown, the synthesis gas obtained from the separation unit is fed into the synthesis unit for a synthesis reaction to obtain crude methanol. The crude methanol is then refined to obtain methanol with a purity of at least 99.5%. In one embodiment of the invention, the synthesis reaction is carried out, for example, in a synthesis tower, and the temperature of the synthesis reaction is, for example, 220-280°C, the pressure is, for example, 5-10 MPa, and the catalyst is, for example, a copper-based catalyst.
[0038] Please see Figure 1 As shown, methanol synthesized and purified in the synthesis unit is fed into the dehydration unit for a dehydration reaction to prepare dimethyl ether. In one embodiment of the invention, the dehydration reaction is carried out, for example, in a reactive distillation column reactor, at a temperature of, for example, 130-170°C, a pressure of, for example, 0.5-2 MPa, and a catalyst of, for example, a solid acid catalyst. The dimethyl ether produced is collected, for example, from the top of the column, and the purity of the obtained dimethyl ether is not less than 99%.
[0039] Please see Figure 1 As shown, dimethyl ether obtained from the dehydration unit and the first portion of carbon monoxide separated from the separation unit are fed into the carbonylation unit for a carbonylation reaction to obtain crude methyl acetate. The crude methyl acetate is then purified to obtain industrial-grade methyl acetate with a purity of at least 99.8%. In one embodiment of the invention, the molar ratio of the first portion of carbon monoxide to dimethyl ether added to the carbonylation unit is 1:1, the temperature of the carbonylation reaction is, for example, 240-300°C, the pressure is, for example, 3-8 MPa, and the catalyst is, for example, an eight-membered ring molecular sieve.
[0040] Please see Figure 1 As shown, the present invention provides a method for producing bio-based methyl acetate, which includes, for example, an energy utilization unit. In one embodiment of the present invention, the biocombustible gas obtained through the thermal fractionation unit supplies the energy requirements of the entire process through the energy utilization unit. The carbonylation unit provided by the present invention is also equipped with a circulation system. The mixed product containing methyl acetate obtained through the carbonylation unit is separated into unreacted carbon monoxide and dimethyl ether through the circulation system, and then returned to the feed end of the carbonylation unit through the circulation pipeline to participate in the reaction again.
[0041] This invention provides a method for producing bio-based methyl acetate. Material transportation in each step is achieved through pipelines and pumps, forming a continuous production process. The specific operating parameters of each unit can be adapted and adjusted according to the type of raw materials and the purity requirements of the product.
[0042] Example 1: The production method of bio-based methyl acetate includes the following steps:
[0043] like Figure 1As shown, corn stalks were selected as the non-grain biomass raw material with a moisture content of 20%. After impurity removal, crushing to a particle size of 30 mm, and dehydration to a moisture content of 8%, the material was fed into a thermal fractionation unit. Pyrolysis and fractionation were performed under atmospheric pressure and 500℃ to obtain biochar and biocombustible gas. The main components (by volume) of the biocombustible gas were 25% carbon monoxide, 18% hydrogen, and 12% methane, with a calorific value of approximately 3200 kcal / Nm³. 3 Biochar is fed into the energy utilization unit to directly supply the heat energy needs of all units in the process. Biochar has a calorific value of about 4800 Kcal / Kg and is fed into the gasification unit.
[0044] like Figure 1 As shown, the biochar obtained from the thermal fractionation unit is fed into the gasification unit. The gasification reaction temperature is controlled at 900℃ and the gasification pressure is 0.2MPa. The gasification reaction is carried out using oxygen-water vapor (volume ratio 1:2) as the gasification medium to obtain crude syngas. The main components (by volume) of the crude syngas include 38% carbon monoxide, 35% hydrogen, and 12% carbon dioxide.
[0045] like Figure 1 As shown, the crude syngas is fed into a separation unit to remove carbon dioxide and trace impurities from the mixed gas. Then, a first part of carbon monoxide and a second part of carbon monoxide are separated, with the remainder being syngas. The volume ratio of hydrogen to carbon monoxide in the obtained syngas is 2:1, and the volume ratio of the first part of carbon monoxide to the carbon monoxide in the syngas is 1:2, with a purity of 98.5%. This is used for the subsequent dimethyl ether carbonylation reaction. The second part of carbon monoxide is mixed with biogas and fed into an energy utilization unit for green energy supply.
[0046] like Figure 1 As shown, the synthesis gas obtained from the separation unit is fed into the synthesis unit, and a Cu-Zn-Al-O copper-based catalyst is used to carry out the synthesis reaction at a controlled temperature of 260℃ and a pressure of 6MPa to synthesize crude methanol. The synthesized crude methanol is then refined to obtain methanol with a purity of 99.9%.
[0047] like Figure 1 As shown, the refined methanol was fed into a dehydration unit, where a molecular sieve solid acid was used as a catalyst. The reaction temperature was controlled at 150°C and the pressure at 1.0 MPa to carry out the dehydration reaction, and dimethyl ether with a purity of 99.2% was obtained.
[0048] like Figure 1 As shown, the dimethyl ether obtained from the dehydration unit and the first portion of carbon monoxide obtained from the separation unit are mixed at a molar ratio of carbon monoxide to dimethyl ether of 1:1 and fed into the carbonyl insertion unit. A mordenite molecular sieve catalyst is used, and the reaction temperature is controlled at 270℃, the pressure at 5MPa, and the feed gas space velocity at 3000h⁻¹. -1A carbonylation reaction is carried out to obtain a mixed product containing methyl acetate. The mixed product is then separated into gas and liquid phases through a circulation system to obtain crude methyl acetate and unreacted carbon monoxide and dimethyl ether. The obtained crude methyl acetate is purified by multi-tower distillation to obtain industrial-grade methyl acetate with a purity of 99.9%. The unreacted carbon monoxide and dimethyl ether are returned to the feed end of the carbonylation unit through a circulation pipeline to participate in the reaction again, achieving a raw material recycling rate of 92%.
[0049] In this embodiment, the preparation of 1 ton of methyl acetate requires 4.4 tons of corn stalks with a moisture content of 20%. The price of this specification of corn stalks is 350 yuan per ton. Based on this, the raw material cost of 1 ton of methyl acetate is calculated to be 1540 yuan. At the same time, the operating and capital costs of 1 ton of methyl acetate in the preparation process are 2500 yuan. Taking into account the raw material cost and the operating and capital costs, the final total cost of 1 ton of methyl acetate is 4040 yuan.
[0050] Example 2: The production method of bio-based methyl acetate includes the following steps:
[0051] like Figure 1 As shown, kitchen waste fermentation residue was selected as a non-grain biomass raw material. After impurity removal, crushing to a particle size of 30mm, and dehydration to a moisture content of 9%, it was sent to a thermal fractionation unit for pyrolysis and fractionation under normal pressure and 450℃ to obtain biochar and biocombustible gas. The main components (by volume) of the biocombustible gas were 22% carbon monoxide, 15% hydrogen, and 10% methane, with a calorific value of approximately 2900 kcal / Nm³. 3 Biochar is fed into the energy utilization unit to directly supply the heat energy needs of all units in the process. Biochar has a calorific value of about 4600 Kcal / Kg and is fed into the gasification unit.
[0052] like Figure 1 As shown, the biochar obtained from the thermal fractionation unit is fed into the gasification unit. The gasification reaction temperature is controlled at 850°C and the gasification pressure is 0.2 MPa. The gasification reaction is carried out using oxygen-water vapor (volume ratio 1:1.8) as the gasification medium to obtain crude syngas. The main components (by volume) of the crude syngas include 35% carbon monoxide, 32% hydrogen, and 14% carbon dioxide.
[0053] like Figure 1 As shown, the crude syngas is fed into a separation unit to remove carbon dioxide and trace impurities from the mixed gas. Then, a first portion of carbon monoxide and a second portion of carbon monoxide are separated to obtain syngas with a hydrogen to carbon monoxide volume ratio of 2:1. The first portion of carbon monoxide has a volume ratio of 1:2 to the total carbon monoxide in the syngas, and its purity reaches 98.2%. This first portion of carbon monoxide is used for the dimethyl ether carbonylation reaction. The second portion of carbon monoxide is mixed with biogas and fed into an energy utilization unit for green energy supply.
[0054] like Figure 1 As shown, the synthesis gas obtained from the separation unit is fed into the synthesis unit, and a Cu-Zn-Al-O copper-based catalyst is used to carry out the synthesis reaction at a controlled temperature of 250℃ and a pressure of 5MPa to synthesize crude methanol. The synthesized crude methanol is then refined to obtain methanol with a purity of 99.8%.
[0055] like Figure 1 As shown, the refined methanol was fed into a dehydration unit, where a molecular sieve solid acid was used as a catalyst. The reaction temperature was controlled at 140°C and the pressure at 0.8 MPa to carry out the dehydration reaction, and dimethyl ether with a purity of 99.1% was obtained.
[0056] like Figure 1 As shown, the dimethyl ether obtained from the dehydration unit and the first portion of carbon monoxide obtained from the separation unit are mixed at a molar ratio of carbon monoxide to dimethyl ether of 1:1 and fed into the carbonyl insertion unit. An eight-membered ring molecular sieve catalyst is used, and the reaction temperature is controlled at 260℃, the pressure at 4MPa, and the feed gas space velocity at 3000h. -1 A carbonylation reaction is carried out to obtain a mixed product containing methyl acetate. The mixed product is then separated into gas and liquid phases through a circulation system to obtain crude methyl acetate and unreacted carbon monoxide and dimethyl ether. The obtained crude methyl acetate is purified by multi-tower distillation to obtain industrial-grade methyl acetate with a purity of 99.85%. The unreacted carbon monoxide and dimethyl ether are returned to the feed end of the carbonylation unit through a circulation pipeline to participate in the reaction again, achieving a raw material recycling rate of 90%.
[0057] As demonstrated by the above embodiments, the bio-based methyl acetate production method provided by this invention overcomes the shortcomings of existing methyl acetate production methods, such as reliance on fossil resources, tar blockage, ash slagging, high pretreatment energy consumption, and low raw material utilization in direct biomass gasification processes. By employing the core processes of biomass thermal fractionation and biochar gasification, the technical bottlenecks of direct biomass gasification are avoided at the source. Simultaneously, the cascade recovery and utilization of biocombustible gas is achieved, and material recycling design reduces raw material loss, thus achieving the goal of continuous and stable, energy-controlled, and environmentally friendly methyl acetate production.
[0058] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0059] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.
Claims
1. A method for producing bio-based methyl acetate, characterized in that, At least the following steps are included: The pretreated non-grain biomass raw materials are added to the thermal fractionation unit, and after pyrolysis and fractionation, biochar and biocombustible gas are obtained. The biochar is added to the gasification unit, and after the gasification reaction, crude syngas is obtained. The crude syngas is added to a separation unit to separate a first part of carbon monoxide and a second part of carbon monoxide, thereby obtaining syngas. The syngas is added to the synthesis unit, and after the synthesis reaction, it is purified to obtain methanol. The methanol is added to the dehydration unit, and after the dehydration reaction, dimethyl ether is obtained; The first portion of carbon monoxide and the dimethyl ether are added to the carbonyl insertion unit, and after the carbonyl insertion reaction, the mixture is purified to obtain methyl acetate. The non-grain biomass raw materials include at least straw, agricultural and forestry waste, fermentation residue or kitchen waste, the moisture content of the pretreated non-grain biomass raw materials is ≤20%, and the pyrolysis fractionation pressure is atmospheric pressure and the temperature is 400-700℃.
2. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The biogas contains at least carbon monoxide, hydrogen, and methane, and the calorific value of the biogas is 2800-4000 kcal / Nm³. 3 The biochar has a calorific value of 4500-6500 Kcal / Kg.
3. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The gasification reaction is carried out at a temperature of 800-1200℃, and the gasification medium is a mixture of water vapor and oxygen.
4. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The volume ratio of hydrogen to carbon monoxide in the synthesis gas is 2:1, the purity of the first portion of carbon monoxide is ≥98%, and the volume ratio of the first portion of carbon monoxide to the carbon monoxide in the synthesis gas is 1:
2.
5. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The synthesis reaction is carried out at a temperature of 220-280℃ and a pressure of 5-10MPa.
6. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The methanol has a purity of ≥99.5%, the dehydration reaction is carried out at a temperature of 130-170℃ and a pressure of 0.5-2MPa, and the catalyst is a solid acid catalyst. The dimethyl ether has a purity of ≥99%.
7. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The molar ratio of carbon monoxide to dimethyl ether in the first part is 1:1, the temperature of the carbonyl insertion reaction is 240-300℃, the pressure is 3-8MPa, the catalyst is a molecular sieve catalyst, and the purity of the methyl acetate is ≥99.8%.
8. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The production method further includes: The second part of carbon monoxide and biogas are added to the energy utilization unit to obtain energy to meet the energy requirements of the production method.
9. The method for producing bio-based methyl acetate according to claim 1, characterized in that, The carbonylation unit is also equipped with a circulation system, which separates the mixed products obtained from the carbonylation reaction to obtain crude methyl acetate, unreacted carbon monoxide, and unreacted dimethyl ether. In this process, the unreacted carbon monoxide and the unreacted dimethyl ether are returned to the carbonylation unit to participate in the carbonylation reaction again, and the crude methyl acetate is purified.