A method for producing mixed alcohols with bio-based methyl acetate as green hydrogen acceptor
By using bio-based methyl acetate as a green hydrogen acceptor to produce mixed alcohols through hydrogenation reactions, the problems of green hydrogen storage and transportation and the low added value of bio-based methyl acetate have been solved. This has enabled the efficient conversion of green hydrogen and the high-value utilization of bio-based resources, reduced storage and transportation costs, improved the absorption capacity of renewable energy and the economic benefits of the bio-based industry.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGTZE DELTA REGION INST OF TSINGHUA UNIV ZHEJIANG
- Filing Date
- 2026-03-23
- Publication Date
- 2026-06-02
AI Technical Summary
Existing methods for producing mixed alcohols suffer from problems such as difficulties in storing and transporting green hydrogen, poor utilization of surplus wind/solar power, and low added value of bio-based methyl acetate.
Using bio-based methyl acetate as a green hydrogen acceptor, a mixed alcohol is produced through a hydrogenation reaction. A closed-loop recycling system is constructed using gas-liquid separation and distillation units to achieve efficient recovery and reuse of unreacted materials. The resulting mixed alcohol can be used directly as fuel for vehicles and ships without further separation.
It has achieved efficient carrying capacity of green hydrogen and high-value utilization of bio-based resources, reduced storage and transportation costs, improved the local consumption capacity of renewable energy, expanded the resource utilization path of bio-based methyl acetate, and enhanced the economic benefits of the bio-based industry.
Smart Images
Figure CN122128022A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of biomass energy chemical technology, specifically to a method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor. Background Technology
[0002] Guided by the global goal of "dual carbon" (carbon diversification and carbon emission reduction), green hydrogen, as a clean energy carrier with zero carbon emissions, has broad application prospects in energy, chemical industry, transportation, and other fields due to its clean and efficient characteristics. Its mainstream production route utilizes renewable energy sources such as wind and solar power to drive water electrolysis for hydrogen production. This approach can efficiently absorb renewable energy and aligns with the concept of green development.
[0003] However, the industrialization and promotion of green hydrogen still faces key bottlenecks: First, renewable energy (such as wind and solar resources in Northwest China) is abundant, but the grid's absorption capacity is insufficient. Although surplus electricity can be used to produce hydrogen locally, it faces storage and transportation challenges. Second, green hydrogen storage and transportation costs are high and the technology is difficult—gaseous hydrogen storage requires sophisticated equipment and poses safety risks, while liquid hydrogen storage requires an ultra-low temperature environment, resulting in extremely high energy consumption. The high storage and transportation costs significantly weaken the market competitiveness of green hydrogen, becoming the core obstacle to its large-scale implementation.
[0004] Meanwhile, with the development of green chemistry, the bio-based chemicals industry is maturing. Bio-based methyl acetate, as an important green chemical intermediate, can be produced through green processes such as biomass thermochemical methods, biochemical (fermentation) methods, or electrochemical methods. However, in existing technologies, the downstream applications of bio-based methyl acetate are relatively limited, and the added value of the product needs to be improved. Currently, there is no technological solution in the industry that can synergistically combine the efficient conversion of green hydrogen with the high-value utilization of bio-based methyl acetate.
[0005] Therefore, developing a method to produce high-value green mixed alcohols through hydrogenation using bio-based methyl acetate as a green hydrogen acceptor can not only solve the problem of green hydrogen storage and transportation and improve the local consumption capacity of renewable energy, but also promote the transformation of low-value bio-based methyl acetate into high-value products. This aligns with the trend of green transformation and efficient resource utilization, and has significant practical significance and industrialization value. Summary of the Invention
[0006] The purpose of this invention is to provide a method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor, thereby solving the following technical problems:
[0007] Existing methods for producing mixed alcohols suffer from problems such as difficulties in storing and transporting green hydrogen, poor utilization of surplus wind / solar power, and low added value of bio-based methyl acetate.
[0008] The objective of this invention can be achieved through the following technical solutions:
[0009] A method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor, comprising at least the following steps:
[0010] Green hydrogen and bio-based methyl acetate are added to the hydrogenation reaction unit. After the hydrogenation reaction, a mixture is obtained.
[0011] The mixture is added to a gas-liquid separation unit. After gas-liquid separation, unreacted green hydrogen and a mixed liquid are obtained.
[0012] The mixture was added to a distillation unit, and after distillation, unreacted bio-based methyl acetate and mixed alcohol were obtained.
[0013] As a further aspect of the present invention: the unreacted green hydrogen and the unreacted bio-based methyl acetate are returned to the hydrogenation reaction unit to participate in the hydrogenation reaction.
[0014] As a further aspect of the present invention: the molar ratio of the green hydrogen to the bio-based methyl acetate is 8-15:1, the hydrogenation reaction temperature is 180-280℃, the pressure is 2-5 MPa, and the liquid hourly space velocity is 0.5-2 h⁻¹. -1 The catalyst is a copper-zinc-aluminum composite catalyst.
[0015] As a further aspect of the present invention: the green hydrogen is produced by electrolysis of water driven by photovoltaic power or wind power alone or in combination, and the purity of the green hydrogen is ≥99.9% and the moisture content is ≤10ppm; the bio-based methyl acetate is produced by green bio-based raw materials through biomass thermochemical method, biochemical (fermentation) method or electrochemical method, and the purity of the green bio-based raw materials is ≥99.0%.
[0016] As a further aspect of the invention: the mixture comprises methanol, ethanol and the unreacted bio-based methyl acetate.
[0017] As a further aspect of the present invention: the pressure of the gas-liquid separation is 1-3 MPa and the temperature is 10-30℃.
[0018] As a further aspect of the present invention: the mixture comprises methanol, ethanol and the unreacted bio-based methyl acetate.
[0019] As a further aspect of the present invention: the distillation unit is a distillation column, the top temperature of the distillation column is 64-66℃, the bottom temperature is 75-80℃, the pressure is atmospheric pressure, and the purity of the unreacted bio-based methyl acetate is ≥99%.
[0020] As a further aspect of the present invention: the moisture content of the mixed alcohol is ≤0.05%, and the mixed alcohol contains 40-45 wt% methanol and 55-60 wt% ethanol.
[0021] The beneficial effects of this invention are:
[0022] This invention provides a method for producing green mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor. Green hydrogen and bio-based methyl acetate are introduced into a reactor in a specific ratio for hydrogenation reaction to generate a green mixed alcohol product of ethanol and methanol. After the reaction, unreacted materials are recycled through gas-liquid separation and distillation. The mixed alcohol product can be used directly as fuel for vehicles and ships without further separation. No dehydrogenation step is required throughout the process, achieving synergy between efficient green hydrogen carrying capacity and high-value utilization of bio-based resources.
[0023] This invention uses bio-based methyl acetate as a green hydrogen acceptor, directionally converting low-value-added bio-based methyl acetate into a high-value ethanol-methanol green mixed alcohol. This allows green hydrogen to be efficiently carried and converted through chemical bonding, eliminating the need for expensive facilities such as high-pressure hydrogen storage tanks and cryogenic liquefaction equipment, significantly reducing the cost and technical barriers of green hydrogen storage and transportation. Simultaneously, it can directly utilize green hydrogen produced from surplus wind / solar power, effectively solving the problems of difficult grid connection and severe curtailment of wind / solar power, significantly improving the utilization rate of renewable energy, and expanding the resource utilization pathway of bio-based methyl acetate, thereby enhancing the overall economic benefits of the bio-based industry and contributing to the transformation and upgrading of the bio-based chemical industry.
[0024] This invention constructs a closed-loop recycling system through gas-liquid separation and distillation, achieving efficient recovery and reuse of unreacted green hydrogen and bio-based methyl acetate, significantly reducing raw material loss. The product can be directly used as vehicle and ship fuel without additional separation, simplifying the production process and reducing separation energy consumption and production costs. The entire process uses green hydrogen and bio-based raw materials, resulting in extremely low carbon emissions. The product is a clean and environmentally friendly green mixed alcohol, which can be directly used as a high-quality clean fuel for vehicles and ships, directly replacing traditional fossil fuels, and possessing significant environmental value and policy compatibility. Attached Figure Description
[0025] 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.
[0026] Figure 1 This is a process flow diagram of the biothermochemical method for preparing acetic acid in one embodiment. Detailed Implementation
[0027] 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.
[0028] Please see Figure 1 As shown, this invention proposes a method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor. Green hydrogen and bio-based methyl acetate are added to a hydrogenation reaction unit in a specific ratio to carry out a hydrogenation reaction, obtaining a mixture. In one embodiment of this invention, the bio-based methyl acetate is metered out via a pump, and the green hydrogen is metered out via a flow meter to ensure that the molar ratio of hydrogen to methyl acetate is, for example, 8-15:1. The hydrogenation reaction unit is, for example, a fixed-bed reactor, and the temperature of the hydrogenation reaction is set, for example, to 180-280°C, the pressure is set, for example, to 2-5 MPa, the liquid hourly space velocity is set, for example, to 0.5-2 h⁻¹, and the catalyst is, for example, a copper-zinc-aluminum composite catalyst. In one embodiment of the present invention, green hydrogen is produced, for example, by electrolysis of water driven by photovoltaic power or wind power alone or in combination, and the purity of the green hydrogen is, for example, at least 99.9% and the water content is, for example, at most 10 ppm. Bio-based methyl acetate is produced, for example, from green bio-based raw materials through biomass thermochemical methods, biochemical (fermentation) methods, or electrochemical methods, and the purity of the green bio-based raw materials is, for example, at least 99.0%, free of mechanical impurities and heavy components. In one embodiment of the present invention, the mixture obtained by directional hydrogenation of green hydrogen and bio-based methyl acetate includes at least methanol, ethanol, unreacted green hydrogen, and unreacted bio-based methyl acetate.
[0029] Please see Figure 1 As shown, the mixture obtained after directional hydrogenation in the hydrogenation reaction unit is added to the gas-liquid separation unit for gas-liquid separation, yielding a gaseous component and a liquid component. The gaseous component is unreacted green hydrogen with a purity of at least 99.6%, and the liquid component is, for example, a mixture containing at least methanol, ethanol, and unreacted bio-based methyl acetate. In one embodiment of the invention, the pressure and temperature of the gas-liquid separation are, for example, 1-3 MPa and 10-30°C. In another embodiment of the invention, the unreacted green hydrogen obtained from the gas-liquid separation is returned to the hydrogenation reaction unit via a recirculation pipeline after pressurization to participate in the hydrogenation reaction again, achieving efficient recovery and utilization of green hydrogen.
[0030] Please see Figure 1As shown, the mixture obtained from the gas-liquid separation unit is added to the distillation unit. After distillation, unreacted bio-based methyl acetate and a mixed alcohol are obtained. In one embodiment of the invention, the distillation unit is, for example, a distillation column, with the top temperature set at, for example, 64-66°C, the bottom temperature set at, for example, 75-80°C, and the pressure set at, for example, atmospheric pressure. In one embodiment of the invention, the water content of the mixed alcohol is, for example, at most 0.05%, and the mixed alcohol contains, for example, methanol and ethanol, with the methanol content at, for example, 40-45 wt% and the ethanol content at, for example, 55-60 wt%. The obtained mixed alcohol does not require further separation and purification and can be used directly as vehicle and marine fuel or general fuel. In one embodiment of the invention, the purity of the unreacted bio-based methyl acetate obtained after distillation is at least 99%, and the unreacted bio-based methyl acetate is, for example, pumped back to the hydrogenation reaction unit via a circulation pipeline to participate in the hydrogenation reaction again, achieving efficient utilization of materials.
[0031] The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor includes the following steps:
[0032] like Figure 1 As shown, green hydrogen and bio-based methyl acetate were used as reaction raw materials. The bio-based methyl acetate was obtained by esterifying acetic acid prepared by a biochemical (fermentation) method with green methanol, free of mechanical impurities and heavy components, with a purity ≥99.2%. The green hydrogen was produced by photovoltaic power electrolysis of water, directly connected to the reaction system at the water electrolysis hydrogen production site, eliminating the need for long-distance transportation, with a purity ≥99.9% and a moisture content ≤10ppm. The green hydrogen and bio-based methyl acetate were added to the hydrogenation reaction unit at a molar ratio of 12:1 for directional hydrogenation to obtain a mixture. The hydrogenation reaction unit was a fixed-bed reactor with an internal copper-zinc-aluminum composite catalyst made of 316L stainless steel. The hydrogenation reaction temperature was set to 240℃, the pressure to 4MPa, and the liquid hourly space velocity to 1h. -1 The mixture obtained after the directed hydrogenation reaction includes methanol, ethanol, unreacted green hydrogen, and unreacted bio-based methyl acetate, with no obvious byproducts generated.
[0033] Please see Figure 1 As shown, the mixture obtained above is added to a gas-liquid separation unit for gas-liquid separation. The gas-liquid separation unit employs a gravity sedimentation separation structure, is made of 316L stainless steel, and the gas-liquid separation pressure is 2 MPa and the temperature is 20°C. After gas-liquid separation, the mixture yields a gaseous component and a liquid component. The gaseous component is unreacted green hydrogen with a purity ≥99.6%, and the liquid component is a mixture containing methanol, ethanol, and unreacted bio-based methyl acetate. The unreacted green hydrogen obtained from gas-liquid separation is returned to the hydrogenation reaction unit via a circulation pipeline after pressurization to participate in the hydrogenation reaction again, achieving efficient recovery and utilization of green hydrogen. The resulting mixture is then distilled in the distillation unit.
[0034] Please see Figure 1 As shown, the obtained mixture is added to a distillation unit for distillation. The distillation unit is a distillation column with stainless steel packing. Temperature control systems are installed at the top and bottom of the column. The top temperature is set to 65℃, the bottom temperature to 77℃, and the pressure to atmospheric pressure. After distillation, unreacted bio-based methyl acetate with a purity ≥99.2% is separated from the top of the column. This unreacted bio-based methyl acetate is then pumped back to the hydrogenation reaction unit via a circulation pipeline to participate in the hydrogenation reaction again, achieving efficient material utilization. A green mixed alcohol is collected from the bottom of the distillation column, cooled, and sent to a product storage tank. Testing shows that the mixed alcohol contains 41wt% methanol and 59wt% ethanol, with a water content ≤0.05% and no other impurities. The obtained mixed alcohol requires no further separation or purification and directly meets vehicle and vessel fuel standards. It can be used directly as vehicle and vessel fuel through an external product supply system, falling under the category of green fuel coupled with green hydrogen utilization.
[0035] Using the method for producing mixed alcohols with bio-based methyl acetate as the green hydrogen acceptor provided in this embodiment, a medium-sized mixed alcohol tanker can transport 23 tons of mixed alcohol, which is equivalent to transporting 1.18 tons of green hydrogen (the amount consumed by hydrogenating 22 tons of methyl acetate), significantly reducing the transportation cost of green hydrogen. Moreover, the cost of the mixed alcohol obtained by the method provided in the above embodiment is 4,650 yuan / ton (the cost of bio-based methyl acetate is 3,820 yuan / ton, and the cost of green hydrogen is 20 yuan / kg), which is lower than the current market price of green methanol and ethanol, indicating that the method provided by this invention is feasible and economical.
[0036] As can be seen from the above embodiments, the method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor provided by the present invention achieves continuous production by cooperating with pipelines and pumps for material transportation in each unit. While realizing the efficient conversion of green hydrogen and the high-value utilization of bio-based methyl acetate to prepare green mixed alcohols that can be directly used as fuel for vehicles and ships, it can also reduce raw material loss by recycling unreacted materials and reduce storage and transportation energy consumption by consuming green hydrogen on-site, effectively achieving energy conservation and consumption reduction, and has significant economic and environmental benefits.
[0037] 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.
[0038] 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 mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor, characterized in that, At least the following steps are included: Green hydrogen and bio-based methyl acetate are added to the hydrogenation reaction unit. After the hydrogenation reaction, a mixture is obtained. The mixture is added to a gas-liquid separation unit. After gas-liquid separation, unreacted green hydrogen and a mixed liquid are obtained. The mixture was added to a distillation unit, and after distillation, unreacted bio-based methyl acetate and mixed alcohol were obtained.
2. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The unreacted green hydrogen and the unreacted bio-based methyl acetate are returned to the hydrogenation reaction unit to participate in the hydrogenation reaction.
3. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The molar ratio of the green hydrogen to the bio-based methyl acetate is 8-15:1, and the hydrogenation reaction is carried out at a temperature of 180-280℃, a pressure of 2-5 MPa, and a liquid hourly space velocity of 0.5-2 h⁻¹. -1 The catalyst is a copper-zinc-aluminum composite catalyst.
4. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The green hydrogen is produced by electrolyzing water using photovoltaic power or wind power alone or in combination, and the purity of the green hydrogen is ≥99.9% and the moisture content is ≤10ppm. The bio-based methyl acetate is produced from green bio-based raw materials through biomass thermochemical method, biochemical (fermentation) method or electrochemical method, and the purity of the green bio-based raw materials is ≥99.0%.
5. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The mixture comprises methanol, ethanol, the unreacted green hydrogen, and unreacted bio-based methyl acetate.
6. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The pressure for gas-liquid separation is 1-3 MPa, and the temperature is 10-30℃.
7. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The mixture contains methanol, ethanol, and the unreacted bio-based methyl acetate.
8. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The distillation unit is a distillation column, the top temperature of the distillation column is 64-66℃, the bottom temperature is 75-80℃, and the pressure is atmospheric pressure, and the purity of the unreacted bio-based methyl acetate is ≥99%.
9. The method for producing mixed alcohols using bio-based methyl acetate as a green hydrogen acceptor according to claim 1, characterized in that, The mixed alcohol has a moisture content of ≤0.05% and contains 40-45 wt% methanol and 55-60 wt% ethanol.