A method of converting primary biomass to lactic acid by coupling enzymatic hydrolysis and thermal catalysis
Patent Information
- Application Number
- CN202610833486.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-10
- Publication Date
- 2026-08-21
AI Technical Summary
然而，该过程中所用的反应底物为加工提纯后的生物质，并且很多时候糖类物质来源于粮食，反应原料相对农林废弃物比较昂贵，经济性及环保价值不高
[0015] This invention utilizes native biomass from agricultural and forestry waste as raw material, and performs enzymatic hydrolysis and catalytic conversion to ultimately obtain high-value-added lactic acid. Compared with traditional lactic acid preparation methods, it has the following advantages:
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of high-value utilization technology of biomass resources, and in particular, it is a method that combines enzymatic hydrolysis and thermal catalysis to convert primary biomass into lactic acid. Background Technology
[0002] With the increasing demand for renewable resources, biomass has become a hot research topic. Biomass is the only renewable solid carbon resource on Earth, characterized by its ease of storage and transportation. The main components of biomass are cellulose, hemicellulose, and lignin. Typical examples of lignocellulosic biomass include agricultural and forestry waste. The cellulose and hemicellulose components in these primary biomass can be separated using acid-base extraction methods to obtain low-molecular-weight oligosaccharides. These oligosaccharides can then be further processed chemically or biologically to transform them into bulk chemicals needed in our daily lives.
[0003] Lactic acid, an important chemical, is used in the cosmetics, food, and polyester industries. In recent years, environmental regulations have led to a surge in demand for polylactic acid (PLA), a biodegradable plastic. Traditional methods for preparing lactic acid primarily involve anaerobic fermentation of corn, rice, and wheat by lactic acid bacteria. This process is complex, time-consuming, and competes with human food production. In recent years, researchers have sought suitable catalysts to catalyze the conversion of sugars or glycerol from biomass into lactic acid. They have found that glucose, fructose, and sucrose can be converted into lactic acid in a one-step process under solid Lewis acid catalysis, achieving high yields. However, the reaction substrates used in this process are processed and purified biomass, and often the sugars are derived from grains. The raw materials are relatively expensive compared to agricultural and forestry waste, resulting in low economic and environmental value. Summary of the Invention
[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for converting biomass, especially agricultural and forestry waste, into high-value-added lactic acid compounds through enzymatic hydrolysis and hydrothermal catalysis. This method combines biological fermentation and chemical catalysis to turn biomass into a valuable resource and achieve its efficient conversion.
[0005] To achieve the above objectives, the present invention provides a method for converting protobiomass to lactic acid through coupled enzyme hydrolysis and thermochemical conversion, comprising the following steps:
[0006] (1) A primary biomass, especially agricultural and forestry waste, is used as a reactant and hydrolyzed under the action of biological enzymes to extract the three components in the biomass. The cellulose and hemicellulose components are hydrolyzed to generate small molecule sugars such as glucose, fructose and xylose.
[0007] (2) Small molecule sugars dehydrate and break C-C bonds under hydrothermal conditions and with the action of a catalyst to generate lactic acid.
[0008] (3) Biomass macromolecules are hydrolyzed and transformed simultaneously on a solid catalyst with embedded biological enzymes using water as a medium, thereby realizing the one-step conversion from primary biomass to lactic acid.
[0009] In some embodiments of the present invention, the biological enzyme is selected from one or more combinations of cellulase, hemicellulase, ligninase, amylase, etc.
[0010] In some embodiments of the present invention, the catalyst is a molecular sieve catalyst, a combination of one or more of a metal framework material and a metal oxide. The molecular sieve catalyst is one or more of the following molecular formulas: β-type molecular sieve, Sn-β molecular sieve, Al-β molecular sieve, W-β molecular sieve, Zr-β molecular sieve, SBA molecular sieve, and ZSM; the metal oxide includes one or more of Al2O3, ZnO, ZrO, and La2O3.
[0011] The catalyst used in step (3) of this invention is a solid catalyst with embedded biological enzymes. The biological enzymes used are selected from one or more combinations of cellulase, hemicellulase, ligninase, amylase, etc.; the solid catalysts used are selected from one or more combinations of molecular sieves and metal oxides.
[0012] The reaction conditions in step (1) are: temperature 20~60°C. o C, pH value 5.0~6.5, time 12~96h, stirring speed 50~200 rpm.
[0013] The reaction conditions in step (2) are: temperature 50~200°C. o The reaction is carried out under a protective gas pressure of 2.0~10.0 MPa in the presence of a highly active and selective catalyst, with a catalyst-to-reactant ratio of 0.01~10 and a reaction time of 0.5~24 h.
[0014] Step (3) is carried out under relatively mild conditions, requiring consideration of both the activity of the enzyme and the solid catalyst, at a temperature of 40-80°C. oThe C and N2 protective gas pressure does not exceed 2.0 MPa, and the reaction is carried out in the presence of a highly active and selective catalyst with a catalyst-to-reactant ratio of 0.1 to 10 and a reaction time of 5 to 60 h.
[0015] This invention utilizes native biomass from agricultural and forestry waste as raw material, and performs enzymatic hydrolysis and catalytic conversion to ultimately obtain high-value-added lactic acid. Compared with traditional lactic acid preparation methods, it has the following advantages:
[0016] (1) The lignocellulosic biomass of agricultural and forestry waste is converted into lactic acid, realizing the sustainable utilization of agricultural and forestry waste from waste to treasure;
[0017] (2) This process couples fermentation and thermocatalysis, breaking the barrier of low fermentation product concentration. The sugar solution is concentrated before thermocatalysis to obtain a high-concentration product solution and reduce product separation costs.
[0018] (3) The reaction conditions are mild, the process is simple and easy to implement, the product yield is high, the process is green and environmentally friendly, and it has a wide range of application prospects. Attached Figure Description
[0019] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation
[0020] The technical solutions of the present invention are not limited to the specific embodiments listed below, but also include any combination of various specific embodiments.
[0021] Unless otherwise specified, all chemical reagents involved in this invention are commercially available products.
[0022] The native biomass used in this invention is one or a mixture of several of the following: rice straw, corn straw, corn cob residue, Miscanthus sinensis, Jerusalem artichoke, potato tubers, sugarcane bagasse, licorice residue, tree branches and leaves.
[0023] like Figure 1 As shown, the method described in this invention combines enzymatic hydrolysis and hydrothermal catalysis to directly convert native biomass into high-value-added lactic acid. Specific steps include:
[0024] (1) A primary biomass raw material, especially agricultural and forestry waste, is used as a reactant and hydrolyzed under the action of biological enzymes to extract the three components in the biomass. The cellulose and hemicellulose components are hydrolyzed to generate C5 / C6 small molecule sugars.
[0025] (2) Small molecule sugars dehydrate and break C-C bonds under hydrothermal conditions and with the action of a catalyst to generate lactic acid.
[0026] (3) Biomass macromolecules are hydrolyzed and transformed simultaneously on a solid catalyst with embedded biological enzymes using water as a medium, thereby realizing the one-step conversion from primary biomass to lactic acid.
[0027] Example 1
[0028] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing biomass raw materials (such as rice straw, wheat straw, and tree branches and leaves) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of cellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 60°C. o At C, the amount of cellulase used was 10 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of acidic molecular sieve Sn-Beta to obtain lactic acid product with a yield of 85%.
[0029] Example 2
[0030] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing biomass raw materials (such as rice straw, wheat straw, and tree branches and leaves) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of cellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 60°C. o At C, the amount of cellulase used was 10 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis under acidic Al2O3 to obtain lactic acid product with a yield of 63%.
[0031] Example 3
[0032] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing biomass raw materials (such as rice straw, wheat straw, and tree branches and leaves) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of cellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 60°C. o At C, the amount of cellulase used was 10 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of La2O3 to obtain lactic acid product with a yield of 58%.
[0033] Example 4
[0034] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing biomass raw materials (such as rice straw, wheat straw, and tree branches and leaves) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of cellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 60°C. o At C, the amount of cellulase used was 10 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of ZnO to obtain lactic acid product with a yield of 46%.
[0035] Example 5
[0036] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing the biomass raw materials (corn cobs, sugarcane bagasse, etc.) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of hemicellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 40°C. o At C, the amount of hemicellulase used was 8 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of acidic molecular sieve Sn-Beta to obtain lactic acid product with a yield of 78%.
[0037] Example 6
[0038] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing the biomass raw materials (corn cobs, sugarcane bagasse, etc.) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of hemicellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 40°C. o At C, the amount of hemicellulase used was 8 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis under acidic Al2O3 to obtain lactic acid product with a yield of 65%.
[0039] Example 7
[0040] A method for converting primary biomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first crushing the biomass raw materials (corn cobs, sugarcane bagasse, etc.) and sieving them through a 20-120 mesh sieve; then, adding the sieved raw materials to distilled water and mixing with an appropriate amount of hemicellulase, with a reactant substrate concentration of 2% and a hydrolysis temperature of 40°C. oAt C, the amount of hemicellulase used was 8 FPU / (g reactant substrate). After fermentation for 72 h, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of La2O3 to obtain lactic acid product with a yield of 62%.
[0041] Example 8
[0042] A method for converting protobiomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first pulverizing the biomass (such as Jerusalem artichoke or potato tubers) and sieving it through a 20-120 mesh sieve; then adding the sieved material to distilled water and mixing it with an appropriate amount of amylase. The concentration of the reactant substrate is 2%, and the hydrolysis temperature is 40°C. o At C, the amount of amylase used was 16 FPU / (g reactant substrate). After 60 h of fermentation, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of acidic molecular sieve Sn-Beta to obtain lactic acid product with a yield of 78%.
[0043] Example 9
[0044] A method for converting protobiomass to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first pulverizing the biomass (such as Jerusalem artichoke or potato tubers) and sieving it through a 20-120 mesh sieve; then adding the sieved material to distilled water and mixing it with an appropriate amount of amylase. The concentration of the reactant substrate is 2%, and the hydrolysis temperature is 40°C. o At C, the amount of amylase used was 16 FPU / (g reactant substrate). After 60 h of fermentation, the fermented sugar solution was obtained by filtration. The fermented sugar solution was concentrated to 50 wt% by evaporation and then subjected to hydrothermal catalysis in the presence of La2O3 to obtain lactic acid product with a yield of 59%.
[0045] Example 10
[0046] A method for converting protobiota to lactic acid via coupled enzyme hydrolysis and thermocatalysis involves first preparing a porous framework material, embedding the cellulase into the porous material, and then mixing it with pulverized and sieved protobiota using water as a solvent at 60°C. o The reaction is carried out under C conditions. Under the action of enzymatic hydrolysis and chemical catalysis, the biomass raw material releases small molecule sugars while generating lactic acid under the action of the catalyst, thus realizing the one-step production of lactic acid compounds from primary biomass under mild conditions.
Claims
1. A method for converting protobiota to lactic acid via coupled enzyme hydrolysis and thermocatalysis, characterized in that, The method described is a combination of enzymatic hydrolysis and hydrothermal catalysis to directly convert native biomass into high-value-added lactic acid. Specific steps include: (1) A primary biomass raw material, especially agricultural and forestry waste, is used as a reactant and hydrolyzed under the action of biological enzymes to extract the three components in the biomass. The cellulose and hemicellulose components are hydrolyzed to generate C5 / C6 small molecule sugars. (2) Small molecule sugars dehydrate and break C-C bonds under hydrothermal conditions and with the action of a catalyst to generate lactic acid. (3) The solid oxide catalyst is hydrolyzed and converted simultaneously with water as a medium, thereby realizing the one-step conversion from primary biomass to lactic acid.
2. The method according to claim 1, characterized in that, The primary biomass raw materials include corn cobs, rice straw, wheat straw, miscanthus, Jerusalem artichoke, potato tubers, sugarcane bagasse, licorice residue, and tree branches and leaves.
3. The method as described in claim 1, characterized in that, Enzymatic hydrolysis of protobiomass extracts C5 and C6 sugars from the biomass, and then the small molecule sugars are converted into lactic acid under the action of a solid oxide catalyst. The solid oxide catalyst is a solid catalyst embedded with a biological enzyme, and the biological enzyme used is selected from one or more combinations of cellulase, hemicellulase, ligninase, amylase, etc.
4. The method as described in claim 3, characterized in that, The protobiomass is crushed and pulped, then mixed with cellulase, hemicellulase and amylase to extract the C5 and C6 sugars from the protobiomass.
5. The method as described in claim 4, characterized in that, The extracted sugar solution is concentrated and then efficiently converted into lactic acid under the action of heterogeneous catalysts such as molecular sieves, Al2O3, ZnO, and La2O3, which are embedded with biological enzymes.
6. The method as described in claim 1, characterized in that, By coupling enzymatic hydrolysis and hydrothermal catalysis, a one-step process is used to convert protobiota into lactic acid.
7. The method as described in claim 6, characterized in that, Bioenzymes are embedded in solid catalysts to achieve the process of hydrolysis and conversion of primary biomass. The hydrolyzed small molecule sugars are converted into lactic acid under catalysis. The solid catalysts include molecular sieve catalysts and metal oxides. The bioenzymes used are selected from one or more combinations of cellulase, hemicellulase, ligninase, and amylase.
8. The method as described in claim 7, characterized in that, The molecular sieve catalyst is one or more of the following molecular formulas: β-type molecular sieve, Sn-β molecular sieve, Al-β molecular sieve, W-β molecular sieve, Zr-β molecular sieve, SBA molecular sieve, and ZSM; the metal oxide includes one or more of the following: Al2O3, ZnO, ZrO, and La2O3.
9. The method as described in claim 1, characterized in that, The reaction conditions in step (1) are: temperature 20~60°C. o C, pH value 5.0~6.5, time 12~96h, stirring speed 50~200 rpm; The reaction conditions in step (2) are: temperature 50~200°C. o The C and N2 protective gas pressure is 2.0~10.0 MPa, the reaction is carried out in the presence of a highly active and selective catalyst, the specific gravity of the catalyst to the reactants is 0.01~10, and the reaction time is 0.5~24 h. Step (3) is carried out under relatively mild conditions, requiring consideration of both the activity of the enzyme and the solid catalyst, at a temperature of 40-80°C. o The C and N2 protective gas pressure does not exceed 2.0 MPa, and the reaction is carried out in the presence of a highly active and selective catalyst with a catalyst-to-reactant ratio of 0.1 to 10 and a reaction time of 5 to 60 h.