Device and method for producing methane by coupling crude enzyme prepared from trichoderma viride with yeast glycerol for fermentation reinforcement of straw anaerobic fermentation

Abstract

The invention discloses a device and a method for producing methane by coupling crude enzyme liquid prepared from trichoderma viride with yeast glycerol for fermentation reinforcement of straw anaerobic fermentation. The method comprises the following steps: firstly, adding a trichoderma viride enzyme production culture medium and a trichoderma viride spore suspension into a trichoderma viride enzyme production culture tank for domestication enzyme production; mixing cellulose and water, adding the mixture into the trichoderma viride crude enzyme solution, converting into a cellulose mixed solution containing reducing sugar, and adding a yeast mixed solution after expanding culture to directionally produce glycerol in a yeast fermentation tank; finally, anaerobic digestion is carried out in an anaerobic digestion methane production tank; specific hydraulic retention time, pH value and temperature are set in a trichoderma viride enzyme production culture tank, a yeast culture tank, a yeast fermentation tank and a methane production tank, the utilization rate of cellulose is remarkably increased, the anaerobic digestion methane production rate is greatly increased, and then the methane yield is increased. The technology is low in investment cost and easy and convenient to operate, the production efficiency is effectively improved, and great application potential is shown.

Description

Technical Field

[0001] The present invention belongs to the technical field of efficient anaerobic digestion of organic solid waste to produce methane, and particularly relates to a device and method for enhancing anaerobic fermentation of straw to produce methane by coupling the preparation of crude enzyme solution with Trichoderma viride and glycerol fermentation of yeast. Background Art

[0002] Glucose, as a monosaccharide widely existing in nature and having important biological significance, has the molecular formula C6H 12 O6. With its unique chemical structure and diverse physical and chemical properties, it has shown indispensable value in many fields. In the food industry, as an important carbohydrate, glucose can not only provide energy for the human body but also play a key role in the production of many foods such as candies, pastries, and beverages. For example, in some low-sugar foods, the reasonable use of glucose can not only meet people's demand for sweetness but also effectively control sugar intake; in the pharmaceutical field, glucose plays an important role. From being the main raw material for the production of large infusions, various glucose injections, and dialysis solutions to serving as a carrier and nutritional additive in some pharmaceutical preparations, it reflects its importance in maintaining human health; in the chemical industry, due to its reducibility, glucose is widely used as a reducing agent in the printing and leather-making industry, mirror-making industry, and the manufacture of chromium tanning agents, promoting the development of these industries; in the fermentation industry, as an excellent carbon source required for microbial growth, glucose is a key raw material for the production of many products such as antibiotics, monosodium glutamate, vitamins, amino acids, organic acids, and enzyme preparations, providing the necessary energy and material basis for the microbial fermentation process.

[0003] In the industrial production field, the main source of glucose is starch hydrolysis. Starch, as a polysaccharide, widely exists in crops such as corn, wheat, and potatoes and is an important raw material for industrial production of glucose. At present, the commonly used starch hydrolysis methods include acid hydrolysis method and enzyme hydrolysis method. The acid hydrolysis method is to hydrolyze starch molecules into glucose by using inorganic acid (such as hydrochloric acid) as a catalyst under high temperature and high pressure conditions. This method has the advantages of fast hydrolysis speed and high efficiency, but the reaction conditions are relatively harsh, it is easy to produce some by-products, and it has strong corrosiveness to equipment. The enzyme hydrolysis method is to gradually hydrolyze starch into glucose by using specific amylases (such as α-amylase, glucoamylase, etc.). This method has the advantages of mild reaction conditions, high selectivity, and high product purity, and has become the mainstream method for modern industrial production of glucose. In the actual production process, first, the starch raw material is pretreated to gelatinize it, then an appropriate amount of amylase is added for liquefaction reaction to degrade starch molecules into shorter dextrin fragments, and then glucoamylase is added to further hydrolyze dextrin into glucose. The obtained saccharified liquid is finally refined through a series of processes such as decolorization with activated carbon and removal of inorganic substances and other impurities with ion exchange resin to obtain high-purity glucose products.

[0004] As a traditional industrial production process, the production of glucose from starch has a wide range of applications in multiple fields such as food, medicine, and chemical industry, and has long been one of the important ways to supply sugars. With the rapid development of social economy and the increasing prominence of environmental problems, people's attention to sustainable development has been continuously improved, which makes the challenges faced by the starch-to-glucose industry in resource utilization and environmental protection gradually attract attention.

[0005] From the perspective of resources, starch, as the main raw material for producing glucose, mainly depends on food crops such as corn, wheat, and rice for its source. However, these food crops are not only an important part of human diet globally but also the key guarantee for maintaining food security. With the continuous growth of the population and the increasing demand for food, using a large amount of food for industrial production of glucose will undoubtedly exacerbate the tension of food resources and pose a potential threat to global food security.

[0006] In terms of the environment, the production process of glucose from starch involves multiple complex links. From the pretreatment of raw materials, the hydrolysis and saccharification of starch to the refining and purification of products, each link is accompanied by a large amount of resource consumption and pollutant emissions. For example, in the starch hydrolysis process, whether using the traditional acid hydrolysis method or the more advanced enzyme hydrolysis method, a large amount of wastewater will be generated. These wastewaters contain high concentrations of organic matter, nitrogen and phosphorus nutrients, as well as residual acid or enzyme preparations and other components. If directly discharged without effective treatment, it will cause serious damage to the water ecological environment, trigger a series of problems such as water eutrophication and water quality deterioration, and then affect the survival and reproduction of aquatic organisms and the balance and stability of the water ecosystem.

[0007] Straw cellulose is the main component of plant cell walls and belongs to polysaccharide macromolecules. Its chemical structure has a high degree of regularity and complexity. It is composed of a large number of glucose units connected by β-1,4-glycosidic bonds to form linear macromolecular chains. These chain-like molecules are further arranged and aggregated to form the microscopic structure of cellulose, endowing cellulose with certain strength and stability. If the glucose in straw cellulose can be released in a more economical and feasible way, it will endow straw with higher economic utilization value.

[0008] The research on the utilization of straw cellulose abroad started earlier, with relatively mature technologies, extensive and in-depth research fields, covering various treatment methods and their comprehensive applications in physics, chemistry, biology, etc., aiming to improve the conversion efficiency of straw cellulose and the added value of products, meet the needs of multiple industries such as energy, materials, and chemical engineering, reduce the dependence on traditional fossil resources, and achieve sustainable development. The United States is in the world-leading position in the production technology of straw cellulose ethanol. Through genetic engineering and enzyme engineering technologies, the performance of cellulase has been optimized, the hydrolysis efficiency of straw cellulose has been improved, the production cost has been reduced, and large-scale industrial production of cellulose ethanol has been realized. At the same time, the United States is also actively exploring the application of straw cellulose in the field of bio-based materials, developing a series of high-performance cellulose-based composite materials for industries such as automobiles and construction, replacing traditional petroleum-based materials, reducing greenhouse gas emissions, and promoting the development of green manufacturing. European countries have achieved remarkable results in the energy utilization of straw cellulose, vigorously developing biomass power generation and heating technologies, using biomass resources such as straw cellulose for efficient combustion power generation and district heating, improving energy utilization efficiency, reducing the consumption of fossil fuels such as coal and natural gas, and reducing environmental pollution. In addition, Europe has also conducted in-depth research on the biological conversion technology of straw cellulose, developing a variety of microbial fermentation processes to convert straw cellulose into clean energy such as biogas and biohydrogen, providing support for the diversification of the energy structure. Due to resource scarcity, Japan's research on the utilization of straw cellulose pays more attention to the efficient recovery and high-value utilization of resources. Using advanced chemical and physical technologies, functional materials such as nanocellulose and cellulose derivatives are extracted from straw cellulose for high-end fields such as food, medicine, and cosmetics, improving the added value of products, reducing the dependence on imported raw materials, and enhancing the self-sufficiency of domestic resources.

[0009] In recent years, the research on the utilization of straw cellulose in China has developed rapidly. The research mainly focuses on solving the key technical problems in the process of straw cellulose utilization, improving the utilization efficiency and economic benefits, while reducing environmental pollution and promoting the sustainable development of agriculture. In terms of the pretreatment technology of straw cellulose, domestic researchers have developed a variety of new pretreatment methods, such as steam explosion, microwave pretreatment, ionic liquid pretreatment, etc. These methods can effectively destroy the crystalline structure of straw cellulose, improve the accessibility and enzymatic hydrolysis efficiency of cellulose, and lay a foundation for subsequent conversion and utilization. Significant progress has also been made in the production and application of cellulase in China. By screening and cultivating high-efficiency cellulase-producing strains and optimizing the fermentation production process of the enzyme, the production cost of cellulase has been reduced, and the activity and stability of the enzyme have been improved, making the enzymatic hydrolysis and saccharification process of straw cellulose more efficient and economical. In the aspect of the conversion and utilization of straw cellulose, China has actively explored diversified utilization ways. In addition to the traditional energy utilization and feed utilization, a large amount of research work has been carried out in the fields of cellulose-based materials and biochemicals, and a series of technologies and products with independent intellectual property rights have been developed, such as straw cellulose-based degradable plastics, cellulose ethers, bioethanol, etc. Some products have been industrialized and applied in the market, achieving good economic and social benefits.

[0010] In addition, it has been proven by research that adding a small amount of glycerol can significantly stimulate DIET and efficiently convert methane in anaerobic digestion. The main reason is that glycerol has a stronger stimulating effect on DIET in anaerobic digestion, and more effective electron transfer may compete with the available electrons in non-biodegradable organic matter, humus or organometallic substances in the substrate, thus promoting the conversion of biodegradable organic matter to methane as much as possible.

[0011] To sum up, using the glucose released from straw cellulose for fermentative production of glycerol and adding an appropriate amount of glycerol to the anaerobic digestion system to promote more efficient methane production in the anaerobic digestion reaction system is considered to be a new way to effectively utilize straw and realize the resource utilization of agricultural solid waste straw, and it is also an effective measure to promote methane production in the anaerobic digestion system. Summary of the Invention

[0012] In order to effectively utilize straw cellulose, strengthen the anaerobic digestion to produce methane with straw cellulose as the substrate, improve the methane production, and solve the problem of low efficiency of anaerobic digestion to produce methane, the purpose of the present invention is to provide a device and method for strengthening the anaerobic fermentation of straw to produce methane by coupling the fermentation of crude enzyme solution prepared from Trichoderma viride and yeast glycerol.

[0013] To achieve the above purpose, the present invention provides the following technical solutions:

[0014] The present invention provides a device for enhancing methane production from straw anaerobic fermentation by coupling the preparation of crude enzyme solution with Trichoderma viride and yeast glycerol fermentation. The device mainly includes a Trichoderma viride enzyme production culture system, a cellulase hydrolysis system, a yeast culture system, a yeast fermentation system, and an anaerobic digestion methane production system. The outlet of the Trichoderma viride enzyme production culture system is connected to the inlet of an ultrasonic crusher 18. The outlet of the ultrasonic crusher 18 is connected to the inlet of the cellulase hydrolysis system through a pipeline. The outlet of the cellulase hydrolysis system is connected to the inlet of the yeast fermentation system through a pipeline. The outlet of the yeast culture system is connected to the inlet of the yeast fermentation system through a pipeline. The outlet of the yeast fermentation system is connected to the inlet of the anaerobic digestion methane production system through a pipeline;

[0015] The Trichoderma viride enzyme production culture system mainly includes a feeding tank ⅰ-1 and a Trichoderma viride enzyme production culture tank -8. The outlet of the feeding tank ⅰ-1 is connected to the Trichoderma viride enzyme production culture tank -8 through a pipeline. A heat preservation layer ⅰ-7 is provided on the outer wall side of the Trichoderma viride enzyme production culture tank -8. A stirrer ⅰ-11 is fixedly installed outside the center of the top plate of the Trichoderma viride enzyme production culture tank -8. The main shaft of the stirrer ⅰ-11 penetrates through the top plate and vertically extends into the Trichoderma viride enzyme production culture tank -8. A feeding port ⅰ-9 and a ventilation hole ⅰ-10 are provided on the top plate. A cover is provided on the feeding port ⅰ-9, and the ventilation hole ⅰ-10 is sealed by a sterile breathable sealing film;

[0016] The yeast culture tank system mainly includes a yeast culture tank -37 and a feeding tank ⅱ-12. The yeast culture tank -37 is connected to the feeding tank ⅱ-12 through a pipeline. A heat preservation layer ⅲ-36 is provided on the outer wall side of the yeast culture tank -37. A stirrer ⅲ-34 is fixedly installed outside the center of the top plate of the yeast culture tank -37. The main shaft of the stirrer ⅲ-34 penetrates through the top plate and vertically extends into the yeast culture tank -37. A feeding port ⅱ-35 and a ventilation hole ⅱ-38 are provided on the top plate. A cover is provided on the feeding port ⅱ-35, and the ventilation hole ⅱ-38 is sealed by a sterile breathable sealing film;

[0017] The cellulose enzymatic hydrolysis system mainly includes a cellulose enzymatic hydrolysis tank - 25 and a feed tank III - 49. There is a pipeline connection between the outlet of the feed tank III - 49 and the cellulose enzymatic hydrolysis tank - 25. A stirrer VI - 53 is fixed on the outer side of the center of the top of the feed tank III - 49. The main shaft of the stirrer VI - 53 penetrates through the top of the feed tank III - 49 and vertically extends into the interior of the feed tank III - 49. A feed inlet III - 50 and a water inlet pipe - 52 are provided on the top of the feed tank III - 49. A lid is provided on the feed inlet III - 50, and a water inlet valve - 51 is provided on the water inlet pipe - 52; a heat preservation layer II - 24 is provided on the outer wall side of the cellulose enzymatic hydrolysis tank - 25. A stirrer II - 28 and an air inlet pipe I - 27 are fixed on the outer side of the center of the top plate of the cellulose enzymatic hydrolysis tank - 25. The main shaft of the stirrer II - 28 penetrates through the top plate of the cellulose enzymatic hydrolysis tank - 25 and vertically extends into the interior of the cellulose enzymatic hydrolysis tank - 25. An air inlet valve I - 26 is provided on the air inlet pipe I - 27;

[0018] The yeast fermentation system mainly includes a yeast fermentation tank - 30 with a heat preservation layer IV - 29 on its outer wall side. A stirrer IV - 33 and an air inlet pipe II - 32 are fixed on the outer side of the center of the top plate of the yeast fermentation tank - 30. The main shaft of the stirrer IV - 33 penetrates through the top plate of the yeast fermentation tank - 30 and vertically extends into the interior of the yeast fermentation tank - 30. An air inlet valve II - 31 is provided on the air inlet pipe II - 32;

[0019] The anaerobic digestion and methane production system mainly includes an anaerobic digestion and methane production tank - 40 with a heat preservation layer V - 39 on its outer wall side. The anaerobic digestion and methane production tank - 40 is provided with a discharge pipe 68, and a discharge valve - 67 is provided on the discharge pipe; a stirrer V - 43 and an exhaust pipe - 42 are fixed on the outer side of the center of the top plate of the anaerobic digestion and methane production tank - 40. The main shaft of the stirrer V - 43 penetrates through the top plate of the anaerobic digestion and methane production tank - 40 and vertically extends into the interior of the anaerobic digestion and methane production tank - 40. An exhaust valve - 41 is provided on the exhaust pipe - 42.

[0020] Based on the above technical solutions, further, the outlet of the ultrasonic crusher 18 is connected to the inlet of the cellulose enzymatic hydrolysis system through pipe III - 19, valve III - 20, feed pump II - 21, pipe IV - 22, and valve IV - 23; the outlet of the cellulose enzymatic hydrolysis system is connected to the inlet of the yeast fermentation system through pipe XI - 57, valve XI - 58, feed pump VI - 59, pipe XII - 60, and valve XII - 61. The outlet of the yeast culture system is connected to the inlet of the yeast fermentation system through pipe VII - 44, valve VII - 45, feed pump IV - 46, pipe VIII - 47, and valve VIII - 48. The outlet of the yeast fermentation system is connected to the inlet of the anaerobic digestion and methane production system through pipe XIII - 62, valve XIII - 63, feed pump VII - 64, pipe XIV - 65, and valve XIV - 66.

[0021] Based on the above technical solution, further, a pipe ⅰ-2, a valve ⅰ-3, a feed pump ⅰ-4, a pipe ⅱ-5 and a valve ⅱ-6 are sequentially arranged between the outlet of the feed tank ⅰ-1 and the Trichoderma viride enzyme-producing culture tank -8; a pipe ⅴ-13, a valve ⅴ-14, a feed pump ⅲ-15, a pipe ⅵ-16 and a valve ⅵ-17 are sequentially arranged between the yeast culture tank -37 and the feed tank ⅱ-12; a pipe xv-69, a valve xv-70, a feed pump ⅴ-54, a pipe x-55 and a valve x-56 are sequentially arranged between the outlet of the feed tank ⅲ-49 and the cellulase hydrolysis tank -25.

[0022] Based on the above technical solution, further, the power of the ultrasonic crusher 18 is 10 - 500W.

[0023] The present invention also provides a method for enhancing methane production by anaerobic fermentation of straw through the preparation of crude enzyme solution by Trichoderma viride coupled with yeast glycerol fermentation using the above device, comprising the following steps:

[0024] 1) Transfer the Trichoderma viride enzyme-producing medium to the feed tank ⅰ-1, open the valve ⅰ-3 and the valve ⅱ-6, and the medium in the feed tank ⅰ-1 is transported into the Trichoderma viride enzyme-producing culture tank -8 through the feed pump ⅰ-4;

[0025] 2) Open the cover of the feed port ⅰ-9 of the Trichoderma viride enzyme-producing culture tank, add the Trichoderma viride spore suspension to the Trichoderma viride enzyme-producing culture tank -8 through the feed port ⅰ-9 at an inoculation rate of 10%, and close the cover of the feed port ⅰ-9; close the valve ⅱ-6, open the stirrer ⅰ-11, control the stirrer speed to be 100 - 200 rpm, and continuously stir to increase the dissolved oxygen in the solution; the water bath temperature in the heat preservation layer ⅰ-7 of the Trichoderma viride enzyme-producing culture tank -8 is controlled at 28 - 32 °C, and the hydraulic retention time is 160 - 180 h;

[0026] 3) Transfer the yeast expansion medium to the feed tank ⅱ-12, open the valve v-14 and the valve vi-17, and the medium in the feed tank ⅱ-12 is transported into the yeast culture tank -37 through the feed pump iii-15; open the cover of the feed port ⅱ-35 of the yeast culture tank, add the mother liquor of Candida glycerinogenes to the yeast culture tank -37 through the feed port ⅱ-35 at an inoculation rate of 10%, and close the cover of the feed port ⅱ-35; close the valve ⅵ-17, open the stirrer ⅲ-34, control its speed to be 100 - 200 rpm, and continuously stir to increase the dissolved oxygen in the solution; the water bath temperature of the heat preservation layer ⅲ-36 of the yeast culture tank -37 is 28 - 34 °C, and the hydraulic retention time is 8 - 16 h;

[0027] 4) Open the inlet valve - 51, add high - purity water into the feed tank iii - 49 through the inlet pipe - 52, start the stirrer vi - 53, control the stirrer speed at 100 - 200 rpm, add cellulose powder through the feed port iii - 50 to make a cellulose aqueous solution, and adjust the pH value to 4 - 6; Open the valve xv - 70 and the valve x - 56, and the cellulose aqueous solution in the feed tank iii - 49 is transported into the cellulose enzymolysis tank - 25 through the feed pump v - 54. The stirrer vi - 53 keeps stirring to avoid cellulose sedimentation and prevent it from remaining at the bottom of the feed tank; Open the ultrasonic crusher - 18, the valve iii - 20 and the valve iv - 23, and the cellulase - producing culture solution of Trichoderma viride in the Trichoderma viride cellulase - producing culture tank - 8 is transported into the cellulose enzymolysis tank - 25 through the feed pump ii - 21. Close the valve iv - 23 and the valve x - 56, open the stirrer ii - 28, control the stirrer speed at 100 - 200 rpm, and keep stirring to make the solution mix evenly. The water - bath temperature of the insulation layer ii - 24 of the cellulose enzymolysis tank - 25 is controlled at 28 - 32 °C, and the optimal value of the hydraulic retention time is 6 - 10 d;

[0028] 5) Take the enzymolyzed cellulose and reducing - sugar mixture in the cellulose enzymolysis tank - 25 in step 4) as the raw material of the yeast fermentation tank - 30. Open the valve xi - 58 and the valve xii - 61, and the cellulose and reducing - sugar mixture is transported into the yeast fermentation tank - 30 through the feed pump vi - 59; The stirrer ii - 28 keeps stirring to avoid cellulose sedimentation and prevent it from remaining at the bottom of the cellulose enzymolysis tank - 25; Open the valve vii - 45 and the valve viii - 48, and the yeast culture solution in the yeast culture tank - 37 is transported into the yeast fermentation tank - 30 through the feed pump iv - 46; Close the valve viii - 48, open the stirrer iv - 33, control the stirrer speed at 100 - 200 rpm, and keep stirring to make the solution mix evenly; The water - bath temperature of the water - bath insulation layer iv - 29 of the yeast fermentation tank - 30 is controlled at 28 - 34 °C, and the hydraulic retention time is 2 - 5 d;

[0029] 6) Open valve xiii-63 and valve xiv-66. The mixture after fermentation in the yeast fermenter-30 enters the anaerobic digestion methane-producing tank-40 from the bottom through the feed pump vii-64. Close valve xiv-66, turn on the stirrer v-43, control the stirrer speed at 80 - 120 rpm, use the sludge as the source of inoculated microorganisms, mix the fermented mixture evenly with the sludge, with the sludge concentration being 5 - 50 g / L, and control the pH in the anaerobic digestion methane-producing tank-40 at 6.8 - 7.2; the water bath temperature of the water bath insulation layer v-39 of the anaerobic digestion methane-producing tank-40 is 35 - 40 °C, and the hydraulic retention time is controlled at 30 - 60 d; during anaerobic digestion, open the exhaust valve-41, and the gas generated in the anaerobic digestion methane-producing tank-40 is discharged through the exhaust pipe-42; after anaerobic digestion is completed, open the discharge valve-67, and the fermented waste is discharged through the discharge pipe-68.

[0030] Based on the above technical solution, further, the Trichoderma viride enzyme-producing medium described in step 1) is prepared by mixing glucose, potato powder, cellulose, potassium dihydrogen phosphate, magnesium sulfate heptahydrate, and water in a mass ratio of 10:10:10:3:1.5:1000, and sterilizing.

[0031] Based on the above technical solution, further, control the stirrer speed at 150 rpm in step 2); the total volume of the Trichoderma viride mixture is 1.1 L, of which 1 L is used as the source of cellulase in the cellulase hydrolysis tank-25, and 100 ml remains in the Trichoderma viride enzyme-producing culture tank-8 as the Trichoderma viride mother liquor for the next batch; the water bath temperature in the insulation layer ⅰ-7 of the Trichoderma viride enzyme-producing culture tank-8 is 30 °C, and the hydraulic retention time is 168 h.

[0032] Based on the above technical solution, further, the yeast expansion culture medium described in step 3) is prepared by mixing glucose, yeast extract powder, peptone, and water in a mass ratio of 20:10:20:1000, adjusting the pH value to 4 - 5, and sterilizing; the total volume of the glycerol-producing Candida yeast liquid mixture after expansion culture is 1.1 L, of which 1 L is used as the inoculated microorganism in the yeast fermenter-30, and 100 ml remains in the yeast culture tank-37 as the yeast mother liquor for the next batch of expansion culture; the water bath temperature of the insulation layer ⅲ-36 of the yeast culture tank-37 is 32 °C, and the hydraulic retention time is 12 h.

[0033] Based on the above technical solution, further, the mass ratio of the cellulose powder to the high-purity water in step 4) is 1:50 - 500; the volume ratio of the cellulose solution entering the cellulase hydrolysis tank-25 to the Trichoderma viride enzyme solution is 100:8; the water bath temperature of the insulation layer ii-24 of the cellulase hydrolysis tank-25 is controlled at 30 °C, and the optimal value of the hydraulic retention time is 8.09 d.

[0034] Based on the above technical solution, further, the volume ratio of the cellulose and reducing sugar mixture to the yeast culture solution in step 5) is 50 to 5:1. The water bath temperature of the water bath insulation layer iv-29 of the yeast fermenter -30 is controlled at 32 °C, and the hydraulic retention time is 3 d.

[0035] Based on the above technical solution, further, the water bath temperature of the water bath insulation layer v-39 of the anaerobic digestion methane production tank -40 in step 6) is 37 °C, and the hydraulic retention time is controlled at 45 d; the anaerobic digestion methane production tank -40 adopts a CSTR completely mixed anaerobic reactor, the sludge concentration is 10 to 20 g / L, and the pH in the anaerobic digestion methane production tank -40 is controlled at 7.0.

[0036] The main mechanism of the application of the present invention is as follows:

[0037] 1. Using Trichoderma viride to prepare crude enzyme solution for enzymatic hydrolysis of cellulose to produce reducing sugar has less investment, higher yield and simpler operation compared with using industrial cellulase. The advantage of this method is that during the pretreatment of cellulose, only 8% of the crude enzyme solution dosage is used, and by adjusting the enzymatic hydrolysis time and the system pH, a better reducing sugar yield can be obtained. The crude enzyme solution refers to an enzyme solution that is not highly purified obtained by methods such as microbial fermentation or biological extraction, which contains various enzyme classes and other bioactive components. During the cellulase hydrolysis process, the crude enzyme solution usually contains cellulase components such as endoglucanase, exoglucanase, and β-glucosidase. These enzymes act synergistically to effectively decompose cellulose into fermentable sugars. Compared with pure enzyme preparations, the crude enzyme solution has the advantages of low cost, wide source, and rich enzyme system. The various auxiliary enzymes and bioactive substances it contains may play a synergistic promoting role during the cellulase hydrolysis process, improving the enzymatic hydrolysis efficiency and product yield. The preparation process of the crude enzyme solution is relatively simple, does not require complex purification steps, can retain the original activity and stability of the enzyme, and is more suitable for the needs of large-scale industrial applications.

[0038] 2. Crude enzyme liquid usually contains a variety of enzymes, and there is a synergistic effect between these enzymes, which can significantly improve the enzymatic hydrolysis efficiency of cellulose. Taking the crude enzyme liquid produced by green Trichoderma fermentation as an example, the endoglucanase in it can randomly act on the glycosidic bonds inside the cellulose molecules, cutting the long-chain cellulose molecules into shorter oligosaccharide chains, increasing the accessibility of cellulose; exoglucanase cuts off the glucose units one by one from the end of the cellulose chain, further degrading the oligosaccharide chain; β-glucosidase can hydrolyze oligosaccharides such as cellobiose into glucose, relieving the inhibitory effect of cellobiose on other cellulases, thereby promoting the continuation of the entire enzymatic hydrolysis process. The synergistic effect of these three enzymes enables cellulose to be efficiently degraded into glucose, while a single cellulase is often difficult to achieve such an efficient degradation effect. Experimental data show that under the same reaction conditions, the use of green Trichoderma crude enzyme liquid to enzymatically hydrolyze microcrystalline cellulose, the amount of glucose generated within 48 hours is 30%-50% higher than that of endoglucanase or exoglucanase alone, which fully reflects the advantages of the synergistic effect of multiple enzymes.

[0039] 3. The fermentation of glycerol by glycerol-producing Candida albicans requires little investment, high yield and is easy to operate. Only 100 ml of glycerol-producing Candida albicans mother liquor is needed. After expansion, part of it is used for fermentation, and the rest is reserved for the next expansion. No additional bacterial solution is needed, which not only saves a lot of money, but also significantly improves yeast activity and effectively shortens the pre-fermentation time for glycerol production. After expansion, the glycerol-producing Candida albicans is added to the cellulose hydrolysate to directly generate glycerol. The glycerol obtained by fermentation does not need to be extracted separately, and can be put into the methane production tank together with the cellulose fermentation product, which solves the problem of glycerol extraction difficulty in biomass glycerol production technology and reduces the difficulty of operation.

[0040] 4. Adding an appropriate amount of glycerol can significantly stimulate DIET in the anaerobic digestion system and promote the efficient methane production of the system. In the anaerobic digestion process, glycerol has a stronger stimulating effect on DIET. Because more efficient electron transfer will compete with the effective electrons contained in the non-biodegradable organic matter, humus and organic metal substances in the substrate, it can promote the conversion of biodegradable organic matter into methane to the greatest extent. This method uses enzymatic hydrolysis of cellulose to prepare reducing sugars, which are then fermented to produce glycerol. Specifically, reducing sugars are directly produced in the cellulose substrate for anaerobic digestion and methanogenesis, and the reducing sugars are used as substrates for fermentation to produce glycerol. Subsequently, the fermentation mixture containing cellulose is allowed to enter the methanogenesis tank together to carry out anaerobic digestion and methanogenesis operations, thereby constructing a methanogenesis pathway with direct interspecies electron transfer as the core, effectively improving the efficiency of anaerobic digestion, the rate of methanogenesis and the yield of methane.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The crude enzyme solution containing cellulase is prepared from Trichoderma viride, and used to hydrolyze cellulose to accumulate reducing sugar. Then, using the reducing sugar as the substrate, Candida glycerinogenes is used for fermentation to produce glycerol. It is also known that glycerol can greatly promote the formation of a DIET-dominated methanogenic pathway in the methanogenic tank, effectively alleviating problems such as system acidification collapse caused by the accumulation of organic acids during the fermentation of cellulose, thereby improving the methanogenic efficiency and rate of the system. The crude enzyme solution prepared after the expansion culture of Trichoderma viride significantly reduces the high cost of industrial cellulase; at the same time, Candida glycerinogenes is expanded and then fermented to produce glycerol, thus shortening the fermentation time. During the expansion culture process, stirring brings appropriate dissolved oxygen, enabling Trichoderma viride to proliferate and synthesize cellulase more efficiently; during the fermentation process, stirring homogenizes the system, can improve the glycerol yield of Candida glycerinogenes and shorten the fermentation time; the cellulase in the crude enzyme solution does not need to be extracted, and the incompletely utilized cellulose along with it enters the cellulase hydrolysis tank, and the glycerol produced by the fermentation of reducing sugar in the yeast fermentation tank does not need to be extracted, and the mixed solution enters the methanogenic tank together for anaerobic digestion; the Trichoderma viride enzyme production culture tank, cellulase hydrolysis tank, yeast culture tank and yeast fermentation tank are equipped with stirrers, and the Trichoderma viride enzyme production culture tank and yeast culture tank are equipped with ventilation holes. Stirring is used to promote dissolved oxygen and homogenization, which is beneficial to the proliferation of Trichoderma viride and Candida glycerinogenes, enabling the synthesis of cellulase and the fermentation of glycerol to promote the anaerobic digestion of cellulose to produce methane. When glycerol is present in the methanogenic tank, the anaerobic digestion rate and methane production capacity can be improved; the investment cost of this technology is low, the operation is simple, and the methanogenic efficiency is high. Description of the Drawings

[0043] Figure 1This is a schematic diagram of the device for enhancing methane production from straw anaerobic fermentation by coupling the preparation of crude enzyme solution with Trichoderma viride and yeast glycerol fermentation. In the figure: 1: Feed tank ⅰ, 2: Pipe ⅰ, 3: Valve ⅰ, 4: Feed pump ⅰ, 5: Pipe ⅱ, 6: Valve ⅱ, 7: Thermal insulation layer ⅰ, 8: Trichoderma viride enzyme production culture tank, 9: Feed inlet ⅰ, 10: Vent hole ⅰ, 11: Agitator ⅰ, 12: Feed tank ⅱ, 13: Pipe ⅴ, 14: Valve ⅴ, 15: Feed pump ⅲ, 16: Pipe ⅵ, 17: Valve ⅵ, 18: Ultrasonic crusher, 19: Pipe ⅲ, 20: Valve ⅲ, 21: Feed pump ⅱ, 22: Pipe ⅳ, 23: Valve ⅳ, 24: Thermal insulation layer ⅱ, 25: Cellulose enzymatic hydrolysis tank, 26: Intake valve ⅰ, 27: Intake pipe ⅰ, 28: Agitator ⅱ, 29: Thermal insulation layer ⅳ, 30: Yeast fermentation tank, 31: Intake valve ⅱ, 32: Intake pipe ⅱ, 33: Agitator ⅳ, 34: Agitator ⅲ, 35: Feed inlet ⅱ, 36: Thermal insulation layer ⅲ, 37: Yeast culture tank, 38: Vent hole ⅱ, 39: Thermal insulation layer ⅴ, 40: Anaerobic digestion methane production tank, 41: Exhaust valve, 42: Exhaust pipe, 43: Agitator ⅴ, 44: Pipe ⅶ, 45: Valve ⅶ, 46: Feed pump ⅳ, 47: Pipe ⅷ, 48: Valve ⅷ, 49: Feed tank ⅲ, 50: Feed inlet ⅲ, 51: Water inlet valve, 52: Water inlet pipe, 53: Agitator ⅵ, 54: Feed pump ⅴ, 55: Pipe x, 56: Valve x, 57: Pipe xi, 58: Valve xi, 59: Feed pump vi, 60: Pipe xii, 61: Valve xii, 62: Pipe xiii, 63: Valve xiii, 64: Feed pump vii, 65: Pipe xiv, 66: Valve xiv, 67: Discharge valve, 68: Discharge pipe, 69: Pipe xv, 70: Valve xv.

[0044] Figure 2 This is a top view of the top plates of the Trichoderma viride enzyme production culture tank 8 and the yeast culture tank 37 in the device for enhancing methane production from straw anaerobic fermentation by coupling the preparation of crude enzyme solution with Trichoderma viride and yeast glycerol fermentation. In the figure, 8: Trichoderma viride enzyme production culture tank, 9: Feed inlet ⅰ, 10: Vent hole ⅰ, 11: Agitator ⅰ, 34: Agitator ⅲ, 35: Feed inlet ii, 37: Yeast culture tank, 38: Vent hole ⅱ.

[0045] Figure 3 This is the growth curve of Candida glycerinogenes of the present invention during amplification culture at 32 °C and pH 5.5. Detailed implementation manners

[0046] The present invention will be described in detail below in conjunction with the embodiments. However, the implementation manners of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, without creative efforts, obtaining other similar embodiments will fall within the protection scope of the present invention.

[0047] The source of Trichoderma viride is: Henan Engineering and Technology Research Center for Industrial Microbial Strains.

[0048] The source of Candida glycerinogenes is: Shanghai Ruichu Biotechnology Co., Ltd.

[0049] Example 1

[0050] This example provides a device for enhancing methane production from straw anaerobic fermentation by coupling the preparation of crude enzyme solution with Trichoderma viride and yeast glycerol fermentation. As Figure 1 shown, the device mainly includes a Trichoderma viride enzyme production culture system, a cellulase hydrolysis system, a yeast culture system, a yeast fermentation system, and an anaerobic digestion methane production system. The outlet of the Trichoderma viride enzyme production culture system is connected to the inlet of the ultrasonic crusher 18. The outlet of the ultrasonic crusher 18 is connected to the inlet of the cellulase hydrolysis system through pipe iii - 19, valve iii - 20, feed pump ii - 21, pipe iv - 22, and valve iv - 23. The outlet of the cellulase hydrolysis system is connected to the inlet of the yeast fermentation system through pipe xi - 57, valve xi - 58, feed pump vi - 59, pipe xii - 60, and valve xii - 61. The outlet of the yeast culture system is connected to the inlet of the yeast fermentation system through pipe vii - 44, valve vii - 45, feed pump iv - 46, pipe viii - 47, and valve viii - 48. The outlet of the yeast fermentation system is connected to the inlet of the anaerobic digestion methane production system through pipe xiii - 62, valve xiii - 63, feed pump vii - 64, pipe xiv - 65, and valve xiv - 66;

[0051] The Trichoderma viride enzyme production culture system mainly includes a feed tank i - 1 and a Trichoderma viride enzyme production culture tank - 8. Between the outlet of the feed tank i - 1 and the Trichoderma viride enzyme production culture tank - 8, there are successively arranged pipe i - 2, valve i - 3, feed pump i - 4, pipe ii - 5, and valve ii - 6. The outer wall side of the Trichoderma viride enzyme production culture tank - 8 is provided with a heat preservation layer i - 7. The outer center of the top plate of the Trichoderma viride enzyme production culture tank - 8 is fixed with a stirrer i - 11. The main shaft of the stirrer i - 11 penetrates through the top plate and vertically extends into the Trichoderma viride enzyme production culture tank - 8. There are a feed port i - 9 and a ventilation hole i - 10 on the top plate. The feed port i - 9 is provided with a cover, and the ventilation hole i - 10 is sealed by a sterile breathable sealing film;

[0052] The yeast culture tank system mainly includes a yeast culture tank - 37 and a feed tank ii - 12. Between the yeast culture tank - 37 and the feed tank ii - 12, there are successively arranged a pipe v - 13, a valve v - 14, a feed pump iii - 15, a pipe vi - 16, and a valve vi - 17. On the outer wall side of the yeast culture tank - 37, there is a heat preservation layer iii - 36. At the center outside of the top plate of the yeast culture tank - 37, a stirrer iii - 34 is fixed. The main shaft of the stirrer iii - 34 penetrates through the top plate and vertically extends into the yeast culture tank - 37. On the top plate, there are a feed port ii - 35 and a ventilation hole ii - 38. There is a lid on the feed port ii - 35, and the ventilation hole ii - 38 is sealed by a sterile breathable sealing film;

[0053] The cellulose enzymolysis system mainly includes a cellulose enzymolysis tank - 25 and a feed tank iii - 49. Between the outlet of the feed tank iii - 49 and the cellulose enzymolysis tank - 25, there are successively arranged a pipe xv - 69, a valve xv - 70, a feed pump v - 54, a pipe x - 55, and a valve x - 56. At the center outside of the top of the feed tank iii - 49, a stirrer vi - 53 is fixed. The main shaft of the stirrer vi - 53 penetrates through the top of the feed tank iii - 49 and vertically extends into the interior of the feed tank iii - 49. On the top of the feed tank iii - 49, there are a feed port iii - 50 and a water inlet pipe - 52. There is a lid on the feed port iii - 50, and a water inlet valve - 51 is provided on the water inlet pipe - 52; On the outer wall side of the cellulose enzymolysis tank - 25, there is a heat preservation layer ii - 24. At the center outside of the top plate of the cellulose enzymolysis tank - 25, a stirrer ii - 28 and an air inlet pipe i - 27 are fixed. The main shaft of the stirrer ii - 28 penetrates through the top plate of the cellulose enzymolysis tank - 25 and vertically extends into the cellulose enzymolysis tank - 25. An air inlet valve i - 26 is provided on the air inlet pipe i - 27;

[0054] The yeast fermentation system mainly includes a yeast fermentation tank - 30 with a heat preservation layer iv - 29 on its outer wall side. At the center outside of the top plate of the yeast fermentation tank - 30, a stirrer iv - 33 and an air inlet pipe ii - 32 are fixed. The main shaft of the stirrer iv - 33 penetrates through the top plate of the yeast fermentation tank - 30 and vertically extends into the yeast fermentation tank - 30. An air inlet valve ii - 31 is provided on the air inlet pipe ii - 32;

[0055] The anaerobic digestion and methane production system mainly includes an anaerobic digestion and methane production tank - 40 with a heat preservation layer v - 39 on its outer wall side. The anaerobic digestion and methane production tank - 40 is provided with a discharge pipe 68, and a discharge valve - 67 is arranged on the discharge pipe; At the center outside of the top plate of the anaerobic digestion and methane production tank - 40, a stirrer v - 43 and an exhaust pipe - 42 are fixed. The main shaft of the stirrer v - 43 penetrates through the top plate of the anaerobic digestion and methane production tank - 40 and vertically extends into the anaerobic digestion and methane production tank - 40. An exhaust valve - 41 is provided on the exhaust pipe - 42.

[0056] Example 2

[0057] This embodiment provides a method for preparing a crude enzyme solution using the apparatus of Embodiment 1 and coupling the glycerol fermentation of yeast to enhance the anaerobic fermentation of straw to produce methane by Trichoderma viride, including the following steps:

[0058] 1) Glucose, potato powder, cellulose, potassium dihydrogen phosphate, magnesium sulfate heptahydrate, and water were sequentially mixed into a solution in a ratio of 10 g, 10 g, 10 g, 3 g, 1.5 g, and 1 L, sterilized, used as the Trichoderma viride enzyme production medium, and transferred to the feed tank ⅰ-1;

[0059] 2) Valve ⅰ-3 and valve ⅱ-6 were opened, and the medium in the feed tank ⅰ-1 entered the feed pump ⅰ-4 through the pipe ⅰ-2 and was finally transported into the Trichoderma viride enzyme production culture tank -8 through the pipe ⅱ-5;

[0060] 3) The lid of the feed port ⅰ-9 of the Trichoderma viride enzyme production culture tank was opened, and 100 ml of Trichoderma viride spore suspension was added to the Trichoderma viride enzyme production culture tank -8 through the feed port ⅰ-9 at an inoculation rate of 10%, and the lid of the feed port ⅰ-9 was closed;

[0061] 4) Valve ⅱ-6 was closed, the stirrer ⅰ-11 was turned on, and its rotation speed was controlled at 150 rpm, and continuous stirring was performed to increase the dissolved oxygen in the solution;

[0062] 5) The total volume of the Trichoderma viride mixture was 1.1 L, of which 1 L was used as the source of cellulase in the cellulase hydrolysis tank -25, and 100 ml was left in the Trichoderma viride enzyme production culture tank -8 as the Trichoderma viride mother liquor for the next domestication and enzyme production;

[0063] 6) The Trichoderma viride enzyme production culture tank -8 was water-bath insulated by the insulation layer ⅰ-7, the water-bath temperature was 30 °C, and the hydraulic retention time was 168 h;

[0064] 7) Glucose, yeast extract, peptone, and water were sequentially mixed into a solution in a ratio of 20 g, 10 g, 20 g, and 1 L, the pH value was adjusted to 5.5, sterilized, used as the yeast expansion culture medium, and transferred to the feed tank ⅱ-12;

[0065] 8) Valve v-14 and valve vi-17 were opened, and the medium in the feed tank ⅱ-12 entered the feed pump iii-15 through the pipe v-13 and was finally transported into the yeast culture tank -37 through the pipe vi-16;

[0066] 9) The lid of the feed port ⅱ-35 of the yeast culture tank was opened, and 100 ml of the mother liquor of Candida glycerinogenes was added to the yeast culture tank -37 through the feed port ⅱ-35 at an inoculation rate of 10%, and the lid of the feed port ⅱ-35 was closed;

[0067] 10) Valve ⅵ-17 was closed, the stirrer ⅲ-34 was turned on, and its rotation speed was controlled at 150 rpm, and continuous stirring was performed to increase the dissolved oxygen in the solution;

[0068] 11) The total volume of the cultured bacterial liquid mixture after expansion is 1.1 L, of which 1 L is used as the introduced microorganism in the yeast fermenter - 30, and 100 ml is left in the yeast culture tank - 37 as the yeast mother liquid for the next expansion culture.

[0069] 12) The yeast culture tank - 37 is kept warm by a water bath with the heat preservation layer iii - 36. The water bath temperature is 32 °C, and the hydraulic retention time is 12 h.

[0070] 13) Open the inlet valve - 51, add 10 L of high - purity water into the feed tank iii - 49 through the inlet pipe - 52, start the stirrer vi - 53, and control the rotation speed at 150 rpm.

[0071] 14) Add 100 g of cellulose powder through the feed port iii - 50, mix it with water to make a cellulose aqueous solution, and adjust the pH value to 5.3.

[0072] 15) Open the valve xv - 70 and the valve x - 56. The cellulose solution in the feed tank iii - 49 enters the feed pump v - 54 through the pipe xv - 69, and finally is transported into the cellulose enzymolysis tank - 25 through the pipe x - 55. The stirrer vi - 53 keeps stirring to avoid cellulose sedimentation and prevent it from remaining at the bottom of the feed tank.

[0073] 16) Open the ultrasonic crusher - 18 (the parameters of the ultrasonic crusher should be set as follows: power 50% - 150 W, ultrasonic crushing time 12 min, both the ultrasonic on - time and off - time are 3 s), the valve iii - 20 and the valve iv - 23. The cellulase - producing culture solution of Trichoderma viride in the Trichoderma viride cellulase - producing culture tank - 8 enters the feed pump ii - 21 through the pipe iii - 19, and finally is transported into the cellulose enzymolysis tank - 25 through the pipe iv - 22.

[0074] 17) The volume ratio of the cellulose solution entering the cellulose enzymolysis tank - 25 to the Trichoderma viride enzyme solution entering the cellulose enzymolysis tank - 25 is 100:8.

[0075] 18) Close the valve iv - 23 and the valve x - 56, open the stirrer ii - 28, control its rotation speed at 150 rpm, and keep stirring to make the solution mix evenly.

[0076] 19) The cellulose enzymolysis tank - 25 is kept warm by a water bath with the heat preservation layer ii - 24. The water bath temperature is 30 °C, and the optimal value of the hydraulic retention time is 8.09 d.

[0077] 20) Using the cellulase-hydrolyzed cellulose and reducing sugar mixture in the above step 19) as the feed for the yeast fermenter - 30, open valve xi - 58 and valve xii - 61. The cellulose and reducing sugar mixture in the cellulase hydrolysis tank - 25 enters the feed pump vi - 59 through pipe xi - 57 and is finally transported through pipe xii - 60 into the yeast fermenter - 30; the agitator ii - 28 continuously stirs to prevent cellulose sedimentation and its retention at the bottom of the cellulase hydrolysis tank - 25;

[0078] 21) Open valve vii - 45 and valve viii - 48. The yeast culture solution in the yeast culture tank - 37 enters the feed pump iv - 46 through pipe vii - 44 and is finally transported through pipe viii - 47 into the yeast fermenter - 30;

[0079] 22) Close valve viii - 48, open agitator iv - 33, control its rotation speed at 150 rpm, and continuously stir to make the solution mix evenly;

[0080] 23) The yeast fermenter - 30 is water - bath insulated by the water - bath insulation layer iv - 29. Control the water - bath temperature at 32 °C and the hydraulic retention time at 3 d;

[0081] 24) Open valve xiii - 63 and valve xiv - 66. The fermented mixture enters the anaerobic digestion and methane - production tank - 40 from the bottom through pipe xiii - 62, feed pump vii - 64, and pipe xiv - 65;

[0082] 25) The anaerobic digestion and methane - production tank - 40 is water - bath insulated by the water - bath insulation layer v - 39. Control the water - bath temperature at 37 °C and the hydraulic retention time at 45 d;

[0083] 26) The anaerobic digestion and methane - production tank - 40 of this process uses a CSTR completely - mixed anaerobic reactor. Using sludge as the source of inoculated microorganisms, with a sludge concentration of 15 g / L, control the pH inside the anaerobic digestion and methane - production tank - 40 at 7.0;

[0084] 27) Close valve xiv - 66, open agitator v - 43, control its rotation speed at 100 rpm, and mix the fermented liquid with the sludge evenly for full reaction;

[0085] 28) Open the exhaust valve - 41. The gas generated in the anaerobic digestion and methane - production tank - 40 is discharged through the exhaust pipe - 42;

[0086] 29) According to the hydraulic retention time of the anaerobic digestion and methane - production tank - 40, open the discharge valve - 67, and the fermented waste is discharged through the discharge pipe - 68.

[0087] Cellulose solution with a concentration of 10 g / L is added to the cellulase hydrolysis tank to produce reducing sugar through enzymatic hydrolysis, produce glycerol through fermentation, and promote anaerobic digestion to produce methane. The methane production is about 0.75 m 3 / m 3 / day (methane volume / reactor volume / day). Compared with the control group (cellulose not degraded by Trichoderma viride), the methane production per unit COD increased by 80%-192%, and the improvement effect was most obvious after 45 days.

[0088] Appendix Figure 3 shows the growth curve of Candida glycerinogenes in the present invention during expansion culture at 32 °C and pH 5.5, and determines that the optimal hydraulic retention time in the yeast culture tank 37 is 12 h.

[0089] In terms of circular economy, the utilization of straw cellulose realizes the closed-loop flow and efficient utilization of resources, reduces waste emissions and resource waste; the utilization of straw cellulose makes important contributions to saving resources such as wood and water resources and promoting the development of circular economy. The pretreatment of cellulose by Trichoderma viride to enhance anaerobic digestion for methane production has multiple significant effects: First, it opens up a new utilization path for cellulose and greatly improves its utilization efficiency; Second, it significantly accelerates the anaerobic digestion rate of cellulose as a substrate and increases the methane output; Third, it effectively stabilizes the anaerobic digestion system. Moreover, this technology also has unique advantages, with low investment cost, convenient operation, and quite considerable production efficiency.

Claims

1. A device for preparing crude enzyme solution by using Trichoderma viride coupled with yeast glycerol fermentation to strengthen anaerobic fermentation of straw to produce methane, characterized in that: The device mainly comprises a green Trichoderma enzyme production culture system, a cellulose enzymatic hydrolysis system, a yeast culture system, a yeast fermentation system, and an anaerobic digestion methanogensis system. The outlet of the green Trichoderma enzyme production culture system is connected to the inlet of an ultrasonic disruptor (18), the outlet of the ultrasonic disruptor (18) is connected to the inlet of the cellulose enzymatic hydrolysis system through a pipeline, the outlet of the cellulose enzymatic hydrolysis system is connected to the inlet of the yeast fermentation system through a pipeline, the outlet of the yeast culture system is connected to the inlet of the yeast fermentation system through a pipeline, and the outlet of the yeast fermentation system is connected to the inlet of the anaerobic digestion methanogensis system through a pipeline. The green Trichoderma enzyme production culture system mainly comprises a feed tank i (1) and a green Trichoderma enzyme production culture tank (8), the outlet of the feed tank i (1) and the green Trichoderma enzyme production culture tank (8) are connected by a pipeline, the outer wall side of the green Trichoderma enzyme production culture tank (8) is provided with a heat preservation layer i (7), a stirrer i (11) is fixed on the outer side of the center of the top plate of the green Trichoderma enzyme production culture tank (8), the main shaft of the stirrer i (11) passes through the top plate and vertically extends into the interior of the green Trichoderma enzyme production culture tank (8), a feed port i (9) and a vent i (10) are provided on the top plate, the feed port i (9) is provided with a cover, and the vent i (10) is sealed by a sterile breathable sealing film; The yeast culture tank system mainly comprises a yeast culture tank (37) and a feed tank ii (12), the yeast culture tank (37) and the feed tank ii (12) are connected by a pipeline, a heat preservation layer iii (36) is arranged on the outer wall side of the yeast culture tank (37), an agitator iii (34) is fixed on the outer side of the center of the top plate of the yeast culture tank (37), the main shaft of the agitator iii (34) passes through the top plate and vertically extends into the interior of the yeast culture tank (37), a feed port ii (35) and a vent hole ii (38) are arranged on the top plate, a cover is arranged on the feed port ii (35), and the vent hole ii (38) is sealed by a sterile breathable sealing film; The cellulose enzymatic hydrolysis system mainly comprises a cellulose enzymatic hydrolysis tank (25) and a feed tank ⅲ (49), wherein the outlet of the feed tank ⅲ (49) is connected to the cellulose enzymatic hydrolysis tank (25) through a pipeline, and an agitator ⅵ (53) is fixed to the outer side of the top center of the feed tank ⅲ (49), and the main shaft of the agitator ⅵ (53) passes through the top of the feed tank ⅲ (49) and vertically extends into the interior of the feed tank ⅲ (49), and a feed port ⅲ (50) and a water inlet pipe (52) are arranged on the top of the feed tank ⅲ (49), A cover is provided on the feed port ⅲ (50), and a water inlet valve (51) is provided on the water inlet pipe (52); a heat-insulating layer ⅱ (24) is provided on the outer wall side of the cellulose enzymolysis tank (25), and an agitator ⅱ (28) and an air inlet pipe ⅰ (27) are fixed on the outer side of the center of the top plate of the cellulose enzymolysis tank (25), and the main shaft of the agitator ⅱ (28) penetrates the top plate of the cellulose enzymolysis tank (25) and vertically extends into the interior of the cellulose enzymolysis tank (25), and an air inlet valve ⅰ (26) is provided on the air inlet pipe ⅰ (27); The yeast fermentation system mainly comprises a yeast fermentation tank (30) with an insulation layer ⅳ (29) provided on the outer wall side, a stirrer ⅳ (33) and an air intake pipe ⅱ (32) are fixed on the outer side of the center of the top plate of the yeast fermentation tank (30), the main shaft of the stirrer ⅳ (33) passes through the top plate of the yeast fermentation tank (30) and vertically extends into the interior of the yeast fermentation tank (30), and an air intake valve ⅱ (31) is provided on the air intake pipe ⅱ (32); The anaerobic digestion methane production system mainly comprises an anaerobic digestion methane production tank (40) having an insulation layer V (39) on the outer wall side, the anaerobic digestion methane production tank (40) being provided with a discharge pipe (68), and a discharge valve (67) being arranged on the discharge pipe; an agitator V (43) and an exhaust pipe (42) are fixed to the outer side of the center of the top plate of the anaerobic digestion methane production tank (40), the main shaft of the agitator V (43) passes through the top plate of the anaerobic digestion methane production tank (40) and vertically extends into the interior of the anaerobic digestion methane production tank (40), and an exhaust valve (41) is arranged on the exhaust pipe (42).

2. The device according to claim 1, characterized in that The outlet of the ultrasonic disruptor (18) is connected to the inlet of the cellulose enzymatic hydrolysis system through a pipe iii (19), a valve iii (20), a feed pump ii (21), a pipe iv (22), and a valve iv (23); the outlet of the cellulose enzymatic hydrolysis system is connected to the inlet of the yeast fermentation system through a pipe xi (57), a valve xi (58), a feed pump vi (59), a pipe xii (60), and a valve xii (61); the outlet of the yeast culture system is connected to the inlet of the yeast fermentation system through a pipe ⅶ (44), a valve ⅶ (45), a feed pump iv (46), a pipe ⅷ (47), and a valve ⅷ (48); the outlet of the yeast fermentation system is connected to the inlet of the anaerobic digestion methanogenesis system through a pipe xiii (62), a valve xiii (63), a feed pump vii (64), a pipe xiv (65), and a valve xiv (66).

3. The device according to claim 1, characterized in that A pipe i (2), a valve i (3), a feed pump i (4), a pipe ii (5) and a valve ii (6) are sequentially arranged between the outlet of the feed tank i (1) and the green Trichoderma enzyme production culture tank (8); a pipe v (13), a valve v (14), a feed pump iii (15), a pipe vi (16) and a valve vi (17) are sequentially arranged between the outlet of the feed tank iii (49) and the cellulose enzymatic hydrolysis tank (25); a pipe xv (69), a valve xv (70), a feed pump v (54), a pipe x (55) and a valve x (56) are sequentially arranged between the outlet of the feed tank iii (49) and the cellulose enzymatic hydrolysis tank (25).

4. The device according to claim 1, characterized in that The power of the ultrasonic crusher (18) is 10 to 500W.

5. A method for preparing crude enzyme solution by using the device according to any one of claims 1 to 4 and coupling it with yeast glycerol fermentation to strengthen anaerobic fermentation of straw to produce methane, characterized in that: The steps include: 1) transferring the green Trichoderma enzyme production culture medium to the feed tank i (1), opening valve i (3) and valve ii (6), and conveying the culture medium in the feed tank i (1) into the green Trichoderma enzyme production culture tank (8) through the feed pump i (4); 2) opening the cover of the feed port i (9) of the green Trichoderma enzyme production culture tank, adding the green Trichoderma spore suspension to the green Trichoderma enzyme production culture tank (8) through the feed port i (9) at an inoculation rate of 10%, and closing the cover of the feed port i (9); closing the valve ii (6), turning on the agitator i (11), controlling the agitator speed to 100-200 rpm, and continuously stirring to increase the dissolved oxygen in the solution; controlling the water bath temperature in the insulation layer i (7) of the green Trichoderma enzyme production culture tank (8) to be 28-32°C, and the hydraulic retention time to be 160-180h; 3) Transfer the yeast expansion culture medium to the feed tank ii (12), open valve v (14) and valve vi (17), and transfer the culture medium in the feed tank ii (12) into the yeast culture tank (37) through the feed pump iii (15); open the cover of the yeast culture tank feed port ii (35), add the mother solution of glycerol-producing Candida albicans to the yeast culture tank (37) through the feed port ii (35) at an inoculation rate of 10%, and close the cover of the feed port ii (35); close the valve vi (17), turn on the agitator iii (34), control its rotation speed to 100-200 rpm, and continue stirring to increase the dissolved oxygen in the solution; the water bath temperature of the insulation layer iii (36) of the yeast culture tank (37) is 28-34°C, and the hydraulic retention time is 8-16h; 4) Open the water inlet valve (51), add high-purity water into the feed tank iii (49) through the water inlet pipe (52), start the agitator vi (53), control the agitator speed at 100-200 rpm, add cellulose powder through the feed port iii (50) to prepare a cellulose aqueous solution, and adjust the pH value to 4-6; open the valve xv (70) and the valve ⅹ (56), and the cellulose aqueous solution in the feed tank iii (49) is transported into the cellulose enzymatic hydrolysis tank (25) through the feed pump v (54), and the agitator vi (53) continues to stir to avoid cellulose sedimentation and prevent it from remaining in the feed tank Bottom; open the ultrasonic disruptor (18), valve iii (20) and valve iv (23), the green Trichoderma enzyme production culture solution in the green Trichoderma enzyme production culture tank (8) is transported into the cellulose enzymatic hydrolysis tank (25) through the feed pump ii (21), close the valve iv (23) and valve x (56), turn on the agitator ii (28), control the agitator speed to 100-200 rpm, continue to stir to mix the solution evenly, the water bath temperature of the insulation layer ii (24) of the cellulose enzymatic hydrolysis tank (25) is controlled at 28-32°C, and the optimal value of the hydraulic retention time is 6-10d; 5) The cellulose and reducing sugar mixture after enzymatic hydrolysis in the cellulose enzymatic hydrolysis tank (25) of step 4 is used as the raw material of the yeast fermentation tank (30), and the valve xi (58) and the valve xii (61) are opened, and the cellulose and reducing sugar mixture is transported into the yeast fermentation tank (30) through the feed pump vi (59); the agitator ii (28) is continuously stirred to prevent the cellulose from settling and preventing it from remaining at the bottom of the cellulose enzymatic hydrolysis tank (25); the valve vii (45) and the valve viii (48) are opened, and the yeast culture solution in the yeast culture tank (37) is transported into the yeast fermentation tank (30) through the feed pump iv (46); the valve viii (48) is closed, and the agitator iv (33) is turned on, and the agitator speed is controlled to be 100 to 200 rpm, and the agitator is continuously stirred to mix the solution evenly; the water bath temperature of the water bath insulation layer iv (29) of the yeast fermentation tank (30) is controlled to be 28 to 34° C., and the hydraulic retention time is 2 to 5 days; 6) Open valve xiii (63) and valve xiv (66), and the fermented mixture in the yeast fermentation tank (30) enters the anaerobic digestion methane production tank (40) from the bottom through the feed pump vii (64), close valve xiv (66), turn on the agitator v (43), control the agitator speed to 80-120 rpm, use sludge as the source of introduced microorganisms, mix the fermented mixed liquid and sludge evenly, and the sludge concentration is 5-50 g / L, The pH value in the anaerobic digestion methane production tank (40) is controlled to be 6.8-7.2; the water bath temperature of the water bath insulation layer v (39) of the anaerobic digestion methane production tank (40) is 35-40°C, and the hydraulic retention time is controlled to be 30-60 days; during the anaerobic digestion, the exhaust valve (41) is opened, and the gas generated by the anaerobic digestion methane production tank (40) is discharged through the exhaust pipe (42); after the anaerobic digestion is completed, the discharge valve (67) is opened, and the fermented waste is discharged through the discharge pipe (68).

6. The method according to claim 5, characterized in that The green Trichoderma enzyme production medium described in step 1) is prepared by mixing glucose, potato extract powder, cellulose, potassium dihydrogen phosphate, magnesium sulfate heptahydrate, and water in a mass ratio of 10:10:10:3:1.5:1000 and sterilizing the mixture; In step 2), the stirring speed is controlled to be 150 rpm; The green Trichoderma mixed liquid is 1.1L in total, of which 1L is used as the cellulase source of the cellulase hydrolysis tank (25), and 100ml is retained in the green Trichoderma enzyme production culture tank (8) as the green Trichoderma mother liquid of the next batch; the water bath temperature in the insulation layer ⅰ (7) of the green Trichoderma enzyme production culture tank (8) is 30°C, and the hydraulic retention time is 168h.

7. The method according to claim 5, characterized in that The yeast culture medium in step 3) is prepared by mixing glucose, yeast extract powder, peptone and water in a mass ratio of 20:10:20:1000, adjusting the pH value to 4-5, and sterilizing; the mixed solution of the glycerol-producing Candida albicans after culture is 1.1 L in total, of which 1 L is used as the introduction microorganism of the yeast fermentation tank (30), and 100 ml is retained in the yeast culture tank (37) as the yeast mother solution for the next batch of culture; the water bath temperature of the insulation layer ⅲ (36) of the yeast culture tank (37) is 32°C, and the hydraulic retention time is 12 hours.

8. The method according to claim 5, characterized in that The mass ratio of the cellulose powder to the high-purity water in step 4) is 1:50-500; the volume ratio of the cellulose solution to the green Trichoderma enzyme solution entering the cellulose enzymatic hydrolysis tank (25) is 100:8; the water bath temperature of the insulation layer ii (24) of the cellulose enzymatic hydrolysis tank (25) is controlled at 30°C, and the optimal hydraulic retention time is 8.09d.

9. The method according to claim 5, characterized in that The volume ratio of the cellulose and reducing sugar mixture to the yeast culture medium in step 5) is 50-5:1, the water bath temperature of the water bath insulation layer IV (29) of the yeast fermentation tank (30) is controlled at 32°C, and the hydraulic retention time is 3 days.

10. The method according to claim 5, characterized in that The water bath temperature of the water bath insulation layer v (39) of the anaerobic digestion methane production tank (40) described in step 6) is 37° C., and the hydraulic retention time is controlled at 45 days; the anaerobic digestion methane production tank (40) adopts a CSTR completely mixed anaerobic reactor, the sludge concentration is 10 to 20 g / L, and the pH in the anaerobic digestion methane production tank (40) is controlled to be 7.0.

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