Enzymolysis and ultrasonic coupling biomass treatment and residue recycling method

Abstract

The invention discloses an enzymolysis and ultrasonic coupling biomass treatment and residue recycling method. The method comprises the following steps: crushing biomass to obtain a crushed biomass material; mixing the crushed biomass with a compound enzyme, then adjusting the pH value of the system, carrying out ultrasonic reaction to release fermentable sugar, and after the reaction is finished, filtering to obtain solid residues and enzymatic hydrolysate; and mixing the solid residues with polyvinyl alcohol, and carrying out a cross-linking reaction to prepare the biomass-based hydrogel. According to the method, the ultrasonic wave is introduced to strengthen the reaction in the enzymolysis process, and the composite structure of lignin and cellulose is destroyed by utilizing ultrasonic waves, so that the yield of fermentable sugar is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass resource utilization, and in particular to a biomass treatment and residue recycling method coupled with enzymatic hydrolysis and ultrasound. Background Art

[0002] With the rapid development of the global economy, humanity's demand for energy is increasing. However, global fossil energy reserves are fixed. As they are developed and utilized, they are decreasing, leading to energy shortages. Furthermore, the widespread use of fossil energy has led to a dramatic deterioration of the global environment, such as the greenhouse effect and acid rain. Therefore, the search for new renewable energy sources has become an urgent matter.

[0003] Lignocellulose is a biomass resource with vast reserves on Earth, primarily sourced from crop straw, trees, energy plants, and weeds. With the emergence of a series of environmental and energy issues, renewable lignocellulose has become a key energy resource for human development and utilization. Due to its low energy efficiency and severe environmental pollution, the traditional form of direct combustion of lignocellulose has gradually been replaced by other approaches. Currently, the bio-enzymatic hydrolysis of lignocellulose biomass to produce reducing sugars, followed by microbial fermentation to produce fuels and other chemicals, has become a new research hotspot. Traditional enzymatic pretreatment is costly, and the residue is not efficiently utilized, resulting in a waste of resources. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention provides a method for biomass treatment and residue recycling by coupling enzymatic hydrolysis with ultrasound.

[0006] The present invention proposes a biomass treatment and residue recycling method coupled with enzymatic hydrolysis and ultrasound, comprising the following steps:

[0007] (1) crushing the biomass to obtain biomass fragments;

[0008] (2) mixing the biomass fragments with the complex enzyme and adjusting the pH of the system, releasing fermentable sugars through ultrasonic reaction, and filtering to obtain solid residue and enzymatic hydrolyzate after the reaction is completed;

[0009] (3) The solid residue is mixed with polyvinyl alcohol to prepare a biomass-based hydrogel through a cross-linking reaction.

[0010] Furthermore, it also includes:

[0011] using the enzymatic hydrolysate for fermentation to produce ethanol;

[0012] The biomass-based hydrogel is used for water vapor regulation in a fermentation and ethanol gasification reaction, and water vapor and ash are generated in a gasifier.

[0013] Further, the biomass includes one or more of bamboo, rice straw, soybean straw and corn straw.

[0014] Further, the biomass pieces have a particle size less than 5 mm.

[0015] Further, the complex enzyme includes one or more of cellulase, xylanase and laccase.

[0016] Further, the complex enzyme is added in an amount of 5-10 U / g of biomass pieces.

[0017] Further, the pH of the system is adjusted to 4.5-5.5 in step (2).

[0018] Further, the ultrasonic frequency is 20-40 kHz, the ultrasonic power density is 0.5-1.5 W / cm 2 , and the ultrasonic time is 30-60 min.

[0019] Further, the fermentable sugar includes one or more of glucose, fructose and sucrose.

[0020] Further, the ash is recycled as silicate fertilizer.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] In the enzymatic hydrolysis process, the present application introduces ultrasonic wave to strengthen the reaction, and uses the ultrasonic wave to destroy the complex structure of lignin and cellulose, thereby improving the yield of fermentable sugar.

[0023] In the present application, the solid residue is converted into functional material hydrogel, and the ash generated by the decomposition of the hydrogel is recycled as silicate fertilizer, thereby realizing the full component utilization of biomass and avoiding the waste of resources. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 The present application is an enzymatic hydrolysis and ultrasonic coupling biomass treatment and residue recycling method flow chart.

[0026] Figure 2 The present application is an enzymatic hydrolysis and ultrasonic coupling biomass treatment and residue recycling method flow chart. DETAILED DESCRIPTION

[0027] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0028] The following describes the enzymatic and ultrasonic coupled biomass treatment and residue recycling method proposed by the present invention with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the enzymatic ultrasonic coupled biomass treatment and residue recycling method of the present invention comprises the following steps:

[0030] (1) crushing the biomass to obtain biomass fragments;

[0031] (2) After mixing the biomass fragments with the complex enzyme, the pH of the system is adjusted, and fermentable sugars are released by ultrasonic reaction. After the reaction is completed, solid residues and enzymatic hydrolysate are obtained by filtration;

[0032] (3) The solid residue is mixed with polyvinyl alcohol and a biomass-based hydrogel is prepared through a cross-linking reaction.

[0033] Wherein, step (1) is a biomass crushing process, i.e., shearing and crushing large pieces of biomass into biomass fragments. The particle size of the biomass fragments is less than 5 mm. The particle size of the biomass fragments is within a suitable range, which is beneficial to the subsequent enzymatic hydrolysis process. The biomass includes one or more of bamboo, rice straw, soybean straw, and corn straw.

[0034] Step (2) involves enzymatic hydrolysis of the biomass. The biomass fragments are mixed with a complex enzyme, the pH value is adjusted to 4.5 to 5.5, and ultrasound is introduced into the system for an ultrasonic reaction, thereby releasing fermentable sugars from the biomass. After the reaction is complete, the reaction mixture is filtered to obtain a solid residue and an enzymatic hydrolyzate.

[0035] In some embodiments, the enzyme complex comprises one or more of cellulase, xylanase, and laccase.

[0036] In some embodiments, the addition amount of the complex enzyme is 5 to 10 U / g biomass fragments. It can be understood that the addition amount of the complex enzyme per gram of biomass fragments can be 5U, 6U, 7U, 8U, 9U, 10U or a value within a range consisting of any two values.

[0037] In some embodiments, the ultrasonic reaction has an ultrasonic frequency of 20 to 40 kHz and an ultrasonic power density of 0.5 to 1.5 W / cm 2The ultrasonic time is 30 to 60 minutes. It is understood that the ultrasonic frequency of the ultrasonic reaction can be 20kHz, 25kHz, 30kHz, 35kHz, 40kHz or a value within the range of any two values, and the ultrasonic power density can be 0.5W / cm 2 , 1W / cm 2 , 1.5W / cm 2 Or a value within a range consisting of any two numerical values, the ultrasonic time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min or a value within a range consisting of any two numerical values.

[0038] In some embodiments, the temperature of the ultrasonic reaction is 45-55°C. It can be understood that the temperature of the ultrasonic reaction can be 45°C, 50°C, 55°C, or a value within a range consisting of any two values.

[0039] In some embodiments, the fermentable sugars include one or more of glucose, fructose, and sucrose.

[0040] The present invention introduces ultrasonic wave to strengthen the reaction during the enzymatic hydrolysis process, utilizes ultrasound to destroy the composite structure of lignin and cellulose, and improves the yield of fermentable sugar.

[0041] Step (3) is a process for preparing a biomass-based hydrogel, wherein the solid residue obtained by filtration in step (2) is mixed with polyvinyl alcohol (PVA) and subjected to a cross-linking reaction to prepare a biomass-based hydrogel. The amount of polyvinyl alcohol added may be sufficient to cover the solid residue.

[0042] In some embodiments, as Figure 2 As shown, the method further includes the following steps: (a) using the enzymatic hydrolysate for fermentation to produce ethanol; and (b) using the biomass-based hydrogel for fermentation to produce ethanol. After water vapor is regulated in the gasification reaction, the biomass-based hydrogel is decomposed in a gasifier to produce water vapor and ash.

[0043] Step (a) is the process of utilizing the enzymatic hydrolysate, that is, the enzymatic hydrolysate obtained by filtration in the above step (2) is used for fermentation to produce ethanol, thereby obtaining a high-value ethanol product.

[0044] Step (b) is the process of utilizing the biomass-based hydrogel. Specifically, the biomass-based hydrogel prepared in step (3) is used to control water vapor in the gasification reaction of fermentation to produce ethanol. The biomass-based hydrogel absorbs water vapor in the gasification reaction, thereby reducing the water vapor content and optimizing the H2 / CO ratio in the product. After absorbing water vapor, the biomass-based hydrogel decomposes in the gasifier to produce water vapor and ash, thereby reusing the biomass-based hydrogel. The ash produced by the decomposition of the biomass-based hydrogel is recovered as silicate fertilizer, thereby achieving full utilization of the biomass.

[0045] The application will be described in connection with the preferred embodiments.

[0046] Example 1

[0047] The corn straw is crushed to a particle size of less than 5 mm by a crushing device, and the crushed corn straw is mixed with a composite enzyme, and the pH of the system is adjusted, and fermentable sugar is released by ultrasonic reaction. After the reaction is completed, the solid residue and the enzymatic hydrolysate are obtained by filtration. The composite enzyme is laccase, the addition amount of the composite enzyme per gram of biomass crushed material is 8 U, the pH of the system is adjusted to 5, the ultrasonic frequency of the ultrasonic reaction is 30 kHz, the ultrasonic power density is 1 W / cm 2 , the ultrasonic time is 40 min, and the ultrasonic reaction temperature is 50 DEG C.

[0048] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared by cross-linking reaction, wherein the addition amount of polyvinyl alcohol is more than the solid residue.

[0049] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for fermentation to produce ethanol. After the gasification reaction is regulated by water vapor, water vapor and ash are produced in the gasification furnace, and the ash is recovered as silicate fertilizer.

[0050] Example 2

[0051] The corn straw is crushed to a particle size of less than 5 mm by a crushing device, and the crushed corn straw is mixed with a composite enzyme, and the pH of the system is adjusted, and fermentable sugar is released by ultrasonic reaction. After the reaction is completed, the solid residue and the enzymatic hydrolysate are obtained by filtration. The composite enzyme is laccase, the addition amount of the composite enzyme per gram of biomass crushed material is 8 U, the pH of the system is adjusted to 5, the ultrasonic frequency of the ultrasonic reaction is 30 kHz, the ultrasonic power density is 1.5 W / cm 2 , the ultrasonic time is 40 min, and the ultrasonic reaction temperature is 50 DEG C.

[0052] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared by cross-linking reaction, wherein the addition amount of polyvinyl alcohol is more than the solid residue.

[0053] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for fermentation to produce ethanol. After the gasification reaction is regulated by water vapor, water vapor and ash are produced in the gasification furnace, and the ash is recovered as silicate fertilizer.

[0054] Example 3

[0055] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was carried out at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 0.5 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0056] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0057] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0058] Example 4

[0059] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 5 U. The pH of the system was adjusted to 5. The ultrasonic reaction was carried out at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0060] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0061] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0062] Example 5

[0063] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 10 U. The pH of the system was adjusted to 5. The ultrasonic reaction was carried out at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0064] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0065] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0066] Example 6

[0067] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was carried out at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 30 min, and the ultrasonic reaction temperature was 50 °C.

[0068] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0069] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0070] Example 7

[0071] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was carried out at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 60 min, and the ultrasonic reaction temperature was 50 °C.

[0072] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0073] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0074] Example 8

[0075] The corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. An ultrasonic reaction was performed to release fermentable sugars. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was cellulase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was performed at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0076] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0077] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0078] Example 9

[0079] The corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. An ultrasonic reaction was performed to release fermentable sugars. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was xylanase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was performed at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0080] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0081] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0082] Example 10

[0083] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzymes were laccase and xylanase. The amount of laccase added to each gram of biomass was 4 U, and the amount of xylanase added was 4 U. The pH of the system was adjusted to 5. The ultrasonic reaction was performed at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2, the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0084] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0085] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0086] Example 11

[0087] The soybean straw was crushed to a particle size of less than 5 mm using a crushing device. The crushed corn straw was mixed with a complex enzyme and the pH of the system was adjusted. An ultrasonic reaction was performed to release fermentable sugars. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was performed at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0088] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0089] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0090] Example 12

[0091] Rice straw was crushed to a particle size of less than 5 mm using a crushing device. The crushed corn straw was mixed with a complex enzyme and the pH of the system was adjusted. An ultrasonic reaction was performed to release fermentable sugars. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was performed at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0092] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0093] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0094] Comparative Example 1

[0095] Corn straw was crushed to a particle size of less than 5 mm using a crushing device. The crushed corn straw was then mixed with a complex enzyme and the pH of the system was adjusted. The reaction released fermentable sugars. After the reaction, solid residue and enzymatic hydrolyzate were filtered. The complex enzyme was laccase, and the addition rate was 8 units per gram of biomass. The pH of the system was adjusted to 5, and the reaction time was 40 minutes at a temperature of 50°C.

[0096] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0097] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0098] Comparative Example 2

[0099] Corn stalks were crushed to a particle size of less than 5 mm using a crushing device. The crushed corn stalks were mixed with a complex enzyme and the pH of the system was adjusted. Fermentable sugars were released by ultrasonic reaction. After the reaction, solid residue and enzymatic hydrolyzate were obtained by filtration. The complex enzyme was laccase, and the amount of complex enzyme added per gram of biomass was 8 U. The pH of the system was adjusted to 5. The ultrasonic reaction was carried out at an ultrasonic frequency of 30 kHz and an ultrasonic power density of 0.1 W / cm. 2 , the ultrasonic time was 40 min, and the ultrasonic reaction temperature was 50 °C.

[0100] The solid residue is mixed with polyvinyl alcohol, and a biomass-based hydrogel is prepared through a cross-linking reaction, wherein the amount of polyvinyl alcohol added is greater than that of the solid residue.

[0101] The enzymatic hydrolysate is used for fermentation to produce ethanol, and the biomass-based hydrogel is used for water vapor regulation in the gasification reaction of fermentation to produce ethanol. The hydrogel is then decomposed in a gasifier to produce water vapor and ash, which is then recovered as silicate fertilizer.

[0102] Test example

[0103] The conversion rates of fermentable sugars in Examples 1 to 12 and Comparative Examples 1 and 2 were tested. The conversion rate of fermentable sugars is equal to the ratio of the content of fermentable sugars in the enzymatic hydrolysate to the content of fermentable sugars in the biomass. The test results are shown in Table 1 below.

[0104] Table 1:

[0105]

[0106]

[0107] As can be seen from Table 1, the conversion rates of fermentable sugars in Examples 1 to 12 are higher than that of Comparative Example 1, and the conversion rates of fermentable sugars in Examples 1 to 12 are 81% or more, and thus hemicellulose can be well extracted.

[0108] As can be seen from Comparative Example 2 and Example 1, when the ultrasonic power density is too low, the conversion rate of fermentable sugars decreases.

[0109] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms can be directed to different embodiments or examples. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0110] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0111] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for biomass treatment and residue recycling by enzymatic hydrolysis and ultrasonic coupling, characterized in that: The following steps are involved: (1) crushing the biomass to obtain biomass fragments; (2) mixing the biomass fragments with the complex enzyme and adjusting the pH of the system, releasing fermentable sugars through ultrasonic reaction, and filtering to obtain solid residue and enzymatic hydrolyzate after the reaction is completed; (3) The solid residue is mixed with polyvinyl alcohol to prepare a biomass-based hydrogel through a cross-linking reaction.

2. The method according to claim 1, wherein Also includes: using the enzymatic hydrolysate for fermentation to produce ethanol; The biomass-based hydrogel is used for water vapor regulation in a fermentation-to-ethanol gasification reaction, and then decomposed in a gasifier to generate water vapor and ash.

3. The method according to claim 1, wherein The biomass includes one or more of bamboo, rice straw, soybean straw, and corn straw.

4. The method according to claim 1, wherein The particle size of the biomass fragments is less than 5 mm.

5. The method according to claim 1, wherein The complex enzyme comprises one or more of cellulase, xylanase and laccase.

6. The method according to claim 1, wherein The added amount of the complex enzyme is 5 to 10 U / g of biomass fragments.

7. The method according to claim 1, wherein In the step (2), the pH of the system is adjusted to 4.5-5.

5.

8. The method according to claim 1, wherein The ultrasonic frequency of the ultrasonic reaction is 20-40 kHz, and the ultrasonic power density is 0.5-1.5 W / cm 2 , the ultrasound time is 30 to 60 minutes.

9. The method according to claim 1, wherein The fermentable sugars include one or more of glucose, fructose, and sucrose.

10. The method according to claim 1, wherein The ash is recovered as silicate fertilizer.

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