A method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper

Abstract

The present application relates to the technical field of waste resource utilization, and in particular to a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper; the method comprises: pre-treating kitchen waste and waste paper respectively to obtain defatted kitchen waste slurry and waste paper slurry; subjecting saccharifying enzyme and defatted kitchen waste slurry to a first saccharification treatment to obtain saccharified kitchen waste slurry; subjecting cellulase and waste paper slurry to a second saccharification treatment to obtain saccharified waste paper slurry; mixing saccharified kitchen waste slurry and saccharified waste paper slurry to obtain fermentation raw material; and subjecting the fermentation raw material to biological fermentation treatment and distillation to obtain ethanol product. The method can produce ethanol product by saccharification treatment and biological fermentation treatment with kitchen waste and waste paper as raw materials, and can effectively improve the resource utilization rate of kitchen waste and waste paper and the types of resource products.

Description

Technical Field

[0001] The present application relates to the technical field of waste resource utilization, and in particular to a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper. Background Art

[0002] Kitchen waste refers to the waste generated in residents' daily life and food processing, catering services, unit catering and other activities, and waste paper refers to recyclable resources that are discarded after use in production and life. With the continuous improvement of living standards and the continuous advancement of garbage classification, the amount of kitchen waste and waste paper will increase significantly. Therefore, it is necessary to recycle kitchen waste and waste paper to utilize these wastes as resources; at present, the treatment process of kitchen waste mostly uses a combination of pretreatment and anaerobic digestion process, but the resource utilization rate of organic matter in this treatment process is low, and the final product is relatively single; in addition, the treatment process of waste paper mostly uses a combination of pretreatment and paper product recycling path. Although the resource utilization rate of waste paper is high, the final product is relatively single. Summary of the invention

[0003] The present application provides a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper, so as to solve the following technical problem: how to improve the resource utilization rate of kitchen waste and waste paper and the types of resource products.

[0004] In a first aspect, the present application provides a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper, the method comprising:

[0005] Pre-treating kitchen waste and waste paper respectively to obtain defatted kitchen waste slurry and waste paper slurry;

[0006] subjecting the defatted kitchen waste slurry to a first saccharification treatment with a saccharifying enzyme to obtain a saccharified kitchen waste slurry;

[0007] subjecting the cellulase and the waste paper pulp to a second saccharification treatment to obtain saccharified waste paper pulp;

[0008] Mixing the saccharified kitchen waste slurry and the saccharified waste paper slurry to obtain a fermentation raw material; and

[0009] The fermentation raw material is subjected to biological fermentation treatment and distillation to obtain an ethanol product.

[0010] Optionally, the enzyme activity U1 of the saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=(50-1000):1, wherein if the unit of m1 is g, the unit of U1 is U;

[0011] The first organic matter includes starch and / or glucose.

[0012] Optionally, the enzymatic activity U2 of the cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=(50-1000):1, wherein if the unit of m2 is g, the unit of U2 is U;

[0013] The second organic matter includes cellulose.

[0014] Optionally, the temperature of the first saccharification treatment is 50° C. to 60° C., and the time of the first saccharification treatment is 2 h to 3 h; and / or

[0015] The temperature of the second saccharification treatment is 50° C. to 60° C., and the time of the second saccharification treatment is 20 h to 24 h.

[0016] Optionally, the weight m5 of the saccharified kitchen waste slurry and the weight m6 of the saccharified waste paper slurry satisfy the relationship: m5:m6=(1-3):1; and / or

[0017] The weight of the solid phase of the fermentation raw material is 15% to 35% of the total weight of the fermentation raw material.

[0018] Optionally, the bacteria used in the biological fermentation treatment include yeast, and the inoculation amount of the yeast is 0.05% to 0.1%.

[0019] Optionally, the temperature of the biological fermentation treatment is 25°C to 35°C, and the time of the biological fermentation treatment is 2d to 4d.

[0020] Optionally, the method of pre-treating the kitchen waste and waste paper respectively to obtain defatted kitchen waste slurry and waste paper slurry comprises the steps of:

[0021] The kitchen waste and waste paper are crushed and pulped respectively to obtain kitchen waste pulp and waste paper pulp;

[0022] The kitchen waste slurry is subjected to a degreasing treatment to obtain a defatted kitchen waste slurry.

[0023] Optionally, the particle size of the waste paper slurry and the kitchen waste slurry is ≤8 mm; and / or

[0024] The weight of the solid phase of the waste paper pulp is 20% to 50% of the total weight of the waste paper pulp; and / or

[0025] The temperature of the degreasing treatment is ≥80° C., and the time of the degreasing treatment is 0.5 h to 4 h.

[0026] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0027] The embodiment of the present application provides a method for preparing ethanol by utilizing kitchen waste and waste paper through synergistic fermentation. The method is based on the characteristics that the components of kitchen waste and waste paper contain carbohydrate substances such as starch and cellulose. The kitchen waste and waste paper are first pretreated separately so that the organic matter in the kitchen waste and the organic matter in the waste paper are fully extracted, and then the first organic matter in the defatted kitchen waste slurry is subjected to a first saccharification treatment under the catalytic action of saccharifying enzyme, and the second organic matter in the waste paper is subjected to a second saccharification treatment under the catalytic action of cellulase, so that the organic matter in the kitchen waste and the waste paper is converted into reducing sugar components, most of which will be converted into ethanol products in the subsequent fermentation process, thereby improving the resource utilization rate of kitchen waste and waste paper; in addition, the method produces ethanol products, so it can also broaden the types of resource products produced by kitchen waste and waste paper; therefore, the method produces ethanol products using kitchen waste and waste paper as raw materials, which can improve the resource utilization rate of kitchen waste and waste paper and the types of resource products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 A schematic flow chart of a method for preparing ethanol by cooperative fermentation of kitchen waste and waste paper provided in an embodiment of the present application;

[0031] Figure 2 A detailed flow chart of a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0034] In this document, the terms including "including" and "including" mean "including but not limited to". Relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone; where A and B can be singular or plural. "At least one" means one or more, and "plurality" means two or more; "at least one", "at least one of the following" or similar expressions, refers to any combination of these items, including any combination of single or plural items; for example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. "Parts" such as parts by weight and parts by mass indicate the proportional relationship between the components. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, if the mass ratio of substance A, substance B and substance C is 1:2:3, then substance A, substance B and substance C should correspond to the proportional numbers in the proportional formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0035] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this article can be purchased from the market or prepared by existing methods.

[0036] It should be noted that, with regard to the technical problem, based on the characteristics that kitchen waste and waste paper contain sugar substances such as starch and cellulose, the saccharification and fermentation process can be used to ferment the sugar substances in kitchen waste and waste paper to produce ethanol. In addition, the weight content of sugar in kitchen waste is generally lower than the weight content of sugar in waste paper, while the weight content of water in kitchen waste is higher than the weight content of water in waste paper. If the two are fermented synergistically, not only can the moisture content of waste paper be adjusted by kitchen waste to reduce the cost of adjusting the moisture content of the slurry, but a higher ethanol yield can also be guaranteed.

[0037] Figure 1 A schematic flow chart of a method for preparing ethanol by co-fermentation of kitchen waste and waste paper provided in an embodiment of the present application is exemplarily shown;

[0038] like Figure 1 As shown, the present application embodiment provides a method for preparing ethanol by cooperative fermentation of kitchen waste and waste paper, the method comprising:

[0039] S1. Pre-treating the kitchen waste and waste paper to obtain defatted kitchen waste slurry and waste paper slurry;

[0040] S2. subjecting the defatted kitchen waste slurry to a first saccharification treatment with a saccharifying enzyme, so that the first organic matter in the defatted kitchen waste slurry is saccharified to obtain a saccharified kitchen waste slurry;

[0041] S3. subjecting the cellulase and the waste paper pulp to a second saccharification treatment, so that the second organic matter of the waste paper pulp is decomposed to obtain a saccharified waste paper pulp;

[0042] S4. mixing the saccharified kitchen waste slurry and the saccharified waste paper slurry to obtain a fermentation raw material; and

[0043] S5. The fermentation raw material is subjected to biological fermentation treatment and distillation to obtain an ethanol product.

[0044] It should be noted that the saccharifying enzyme may be β-glucosidase.

[0045] It should be noted that the pretreatment can be a degreasing treatment for kitchen waste or an activation treatment for waste paper.

[0046] It should be noted that the distillation treatment can be carried out in a distillation tower, and the temperature of the distillation treatment can be carried out under reduced temperature conditions. For example, the temperature of the distillation treatment can be 78° C., and the time of the distillation treatment can be 5 hours. In addition, the temperature of the distillation treatment can control the purity of the obtained ethanol product.

[0047] It should be noted that the fermentation process can be carried out in a fermentation tank.

[0048] It should be noted that the distillation of the biological fermentation treatment can obtain not only ethanol products but also mash residue, which can be subsequently utilized as a resource. For example, the mash residue can enter the anaerobic digestion process section as a raw material for producing biogas, or enter the aerobic fermentation process section for decomposition and conversion to obtain humus, and can also undergo secondary processing to obtain organic fertilizer products.

[0049] In some optional embodiments, the enzyme activity U1 of the saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=(50-1000):1, wherein if the unit of m1 is g, the unit of U1 is U;

[0050] The first organic matter includes starch and / or glucose;

[0051] In these embodiments, the enzymatic activity U1 of the saccharide saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=(50-1000):1, and the first organic matter may include starch and / or glucose, so that the first saccharification treatment has a sufficient amount of saccharifying enzyme. The sufficient amount of saccharifying enzyme can convert the first organic matter of the defatted kitchen waste slurry into reducing sugar components during the first saccharification treatment, so as to facilitate the conversion of these reducing sugar components into ethanol products during the subsequent biological fermentation treatment.

[0052] The added amount m1 of the saccharifying enzyme can be 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 or 1000.

[0053] In some optional embodiments, the enzymatic activity U2 of the cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=(50-1000):1, wherein if the unit of m2 is g, the unit of U2 is U;

[0054] The second organic matter includes cellulose;

[0055] In these embodiments, the enzymatic activity U2 of the cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=(50-1000):1, and the second organic matter may include cellulose, which promotes the second saccharification treatment to have a sufficient amount of cellulase. The sufficient amount of cellulase can promote the conversion of the second organic matter of the waste paper pulp into reducing sugar components during the second saccharification treatment, so as to facilitate the conversion of these reducing sugar components into ethanol products during the subsequent biological fermentation treatment, thereby improving the resource utilization rate of kitchen waste and waste paper and the types of resource products.

[0056] The value of the added amount m3 of the cellulase can be 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 or 1000.

[0057] In some optional embodiments, the temperature of the first saccharification treatment is 50° C. to 60° C., and the time of the first saccharification treatment is 2 h to 3 h; and / or

[0058] The temperature of the second saccharification treatment is 50°C to 60°C, and the time of the second saccharification treatment is 20h to 24h;

[0059] In these embodiments, the temperature of the first saccharification treatment can be 50°C to 60°C, and the time of the first saccharification treatment can be 2h to 3h. The first saccharification treatment can promote the conversion of organic matter in the defatted kitchen waste slurry into reducing sugar components, so as to facilitate the conversion of these reducing sugar components into ethanol products in the subsequent biological fermentation treatment process; in addition, the temperature of the second saccharification treatment can be 50°C to 60°C, and the time of the second saccharification treatment can be 20h to 24h. The second saccharification treatment can promote the conversion of organic matter in the activated slurry into reducing sugar components, so as to facilitate the conversion of these reducing sugar components into ethanol products in the subsequent biological fermentation treatment process.

[0060] The temperature of the first saccharification treatment may be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C.

[0061] The time of the first saccharification treatment can be 2 h, 2.1 h, 2.2 h, 2.3 h, 2.4 h, 2.5 h, 2.6 h, 2.7 h, 2.8 h, 2.9 h or 3.0 h.

[0062] The temperature of the second saccharification treatment may be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C.

[0063] The time of the second saccharification treatment can be 20.0 h, 20.5 h, 21.0 h, 21.5 h, 22.0 h, 22.5 h, 23.0 h, 23.5 h or 24.0 h.

[0064] In some optional embodiments, the weight m3 of the saccharified kitchen waste slurry and the weight m4 of the saccharified waste paper slurry satisfy the relationship: m3:m4=(1-3):1; and / or

[0065] The weight of the solid phase of the fermentation raw material is 15% to 35% of the total weight of the fermentation raw material;

[0066] In these embodiments, the weight m3 of the saccharified kitchen waste slurry and the weight m4 of the saccharified waste paper slurry can satisfy the relationship: m3:m4=(1~3):1, and the weight of the solid phase of the fermentation raw material can be 15%~35% of the total weight of the fermentation raw material, so as to promote sufficient mixing between the saccharified kitchen waste slurry and the saccharified waste paper slurry to obtain a fermentation raw material containing a large amount of reducing sugar components, so as to facilitate the conversion of these reducing sugar components into ethanol products in the subsequent biological fermentation treatment process, thereby improving the resource utilization rate of kitchen waste and waste paper and the types of resource products.

[0067] The weight m5 of the saccharified kitchen waste slurry can be 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0.

[0068] The weight of the solid phase of the fermentation feedstock can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34% or 35% of the total weight of the fermentation feedstock.

[0069] In some optional embodiments, the bacteria used in the biological fermentation treatment include yeast, and the inoculation amount of the yeast is 0.05% to 0.1%;

[0070] In these embodiments, the bacteria used in the biological fermentation treatment may include yeast, and the inoculation amount of the yeast may be 0.05% to 0.1%, so that the biological fermentation treatment has a sufficient amount of yeast. A sufficient amount of yeast can convert most of the reducing sugar components of the fermentation raw materials into ethanol products, thereby improving the resource utilization rate of kitchen waste and waste paper and the types of resource products.

[0071] The inoculation amount of the yeast may be 0.05%, 0.06%, 0.07%, 0.08%, 0.09% or 0.10%.

[0072] In some optional embodiments, the temperature of the biological fermentation treatment is 25°C to 35°C, and the time of the biological fermentation treatment is 2d to 4d;

[0073] In these embodiments, the temperature of the bio-fermentation treatment can be 25°C to 35°C, and the time of the bio-fermentation treatment can be 2d to 4d. The bio-fermentation treatment can promote the conversion of most of the reducing sugar components of the fermentation raw materials into ethanol products, thereby improving the resource utilization rate of kitchen waste and waste paper and the types of resource products.

[0074] The temperature of the biofermentation treatment can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C.

[0075] The time of the biological fermentation treatment can be 2.0d, 2.1d, 2.2d, 2.3d, 2.4d, 2.5d, 2.6d, 2.7d, 2.8d, 2.9d, 3.0d, 3.1d, 3.2d, 3.3d, 3.4d, 3.5d, 3.6d, 3.7d, 3.8d, 3.9d or 4.0d.

[0076] Figure 2 A detailed schematic diagram of a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper provided in an embodiment of the present application is exemplarily shown;

[0077] In some optional embodiments, such as Figure 2 As shown, the method of pre-treating kitchen waste and waste paper respectively to obtain defatted kitchen waste slurry and waste paper slurry comprises the steps of:

[0078] S101. The kitchen waste and waste paper are crushed and pulped to obtain kitchen waste pulp and waste paper pulp;

[0079] S102. Degreasing the kitchen waste slurry to obtain defatted kitchen waste slurry;

[0080] In these embodiments, the kitchen waste and waste paper are first crushed and pulped to convert large pieces of kitchen waste and waste paper into kitchen waste slurry and waste paper slurry with smaller particles. The kitchen waste slurry is then degreased to remove components such as oil, liquid and solid phases from the kitchen waste slurry. Part of the liquid phase from the removed kitchen waste slurry can be mixed with the solid phase to obtain defatted kitchen waste slurry, and the remaining liquid phase from the removed kitchen waste slurry can be used as a raw material for activating waste paper slurry.

[0081] It should be noted that the degreasing treatment can be carried out using a three-phase separator to separate the oil component, liquid phase and solid phase of the kitchen waste slurry. Part of the liquid phase and the solid phase can be remixed into a defatted kitchen waste slurry, and the remaining liquid phase can be mixed with waste paper to obtain a waste paper slurry; the oil component removed by the three-phase separator can be sold as recycled oil.

[0082] It should be noted that the method of crushing and pulping kitchen waste can be hydraulic decomposition pulping, sorting and impurity removal and squeezing pulping, or hot water decomposition and squeezing pulping.

[0083] It should be noted that the waste paper may be pulped by a cooking pretreatment, the cooking temperature may be 80° C., and the cooking time may be 30 minutes.

[0084] In some optional embodiments, the particle size of the waste paper slurry and the kitchen waste slurry is ≤8 mm; and / or

[0085] The weight of the solid phase of the waste paper pulp is 20% to 50% of the total weight of the waste paper pulp; and / or

[0086] The temperature of the degreasing treatment is ≥80°C, and the time of the degreasing treatment is 0.5h to 4h;

[0087] In these embodiments, the particle size of the waste paper pulp and the kitchen waste pulp is ≤8 mm, which can make the waste paper pulp and the waste paper pulp have a sufficiently fine morphology. The waste paper pulp and the waste paper pulp with a sufficiently fine morphology can facilitate the subsequent first saccharification treatment by saccharifying enzymes and the second saccharification treatment by cellulase, so as to obtain a fermentation raw material containing a large amount of reducing sugar components, so as to facilitate the conversion of these reducing sugar components into ethanol products in the subsequent biological fermentation process, thereby improving the resource utilization rate of kitchen waste and waste paper and the types of resource products; in addition, the waste paper pulp with a sufficiently fine morphology is conducive to the subsequent degreasing treatment to obtain defatted waste paper pulp; in addition, the waste paper pulp with a sufficiently fine morphology is conducive to the subsequent degreasing treatment to obtain defatted waste paper pulp. The weight of the solid phase of the pulp material can be 20% to 50% of the total weight of the waste paper pulp, so that the waste paper pulp has sufficient solid phase. In the subsequent second saccharification treatment process, the sufficient solid phase will be converted into a large amount of reducing sugar components, so as to facilitate the conversion of these reducing sugar components into ethanol products in the subsequent biological fermentation treatment process, thereby improving the resource utilization rate of kitchen waste and waste paper and the types of resource products; in addition, the temperature of the degreasing treatment is ≥80°C, and the time of the degreasing treatment can be 0.5h to 4h, which ensures that the degreasing treatment is fully carried out, and the oil, liquid phase and solid phase of the kitchen waste slurry can be fully separated, so as to obtain pure defatted kitchen waste slurry.

[0088] The weight of the solid phase of the waste paper slurry may be 20%, 25%, 30%, 35%, 40%, 45% or 50% of the total weight of the waste paper slurry.

[0089] The temperature of the degreasing treatment can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C or 95°C.

[0090] The degreasing treatment time can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h.

[0091] It should be noted that the method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper provided in the embodiment of the present application has the following advantages:

[0092] 1. Synergistic resource utilization of kitchen waste and waste paper: This method can effectively convert the organic matter of kitchen waste and waste paper into reducing sugar components through a two-stage saccharification treatment of a first saccharification treatment by saccharifying enzyme and a second saccharification treatment by cellulase. These reducing sugar components are further converted in the subsequent biological fermentation process, and most of them are finally converted into ethanol products. This conversion process not only realizes the resource utilization of kitchen waste and waste paper, but also significantly improves their utilization rate.

[0093] 2. Preparation of high-value products: This method can transform discarded kitchen waste and waste paper into ethanol products with practical application value.

[0094] 3. High economic benefits: Compared with the traditional treatment methods that are limited to simple recycling or landfill, this method uses kitchen waste and waste paper as raw materials to produce ethanol products, which opens up a new way for the resource utilization of kitchen waste and waste paper; therefore, this method not only helps to alleviate the situation of resource tension, but also promotes the development of the circular economy.

[0095] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards / industry standards; if there are no corresponding national standards / industry standards, they are measured in accordance with common international standards, conventional conditions or conditions recommended by the manufacturer.

[0096] Example 1

[0097] like Figure 2 As shown, a method for preparing ethanol by co-fermentation of kitchen waste and waste paper comprises:

[0098] S101. The kitchen waste and waste paper are crushed and pulped to obtain kitchen waste pulp and waste paper pulp;

[0099] S102. Degreasing the kitchen waste slurry to obtain a defatted kitchen waste slurry;

[0100] S2. subjecting the saccharifying enzyme and the defatted kitchen waste slurry to a first saccharification treatment, so that the first organic matter in the defatted kitchen waste slurry is saccharified to obtain a saccharified kitchen waste slurry;

[0101] S3. subjecting the cellulase and the waste paper pulp to a second saccharification treatment, so that the second organic matter of the waste paper pulp is decomposed to obtain a saccharified waste paper pulp;

[0102] S4. The saccharified kitchen waste slurry and the saccharified waste paper slurry are mixed to obtain a fermentation raw material; and

[0103] S5. The fermentation raw materials are subjected to biological fermentation treatment and distillation to obtain ethanol products.

[0104] The enzymatic activity U1 of the saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=50:1, wherein if the unit of m1 is g, the unit of U1 is U; the first organic matter includes starch and glucose.

[0105] The enzymatic activity U2 of the cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=50:1, wherein if the unit of m2 is g, the unit of U2 is U;

[0106] The second organic matter includes cellulose.

[0107] The temperature of the first saccharification treatment is 60°C, and the time of the first saccharification treatment is 2h;

[0108] The temperature of the second saccharification treatment was 60° C., and the time of the second saccharification treatment was 20 h.

[0109] The weight m3 of the saccharified kitchen waste slurry and the weight m4 of the saccharified waste paper slurry satisfy the relationship: m3:m4=1:1;

[0110] The weight of the solid phase of the fermentation raw material is 35% of the total weight of the fermentation raw material.

[0111] The bacteria used in the biological fermentation treatment include yeast, and the inoculation amount of the yeast is 0.05%.

[0112] The temperature of the biological fermentation treatment is 28°C, and the time of the biological fermentation treatment is 3 days.

[0113] The particle size of waste paper pulp and kitchen waste pulp is ≤8mm;

[0114] The weight of the solid phase of the waste paper pulp is 50% of the total weight of the waste paper pulp;

[0115] The degreasing treatment temperature is 80°C and the degreasing treatment time is 1 hour.

[0116] Example 2

[0117] Based on the contents disclosed in Example 1, the following modifications are further made:

[0118] The enzymatic activity U1 of the saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=100:1, wherein if the unit of m1 is g, the unit of U1 is U.

[0119] The enzymatic activity U2 of cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=100:1, wherein if the unit of m2 is g, the unit of U2 is U.

[0120] The temperature of the first saccharification treatment is 58°C, and the time of the first saccharification treatment is 2.5h;

[0121] The temperature of the second saccharification treatment was 58° C., and the time of the second saccharification treatment was 22 h.

[0122] Example 3

[0123] Based on the contents disclosed in Example 1, the following modifications are further made:

[0124] The enzymatic activity U1 of the saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=500:1, wherein if the unit of m1 is g, the unit of U1 is U.

[0125] The enzymatic activity U2 of cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=500:1, wherein, if the unit of m2 is g, the unit of U2 is U.

[0126] The temperature of the first saccharification treatment is 55°C, and the time of the first saccharification treatment is 3h;

[0127] The temperature of the second saccharification treatment was 55° C., and the time of the second saccharification treatment was 24 h.

[0128] Example 4

[0129] Based on the contents disclosed in Example 1, the following modifications are further made:

[0130] The weight m3 of the saccharified kitchen waste slurry and the weight m4 of the saccharified waste paper slurry satisfy the relationship: m3:m4=2:1;

[0131] The weight of the solid phase of the fermentation raw material is 30% of the total weight of the fermentation raw material.

[0132] The inoculum level of yeast was 0.08%.

[0133] Example 5

[0134] Based on the contents disclosed in Example 1, the following modifications are further made:

[0135] The weight m3 of the saccharified kitchen waste slurry and the weight m4 of the saccharified waste paper slurry satisfy the relationship: m3:m4=3:1;

[0136] The weight of the solid phase of the fermentation feedstock was 27.5% of the total weight of the fermentation feedstock.

[0137] The inoculum level of yeast was 0.1%.

[0138] Comparative Example 1

[0139] Based on the contents disclosed in Example 1, the following modifications are further made:

[0140] No waste paper was added and no second saccharification process was performed.

[0141] Comparative Example 2

[0142] Based on the contents disclosed in Example 1, the following modifications are further made:

[0143] The first saccharification treatment and the second saccharification treatment were not used.

[0144] Comparative Example 3

[0145] Based on the contents disclosed in Example 1, the following modifications are further made:

[0146] The temperature of the biological fermentation treatment is 20°C, and the time of the biological fermentation treatment is 1 day;

[0147] Comparative Example 4

[0148] Based on the contents disclosed in Example 1, the following modifications are further made:

[0149] The temperature of the biological fermentation treatment is 40°C, and the time of the biological fermentation treatment is 5 days;

[0150] Related experiments and effect data:

[0151] The concentration and yield of the ethanol products obtained in each embodiment and comparative example were statistically analyzed, and the results are shown in Table 1.

[0152] Table 1 Concentration and yield of ethanol products obtained in various embodiments and comparative examples

[0153]

[0154] As can be seen from Table 1, the embodiment of the present application provides a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper. The method uses kitchen waste and waste paper as raw materials to produce ethanol products through saccharification and bio-fermentation. The concentration of the ethanol product can be above 95%, and the ethanol yield can reach 8% or more, which shows that the method can effectively improve the resource utilization rate of kitchen waste and waste paper and the types of resource products.

[0155] In addition, comparative example 4 uses a relatively high biological fermentation treatment temperature. Under the biological fermentation treatment temperature, the activity of the yeast will be inhibited, and the yeast may even be inactivated under high temperature conditions, thereby seriously affecting the yield of ethanol.

[0156] In addition, an embodiment of the present application provides a method for preparing ethanol by utilizing the synergistic fermentation of kitchen waste and waste paper. The method achieves large-scale preparation of ethanol through the synergistic treatment of kitchen waste and waste paper. In addition, the method combines the characteristics of high moisture content of kitchen waste and high content of cellulose sugar substances in waste paper, and can synergistically ferment to produce a large amount of ethanol products.

[0157] In addition, a method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper provided in an embodiment of the present application can achieve effective utilization of urban solid waste resources; in addition, the ethanol produced by this method broadens the preparation path of renewable energy, thereby reducing the current pressure to produce ethanol using food and chemical waste as raw materials, thereby alleviating the food crisis and achieving energy conservation and carbon reduction in the production and living processes.

[0158] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown in the present application, but will conform to the widest range consistent with the principles and novel features applied for by the present application.

Claims

1. A method for preparing ethanol by synergistic fermentation of kitchen waste and waste paper, the method comprising: Pre-treating kitchen waste and waste paper respectively to obtain defatted kitchen waste slurry and waste paper slurry; subjecting the defatted kitchen waste slurry to a first saccharification treatment with a saccharifying enzyme, so that the first organic matter in the defatted kitchen waste slurry is saccharified to obtain saccharified kitchen waste slurry; subjecting the cellulase and the waste paper pulp to a second saccharification treatment, so that the second organic matter of the waste paper pulp is decomposed to obtain saccharified waste paper pulp; Mixing the saccharified kitchen waste slurry and the saccharified waste paper slurry to obtain a fermentation raw material; and The fermentation raw material is subjected to biological fermentation treatment and distillation to obtain an ethanol product.

2. The method according to claim 1, wherein the enzymatic activity U1 of the saccharifying enzyme and the weight m1 of the first organic matter satisfy the relationship: U1:m1=(50-1000):1, wherein If the unit of m1 is g, the unit of U1 is U; The first organic matter includes starch and / or glucose.

3. The method according to claim 1, wherein the enzymatic activity U2 of the cellulase and the weight m2 of the second organic matter satisfy the relationship: U2:m2=(50-1000):1, wherein If the unit of m2 is g, the unit of U2 is U; The second organic matter includes cellulose.

4. The method according to claim 1, wherein the temperature of the first saccharification treatment is 50°C to 60°C, and the time of the first saccharification treatment is 2h to 3h; and / or The temperature of the second saccharification treatment is 50° C. to 60° C., and the time of the second saccharification treatment is 20 h to 24 h.

5. The method according to claim 1, wherein the weight m3 of the saccharified kitchen waste slurry and the weight m4 of the saccharified waste paper slurry satisfy the relationship: m3:m4=(1-3):1; and / or The weight of the solid phase of the fermentation raw material is 15% to 35% of the total weight of the fermentation raw material.

6. The method according to claim 1, wherein the bacteria used in the biological fermentation treatment include yeast, and the inoculation amount of the yeast is 0.05% to 0.1%.

7. The method according to claim 1, wherein the temperature of the biological fermentation treatment is 25°C to 35°C, and the time of the biological fermentation treatment is 2 days to 4 days.

8. The method according to claim 1, wherein the kitchen waste and waste paper are pre-treated to obtain defatted kitchen waste slurry and waste paper slurry, respectively, comprising the steps of: The kitchen waste and waste paper are crushed and pulped respectively to obtain kitchen waste pulp and waste paper pulp; The kitchen waste slurry is subjected to a degreasing treatment to obtain a defatted kitchen waste slurry.

9. The method according to claim 8, wherein the particle size of the waste paper slurry and the kitchen waste slurry is ≤ 8 mm; and / or The weight of the solid phase of the waste paper pulp is 20% to 50% of the total weight of the waste paper pulp; and / or The temperature of the degreasing treatment is ≥80° C., and the time of the degreasing treatment is 0.5 h to 4 h.

Images