Method for hydrothermally corrupting and steam exploding agricultural and forestry organic waste

Abstract

The invention discloses a method for hydrothermal decay steam explosion of agricultural and forestry organic waste. The method comprises the following steps: step 1, pretreatment of the agricultural and forestry organic waste; the method comprises the following steps: chopping the agricultural and forestry organic wastes, adding a proper amount of water into the chopped wastes, then adding a proper amount of a microbial corrosion promoting agent into the chopped wastes, uniformly mixing and stirring to obtain a mixture, and continuously stirring and hydrolyzing for a period of time to obtain a pre-rotten material; step 2, hydrothermal corrosion; 2, transferring the pre-decayed product obtained in the step 1 to a high-pressure reaction kettle, and carrying out a hydrothermal decaying reaction under certain conditions to obtain a hydrothermal decayed product after the reaction is completed; step 3, post-treatment of the hydrothermal corrosion product; and 3, filtering the hydrothermal corrosion product obtained in the step 2, taking a solid product, drying, and sieving. The agricultural and forestry waste pretreated by a hydrolysis method is subjected to hydrothermal corruption and then steam explosion treatment, corruption products become loose and porous, ester bonds of hemicelluloses with poor corruption effects are broken, and the humic acid content and fulvic acid content of the products are increased.

Description

Technical Field

[0001] The invention relates to the field of environmental engineering, and in particular to a method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes. Background Art

[0002] Agricultural and forestry organic waste is the general term for organic waste generated during the production, harvesting and processing of agricultural and forestry crops.

[0003] Agricultural and forestry organic waste mainly includes agricultural and forestry product processing waste such as crop straw, fruit shells, husks, shrub branches, wood chips, wood shavings, edible fungus culture medium waste, etc. The characteristics of agricultural and forestry organic waste are huge quantity and various types. With the improvement of agricultural and forestry production level, the utilization of agricultural and forestry organic waste is becoming less and less. Only about 2.6% of crop straw is reused after treatment, and most of them are treated in traditional extensive ways, such as incineration and composting.

[0004] How to rationally utilize and treat the large amount of organic waste generated in agricultural and forestry production in a high-value manner and realize the effective resource utilization of agricultural and forestry organic waste has important practical significance for solving environmental-related problems and has broad application prospects.

[0005] Composting is an important technical means for resource utilization of agricultural and forestry organic waste, but traditional organic solid waste composting adopts the strip-stack or bin-style, which occupies a large area and is difficult to control odor. The loss of carbon and nitrogen during the composting process will reduce the agricultural value of the product and cause greenhouse gas emissions.

[0006] In summary, the market needs a technical solution that can quickly and efficiently decompose agricultural and forestry organic waste, is simple to operate, and is economically feasible. Summary of the invention

[0007] Purpose of the invention: To address the deficiencies of the prior art, the purpose of the present invention is to provide a method for hydrothermal decomposition and steam explosion of agricultural and forestry organic waste. In view of the long time of traditional decomposition and composting, the loss of carbon and nitrogen during the decomposition process will reduce the agricultural value of the product and cause greenhouse gas emissions. This application controls the decomposition process in a closed warehouse, the odor is controllable, the material is evenly decomposed, and the nutrient loss is small. While being beneficial to carbon emission reduction, it is more environmentally friendly. This technical solution can break through the technical bottlenecks that affect the efficient utilization of waste resources, such as low decomposition efficiency of solid waste and poor quality of compost products.

[0008] Technical solution: A method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes, comprising the following steps:

[0009] A method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes comprises the following steps:

[0010] Step 1: Pretreatment of agricultural and forestry organic waste;

[0011] Chop the agricultural and forestry organic waste, then add an appropriate amount of water to it, and then add an appropriate amount of microbial accelerating decay agent to it. Mix and stir evenly to obtain a mixture, and continue to stir and hydrolyze for a period of time to obtain a pre-rotted product;

[0012] Step Two: Hydrothermal decay;

[0013] Transfer the pre-rotted product obtained in Step One to an autoclave and carry out a hydrothermal decay reaction under certain conditions. After the reaction is completed, a hydrothermally decayed product is obtained;

[0014] Step Three: Post-treatment of the hydrothermally decayed product;

[0015] Filter the hydrothermally decayed product obtained in Step Two, take the solid product, dry it and then sieve it.

[0016] The innovation of a method for hydrothermal decay and steam explosion of agricultural and forestry organic waste disclosed in this application lies in:

[0017] The hydrothermal decay and steam explosion treatment uses high-temperature liquid water as the reaction medium and reactant to carry out pyrolysis and steam explosion treatment on biomass organic waste. The hydrothermal decay is carried out in a closed silo, and the odor is controllable. The resourceful and recyclable utilization of agricultural and forestry organic waste is more environmentally friendly while facilitating carbon emission reduction. Moreover, the hydrothermal decay has the advantages of fast reaction speed, high product separation efficiency, and high degree of resource utilization.

[0018] Compared with other ways of resource utilization of agricultural and forestry waste, the high-temperature hydrothermal decay and steam explosion treatment has many unique advantages:

[0019] 1. The reaction medium is water, and the waste itself does not need to be dried, so the cost is relatively low;

[0020] 2. Water can control the unique physical and chemical properties of the products under high-temperature hydrothermal conditions, and the chemical activity is enhanced.

[0021] 3. Agricultural and forestry organic waste contains many organic substances such as cellulose, hemicellulose, and lignin. It is necessary to split the components or structures as much as possible during the hydrothermal process. Steam explosion can use the change of pressure to break through its complex and dense structural barrier, thereby improving the resource conversion efficiency.

[0022] Beneficial effects: A method for hydrothermal decay and steam explosion of agricultural and forestry organic waste disclosed in the present invention has the following beneficial effects:

[0023] 1. The hydrothermal decay process is carried out in a closed silo, with a short decay time, controllable odor, uniform material decay, less nutrient loss, more environmentally friendly while facilitating carbon emission reduction;

[0024] 2. Adopt the method of multi-material mixed hydrothermal decay to construct an accurately controllable and continuously stable raw material ratio for hydrothermal decay, and achieve the controllable synthesis of high-quality chemicals;

[0025] 3. Add an appropriate amount of microbial decay promoter and adopt the hydrolysis method to pretreat agricultural and forestry organic waste. The access of the microbial decay promoter accelerates the hydrolysis process. Hydrolysis pretreatment enables the cellulose, hemicellulose, and lignin components in agricultural and forestry organic waste to produce end products under the action of various bacterial groups, which is beneficial to hydrothermal decay. The products are more easily consumed by microorganisms or hydrothermally converted into more complex and highly active humus components. Therefore, hydrolysis pretreatment can increase the carbon content, humic acid content, and fulvic acid content of the products;

[0026] 4. First carry out hydrothermal decay on the agricultural and forestry waste pretreated by the hydrolysis method, and then carry out steam explosion treatment. The decay products become loose and porous, and the ester bonds of some poorly decayed hemicellulose are broken, further increasing the humic acid content and fulvic acid content of the products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flowchart of a method for hydrothermal decay and steam explosion of agricultural and forestry organic waste disclosed by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following details the specific embodiments of the present invention.

[0029] The "range" disclosed by the present invention is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The range defined in this way can include or not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 10-50 is listed for a specific parameter, ranges of 10-40 and 20-50 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise specified, the numerical range "a-b" represents the abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are fully listed in this article, and "0-5" is only the abbreviated representation of these numerical combinations.

[0030] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0031] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions.

[0032] Unless otherwise specified, all steps of this application can be carried out sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) carried out sequentially, or may also include steps (b) and (a) carried out sequentially. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may also include steps (a), (c) and (b), or may also include steps (c), (a) and (b), etc.

[0033] Unless otherwise specified, the "including" and "comprising" mentioned in this application mean open-ended, and can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or can only include or comprise the listed components.

[0034] Unless otherwise specified, the reaction is carried out under normal temperature and pressure conditions.

[0035] Unless otherwise specified, all parts or percentages are by weight or weight percentage.

[0036] In the present invention, the substances used are all known substances, which can be purchased or synthesized by known methods.

[0037] In the present invention, the devices or equipment used are all conventional devices or equipment known in the field and can all be purchased.

[0038] A method for hydrothermal corrosion and steam explosion of agricultural and forestry organic waste, comprising the following steps:

[0039] Step 1. Pretreatment of agricultural and forestry organic waste;

[0040] The agricultural and forestry organic waste is shredded, then an appropriate amount of water is added thereto, and then an appropriate amount of microbial accelerating decay agent is added thereto, and the mixture is stirred evenly to obtain a mixture, and the mixture is continuously stirred and hydrolyzed for a period of time to obtain a pre-decayed product;

[0041] Step 2. Hydrothermal corrosion;

[0042] The pre-decayed product obtained in Step 1 is transferred to a high-pressure reactor, and a hydrothermal corrosion reaction is carried out under certain conditions, and a hydrothermally decayed product is obtained after the reaction is completed;

[0043] Step 3. Post-treatment of the hydrothermally decayed product;

[0044] Filter the hydrothermally decomposed product obtained in Step 2, take the solid product, dry it and then sieve it.

[0045] Further, by mass, the agricultural and forestry organic waste in Step 1 consists of 1 part of shrub branches, 1 - 3 parts of straw, and 2 - 5 parts of edible mushroom culture residue waste.

[0046] Furthermore, the straw is one or a mixture of rice straw, corn straw, and wheat straw.

[0047] Further, the particle size of the intermediate product after chopping the agricultural and forestry organic waste in Step 1 is ≤ 5 mm.

[0048] Further, based on the total mass of water and agricultural and forestry organic waste in Step 1, the mass content of water is 60% - 80%, and / or

[0049] The water in Step 1 is one of river water, deionized water, tap water, and distilled water.

[0050] Further, the microbial accelerating decomposing agent in Step 1 is a compound microbial agent composed of multiple beneficial bacteria. The microbial accelerating decomposing agent consists of cellulase, Bacillus, Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is (6 - 10):(0.5 - 2):(0.5 - 2):1, and / or

[0051] The bacterial concentration of the beneficial bacteria in the microbial accelerating decomposing agent is at least 0.5 billion / g, and / or

[0052] Based on the total mass of water and agricultural and forestry organic waste, the addition amount of the microbial accelerating decomposing agent is 0.1 wt% - 0.5 wt%.

[0053] Further, the hydrolysis temperature in Step 1 is controlled at 37°C - 40°C, and the hydrolysis time is at least 24 h.

[0054] Further, the specific steps of Step 2 are as follows:

[0055] Transfer the pre - decomposed product obtained in Step 1 to an autoclave, heat the autoclave to 180 - 260°C, introduce saturated steam until at least 1.0 MPa, and maintain for 10 - 20 min. Continuously pass saturated steam until the pressure reaches 1.6 - 2.0 MPa, then perform instantaneous decompression blasting. After the pressure drops to the normal value and the temperature drops to room temperature, the hydrothermally decomposed product is obtained.

[0056] Further, the drying temperature in Step 3 is 100 - 120°C, and the drying time is 12 - 36 h.

[0057] Further, the sieve in Step 3 uses an 80 - 100 - mesh sieve.

[0058] In one embodiment:

[0059] A method for hydrothermal decay and steam explosion of agricultural and forestry organic waste, comprising the following steps:

[0060] Step 1. Pretreatment of agricultural and forestry organic waste;

[0061] Chop the agricultural and forestry organic waste, then add an appropriate amount of water thereto, and then add an appropriate amount of microbial decay promoter thereto, mix and stir evenly to obtain a mixture, and continue to stir and hydrolyze for a period of time to obtain a pre-decayed product;

[0062] Step 2. Hydrothermal decay;

[0063] Transfer the pre-decayed product obtained in Step 1 to a high-pressure reactor, and carry out a hydrothermal decay reaction under certain conditions. After the reaction is completed, a hydrothermally decayed product is obtained;

[0064] Step 3. Post-treatment of the hydrothermally decayed product;

[0065] Filter the hydrothermally decayed product obtained in Step 2, take the solid product, dry it and then sieve it.

[0066] Further, by mass, the agricultural and forestry organic waste in Step 1 is composed of 1 part of shrub branches; 1 part of straw; and 2 parts of edible mushroom culture medium waste residue.

[0067] Still further, the straw is rice straw.

[0068] Further, the particle size of the intermediate product after chopping the agricultural and forestry organic waste in Step 1 is ≤5 mm.

[0069] Further, based on the total mass of water and agricultural and forestry organic waste in Step 1, the mass content of the water is 60%;

[0070] The water in Step 1 is river water.

[0071] Further, the microbial decay promoter in Step 1 is a compound microbial agent composed of a variety of beneficial bacteria. The microbial decay promoter is composed of cellulase, Bacillus, Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 6:0.5:0.5:1;

[0072] The bacterial concentration of the beneficial bacteria in the microbial decay promoter is at least 0.5×10^8 / g;

[0073] Based on the total mass of water and agricultural and forestry organic waste, the addition amount of the microbial decay promoter is 0.1 wt%.

[0074] Further, the hydrolysis temperature in Step 1 is controlled at 37°C, and the hydrolysis time is 60 h.

[0075] Further, the specific steps of Step 2 are as follows:

[0076] Transfer the pre-corroded material obtained in Step 1 to an autoclave, heat the autoclave to 180°C, introduce saturated steam until the pressure reaches 1.0 MPa, and maintain for 20 min. Continuously pass saturated steam until the pressure reaches 1.6 MPa, then perform instantaneous decompression blasting. After the pressure drops to the normal value and the temperature drops to room temperature, the hydrothermally corroded material is obtained.

[0077] Further, in Step 3, the drying temperature is 100°C and the drying time is 36 h.

[0078] Further, in Step 3, an 80-mesh sieve is used.

[0079] In another embodiment:

[0080] A method for hydrothermal corrosion and steam explosion of agricultural and forestry organic waste, comprising the following steps:

[0081] Step 1. Pretreatment of agricultural and forestry organic waste;

[0082] Chop the agricultural and forestry organic waste, then add an appropriate amount of water thereto, and then add an appropriate amount of microbial accelerating agent for corrosion, mix and stir evenly to obtain a mixture, and continue to stir and hydrolyze for a period of time to obtain a pre-corroded material;

[0083] Step 2. Hydrothermal corrosion;

[0084] Transfer the pre-corroded material obtained in Step 1 to an autoclave, carry out hydrothermal corrosion reaction under certain conditions, and obtain hydrothermally corroded material after the reaction is completed;

[0085] Step 3. Post-treatment of hydrothermally corroded material;

[0086] Filter the hydrothermally corroded material obtained in Step 2, take the solid product, dry it and then pass it through a sieve.

[0087] Further, in terms of mass parts, the agricultural and forestry organic waste in Step 1 consists of 1 part of shrub branches; 3 parts of straw; 5 parts of edible mushroom culture medium waste residue.

[0088] Furthermore, the straw is corn straw.

[0089] Further, the particle size of the intermediate product after chopping the agricultural and forestry organic waste in Step 1 is ≤5 mm.

[0090] Further, based on the total mass of water and agricultural and forestry organic waste in Step 1, the mass content of water is 80%;

[0091] The water in Step 1 is deionized water.

[0092] Further, the microbial decay promoter described in Step 1 is a compound microbial agent composed of multiple beneficial bacteria. The microbial decay promoter is composed of cellulase, Bacillus spp., Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 10:2:2:1;

[0093] The bacterial concentration of the beneficial bacteria in the microbial decay promoter is at least 0.5×10^8 / g;

[0094] Based on the total mass of water and agricultural and forestry organic waste, the addition amount of the microbial decay promoter is 0.5 wt%.

[0095] Further, the hydrolysis temperature in Step 1 is controlled at 40°C, and the hydrolysis time is 24 h.

[0096] Further, the specific steps of Step 2 are as follows:

[0097] Transfer the pre-decayed product obtained in Step 1 to a high-pressure reactor. Heat the high-pressure reactor to 260°C, introduce saturated steam until the pressure reaches 1.0 MPa, and maintain it for 10 min. Continuously pass saturated steam until the pressure reaches 2.0 MPa, then perform instantaneous decompression blasting. After the pressure drops to the normal value and the temperature drops to room temperature, the hydrothermally decayed product is obtained.

[0098] Further, the drying temperature in Step 3 is 120°C, and the drying time is 12 h.

[0099] Further, the sieve used in Step 3 is a 100-mesh sieve.

[0100] In another embodiment:

[0101] A method for hydrothermal decay and steam explosion of agricultural and forestry organic waste includes the following steps:

[0102] Step 1. Pretreatment of agricultural and forestry organic waste;

[0103] Chop the agricultural and forestry organic waste, then add an appropriate amount of water to it, and then add an appropriate amount of microbial decay promoter to it. Mix and stir evenly to obtain a mixture, and continue to stir and hydrolyze for a period of time to obtain a pre-decayed product;

[0104] Step 2. Hydrothermal decay;

[0105] Transfer the pre-decayed product obtained in Step 1 to a high-pressure reactor, and carry out a hydrothermal decay reaction under certain conditions. After the reaction is completed, a hydrothermally decayed product is obtained;

[0106] Step 3. Post-treatment of the hydrothermally decayed product;

[0107] Filter the hydrothermally decayed product obtained in Step 2, take the solid product, dry it and then sieve it.

[0108] Further, by mass, the agricultural and forestry organic waste in Step 1 consists of 1 part of shrub branches, 2 parts of straw, and 3 parts of mushroom culture residue waste.

[0109] Furthermore, the straw is a mixture of rice straw, corn straw, and wheat straw, and their mass ratio is 1:2:2. In another embodiment, the straw is wheat straw.

[0110] Further, the particle size of the intermediate product after chopping the agricultural and forestry organic waste in Step 1 is ≤ 5 mm.

[0111] Further, based on the total mass of water and the agricultural and forestry organic waste in Step 1, the mass content of water is 63%;

[0112] The water in Step 1 is distilled water. In other embodiments, the water in Step 1 is tap water.

[0113] Further, the microbial accelerating decay agent in Step 1 is a compound bacterium agent composed of multiple beneficial bacteria. The microbial accelerating decay agent consists of cellulase, Bacillus sp., Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 8:1:1:1;

[0114] The bacterial concentration of the beneficial bacteria in the microbial accelerating decay agent is at least 0.5×10⁸ / g;

[0115] Based on the total mass of water and the agricultural and forestry organic waste, the addition amount of the microbial accelerating decay agent is 0.25 wt%.

[0116] Further, the hydrolysis temperature in Step 1 is controlled at 38 °C, and the hydrolysis time is 36 h.

[0117] Further, the specific steps of Step 2 are as follows:

[0118] Transfer the pre-decayed product obtained in Step 1 to a high-pressure reactor, heat the high-pressure reactor to 220 °C, introduce saturated steam until the pressure reaches 1.2 MPa, and maintain for 15 min. Continuously introduce saturated steam until the pressure reaches 1.8 MPa, then perform instantaneous decompression blasting. After the pressure drops to the normal value and the temperature drops to room temperature, the hydrothermal decayed product is obtained.

[0119] Further, the drying temperature in Step 3 is 110 °C, and the drying time is 24 h.

[0120] Further, the sieve used in Step 3 is an 80-mesh sieve.

[0121] Samples 1 - 3 were prepared according to the following Examples 1 - 3, and Comparative Samples 1 - 2 were prepared.

[0122] Example 1

[0123] A method for hydrothermal decay and steam explosion of agricultural and forestry organic waste, comprising the following steps:

[0124] Step 1. Pretreatment of agricultural and forestry organic waste;

[0125] Take 2.0 kg of fresh rice straw, 1.0 kg of shrub branches, and 3.0 kg of edible mushroom culture medium waste residue, mix them evenly, crush them into particles with a particle size of ≤ 5 mm using a crusher, add an appropriate amount of water to obtain an agricultural and forestry organic waste mixture, make the moisture content of the agricultural and forestry organic waste mixture 60%, add 8.0 g of microbial decay promoter and mix evenly, and perform mixing and stirring hydrolysis at 37 °C for 48 h to obtain a pre-decayed product;

[0126] Step 2. Hydrothermal decay;

[0127] Transfer the pre-decayed product to a high-pressure reactor for hydrothermal decay reaction, heat the high-pressure reactor to 180 °C, introduce saturated water vapor to 1.0 MPa, and maintain for 10 min. Continue to introduce saturated water vapor until the pressure reaches 1.6 MPa for instantaneous decompression blasting. After the pressure drops to the normal value and the temperature drops to room temperature, take out the hydrothermal decay product;

[0128] Step 3. Post-treatment of hydrothermally decayed products;

[0129] Filter and separate the hydrothermal decay product, take the solid product, dry it in an oven at 100 °C for 36 h, and pass through an 80-mesh sieve to obtain Sample 1.

[0130] Further, the microbial decay promoter in Step 1 is a composite bacterial agent composed of a variety of beneficial bacteria. The microbial decay promoter is composed of cellulase, Bacillus, Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 7:1:1:1;

[0131] The bacterial concentration of the beneficial bacteria in the microbial decay promoter is at least 0.5 billion / g.

[0132] Example 2

[0133] A method for hydrothermal decay and steam explosion of agricultural and forestry organic waste, comprising the following steps:

[0134] Step 1. Pretreatment of agricultural and forestry organic waste;

[0135] Take 2.0 kg of fresh rice straw, 1.0 kg of shrub branches, and 4.0 kg of edible mushroom culture medium waste residue, mix them evenly, crush them into particles with a particle size of ≤ 5 mm using a crusher, add an appropriate amount of water to obtain an agricultural and forestry organic waste mixture, make the moisture content of the obtained agricultural and forestry organic waste mixture 62%, add 10.0 g of microbial decay promoter and mix evenly, and perform mixing and stirring hydrolysis at 38 °C for 36 h to obtain a pre-decayed product;

[0136] Step 2. Hydrothermal decay;

[0137] Transfer the pre-corrupted material to an autoclave for hydrothermal corrosion reaction. Heat the autoclave to 200 °C, introduce saturated steam to 1.0 MPa, and maintain for 15 min. Continue to introduce saturated steam until the pressure reaches 1.8 MPa for instantaneous decompression and blasting. After the pressure drops to the normal value and the temperature drops to room temperature, take out the hydrothermal corrosion product;

[0138] Step 3. Post-treatment of hydrothermally corroded material;

[0139] Filter and separate the hydrothermal corrosion product, take the solid product, then dry it at 120 °C for 12 h, and pass through a 100-mesh sieve to obtain Sample 2.

[0140] Furthermore, the microbial accelerating corrosion agent described in Step 1 is a composite microbial agent composed of multiple beneficial bacteria. The microbial accelerating corrosion agent is composed of cellulase, Bacillus sp., Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 7:1:1:1;

[0141] The bacterial concentration of the beneficial bacteria in the microbial accelerating corrosion agent is at least 0.5×10⁸ / g.

[0142] Example 3

[0143] A method for hydrothermal corrosion and steam explosion of agricultural and forestry organic waste, comprising the following steps:

[0144] Step 1. Pretreatment of agricultural and forestry organic waste;

[0145] Take 2.0 kg of fresh rice straw, 1.0 kg of shrub branches, and 5.0 kg of edible mushroom culture residue, mix them evenly, crush them into particles with a particle size of ≤5 mm using a pulverizer, add an appropriate amount of water to obtain a mixture of agricultural and forestry organic waste, make the total moisture content of the material 66%, add 12.0 g of microbial accelerating corrosion agent, mix evenly, and carry out mixing and stirring hydrolysis at 40 °C for 24 h to obtain pre-corrupted material;

[0146] Step 2. Hydrothermal corrosion;

[0147] Transfer the pre-corrupted material to an autoclave for hydrothermal corrosion reaction. Heat the autoclave to 220 °C, introduce saturated steam to 1.0 MPa, and maintain for 20 min. Continue to introduce saturated steam until the pressure reaches 2.0 MPa for instantaneous decompression and blasting. After the pressure drops to the normal value and the temperature drops to room temperature, take out the hydrothermal corrosion product;

[0148] Step 3. Post-treatment of hydrothermally corroded material;

[0149] Filter and separate the hydrothermal corrosion product, take the solid product, and then dry it at 105 °C for 24 h and pass through an 80-mesh sieve to obtain Sample 3.

[0150] Further, the microbial decay promoter described in Step 1 is a compound microbial agent composed of multiple beneficial bacteria. The microbial decay promoter is composed of cellulase, Bacillus sp., Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 7:1:1:1;

[0151] The bacterial concentration of the beneficial bacteria in the microbial decay promoter is at least 0.5×10^8 / g.

[0152] Comparative Example 1 (no steam explosion treatment in this example)

[0153] A method for hydrothermal decay of agricultural and forestry organic waste, comprising the following steps:

[0154] Step 1. Pretreatment of agricultural and forestry organic waste;

[0155] Take 2.0 kg of fresh rice straw, 1.0 kg of shrub branches, and 5.0 kg of edible mushroom culture residue, mix them evenly, crush them into particles with a particle size of ≤5 mm using a crusher, add an appropriate amount of water to obtain a mixture of agricultural and forestry organic waste, make the total moisture content of the mixture of agricultural and forestry organic waste 66%, add 12.0 g of microbial decay promoter and mix evenly, and carry out mixing and stirring hydrolysis at 40°C for 24 h to obtain a pre-decayed product;

[0156] Step 2. Hydrothermal decay;

[0157] Transfer the pre-decayed product to an autoclave for hydrothermal decay reaction, heat the autoclave to 220°C, introduce saturated steam to 1.0 MPa, and maintain for 20 min. After the pressure drops to the normal value and the temperature drops to room temperature, take out the hydrothermal decay product;

[0158] Step 3. Post-treatment of hydrothermally decayed products;

[0159] Filter and separate the hydrothermal decay product, take the solid product, and then dry it at 105°C for 24 h and pass through an 80-mesh sieve to obtain Comparative Sample 1.

[0160] Further, the microbial decay promoter described in Step 1 is a compound microbial agent composed of multiple beneficial bacteria. The microbial decay promoter is composed of cellulase, Bacillus sp., Trichoderma longibrachiatum, and Aspergillus niger, and their mass ratio is 7:1:1:1;

[0161] The bacterial concentration of the beneficial bacteria in the microbial decay promoter is at least 0.5×10^8 / g.

[0162] Comparative Example 2 (no hydrolysis pretreatment in this example)

[0163] A method for hydrothermal decay of steam-exploded agricultural and forestry organic waste, comprising the following steps:

[0164] Step 1. Pretreatment of agricultural and forestry organic waste;

[0165] 2.0 kg of fresh rice straw, 1.0 kg of shrub branches, and 4.0 kg of edible fungus culture medium waste residue were mixed evenly, crushed into particles with a particle size of ≤5 mm by a crusher, and an appropriate amount of water was added to obtain an agricultural and forestry organic waste mixture, so that the moisture content of the agricultural and forestry organic waste mixture was 62% to obtain a premix;

[0166] Step 2: hydrothermal decay;

[0167] The premix is ​​transferred to a high-pressure reactor for hydrothermal corrosion reaction. The high-pressure reactor is heated to 200°C, saturated steam is introduced to 1.0 MPa, and maintained for 15 minutes. Saturated steam is continued to be introduced until the pressure reaches 1.8 MPa, and then instantaneous decompression explosion is performed. After the pressure drops to normal values ​​and the temperature drops to room temperature, the hydrothermal corrosion product is taken out;

[0168] Step 3: Post-treatment of hydrothermal decay products;

[0169] The hydrothermal decomposition product was separated by filtration, and the solid product was taken out and then dried at 120°C for 12 hours. After passing through a 100-mesh sieve, comparative sample 2 was obtained.

[0170] Samples 1-3 and comparative samples 1-2 were tested;

[0171] Test 1: Carbon content test

[0172] Detection method:

[0173] The carbon content was determined using an elemental analyzer;

[0174] The test results are shown in Table 1:

[0175] Carbon content Sample 1 59.91％ Sample 2 60.80％ Sample 3 60.62％ Control sample 1 59.32％ Control sample 2 54.73％

[0176] Test 2: Humic acid content test

[0177] Detection method:

[0178] The samples were extracted with alkali and acid (0.1 mol / L NaOH, 2.0 mol / L H 2 SO4 washing), the precipitated part is humic acid (HA), the solid part of the supernatant is eluted with 0.5mol / L NaOH solution, which is fulvic acid (FA). The test results are shown in Table 2:

[0179] Humic acid content Fulvic acid content Sample 1 320.40 g / Kg 198.36 g / Kg Sample 2 322.11 g / Kg 199.90 g / Kg Sample 3 323.56 g / Kg 197.88 g / Kg Control sample 1 251.87 g / Kg 144.69 g / Kg Control sample 2 176.33 g / Kg 146.34 g / Kg

[0180] Result analysis:

[0181] It can be seen from the results of samples 1-3 and comparative samples 1-2 that the humus obtained using the formulation and preparation method of the present invention has a good carbon content and yield.

[0182] From the comparison of the results of Samples 1-3 and Comparative Samples 1-2, it can be seen that steam explosion treatment can increase the humic acid content and fulvic acid content of the product;

[0183] From the comparison of the results of Samples 1-3 and Comparative Sample 2, it can be seen that hydrolysis pretreatment can increase the carbon content, humic acid content and fulvic acid content of the product.

[0184] The above has made a detailed description of the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A method for hydrothermal decomposition and steam explosion of agricultural and forestry organic waste, characterized in that: The steps include: Step 1: Pretreatment of agricultural and forestry organic waste; The agricultural and forestry organic waste is chopped, and then a proper amount of water is added thereto, and then a proper amount of microbial decay-promoting agent is added thereto, and the mixture is mixed and stirred to obtain a mixture, and the mixture is stirred and hydrolyzed for a period of time to obtain a pre-rotten material; Step 2: hydrothermal decay; The pre-corrosion product obtained in step 1 is transferred to a high-pressure reactor, and a hydrothermal corrosion reaction is carried out under certain conditions to obtain a hydrothermal corrosion product after the reaction is completed; Step 3: Post-treatment of hydrothermal decay products; The hydrothermal decomposition product obtained in step 2 is filtered, and the solid product is taken out, dried and sieved.

2. A method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: In terms of weight, the agricultural and forestry organic waste in step one consists of 1 part of shrub branches, 1-3 parts of straws, and 2-5 parts of edible fungus culture medium waste residues.

3. A method for hydrothermal decomposition and steam explosion of agricultural and forestry organic waste as claimed in claim 2, characterized in that: The straw is one of rice straw, corn straw, wheat straw or a mixture thereof.

4. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: The particle size of the intermediate product after the agricultural and forestry organic waste is shredded in step 1 is ≤5mm.

5. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: In step 1, the total mass of water and agricultural and forestry organic waste is used as the basis, and the mass content of water is 60%-80%, and / or The water in step 1 is one of river water, deionized water, tap water and distilled water.

6. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: The microbial decay promoting agent in step 1 is a composite bacterial agent composed of multiple beneficial bacteria, and the microbial decay promoting agent is composed of cellulolytic enzymes, Bacillus, Trichoderma longicornis, and Aspergillus niger, and the mass ratio thereof is (6-10):(0.5-2):(0.5-2):1, and / or The concentration of beneficial bacteria in the microbial probiotic is at least 50 million / g, and / or Based on the total mass of water and agricultural and forestry organic wastes, the added amount of the microbial decay-promoting agent is 0.1wt%-0.5wt%.

7. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: In step 1, the hydrolysis temperature is controlled at 37° C.-40° C., and the hydrolysis time is at least 24 hours.

8. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: The specific steps of step 2 are as follows: The pre-corrosion product obtained in step 1 is transferred to a high-pressure reactor, and the temperature of the high-pressure reactor is raised to 180-260°C, and saturated steam is introduced to at least 1.0 MPa, and maintained for 10-20 minutes. When the saturated steam is continuously introduced until the pressure reaches 1.6-2.0 MPa, instantaneous decompression explosion is performed, and when the pressure drops to normal values ​​and the temperature drops to room temperature, a hydrothermal corrosion product is obtained.

9. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: In step 3, the drying temperature is 100-120°C and the drying time is 12-36h.

10. The method for hydrothermal decomposition and steam explosion of agricultural and forestry organic wastes as claimed in claim 1, characterized in that: In step three, the sieve is 80-100 mesh.

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