Method for processing granular fuel from household garbage, sludge and cow dung

Abstract

The invention belongs to the technical field of granular fuel, and particularly relates to a method for processing household garbage, sludge and cow dung into granular fuel, which comprises the following steps: (1) performing coarse crushing on the household garbage, sorting metal materials, crushing the residual materials in a fine crusher again, and crushing in a throwing sheet type crusher until a cotton fiber state is reached, a material A is obtained; sludge is dried, and a material B is obtained; drying cow dung to obtain a material C; and (2) mixing the material A, the material B and the material C, adding a modifier in the stirring process to carry out grafting reaction, and finally feeding the completely stirred material into a forming granulator to prepare the biomass pellet fuel. According to the invention, efficient utilization and conversion of household garbage, sludge and cow dung are realized. The prepared granular fuel has the advantages of high density, high yield, low energy consumption, high compressive strength and the like, not only solves the problems of shortage of traditional fuel resources and environmental pollution, but also promotes cyclic utilization and sustainable development of resources.

Description

Technical Field

[0001] The invention belongs to the technical field of particle fuels, and in particular relates to a method for processing particle fuels from domestic garbage, sludge and cow dung. Background Art

[0002] With the acceleration of urbanization and the continuation of agricultural activities, the amount of waste such as domestic garbage, sludge and cow dung is increasing, which has brought great pressure to the environment. If these wastes are not properly treated, they will not only occupy a large amount of land resources, but also pollute the soil, water and atmosphere through infiltration, volatilization and other means, seriously affecting the ecological balance and human health. Therefore, how to achieve the effective treatment and resource utilization of these wastes has become an important issue that needs to be solved urgently.

[0003] Traditionally, domestic waste is mostly disposed of by landfill or incineration. Landfill takes up land resources and is prone to produce leachate and foul-smelling gases; although incineration can reduce the volume, it will produce a large amount of air pollutants, such as particulate matter, sulfur dioxide, nitrogen oxides, etc., which have a serious impact on the atmospheric environment. The treatment of sludge and cow dung also faces similar problems. Traditional treatment methods are often inefficient and prone to secondary pollution.

[0004] In recent years, with the continuous development of biomass energy technology, converting waste into biomass pellet fuel has become a new treatment idea. Biomass pellet fuel has the advantages of being renewable, environmentally friendly, and low-carbon. It can not only effectively alleviate the shortage of traditional fuel resources, but also reduce greenhouse gas emissions and promote sustainable development. However, converting waste such as domestic garbage, sludge and cow dung into biomass pellet fuel is not an easy task and requires solving a series of technical problems.

[0005] First, the composition of these wastes is complex and their properties vary. Directly mixing them together often makes it difficult to achieve the desired combustion effect. Domestic waste contains a large amount of organic and inorganic matter. The organic part is combustible, but the inorganic part, such as metal and glass, will affect the combustion performance. Silt and cow dung contain high levels of moisture and organic matter. Direct use can easily lead to incomplete combustion and smoke emission problems.

[0006] Secondly, the mixing ratio of waste and the addition of modifiers have a crucial impact on the performance of biomass pellet fuel. Mixing wastes in different ratios may lead to differences in combustion performance, calorific value and compressive strength. The addition of modifiers can improve the compatibility and stability of wastes and improve the overall performance of biomass pellet fuel. However, how to determine the optimal mixing ratio and amount of modifier added, as well as choosing the appropriate type of modifier and reaction conditions, is one of the difficulties in the current technical field.

[0007] Therefore, developing an efficient and environmentally friendly method for processing granular fuel from domestic waste, sludge, and cow dung has important practical significance and application value. Through a series of optimization measures and innovative designs, the present invention realizes the efficient utilization and transformation of these waste materials. Through pretreatment steps such as coarse crushing, fine crushing, and flake-type crushing, the waste materials are crushed to an appropriate particle size, improving the uniformity and reactivity of the materials. By adding a modifier and conducting a grafting reaction, the compatibility and stability between the materials are improved, enhancing the overall performance of the biomass granular fuel. At the same time, by precisely controlling parameters such as the moisture content, mixing ratio, and reaction conditions of the materials, the quality and performance of the biomass granular fuel are ensured to reach the optimal level.

[0008] In summary, the background technology of the present invention is proposed based on the severe challenges and urgent needs in the current field of waste treatment and resource utilization, aiming to achieve the efficient utilization and transformation of waste materials such as domestic waste, sludge, and cow dung through technological innovation, and contribute to sustainable development and environmental protection. Summary of the Invention

[0009] The present invention aims to solve the above technical problems and provides a method for processing granular fuel from domestic waste, sludge, and cow dung. The granular fuel prepared by this method has a high density, large output, low energy consumption, high compressive strength, and high calorific value.

[0010] The technical solution of the present invention is as follows:

[0011] A method for processing granular fuel from domestic waste, sludge, and cow dung, comprising the following steps:

[0012] (1) The domestic waste is first subjected to coarse crushing, then the metal materials are separated, and the remaining materials enter the fine crusher for further crushing, and then enter the flake-type crusher for crushing until it reaches a cotton-like state to obtain material A; the sludge is dried to obtain material B; the cow dung is dried to obtain material C;

[0013] (2) Mix material A, material B, and material C, and add a modifier during the stirring process for grafting reaction. The fully stirred material finally enters the forming granulator to make biomass granular fuel.

[0014] Furthermore, the modifier includes a grafting monomer and an initiator. The grafting monomer is composed of butyl acrylate and glycidyl methacrylate, and the initiator is benzoyl peroxide.

[0015] Furthermore, the moisture content of the material A is controlled between 10% and 20%; the moisture content of the material B is controlled between 5% and 10%; the moisture content of the material C is controlled between 10% and 15%. The moisture content and their proportions of the material A, the material B and the material C are all key factors, which will directly affect the quality and production efficiency of the final product. Excessive or too low moisture will lead to difficulties in subsequent molding, reduce production efficiency, and also affect the calorific value and stability of the fuel.

[0016] Furthermore, the ratio of the material A, the material B and the material C is (4 - 5):(2 - 3):(2 - 3).

[0017] Furthermore, the addition ratio of the graft monomer is 6 - 8% of the total weight of the material A, the material B and the material C.

[0018] Furthermore, the molar ratio of butyl acrylate and glycidyl methacrylate is 1:(1 - 3).

[0019] Furthermore, the molar ratio of the graft monomer and the initiator is 100:(0.5 - 1).

[0020] Furthermore, the temperature of the graft reaction is 80 - 90 °C, and the reaction time is 4 - 6 hours.

[0021] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0022] (1) Through the graft copolymerization reaction of the present invention, hydrophilic functional groups are introduced onto the surface of the organic matter in domestic waste, thereby improving the compatibility with sludge and cow dung. In this way, during the stirring process, the dispersibility between the materials is improved, and phenomena such as stratification and agglomeration are reduced, making the mixing more uniform. After adding the modifier in the present invention, under the same environmental compression ratio, the density of the pellet fuel is higher, the output is larger, and the energy consumption is lower.

[0023] (2) By precisely controlling the moisture content of the material A, the material B and the material C, the present invention ensures the stability and consistency of the mixed material during the graft reaction and the molding process. The appropriate control of moisture not only facilitates the progress of the graft reaction but also avoids the problem of unstable pellet quality caused by excessive or too little moisture during the molding process. The ratio of the material A, the material B and the material C in the present invention is reasonably designed, fully considering the characteristics of each material and the influence on the performance of the pellet fuel. By optimizing the ratio, the mixed material can form a more compact structure after the graft reaction, thereby improving the compressive strength and calorific value of the pellet fuel.

[0024] (3) The addition ratio of the graft monomer is moderate, which can not only fully react with the functional groups on the surface of the material, but also avoid the problems of increased cost or incomplete reaction caused by excessive addition. At the same time, the molar ratio of butyl acrylate and glycidyl methacrylate is reasonably designed, so that the graft monomer can be evenly distributed on the surface of the material, improving the overall performance of the pellet fuel. The molar ratio of the graft monomer and the initiator is properly controlled to ensure the smooth progress and efficient completion of the graft reaction. The appropriate addition of the initiator can initiate the chain reaction of the graft monomer, thereby forming more functional groups on the surface of the material and improving the compatibility and stability of the pellet fuel. The temperature and time of the graft reaction are precisely controlled, which is beneficial to the progress of the reaction and the formation of the product. At an appropriate temperature, the reaction rate is moderate, which can avoid side reactions caused by too high temperature or incomplete reaction caused by too low temperature. At the same time, the control of the reaction time ensures the full progress of the reaction and the complete formation of the product, thereby improving the quality and performance of the pellet fuel.

[0025] In summary, through a series of optimization measures and innovative designs, the present invention realizes the efficient utilization and conversion of domestic waste, sludge and cow dung. The prepared biomass pellet fuel has the advantages of high density, large output, low energy consumption, high compressive strength and high calorific value. It not only solves the problems of traditional fuel resource shortage and environmental pollution, but also promotes the recycling of resources and sustainable development. Specific Embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1

[0028] (1) Preparation of materials:

[0029] Material A: Domestic waste is coarsely crushed, sorted and finely crushed, and then pulverized to a cotton-like state by a flake mill, and the moisture content is controlled at 15%;

[0030] Material B: Sludge is dried, and the moisture content is controlled at 7%;

[0031] Material C: Cow dung is dried, and the moisture content is controlled at 12%;

[0032] (2) Mixing and reaction:

[0033] Mix in the ratio of Material A: Material B: Material C = 4.5:2.5:2.5;

[0034] Add a modifier accounting for 7% of the total weight of the added materials (the molar ratio of butyl acrylate to glycidyl methacrylate is 1:2, and the molar ratio of the graft monomer to benzoyl peroxide initiator is 100:0.7); carry out a grafting reaction with stirring at 85 °C for 5 hours.

[0035] (3) Molding and testing:

[0036] Feed the reacted materials into a molding granulator to produce biomass pellet fuel.

[0037] Test results: density 0.85 g / cm 3 , output 1.2 tons per hour, energy consumption 121 kWh / ton, compressive strength 20 MPa.

[0038] Example 2

[0039] (1) Preparation of materials:

[0040] Material A: Domestic waste is processed to a cotton floc state with the moisture content controlled at 10%;

[0041] Material B: Sludge is dried to a moisture content of 5%;

[0042] Material C: Cow dung is dried to a moisture content of 10%;

[0043] (2) Mixing and reaction:

[0044] The mixing ratio is Material A: Material B: Material C = 4:2:3;

[0045] Add a modifier accounting for 6% of the total weight of the added materials (the molar ratio of butyl acrylate to glycidyl methacrylate is 1:1, and the molar ratio of the graft monomer to benzoyl peroxide initiator is 100:0.5);

[0046] Carry out a stirring reaction at 80 °C for 4 hours;

[0047] (3) Molding and testing:

[0048] Produce biomass pellet fuel.

[0049] Test results: density 0.82 g / cm 3 , output 1.1 tons per hour, energy consumption 132 kWh / ton, compressive strength 18 MPa.

[0050] Example 3

[0051] (1) Preparation of materials:

[0052] Material A: Domestic waste is processed to a cotton floc state with the moisture content controlled at 20%;

[0053] Material B: Sludge is dried to a moisture content of 10%;

[0054] Material C: Cow dung is dried to a moisture content of 15%.

[0055] (2) Mixing and reaction:

[0056] The mixing ratio is Material A: Material B: Material C = 5:3:2;

[0057] Add a modifier accounting for 8% of the total weight of the added materials (the molar ratio of butyl acrylate to glycidyl methacrylate is 1:3, and the molar ratio of the graft monomer to benzoyl peroxide initiator is 100:1);

[0058] Stir and react at 90 °C for 6 hours;

[0059] (3) Molding and testing:

[0060] Produce biomass pellet fuel.

[0061] Test results: Density 0.88 g / cm 3 , Output 1.3 tons / hour, Energy consumption 115 kWh / ton, Compressive strength 22 MPa.

[0062] Example 4

[0063] (1) Prepare materials:

[0064] Material A: Municipal solid waste is processed to a cotton floc state, and the moisture content is controlled at 12%;

[0065] Material B: Sludge is dried to a moisture content of 8%;

[0066] Material C: Cow dung is dried to a moisture content of 13%;

[0067] (2) Mixing and reaction:

[0068] The mixing ratio is Material A: Material B: Material C = 4.8:2.2:2.8;

[0069] Add a modifier accounting for 7.5% of the total weight of the added materials (the molar ratio of butyl acrylate to glycidyl methacrylate is 1:1.5, and the molar ratio of the graft monomer to benzoyl peroxide initiator is 100:0.6);

[0070] Stir and react at 87 °C for 5.5 hours;

[0071] (3) Molding and testing:

[0072] Produce biomass pellet fuel.

[0073] Test results: Density 0.86 g / cm 3 , Output 1.25 tons / hour, Energy consumption 117 kWh / ton, Compressive strength 21 MPa.

[0074] Example 5

[0075] (1) Preparation materials:

[0076] Material A: Domestic waste is processed to a cotton-like state, and the moisture content is controlled at 18%;

[0077] Material B: Sludge is dried to a moisture content of 6%;

[0078] Material C: Cow dung is dried to a moisture content of 14%;

[0079] (2) Mixing and reaction:

[0080] The mixing ratio is Material A: Material B: Material C = 4.2:2.8:2.6;

[0081] Add a modifier accounting for 6.5% of the total weight of the added materials (the molar ratio of butyl acrylate to glycidyl methacrylate is 1:2.5, and the molar ratio of graft monomer to initiator benzoyl peroxide is 100:0.8);

[0082] Stir and react at 82 °C for 4.5 hours;

[0083] (3) Molding and testing:

[0084] Produce biomass pellet fuel.

[0085] Test results: Density 0.84 g / cm 3 , Output 1.15 tons / hour, Energy consumption 126 kWh / ton, Compressive strength 19 MPa.

[0086] To illustrate the technical effects of the present invention, the inventor set the following comparative examples and comparative tests:

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 1 is only that the modifier only uses butyl acrylate.

[0089] Specifically as follows:

[0090] (1) Preparation materials:

[0091] Material A: Domestic waste is coarsely crushed, sorted, and finely crushed, and then pulverized to a cotton-like state by a flail mill, and the moisture content is controlled at 15%;

[0092] Material B: Sludge is dried, and the moisture content is controlled at 7%;

[0093] Material C: Cow dung is dried, and the moisture content is controlled at 12%;

[0094] (2) Mixing and reaction:

[0095] Mix according to the ratio of material A: material B: material C = 4.5:2.5:2.5;

[0096] Add a modifier accounting for 7% of the total weight of the materials (the graft monomer is butyl acrylate, and the molar ratio of the graft monomer to the initiator benzoyl peroxide is 100:0.7); carry out a graft reaction with stirring at 85°C for 5 hours.

[0097] (3) Molding and testing:

[0098] Feed the reacted materials into a molding granulator to make biomass pellet fuel.

[0099] Test results: density 0.76 g / cm 3 , output 0.9 tons per hour, energy consumption 162 kWh / ton, compressive strength 13 MPa

[0100] Comparative example 2

[0101] The difference between comparative example 2 and example 1 is only that the modifier used is only glycidyl methacrylate.

[0102] Specifically as follows:

[0103] (1) Preparation of materials:

[0104] Material A: Domestic waste is coarsely crushed, sorted, and finely crushed, and then pulverized to a cotton-like state by a flake mill, with the moisture content controlled at 15%;

[0105] Material B: Sludge is dried, and the moisture content is controlled at 7%;

[0106] Material C: Cow dung is dried, and the moisture content is controlled at 12%;

[0107] (2) Mixing and reaction:

[0108] Mix according to the ratio of material A: material B: material C = 4.5:2.5:2.5;

[0109] Add a modifier accounting for 7% of the total weight of the materials (the graft monomer is glycidyl methacrylate, and the molar ratio of the graft monomer to the initiator benzoyl peroxide is 100:0.7); carry out a graft reaction with stirring at 85°C for 5 hours.

[0110] (3) Molding and testing:

[0111] Feed the reacted materials into a molding granulator to make biomass pellet fuel.

[0112] Test results: density 0.69 g / cm 3 , output 0.8 tons per hour, energy consumption 172 kWh / ton, compressive strength 16 MPa.

[0113] Note: In the above-mentioned examples and comparative examples, during the granulation process of the pellet fuel, the environmental compression ratio is 5.0 for all cases.

[0114] From the test results of the comparative examples, it can be seen that through graft copolymerization reaction in the present invention, hydrophilic functional groups are introduced on the surface of the organic matter in the domestic waste, thereby improving the compatibility with sludge and cow dung. After adding the modifier in the present invention, at the same environmental compression ratio, the pellet fuel has a higher density, a larger output, lower energy consumption, and greater compressive strength.

[0115] The above description is a detailed description of the preferred and feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications made under the technical spirit disclosed by the present invention shall fall within the scope of the patent covered by the present invention.

Claims

1. A method for processing pellet fuel from domestic garbage, sludge and cow dung, characterized in that: The following steps are involved: (1) The domestic garbage is first coarsely crushed, and then the metal materials are sorted out. The remaining materials are crushed again in a fine crusher, and then crushed in a swing-blade crusher until they reach a cotton-wool state, thereby obtaining material A; the sludge is dried to obtain material B; and the cow dung is dried to obtain material C; (2) Material A, material B and material C are mixed, and a modifier is added during the stirring process for grafting reaction. The completely stirred materials finally enter a forming pellet machine to produce biomass pellet fuel.

2. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 1, characterized in that: The modifier comprises a grafting monomer and an initiator, wherein the grafting monomer is composed of butyl acrylate and glycidyl methacrylate, and the initiator is benzoyl oxide.

3. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 1, characterized in that: The moisture content of the material A is controlled between 10% and 20%; the moisture content of the material B is controlled between 5% and 10%; and the moisture content of the material C is controlled between 10% and 15%.

4. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 2, characterized in that: The ratio of material A, material B and material C is (4-5):(2-3):(2-3).

5. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 2, characterized in that: The addition ratio of the grafting monomer is 6-8% of the total weight of material A, material B and material C.

6. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 1, characterized in that: The molar ratio of butyl acrylate to glycidyl methacrylate is 1:(1-3).

7. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 1, characterized in that: The molar ratio of the grafting monomer to the initiator is 100:(0.5-1).

8. The method for processing pellet fuel from household garbage, sludge and cow dung as claimed in claim 1, characterized in that: The grafting reaction temperature is 80-90° C., and the reaction time is 4-6 hours.