Preparation method of low-cost biomass charcoal particle briquette fuel

Abstract

The invention is suitable for the technical field of biomass utilization, and provides a low-cost biomass charcoal particle briquette fuel preparation method, which comprises: S1, crushing, screening, carbonizing and re-crushing air-dried forestry branches to obtain biomass charcoal; s2, adding water into the industrial manioc waste for pre-gelatinization; s3, uniformly mixing the forestry branch biomass charcoal with the pre-gelatinized manioc waste, then uniformly mixing with the industrial furfural residue, and adjusting the water content of the mixture; and S4, filling a mold with the mixture, heating, and pressurizing to prepare the biomass charcoal particle briquette fuel. The crushed forestry branches are firstly carbonized to prepare the biomass charcoal, the biomass is compounded with the cassava residues and the furfural residues in a certain proportion, the biomass charcoal particle briquette fuel is prepared through pre-gelatinization, heating and pressurization, and the fuel has the advantages of being high in energy density, stable in mechanical performance, low in cost and the like; the defects that biomass briquette fuel is low in energy density, and biomass charcoal particle briquette fuel is unstable in mechanical performance are overcome.

Description

Technical Field

[0001] This invention relates to the field of biomass utilization technology, specifically to a low-cost method for preparing biomass char pellet fuel. Background Technology

[0002] Biomass briquettes are characterized by low ash content, high calorific value, and good durability. They also have a low ignition point, are easy to ignite, and have a low CO / NO content. X Biomass briquettes offer advantages such as low emissions, renewability, low raw material costs, and flexible applications. They can be widely used in various types of household stoves, fireplaces, hot water boilers, hot air furnaces, steam boilers, and power generation facilities. Biomass briquettes can replace fossil fuels to alleviate energy shortages, reduce carbon emissions, and improve the ecological environment. However, biomass briquettes still suffer from low energy density, while biomass charcoal pellets have drawbacks such as loose structure, insufficient density, and poor durability.

[0003] Garden and landscaping waste, as a special type of urban organic waste, plays a vital role in green and low-carbon development, ecological civilization construction, and high-quality sustainable urban development through its resource utilization and energy application. In recent years, with the rapid development of urban landscaping, the amount of garden and landscaping waste (forestry branches and timber) generated in some cities, especially megacities and large cities, has been increasing year by year. Such a large-scale amount of garden and landscaping waste urgently needs to be disposed of and treated. Utilizing forestry branches and timber to produce biomass energy has potential economic, social, and ecological benefits.

[0004] Cassava residue and furfural residue are waste products from the production of industrial cassava starch and industrial furfural. Currently, they are only used as ordinary boiler fuel, and their thermal energy value is not fully utilized. The starch and cellulose in cassava residue and the cellulose and lignin in furfural residue have important synergistic effects on the production of high-quality biochar pellet fuel.

[0005] Based on the above problems, this application provides a low-cost biochar pellet fuel preparation method for recycling forest branches and branches. Summary of the Invention

[0006] The purpose of this invention is to provide a low-cost method for preparing biochar pellet fuel, in order to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a low-cost biomass char pellet fuel preparation method, comprising the following steps: S1, the dried forestry branches are crushed, sieved, carbonized and then crushed again to obtain biochar; S2, Pregelatinize industrial cassava residue with water; S3, mix forestry branch biochar with pre-gelatinized cassava residue evenly, then mix with industrial furfural residue evenly, and adjust the moisture content of the mixture. S4, the mixture is filled into a mold and heated and pressurized to prepare biochar pellet fuel.

[0008] Preferably, in S1, the forestry branches are crushed to less than 40mm and the moisture content of the raw materials is less than 10%.

[0009] Preferably, the carbonization temperature of the branches in S1 is 400-450℃, the carbonization time is 3-5h, and after carbonization and cooling, they are crushed to below 5mm.

[0010] Preferably, in step S2, water is added to industrial cassava residue to a moisture content of 50%, and the residue is heated to 85°C for pregelatinization for 15 minutes.

[0011] Preferably, in step S3, the forestry branch biochar is mixed evenly with pre-gelatinized cassava residue, and then mixed evenly with industrial furfural residue. The moisture content of the mixture is controlled at 8-10%, and the dry basis mass ratio of the mixture is cassava residue: furfural residue: forestry branch biochar = (0.3~0.5):(0.5~0.7):9.

[0012] Preferably, in step S4, the mold is first heated to a set temperature of 80-120°C, and held for 2 minutes after reaching the set temperature. Then, the raw material is compressed at 10 mm / min. When the pressure reaches 70.8 MPa, the pressure is held for 3 minutes, and then the compression is stopped. When demolding, the material is demolded at 5 mm / min. After cooling, biomass char pellets are obtained as fuel.

[0013] The present invention has at least the following beneficial effects: This invention provides a low-cost method for preparing biochar pellet fuel. Crushed forestry branches are first carbonized to prepare biochar. The biochar is then mixed with a certain proportion of cassava residue and furfural residue. The mixture is then pregelatinized, heated, and pressurized to obtain biochar pellet fuel. The fuel has advantages such as high energy density, stable mechanical properties, and low cost, overcoming the disadvantages of low energy density and unstable mechanical properties of biochar pellet fuel. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the preparation method of the present invention. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] This invention provides a low-cost method for preparing biochar pellet fuel. First, dried forestry branches are collected, crushed, sieved, and carbonized at high temperature to obtain biochar. Then, industrial cassava residue is hydrated and pregelatinized. Next, industrial furfural residue, pregelatinized cassava residue, and biochar are mixed and stirred in a certain proportion. Finally, the mixture is heated, kept warm, and pressurized to obtain biochar pellet fuel.

[0017] like Figure 1 As shown, the specific process is as follows: 1) Forestry branch crushing: The air-dried forestry branches are crushed to less than 40mm, and the moisture content of the raw materials is less than 10%.

[0018] 2) Carbonization of forest branches and twigs: The crushed branches and twigs are carbonized at a temperature of 400-450℃ for 3-5 hours. After cooling, they are crushed to less than 5mm.

[0019] 3) Pregelatinization of cassava residue: Add water to industrial cassava residue to a moisture content of 50%, heat to 85℃ and pregelatinize for 15 minutes; 4) Mixing of raw materials for shaped fuel: Mix forestry branch biochar with pre-gelatinized cassava residue evenly, and then mix with industrial furfural residue evenly. The moisture content of the mixture is controlled at 8-10%, and the dry basis mass ratio of the mixture is cassava residue: furfural residue: forestry branch biochar = (0.3~0.5):(0.5~0.7):9.

[0020] 5) Preparation of briquettes: Fill the mixed raw materials into the compression holes, heat the mold to the set temperature of 80-120℃, hold for 2 minutes after reaching the set temperature, then start compressing the raw materials at 10 mm / min. When the pressure reaches 70.8 MPa, hold the pressure for 3 minutes, then stop the compression. Demold at 5 mm / min, and after cooling, obtain biochar pellet briquettes.

[0021] Based on the above technical solutions, the present invention provides the following embodiments: Example

[0022] Air-dried forestry branches and twigs are pulverized to below 40mm (raw material moisture content 9%-10%). The pulverized branches and twigs are then carbonized at 450℃ for 3 hours. After cooling, they are pulverized to below 5mm. Industrial cassava residue is mixed with water to a moisture content of 50% and pre-gelatinized at 85℃ for 15 minutes. The forestry branch and twig biochar is then mixed evenly with the pre-gelatinized cassava residue, and then mixed evenly with industrial furfural residue. The moisture content of the mixture is controlled at 8%. The dry basis mass ratio of the mixture is cassava residue: furfural residue: forestry The ratio of branch biochar is 0.3:0.9:8.8. The mixed raw materials are filled into the compression holes. The mold is first heated to the set temperature of 100℃ and held for 2 minutes. Then, the raw materials are compressed at 10 mm / min. When the pressure reaches 70.8 MPa, the pressure is held for 3 minutes and then the compression is stopped. When demolding, the pressure is released at 5 mm / min. After cooling to 40℃, the biochar pellets are packaged to obtain biochar pellet fuel. The calorific value of the product is measured to be 25.9 MJ / kg and the breakage rate is 0.9%. Example

[0023] Air-dried forestry branches and twigs are pulverized to below 40mm (raw material moisture content 9%-10%). The pulverized branches and twigs are then carbonized at 400℃ for 3 hours. After cooling, they are pulverized to below 5mm. Industrial cassava residue is mixed with water to a moisture content of 50% and pre-gelatinized at 85℃ for 15 minutes. The forestry branch and twig biochar is then mixed evenly with the pre-gelatinized cassava residue, and then mixed evenly with industrial furfural residue. The moisture content of the mixture is controlled at 8%. The dry basis mass ratio of the mixture is cassava residue: furfural residue: forestry branch and twig biochar. The ratio of raw material to biochar was 0.5:0.7:8.8. The mixed raw material was filled into the compression hole. The mold was first heated to the set temperature of 80℃ and held for 2 minutes. Then the raw material was compressed at 10 mm / min. When the pressure reached 70.8 MPa, the pressure was held for 3 minutes and then the compression was stopped. When demolding, the pressure was released at 5 mm / min. After cooling to 40℃, the biochar pellets were packaged to obtain biochar pellet fuel. The calorific value of the product was measured to be 25.1 MJ / kg and the breakage rate was 0.5%. Example

[0024] Air-dried forestry branches and twigs are pulverized to below 40mm (raw material moisture content 9%-10%). The pulverized branches and twigs are then carbonized at 430℃ for 3 hours. After cooling, they are pulverized to below 5mm. Industrial cassava residue is mixed with water to a moisture content of 50% and pre-gelatinized at 85℃ for 15 minutes. The forestry branch and twig biochar is then mixed evenly with the pre-gelatinized cassava residue, and then mixed evenly with industrial furfural residue. The moisture content of the mixture is controlled at 10%. The dry basis mass ratio of the mixture is cassava residue: furfural residue: forestry branch and twig biochar. The ratio of raw material to biochar was 0.4:0.8:8.8. The mixed raw materials were filled into the compression holes. The mold was first heated to the set temperature of 120℃ and held for 2 minutes. Then, the raw materials were compressed at 10 mm / min. When the pressure reached 70.8 MPa, the pressure was held for 3 minutes and then the compression was stopped. When demolding, the pressure was released at 5 mm / min. After cooling to 40℃, the biochar pellets were packaged to obtain biochar pellet fuel. The calorific value of the product was measured to be 25.3 MJ / kg and the breakage rate was 0.6%.

[0025] Comparative Example 1 Air-dried forestry branches were crushed to below 40mm (the raw material moisture content of the branches was 9%-10%). The crushed branches were then carbonized at 450℃ for 3 hours. After cooling, the carbonized branches were crushed to below 5mm. The moisture content of the biochar was adjusted to 10%, and the biochar was filled into the compression holes. The mold was first heated to the set temperature of 120℃ and held for 2 minutes. Then, the raw material was compressed at 10mm / min. When the pressure reached 70.8MPa, the pressure was held for 3 minutes, and then the compression was stopped. The biochar pellets were demolded at 5mm / min and cooled to 40℃ before being packaged to obtain biochar pellet fuel. The product calorific value was measured to be 24.7MJ / kg, and the breakage rate was 31.6%.

[0026] Comparative Example 2 Air-dried forestry branches were crushed to less than 5mm, and the moisture content of the crushed raw material was adjusted to 10%. The material was then filled into the compression holes. The mold was first heated to a set temperature of 120℃ and held for 2 minutes. The raw material was then compressed at a rate of 10mm / min. When the pressure reached 70.8MPa, the pressure was held for 3 minutes, and then the compression was stopped. The material was demolded at a rate of 5mm / min and cooled to 40℃ before being packaged to obtain biochar pellet fuel. The product calorific value was measured to be 17.2MJ / kg, and the breakage rate was 0.6%.

[0027] This invention uses forestry branch biochar as raw material and prepares high-quality biochar pellet fuel by pre-gelatinizing cassava residue and adding a certain proportion of furfural residue for hot pressing. This overcomes the shortcomings of low energy density and unstable mechanical properties of biochar pellet fuel.

[0028] The low-cost biomass char pellet fuel preparation method provided by this invention overcomes the disadvantages of low energy density and unstable mechanical properties of biomass char pellet fuel. Its advantages include: (1) High-quality biomass briquettes are prepared entirely from forestry or industrial waste, which can make full use of the residues to improve economic benefits and improve the ecological environment.

[0029] (2) Forestry branch carbonization has the characteristics of high biochar quality and low raw material cost.

[0030] (3) Using industrial cassava residue additives, the residual starch in the cassava residue can be fully utilized as an efficient binder through pregelatinization.

[0031] (4) Using industrial furfural residue additives can improve the bonding performance between biochar, cassava residue and furfural residue, and improve the mechanical strength of shaped fuel.

[0032] (5) The pregelatinized starch and cellulose in cassava residue and the cellulose and lignin in furfural residue have a synergistic effect on the formation of high-quality biochar pellet fuel, which improves the stability of the product and reduces the production cost of the product.

[0033] (6) The higher the cassava residue content, the more flue gas and ash are produced by the combustion of the briquetted fuel. Moreover, the calorific value of starch is lower than that of common agricultural and forestry biomass. Therefore, adding starch binder will reduce the calorific value of the briquetted fuel. By using starch, cellulose and lignin in the compound mixture to synergistically bind biochar, the content of cassava residue and starch in the product is reduced.

[0034] (7) The breakage rate and ash content of the product are reduced during storage and transportation.

[0035] (8) All raw materials are natural, and the products and production process are low-carbon and environmentally friendly, with both economic and ecological benefits.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-cost method for preparing biochar pellet fuel, characterized in that, Includes the following steps: S1, the dried forestry branches are crushed, sieved, carbonized and then crushed again to obtain biochar; S2, Pregelatinize industrial cassava residue with water; S3, mix forestry branch biochar with pre-gelatinized cassava residue evenly, then mix with industrial furfural residue evenly, and adjust the moisture content of the mixture. S4, the mixture is filled into a mold and heated and pressurized to prepare biochar pellet fuel.

2. The method for preparing low-cost biomass char pellet fuel according to claim 1, characterized in that: In S1, the forestry branches and twigs are crushed to less than 40mm, and the moisture content of the raw materials is less than 10%.

3. The method for preparing low-cost biomass char pellet fuel according to claim 1, characterized in that: The carbonization temperature of the branches in S1 is 400-450℃, the carbonization time is 3-5h, and after carbonization and cooling, they are crushed to below 5mm.

4. The method for preparing low-cost biomass char pellet fuel according to claim 1, characterized in that: In step S2, industrial cassava residue is added to water to a moisture content of 50% and heated to 85°C for pre-gelatinization for 15 minutes.

5. The method for preparing low-cost biochar pellet fuel according to claim 1, characterized in that: In step S3, forestry branch biochar is mixed evenly with pre-gelatinized cassava residue, and then mixed evenly with industrial furfural residue. The moisture content of the mixture is controlled at 8-10%, and the dry basis mass ratio of the mixture is cassava residue: furfural residue: forestry branch biochar = (0.3~0.5):(0.5~0.7):

9.

6. The method for preparing low-cost biomass char pellet fuel according to claim 1, characterized in that: S4 first heats the mold to a set temperature of 80-120℃, holds it for 2 minutes after reaching the set temperature, and then starts compressing the raw material at 10 mm / min. When the pressure reaches 70.8 MPa, it holds the pressure for 3 minutes and then ends the compression. When demolding, it demolds at 5 mm / min and obtains biomass char pellet fuel after cooling.

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