A method for preparing biomass particles at room temperature and low pressure

Abstract

The present invention provides a method for preparing normal temperature and low pressure biomass particles, which include the following raw materials in parts by mass: 20-30 parts of cow dung, 10-15 parts of black pine leaves, 5-8 parts of poplar sawdust, 15-20 parts of coal slag, 8-12 parts of vegetable oil, 3-6 parts of bonding aid, and 1-3 parts of combustion improver. The method for preparing normal temperature and low pressure biomass particles includes the following steps: uniformly stirring cow dung, black pine leaves, coal slag, poplar sawdust, vegetable oil, bonding aid, and combustion improver, crushing, and sieving to obtain a mixture; then inoculating a fermentation agent into the mixture, fermenting in a stacking fermentation manner, and obtaining a fermented product; extruding the fermented product into cylindrical particles and drying. The present invention successfully solves the problem of low calorific value of crop biomass fuel, which not only greatly improves the economic benefits of crop waste, but also increases the energy density of biomass fuel.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass pellet fuel, and in particular to a method for preparing biomass pellets at room temperature and low pressure. Background Art

[0002] Biomass fuel, as a way of converting agricultural and forestry waste (such as straw, sawdust, bagasse, rice husks, etc.) into energy through combustion, is in sharp contrast to fossil fuels. However, under the current environmental protection policy framework, direct combustion of such biomass is considered a highly polluting behavior, so its application is mostly limited to traditional stoves in rural areas and is strictly restricted in cities. The main application form of biomass fuel focuses on pelletized fuel, which is an innovative clean energy solution. It is made by finely processing agricultural and forestry waste - including crushing, proportioning, molding, drying and other processes - and finally making it into a solid form (blocks, granules, etc.) that is easy to burn directly. Thanks to the low ignition point and high purity of the raw materials, biomass pelletized fuel exhibits efficient combustion characteristics, but at the same time, its fast combustion rate also brings a double-edged sword effect.

[0003] Rapid combustion means concentrated energy release in a short period of time, which is not a problem for general applications and can even meet demand efficiently. However, this characteristic can become a challenge in the precision machining industry. This is because a stable and long-lasting heat source is key to ensuring precise control of the production process, and the explosive heat release of biomass fuels can cause sudden temperature fluctuations, disrupting the production process, compromising product quality, and even equipment safety.

[0004] Current biomass fuel preparation technologies mostly rely on simple extrusion molding of raw materials. This practice limits the improvement of fuel quality, resulting in a low calorific value of the final product, which in turn limits the application potential of biomass fuel in a wider range of fields. In view of the environmental pressure and carbon emissions caused by the consumption of coal resources, the development of a high-efficiency, low-carbon and environmentally friendly biomass fuel has become an urgent need in scientific research and industry. This new type of fuel aims to significantly increase calorific value output through advanced processing technology, reduce dependence on traditional energy sources such as coal, thereby effectively alleviating environmental pollution and promoting green and sustainable development. In short, exploring efficient and environmentally friendly biomass fuel preparation technologies, aiming to achieve energy structure optimization and environmentally friendly protection, is a current research hotspot and trend. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing biomass particles at room temperature and low pressure.

[0006] On the one hand, the present invention provides a biomass pellet, which includes the following raw materials in parts by weight: 20-30 parts of cow dung, 10-15 parts of black pine needles, 5-8 parts of poplar sawdust, 15-20 parts of coal slag, 8-12 parts of vegetable oil, 3-6 parts of a bonding agent, and 1-3 parts of a combustion aid.

[0007] Preferably, the bonding aid is prepared by the following method:

[0008] Corn straw, peanut shells and rice husks in a mass ratio of 1:1:0.3-0.5 are dried and mixed evenly, and then crushed through a 100-200 mesh sieve to obtain a mixed powder; the mixed powder in a mass ratio of 1:5-8 and a 40% mass fraction hydrogen peroxide solution are evenly mixed; a 0.5M sodium hydroxide solution is added to adjust the pH to 8-9; and the mixture is stirred at 60-80°C for 15-30 minutes; and then centrifuged at 8000-10000 rpm for 3-5 minutes to obtain a suspension; the pH of the suspension is adjusted to 9-10, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain a bonding agent.

[0009] Preferably, the precipitant comprises starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.5-0.8:0.1-0.3.

[0010] Preferably, the mass ratio of the precipitant to the suspension is 0.05-0.08:1.

[0011] Preferably, the combustion aid comprises potassium nitrate and magnesium powder in a mass ratio of 0.3-0.5:1.

[0012] Another aspect of the present invention provides a method for preparing biomass particles at room temperature and low pressure, which adopts the following technical solution:

[0013] S1, the mass parts of cow dung, black pine leaves, coal slag, poplar sawdust, vegetable oil, bonding agent, combustion aid were uniformly stirred, crushed, and passed through a 100-200 mesh sieve to obtain a mixture;

[0014] S2, inoculating a starter into the mixture, and fermenting by stacking fermentation to obtain a fermentation product;

[0015] S3. Extruding the fermented product into cylindrical particles, and drying them at 100° C. for 12-24 hours to obtain room-temperature low-pressure biomass particles.

[0016] Preferably, the fermentation agent comprises Propionibacterium freudenreichii, protease and Bacillus subtilis in a mass ratio of 1:0.3-0.5:0.5-0.8.

[0017] Preferably, the inoculation method is as follows: diluting the starter in deionized water 10-15 times its own weight, and then inoculating in a spraying form.

[0018] Preferably, the stacking fermentation method specifically includes: the mixture is stacked at a height of 2-2.5 m and undergoes a fermentation process of 3-5 days.

[0019] In summary, the present invention has the following beneficial effects:

[0020] The present invention effectively solves the problem of low calorific value of crop biomass fuel combustion, not only significantly improving the economic value of crop waste, but also enhancing the energy density of biomass fuel. This promotes the maximum recycling of resources, and takes solid steps in the field of environmental protection, demonstrating extremely high social promotion value and environmental friendliness. It effectively reduces dependence on limited and increasingly depleted fossil fuels, bringing significant cost savings to enterprises; as a green alternative to traditional energy sources such as coal and oil, it heralds a new path to sustainable energy development, showing broad market prospects and huge development potential. The combustion rate is accelerated, allowing the fuel to be converted into thermal energy more quickly; at the same time, the combustion process becomes more sufficient and thorough, ensuring the maximum utilization of the fuel, thereby achieving a significant increase in calorific value. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the examples, but is not limited thereto. Other features and advantages disclosed in the present invention will become apparent from the following detailed description and examples, which should not be construed as limiting.

[0022] Example 1

[0023] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0024] S1, 20 parts of cow dung, 10 parts of black pine leaves, 5 parts of poplar sawdust, 15 parts of coal slag, 8 parts of vegetable oil, 3 parts of bonding aid, and 1 part of combustion improver were stirred, crushed, and passed through a 200 mesh sieve to obtain a mixture;

[0025] S2. Propionibacterium freudenreichii, protease, and Bacillus subtilis at a mass ratio of 1:0.3:0.5 were diluted in deionized water 10 times their own weight, and then inoculated into the mixture by spraying. The mixture was fermented in a stacking fermentation manner with a stacking height of 2 m. After a fermentation process of 3 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:20;

[0026] S3. Extruding the fermented product into cylindrical particles, and drying them at 80° C. for 24 hours to obtain room-temperature low-pressure biomass particles.

[0027] The bonding agent is prepared by the following method: corn straw, peanut shells and rice husks in a mass ratio of 1:1:0.3 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder in a mass ratio of 1:5 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 8, and stirred at 60°C for 30 minutes; then centrifuged at 8000 rpm for 5 minutes to obtain a suspension, the pH of the suspension is adjusted to 9, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain the bonding agent.

[0028] The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.5:0.1; the mass ratio of the precipitant to the suspension is 0.05:1.

[0029] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.3:1.

[0030] Example 2

[0031] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0032] S1, 30 parts of cow dung, 15 parts of black pine leaves, 8 parts of poplar sawdust, 20 parts of coal slag, 12 parts of vegetable oil, 6 parts of bonding aid, and 3 parts of combustion improver were stirred, crushed, and passed through a 100 mesh sieve to obtain a mixture;

[0033] S2, Propionibacterium freudenreichii, protease, and Bacillus subtilis in a mass ratio of 1:0.5:0.8 were diluted in deionized water 15 times their own weight, and then inoculated into the mixture in the form of a spray, and fermented by stacking fermentation. The stacking height of the mixture was 2.5 m. After a fermentation process of 5 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:25;

[0034] S3. Extruding the fermented product into cylindrical particles, and drying them at 100° C. for 12 hours to obtain room-temperature low-pressure biomass particles.

[0035] Among them, the bonding agent is prepared according to the following method: corn straw, peanut shells and rice husks with a mass ratio of 1:1:0.5 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder with a mass ratio of 1:8 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 9, and stirred at 80°C for 15 minutes; then centrifuged at 10,000 rpm for 3 minutes to obtain a suspension, the pH of the suspension is adjusted to 10, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain the bonding agent.

[0036] The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.8:0.3; the mass ratio of the precipitant to the suspension is 0.08:1.

[0037] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.5:1.

[0038] Example 3

[0039] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0040] S1, 25 parts of cow dung, 12 parts of black pine leaves, 7 parts of poplar sawdust, 18 parts of coal slag, 10 parts of vegetable oil, 5 parts of bonding aid, and 2 parts of combustion improver were stirred, crushed, and passed through a 200 mesh sieve to obtain a mixture;

[0041] S2, Propionibacterium freudenreichii, protease, and Bacillus subtilis in a mass ratio of 1:0.4:0.6 were diluted in deionized water 13 times their own weight, and then inoculated into the mixture in the form of a spray, and fermented by stacking fermentation. The stacking height of the mixture was 2.3 m. After a fermentation process of 4 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:23;

[0042] S3. Extruding the fermented product into cylindrical particles, and drying them at 90° C. for 18 hours to obtain room-temperature low-pressure biomass particles.

[0043] Among them, the bonding agent is prepared according to the following method: corn straw, peanut shells and rice husks with a mass ratio of 1:1:0.4 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder with a mass ratio of 1:7 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 8, and stirred at 70°C for 25 minutes; then centrifuged at 9000rpm for 4 minutes to obtain a suspension, the pH of the suspension is adjusted to 9, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain the bonding agent.

[0044] The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.7:0.2; the mass ratio of the precipitant to the suspension is 0.06:1.

[0045] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.4:1.

[0046] Example 4

[0047] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0048] S1, 22 parts of cow dung, 13 parts of black pine leaves, 6 parts of poplar sawdust, 16 parts of coal slag, 9 parts of vegetable oil, 4 parts of bonding aid, and 1 part of combustion improver were stirred, crushed, and passed through a 100 mesh sieve to obtain a mixture;

[0049] S2, Propionibacterium freudenreichii, protease, and Bacillus subtilis at a mass ratio of 1:0.3:0.7 were diluted in deionized water 12 times their own weight, and then inoculated into the mixture in the form of a spray, and fermented by stacking fermentation. The stacking height of the mixture was 2.1 m. After a fermentation process of 3 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:20;

[0050] S3. Extruding the fermented product into cylindrical particles, and drying them at 85° C. for 16 hours to obtain room-temperature low-pressure biomass particles.

[0051] Among them, the bonding agent is prepared according to the following method: corn straw, peanut shells and rice husks with a mass ratio of 1:1:0.5 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder with a mass ratio of 1:6 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 8, and stirred at 65°C for 20 minutes; then centrifuged at 8000rpm for 3 minutes to obtain a suspension, the pH of the suspension is adjusted to 9, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain the bonding agent.

[0052] The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.6:0.1; the mass ratio of the precipitant to the suspension is 0.07:1.

[0053] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.3:1.

[0054] Comparative Example 1

[0055] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0056] S1, 22 parts of cow dung, 13 parts of black pine leaves, 6 parts of poplar sawdust, 16 parts of coal slag, 9 parts of vegetable oil, 4 parts of bonding agent, stirred evenly, crushed, and passed through a 100 mesh sieve to obtain a mixture;

[0057] S2, Propionibacterium freudenreichii, protease, and Bacillus subtilis at a mass ratio of 1:0.3:0.7 were diluted in deionized water 12 times their own weight, and then inoculated into the mixture in the form of a spray, and fermented by stacking fermentation. The stacking height of the mixture was 2.1 m. After a fermentation process of 3 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:20;

[0058] S3. Extruding the fermented product into cylindrical particles, and drying them at 85° C. for 16 hours to obtain room-temperature low-pressure biomass particles.

[0059] The bonding agent is prepared by the following method: corn straw, peanut shells and rice husks with a mass ratio of 1:1 and 0.5 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder with a mass ratio of 1:6 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 8, and stirred at 65°C for 20 minutes; then centrifuged at 8000rpm for 3 minutes to obtain a suspension, the pH of the suspension is adjusted to 9, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain the bonding agent.

[0060] The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.6:0.1; the mass ratio of the precipitant to the suspension is 0.07:1.

[0061] Comparative Example 2

[0062] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0063] S1, 22 parts of cow dung, 13 parts of black pine leaves, 6 parts of poplar sawdust, 16 parts of coal slag, 9 parts of vegetable oil, 4 parts of bonding aid, and 1 part of combustion improver were stirred, crushed, and passed through a 100 mesh sieve to obtain a mixture;

[0064] S2, Propionibacterium freudenreichii, protease, and Bacillus subtilis at a mass ratio of 1:0.3:0.7 were diluted in deionized water 12 times their own weight, and then inoculated into the mixture in the form of a spray, and fermented by stacking fermentation. The stacking height of the mixture was 2.1 m. After a fermentation process of 3 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:20;

[0065] S3. Extruding the fermented product into cylindrical particles, and drying them at 85° C. for 16 hours to obtain room-temperature low-pressure biomass particles.

[0066] Among them, the bonding agent is prepared according to the following method: corn straw, peanut shells and rice husks with a mass ratio of 1:1; 0.5 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder with a mass ratio of 1:6 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 8, and stirred at 65°C for 20 minutes; then centrifuged at 8000rpm for 3 minutes to obtain a suspension, the suspension pH is adjusted to 9, filtered, dried, crushed and sieved to obtain the bonding agent.

[0067] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.3:1.

[0068] Comparative Example 3

[0069] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0070] S1, 22 parts of cow dung, 13 parts of black pine leaves, 6 parts of poplar sawdust, 16 parts of coal slag, 9 parts of vegetable oil, 4 parts of bonding aid, and 1 part of combustion improver were stirred, crushed, and passed through a 100 mesh sieve to obtain a mixture;

[0071] S2, Propionibacterium freudenreichii, protease, and Bacillus subtilis at a mass ratio of 1:0.3:0.7 were diluted in deionized water 12 times their own weight, and then inoculated into the mixture in the form of a spray, and fermented by stacking fermentation. The stacking height of the mixture was 2.1 m. After a fermentation process of 3 days, a fermentation product was obtained, wherein the mass ratio of the starter to the mixture was 1:20;

[0072] S3. Extruding the fermented product into cylindrical particles, and drying them at 85° C. for 16 hours to obtain room-temperature low-pressure biomass particles.

[0073] The bonding agent is prepared by the following method: corn stalks, peanut shells and rice husks with a mass ratio of 1:1:0.5 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder.

[0074] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.3:1

[0075] Comparative Example 4

[0076] A method for preparing biomass particles at room temperature and low pressure comprises the following steps:

[0077] S1, 22 parts of cow dung, 13 parts of black pine leaves, 6 parts of poplar sawdust, 16 parts of coal slag, 9 parts of vegetable oil, 4 parts of bonding aid, and 1 part of combustion improver were stirred, crushed, and passed through a 100 mesh sieve to obtain a mixture;

[0078] S2, diluting Propionibacterium freudenreichii, protease, and Bacillus subtilis in a mass ratio of 1:0.3:0.7 in deionized water 12 times their own weight, and then inoculating the mixture by spraying. After a fermentation process for 3 days, a fermentation product is obtained, wherein the mass ratio of the starter to the mixture is 1:20;

[0079] S3. Extruding the fermented product into cylindrical particles, and drying them at 85° C. for 16 hours to obtain room-temperature low-pressure biomass particles.

[0080] The bonding agent is prepared by the following method: corn straw, peanut shells and rice husks with a mass ratio of 1:1 and 0.5 are dried and mixed evenly, and then crushed through a 200-mesh sieve to obtain a mixed powder; the mixed powder with a mass ratio of 1:6 and a hydrogen peroxide solution with a mass fraction of 40% are mixed evenly, 0.5M sodium hydroxide solution is added to adjust the pH to 8, and stirred at 65°C for 20 minutes; then centrifuged at 8000rpm for 3 minutes to obtain a suspension, the pH of the suspension is adjusted to 9, a precipitant is added to precipitate lignin in the suspension, and the suspension is filtered, dried, crushed and sieved to obtain the bonding agent.

[0081] The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.6:0.1; the mass ratio of the precipitant to the suspension is 0.07:1.

[0082] Among them, the combustion aid is potassium nitrate and magnesium powder with a mass ratio of 0.3:1

[0083] Performance Testing

[0084] The combustion performance of the biomass pellets prepared in Examples 1-4 and Comparative Examples 1-4 was tested, and the results are shown in the following table.

[0085] Table 1

[0086]

[0087] The test results show that during the preparation of biomass pellets, the pellets prepared according to Examples 1-4 exhibited high calorific value, good combustion performance, and extremely low smoke emissions. In contrast, the biomass pellets prepared according to Comparative Examples 1-4 exhibited low combustion efficiency and were accompanied by high smoke emissions. This demonstrates that a reasonable ratio of combustion aid and precipitant plays a significant role in improving the combustion performance and environmental performance of biomass pellets.

Claims

1. A normal temperature and low pressure biomass pellet, characterized in that: The raw materials include the following parts by weight: 20-30 parts of cow dung, 10-15 parts of black pine needles, 5-8 parts of poplar sawdust, 15-20 parts of coal slag, 8-12 parts of vegetable oil, 3-6 parts of adhesive additive, and 1-3 parts of combustion aid; The bonding agent is prepared by the following method: Corn straw, peanut shells, and rice husks in a mass ratio of 1:1:0.3-0.5 are dried and mixed uniformly, and then crushed through a 100-200 mesh sieve to obtain a mixed powder; the mixed powder in a mass ratio of 1:5-8 is evenly mixed with a 40% hydrogen peroxide solution; 0.5M sodium hydroxide solution is added to adjust the pH to 8-9; and the mixture is stirred at 60-80°C for 15-30 minutes; then centrifuged at 8000-10000 rpm for 3-5 minutes to obtain a suspension; the pH of the suspension is adjusted to 9-10; a precipitant is added to precipitate lignin in the suspension; and the suspension is filtered, dried, crushed, and sieved to obtain a bonding agent. The precipitant is starch, calcium chloride and sodium bicarbonate in a mass ratio of 1:0.5-0.8:0.1-0.3; The combustion aid is potassium nitrate and magnesium powder in a mass ratio of 0.3-0.5:

1.

2. The normal temperature and low pressure biomass particles according to claim 1, characterized in that: The mass ratio of the precipitant to the suspension is 0.05-0.08:

1.

3. A method for preparing normal temperature and low pressure biomass particles according to claim 1 or 2, characterized in that: The method comprises the following steps: S1, the mass parts of cow dung, black pine leaves, coal slag, poplar sawdust, vegetable oil, bonding agent, combustion aid were uniformly stirred, crushed, and passed through a 100-200 mesh sieve to obtain a mixture; S2, inoculating a starter into the mixture, and fermenting by stacking fermentation to obtain a fermentation product; S3, extruding the fermented product into cylindrical particles, and drying at 80-100° C. for 12-24 hours to obtain room temperature low pressure biomass particles; The fermentation agent comprises Propionibacterium freudenreichii, protease and Bacillus subtilis in a mass ratio of 1:0.3-0.5:0.5-0.8, and the mass ratio of the fermentation agent to the mixture is 1:20-25.

4. The method for preparing biomass particles at room temperature and low pressure according to claim 3, characterized in that: The inoculation method is specifically as follows: diluting the starter in deionized water 10-15 times its own weight, and then inoculating in a spraying form.

5. The method for preparing biomass particles at room temperature and low pressure according to claim 3, characterized in that: The stacking fermentation method specifically includes: the mixture is stacked at a height of 2-2.5 meters and undergoes a fermentation process of 3-5 days.

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