Preparation method of anti-slagging biomass pellet fuel

Abstract

The invention discloses a preparation method of an anti-slagging biomass granular fuel, and belongs to the technical field of biomass fuels, and the preparation method comprises the following steps: (1) cleaning agricultural and forestry wastes, removing impurities, and crushing into powder to obtain biomass powder; (2) feeding the biomass powder into a spiral extrusion bulking machine for extrusion bulking to enable the biomass powder to form multiple holes, so as to obtain porous biomass powder; and (3) uniformly mixing the porous biomass powder, an anti-slagging agent, a combustion improver and a silane coupling agent, feeding the mixture into an extruder for extrusion granulation, and cooling to obtain the anti-slagging biomass pellet fuel. According to the preparation method disclosed by the invention, the biomass pellet fuel has good slagging resistance and heat productivity, high combustion efficiency and good combustion effect.

Description

Technical Field

[0001] The invention relates to a method for preparing anti-slagging biomass particle fuel, belonging to the technical field of biomass fuel. Background Art

[0002] Biomass pellet fuel is made from agricultural and forestry waste, such as straw, rice husk, peanut shell, corn cob, fruit shell, bark, rattan, wood core, wood block, etc., through crushing, mixing, extrusion, drying and other processes. It is a new type of clean fuel that can be burned directly, which meets rural needs and solves the problems of resource waste and pollution.

[0003] The calorific value and combustion efficiency of existing biomass pellet fuels need to be improved, and in practice, the slagging of combustion flue gas will bring very serious hidden dangers and increase costs. Summary of the invention

[0004] In order to at least address one problem existing in the above-mentioned prior art, the present invention provides a method for preparing anti-slagging biomass pellet fuel, so that the biomass pellet fuel has good anti-slagging property and calorific value, high combustion efficiency and good combustion effect.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: a method for preparing anti-slagging biomass pellet fuel, comprising the following steps:

[0006] (1) cleaning and removing impurities from agricultural and forestry wastes, crushing them into powder, and obtaining biomass powder; the agricultural and forestry wastes include straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores;

[0007] (2) feeding the biomass powder into a screw extruder for extrusion and expansion to make the biomass powder porous, thereby obtaining porous biomass powder;

[0008] (3) After the porous biomass powder, the anti-slagging agent, the combustion aid, and the silane coupling agent are uniformly mixed, the mixture is sent into an extruder for extrusion granulation, the particle size is maintained at 6 to 8 mm, the length is maintained at 2 to 3 cm, and the mixture is cooled to obtain an anti-slagging biomass pellet fuel;

[0009] The anti-slagging agents include calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether; the combustion aids include potassium permanganate, nano bamboo powder and nano carbon powder.

[0010] Preferably, the extrusion puffing conditions are: heating to a temperature of 220-240° C. and pressurizing to a pressure of 2.5-3.5 MPa, maintaining for 5-10 minutes, and then instantly releasing to normal pressure to expand the biomass powder to form a porous structure.

[0011] Preferably, the extrusion granulation conditions are: the extrusion temperature is 85-95° C., and the extrusion pressure is 80-90 MPa.

[0012] Preferably, the raw materials of the anti-slagging biomass pellet fuel are calculated as follows in parts by weight: 88 to 93 parts of porous biomass powder, 3.5 to 6.5 parts of anti-slagging agent, 2.5 to 5 parts of combustion aid, and 0.5 to 1.2 parts of silane coupling agent; and the sum of the parts by weight of the porous biomass powder, anti-slagging agent, combustion aid and silane coupling agent is 100 parts.

[0013] Preferably, the anti-slagging biomass particle fuel has the following raw materials in parts by weight: 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion aid, and 0.8 parts of silane coupling agent.

[0014] Preferably, the agricultural and forestry waste is mixed according to the mass ratio of straw, rice straw, nut shells, tea oil shells, wood chips and wood cores of 55:25-30:15-20:10-15:25-30:20-25.

[0015] Preferably, the agricultural and forestry waste is mixed according to the mass ratio of straw, rice straw, nut shells, tea oil shells, wood chips and wood cores of 55:27:18:12:28:23.

[0016] Preferably, the anti-slagging agent is prepared by mixing calcium hydrogen phosphate, nanoporous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.5-2:0.8-0.9:0.6-0.65 and then ball milling.

[0017] Preferably, the anti-slagging agent is prepared by mixing calcium hydrogen phosphate, nanoporous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.8:0.85:0.62 and then ball milling.

[0018] Preferably, the ball milling conditions are as follows: the ball milling medium is a steel ball, and the diameter of the steel ball is 2 to 3 mm.

[0019] Preferably, the combustion aid is prepared by mixing potassium permanganate, bamboo powder and carbon powder in a mass ratio of 1:5 to 6:2 to 2.5 and then ball milling.

[0020] Preferably, the combustion aid is prepared by mixing potassium permanganate, bamboo powder and carbon powder in a mass ratio of 1:5.6:2.2 and then ball milling.

[0021] Preferably, the ball milling conditions are as follows: the ball milling medium is a steel ball, and the diameter of the steel ball is 2 to 3 mm.

[0022] Beneficial effects of the present invention:

[0023] 1) The biomass pellet fuel prepared by the present invention adopts agricultural and forestry waste raw materials such as straw, rice straw, nut shells, oil tea shells, wood chips and wood cores, which are first crushed into powder and then extruded and expanded to form porous biomass, and then mixed with anti-slagging agent, combustion aid and silane coupling agent. It has high calorific value and high combustion efficiency, and at the same time, the flue gas slagging rate is very low.

[0024] 2) The agricultural and forestry waste raw materials of the biomass pellet fuel prepared by the present invention have porosity after extrusion and expansion, which allows them to be more fully exposed to oxygen during the combustion process, which helps the fuel to burn completely and fully, thereby improving the combustion efficiency and increasing the overall calorific value of the fuel. At the same time, the porosity, anti-slagging agent and combustion aid work together to make the fuel burn more fully, greatly reduce slagging, and make the combustion more stable, thereby enhancing the applicability of the biomass pellet fuel.

[0025] 3) The anti-slagging agent in the biomass pellet fuel prepared by the present invention is composed of an appropriate amount of calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth, and fatty alcohol polyoxyethylene ether, and the combustion aid is composed of an appropriate amount of potassium permanganate, bamboo powder, and carbon powder. The two are synergistically and evenly dispersed in the fuel, effectively promoting the uniform combustion of the biomass pellet fuel, and forming a more uniform anti-slagging layer, effectively improving the combustion efficiency of the biomass pellet fuel, and reducing its slagging efficiency. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the implementation of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents, instruments, and components used, they are all conventional products that can be purchased commercially.

[0027] Example 1

[0028] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0029] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0030] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 2.5 MPa for 10 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0031] (3) 88 parts of porous biomass powder, 6.5 parts of anti-slagging agent, 5 parts of combustion aid, and 0.5 parts of silane coupling agent were mixed evenly, and then fed into an extruder for extrusion granulation at a temperature of 85°C and a pressure of 80 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. After cooling, an anti-slagging biomass pellet fuel was obtained, and the combustion performance was shown in Table 1;

[0032] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0033] Example 2

[0034] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0035] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0036] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 230° C. and pressurizing the biomass powder to 3 MPa for 8 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0037] (3) After 90 parts of porous biomass powder, 4.5 parts of anti-slagging agent, 4 parts of combustion aid, and 1 part of silane coupling agent were mixed evenly, the mixture was sent into an extruder and extruded and granulated at a temperature of 90°C and a pressure of 85 MPa. The particle size was kept at 6-8 mm and the length was kept at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel. The combustion performance is shown in Table 1.

[0038] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 15 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 30 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0039] Example 3

[0040] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0041] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0042] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 240° C. and pressurizing the biomass powder to 3.5 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0043] (3) After 93 parts of porous biomass powder, 3.5 parts of anti-slagging agent, 2.5 parts of combustion aid, and 1 part of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 95°C and a pressure of 90 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0044] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 25 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 40 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0045] Example 4

[0046] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0047] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0048] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 3 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0049] (3) After 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion aid, and 0.8 parts of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 90° C. and a pressure of 85 MPa, with the particle size maintained at 6 to 8 mm and the length maintained at 2 to 3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0050] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0051] Example 5

[0052] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0053] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:25:15:10:25:20;

[0054] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 3 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0055] (3) After 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion aid, and 0.8 parts of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 90° C. and a pressure of 85 MPa, with the particle size maintained at 6 to 8 mm and the length maintained at 2 to 3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0056] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.5:0.8:0.6, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5:2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0057] Example 6

[0058] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0059] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:30:20:15:30:25;

[0060] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 3 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0061] (3) After 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion aid, and 0.8 parts of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 90° C. and a pressure of 85 MPa, with the particle size maintained at 6 to 8 mm and the length maintained at 2 to 3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0062] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:2:0.9:0.65, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:6:2.5, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0063] Example 7

[0064] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0065] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:30:20:15:30:25;

[0066] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 3 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0067] (3) 89.7 parts of porous biomass powder, 5 parts of anti-slagging agent, 4.5 parts of combustion aid, and 0.8 parts of silane coupling agent were mixed evenly, and then fed into an extruder for extrusion granulation at a temperature of 90° C. and a pressure of 85 MPa, with the particle size maintained at 6 to 8 mm and the length maintained at 2 to 3 cm. After cooling, an anti-slagging biomass pellet fuel was obtained, and the combustion performance was shown in Table 1;

[0068] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:2:0.9:0.65, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:6:2.5, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0069] Example 8

[0070] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0071] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:25:15:10:25:20;

[0072] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 3 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0073] (3) After 91.5 parts of porous biomass powder, 4.5 parts of anti-slagging agent, 3.2 parts of combustion aid, and 0.8 parts of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 90°C and a pressure of 85 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0074] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.5:0.8:0.6, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5:2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0075] Example 9

[0076] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0077] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0078] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 3 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0079] (3) After 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion aid, and 0.8 parts of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 90° C. and a pressure of 85 MPa, with the particle size maintained at 6 to 8 mm and the length maintained at 2 to 3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0080] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.5:0.8:0.6, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:6:2.5, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0081] The anti-slagging biomass pellet fuel of Examples 1 to 9 of the present invention has low slagging and high combustion calorific value during combustion, and the amount of smoke produced by combustion is very small, so that the biomass pellet fuel has high calorific value, combustion efficiency and anti-slagging property; at the same time, the calorific value and slagging rate of the biomass pellet fuel of Examples 1 to 9 of the present invention are relatively stable, which improves the product performance quality and is conducive to the large-scale production of biomass pellet fuel.

[0082] Comparative Example 1

[0083] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0084] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0085] (2) 93 parts of biomass powder, 3.5 parts of anti-slagging agent, 2.5 parts of combustion aid, and 1 part of silane coupling agent were mixed evenly, and then fed into an extruder for extrusion granulation at a temperature of 95°C and a pressure of 90 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. After cooling, an anti-slagging biomass pellet fuel was obtained, and the combustion performance was shown in Table 1;

[0086] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 25 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 40 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0087] Comparative Example 2

[0088] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0089] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0090] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the temperature to 240° C. and pressurizing the pressure to 2 MPa, maintaining the pressure for 20 min, and then instantly releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0091] (3) After 93 parts of porous biomass powder, 3.5 parts of anti-slagging agent, 2.5 parts of combustion aid, and 1 part of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 95°C and a pressure of 90 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0092] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 25 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 40 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0093] Comparative Example 3

[0094] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0095] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0096] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the temperature to 240° C. and pressurizing the pressure to 4 MPa, maintaining the pressure for 2 min, and then instantly releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0097] (3) After 93 parts of porous biomass powder, 3.5 parts of anti-slagging agent, 2.5 parts of combustion aid, and 1 part of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 95°C and a pressure of 90 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0098] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 25 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 40 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0099] Compared with Comparative Examples 1 to 3, Example 1 shows that the biomass powder can be made porous by extrusion expansion. Under appropriate extrusion expansion conditions, the particles of the biomass powder are more uniform with each other, which helps the particles of the biomass powder to be tightly combined to form a more uniform, more stable, and porous structure with appropriate porosity, thereby effectively improving the combustion efficiency of the biomass pellet fuel, and also promoting the increase of the overall calorific value of the fuel, making the fuel burn more fully, greatly reducing slagging, and making the combustion more stable, thereby enhancing the applicability of the biomass pellet fuel; however, if the pressure is too low and the time is short, the binding force between the particles is insufficient and a stable porous structure cannot be formed. If the pressure is too high and the time is long, the binding between the particles is denser and the porosity is reduced, both of which affect the combustion of the biomass pellet fuel, reduce the combustion efficiency, and increase the slagging rate.

[0100] Comparative Example 4

[0101] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0102] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0103] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 240° C. and pressurizing the biomass powder to 3.5 MPa for 5 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0104] (3) After 93 parts of porous biomass powder, 3.5 parts of anti-slagging agent, 2.5 parts of combustion aid, and 1 part of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 95°C and a pressure of 90 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0105] Among them, calcium hydrogen phosphate, nano porous powder quartz and nano diatomaceous earth are mixed in a mass ratio of 3:1.8:0.85, and ball milled for 25 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 40 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0106] Compared with Comparative Example 4, the anti-slagging agent in Example 1 can promote the formation of a more uniform anti-slagging layer of calcium hydrogen phosphate, nanoporous powder quartz and nano diatomaceous earth when the fuel is burned by adding suitable fatty alcohol polyoxyethylene ethers, thereby effectively improving the anti-slagging property of the biomass particle fuel.

[0107] Comparative Example 5

[0108] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0109] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 2.5 MPa for 10 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0110] (3) 88 parts of porous biomass powder, 6.5 parts of anti-slagging agent, 5 parts of combustion aid, and 0.5 parts of silane coupling agent were mixed evenly, and then fed into an extruder for extrusion granulation at a temperature of 85°C and a pressure of 80 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. After cooling, an anti-slagging biomass pellet fuel was obtained, and the combustion performance was shown in Table 1;

[0111] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate and nano bamboo powder are mixed in a mass ratio of 1:5.6, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0112] Comparative Example 6

[0113] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0114] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 2.5 MPa for 10 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0115] (3) 88 parts of porous biomass powder, 6.5 parts of anti-slagging agent, 5 parts of combustion aid, and 0.5 parts of silane coupling agent were mixed evenly, and then fed into an extruder for extrusion granulation at a temperature of 85°C and a pressure of 80 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. After cooling, an anti-slagging biomass pellet fuel was obtained, and the combustion performance was shown in Table 1;

[0116] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate and nano carbon powder are mixed in a mass ratio of 1:2.2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0117] Compared with Comparative Examples 5 and 6, Example 1 adds appropriate potassium permanganate, nano bamboo powder and nano carbon powder as the combustion aid, which is beneficial to the full combustion of the biomass pellet fuel, improves the combustion efficiency, and further reduces the slagging rate of the biomass pellet fuel.

[0118] Comparative Example 7

[0119] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0120] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0121] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 2.5 MPa for 10 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0122] (3) After 95 parts of porous biomass powder, 2.5 parts of anti-slagging agent, 2 parts of combustion aid, and 0.5 parts of silane coupling agent were mixed evenly, the mixture was sent to an extruder for extrusion granulation at a temperature of 85°C and a pressure of 80 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. The mixture was cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance was shown in Table 1;

[0123] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0124] Comparative Example 8

[0125] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0126] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0127] (2) feeding the biomass powder into a screw extruder for extrusion and expansion, heating the biomass powder to 220° C. and pressurizing the biomass powder to 2.5 MPa for 10 min, and then releasing the pressure to normal pressure to make the biomass powder porous, thereby obtaining a porous biomass powder;

[0128] (3) 86 parts of porous biomass powder, 7.5 parts of anti-slagging agent, 6 parts of combustion aid, and 0.5 parts of silane coupling agent were mixed evenly, and then sent to an extruder for extrusion granulation at a temperature of 85°C and a pressure of 80 MPa, with the particle size maintained at 6-8 mm and the length maintained at 2-3 cm. After cooling, an anti-slagging biomass pellet fuel was obtained, and the combustion performance was shown in Table 1;

[0129] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes using a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 35 minutes using a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid.

[0130] Compared with Comparative Examples 7 and 8, Example 1 shows that suitable porous biomass powder cooperates with equivalent anti-slagging agent and combustion aid to reduce the slagging rate of biomass pellet fuel.

[0131] Comparative Example 9

[0132] A method for preparing anti-slagging biomass pellet fuel, the specific steps are as follows:

[0133] (1) cleaning and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; the agricultural and forestry waste is prepared by mixing straw, rice straw, nut shells, tea oil shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23;

[0134] (2) 88 parts of porous biomass powder, 6.5 parts of anti-slagging agent, 5 parts of combustion aid, and 0.5 parts of silane coupling agent were mixed uniformly, heated to 220° C. and pressurized to 2.5 MPa, maintained for 10 min, and then released to normal pressure instantly to obtain a porous mixed material;

[0135] Among them, calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether are mixed in a mass ratio of 3:1.8:0.85:0.62, and ball milled for 20 minutes with a steel ball with a diameter of 2 to 3 mm to obtain an anti-slagging agent; potassium permanganate, nano bamboo powder and nano carbon powder are mixed in a mass ratio of 1:5.6:2.2, and ball milled for 35 minutes with a steel ball with a diameter of 2 to 3 mm to obtain a combustion aid;

[0136] (3) The porous mixed material is sent to a screw extruder for extrusion and expansion, and then sent to an extruder for extrusion granulation at a temperature of 85°C and a pressure of 80 MPa. The particle size is maintained at 6 to 8 mm and the length is maintained at 2 to 3 cm. After cooling, an anti-slagging biomass pellet fuel is obtained, and the combustion performance is shown in Table 1.

[0137] Compared with Comparative Example 9, in Example 1, the biomass powder is first extruded and expanded, and then combined with the anti-slagging agent and the combustion aid, which can promote the improvement of the anti-slagging property of the biomass pellet fuel.

[0138] Table 1 Combustion performance of biomass pellet fuel

[0139] Combustion heat value (MJ / Kg) Smoke volume Slagging rate (%) Example 1 36.3 Very small 0.68 Example 2 37.8 Very small 0.57 Example 3 36.7 Very small 0.64 Example 4 38.6 Very small 0.53 Example 5 37.2 Very small 0.59 Example 6 36.9 Very small 0.62 Example 7 35.3 Very small 0.75 Example 8 35.4 Very small 0.72 Example 9 38.2 Very small 0.56 Comparative Example 1 25.6 big 2.65 Comparative Example 2 32.9 Smaller 1.35 Comparative Example 3 33.3 Smaller 1.31 Comparative Example 4 31.2 Small 1.68 Comparative Example 5 32.1 Smaller 1.65 Comparative Example 6 30.3 Small 1.98 Comparative Example 7 32.5 Smaller 1.65 Comparative Example 8 31.5 Small 1.83 Comparative Example 9 32.3 Smaller 1.67

[0140] The combustion values ​​described in Table 1 above were tested with reference to GB / T 30727-2014 and NB / T 34025-2015.

[0141] It can be seen from the above that the biomass particle fuel of the present invention has good slagging resistance and calorific value, high combustion efficiency and good combustion effect.

[0142] 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 present invention can be implemented in other specific forms without departing from the spirit and essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0143] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing anti-slagging biomass pellet fuel, characterized in that: The following steps are involved: (1) washing and removing impurities from agricultural and forestry waste, and crushing the waste into powder to obtain biomass powder; Agricultural and forestry wastes include straw, rice straw, nut shells, camellia husks, wood chips and wood cores; (2) feeding the biomass powder into a screw extruder for extrusion and expansion to make the biomass powder porous, thereby obtaining porous biomass powder; (3) After the porous biomass powder, the anti-slagging agent, the combustion aid, and the silane coupling agent are uniformly mixed, the mixture is sent into an extruder for extrusion granulation, the particle size is maintained at 6 to 8 mm, the length is maintained at 2 to 3 cm, and the mixture is cooled to obtain an anti-slagging biomass pellet fuel; The anti-slagging agents include calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether; the combustion aids include potassium permanganate, nano bamboo powder and nano carbon powder.

2. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1, characterized in that: In step (2), the extrusion puffing conditions are: heating to a temperature of 220-240° C. and pressurizing to a pressure of 2.5-3.5 MPa, maintaining for 5-10 minutes, and then instantly releasing to normal pressure to expand the biomass powder to form a porous structure.

3. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1, characterized in that: In step (3), the anti-slagging biomass pellet fuel has the following raw materials in parts by weight: 88 to 93 parts of porous biomass powder, 3.5 to 6.5 parts of anti-slagging agent, 2.5 to 5 parts of combustion aid, and 0.5 to 1.2 parts of silane coupling agent; and the sum of the parts by weight of the porous biomass powder, the anti-slagging agent, the combustion aid and the silane coupling agent is 100 parts.

4. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1 or 3, characterized in that: The anti-slagging biomass particle fuel has the following raw materials in parts by weight: 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion aid, and 0.8 parts of silane coupling agent.

5. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1, characterized in that: In step (3), the extrusion granulation conditions are: the extrusion temperature is 85-95° C., and the extrusion pressure is 80-90 MPa.

6. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1, characterized in that: The agricultural and forestry wastes are mixed according to the mass ratio of straw, rice straw, nut shells, oil tea shells, wood chips and wood cores of 55:25-30:15-20:10-15:25-30:20-25.

7. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1, characterized in that: The anti-slagging agent is prepared by mixing calcium hydrogen phosphate, nano porous powder quartz, nano diatomaceous earth and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.5-2:0.8-0.9:0.6-0.65 and then ball milling.

8. The method for preparing a slagging-resistant biomass pellet fuel according to claim 1, characterized in that: The combustion aid is prepared by mixing potassium permanganate, bamboo powder and carbon powder in a mass ratio of 1:5-6:2-2.5 and then ball milling.

9. The method for preparing a slagging-resistant biomass pellet fuel according to claim 7 or 8, characterized in that: The ball milling conditions are as follows: the ball milling medium is a steel ball, and the diameter of the steel ball is 2 to 3 mm.