A method for preparing an anti-caking biomass pellet fuel

Abstract

The application discloses a preparation method of anti-coking biomass pellet fuel and belongs to the technical field of biomass fuel, and comprises the following steps: (1) washing and removing impurities from agricultural and forestry waste, crushing the agricultural and forestry waste into powder to obtain biomass powder; (2) feeding the biomass powder into a spiral extrusion expander to perform extrusion expansion, so that the biomass powder is porous, and porous biomass powder is obtained; (3) uniformly mixing the porous biomass powder, an anti-coking agent, a combustion-supporting agent and a silane coupling agent, feeding the mixture into an extruder to perform extrusion and granulation, and cooling to obtain the anti-coking biomass pellet fuel. According to the preparation method, the biomass pellet fuel has good anti-coking property and calorific value, high combustion efficiency and good combustion effect.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of anti-slagging biomass particle fuel preparation method, belong to biomass fuel technical field. BACKGROUND

[0002] Biomass particle fuel, from agricultural and forestry waste, such as straw, straw, rice husk, peanut shell, corn cob, shell, bark, rattan, wood core, wood block, etc., is processed by crushing, mixing, extrusion, drying and other processes, is a new type of clean fuel that can be directly combusted, meets the needs of rural areas, solves the problem of resource waste and pollution.

[0003] The existing biomass particle fuel heat output, combustion efficiency needs to be improved, and in practice, due to the slagging of combustion flue gas, it can bring very serious hidden dangers and increase costs. SUMMARY

[0004] At least for one problem of the prior art, the present application provides a kind of anti-slagging biomass particle fuel preparation method, so that biomass particle fuel has good anti-slagging and heat output, high combustion efficiency and good combustion effect.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a kind of anti-slagging biomass particle fuel preparation method, comprising the following steps:

[0006] (1) the agricultural and forestry waste is cleaned and impurities are removed, crushed into powder, to obtain biomass powder; the agricultural and forestry waste includes straw, straw, nut shell, oil tea shell, sawdust and wood core;

[0007] (2) the biomass powder is sent into a spiral extrusion expander for extrusion expansion, so that the biomass powder forms a plurality of pores, to obtain a porous biomass powder;

[0008] (3) the porous biomass powder, anti-slagging agent, combustion improver and silane coupling agent are mixed uniformly and then sent into an extruder for extrusion and granulation, the particle size is kept at 6-8mm, the length is kept at 2-3cm, and the anti-slagging biomass particle fuel is obtained after cooling;

[0009] The anti-slagging agent includes calcium hydrogen phosphate, nano-porous powder quartz, nano diatomite and fatty alcohol polyoxyethylene ether; the combustion improver includes potassium permanganate, nano bamboo powder and nano carbon powder.

[0010] Preferably, the extrusion expansion conditions are: heated to a temperature of 220-240℃ while pressurized to a pressure of 2.5-3.5Mpa, kept for 5-10min, and then released to normal pressure instantaneously, so that the biomass powder is expanded to form a plurality of pores.

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

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

[0013] Preferably, the anti-coking biomass pellet fuel, raw materials are as follows in terms of weight parts: porous biomass powder 90.3 parts, anti-coking agent 5.4 parts, combustion-supporting agent 3.5 parts, silane coupling agent 0.8 parts.

[0014] Preferably, the agricultural and forestry waste is mixed according to the mass ratio of straw, rice straw, nut shell, oil tea shell, wood chip, wood core as 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 shell, oil tea shell, wood chip, wood core as 55:27:18:12:28:23.

[0016] Preferably, the anti-coking agent is mixed according to the mass ratio of dicalcium phosphate, nano-porous powder quartz, nano-diatomic earth, fatty alcohol polyoxyethylene ether as 3:1.5-2:0.8-0.9:0.6-0.65, and then ball-milled.

[0017] Preferably, the anti-coking agent is mixed according to the mass ratio of dicalcium phosphate, nano-porous powder quartz, nano-diatomic earth, fatty alcohol polyoxyethylene ether as 3:1.8:0.85:0.62, and then ball-milled.

[0018] Preferably, the ball-milling condition is that the ball-milling medium is steel ball, and the diameter of the steel ball is 2-3 mm.

[0019] Preferably, the combustion-supporting agent is mixed according to the mass ratio of potassium permanganate, bamboo powder, carbon powder as 1:5-6:2-2.5, and then ball-milled.

[0020] Preferably, the combustion-supporting agent is mixed according to the mass ratio of potassium permanganate, bamboo powder, carbon powder as 1:5.6:2.2, and then ball-milled.

[0021] Preferably, the ball-milling condition is that the ball-milling medium is steel ball, and the diameter of the steel ball is 2-3 mm.

[0022] The beneficial effects of the present application are as follows:

[0023] 1) The biomass pellet fuel prepared by the present application adopts agricultural and forestry waste raw materials such as straw, rice straw, nut shell, oil tea shell, wood chip and wood core, is first crushed into powder, then is extruded and expanded to form porous biomass, and is mixed with anti-slagging agent, combustion improver and silane coupling agent, so that the biomass pellet fuel has high calorific value, high combustion efficiency and low flue gas slagging rate.

[0024] 2) The agricultural and forestry waste raw materials of the biomass pellet fuel prepared by the present application have porosity after extrusion and expansion, so that oxygen is more fully contacted in the combustion process, which helps complete and sufficient combustion of the fuel, thereby improving the combustion efficiency and promoting the overall calorific value of the fuel to increase. Meanwhile, the porosity, anti-slagging agent and combustion improver synergize with each other, so that the fuel is more fully combusted, the slagging is greatly reduced, the combustion is more stable, and the applicability of the biomass pellet fuel is enhanced.

[0025] 3) The anti-slagging agent in the biomass pellet fuel prepared by the present application is composed of appropriate amounts of calcium hydrogen phosphate, nano-porous powder quartz and nano-diatomite, and the combustion improver is composed of appropriate amounts of potassium permanganate, bamboo powder and carbon powder. The two synergize and are uniformly dispersed in the fuel, effectively promote the uniform combustion of the biomass pellet fuel, form a more uniform anti-slagging layer, effectively improve the combustion efficiency of the biomass pellet fuel, and reduce the slagging efficiency. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the implementation of the present application. The described embodiments are only a part of the embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments, components used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0027] Embodiment 1

[0028] A preparation method of an anti-slagging biomass pellet fuel, the specific steps are as follows:

[0029] (1) The agricultural and forestry waste is cleaned and impurities are removed, and is crushed into powder to obtain biomass powder; the agricultural and forestry waste is mixed by straw, rice straw, nut shell, oil tea shell, wood chip and wood core according to a mass ratio of 55:27:18:12:28:23;

[0030] (2) The biomass powder is sent into a spiral extrusion expander for extrusion expansion, is heated to a temperature of 220℃ and is pressurized to a pressure of 2.5Mpa at the same time, is kept for 10min, and then is released to normal pressure instantaneously, so that the biomass powder is formed to be porous, and porous biomass powder is obtained;

[0031] (3) After 88 parts of porous biomass powder, 6.5 parts of anti-slagging agent, 5 parts of combustion improver, 0.5 parts of silane coupling agent are uniformly mixed, they are sent into an extruder to be extruded and granulated at a temperature of 85℃ and a pressure of 80MPa, the particle size is kept at 6-8mm, the length is kept at 2-3cm, and the anti-slagging biomass pellet fuel is obtained after cooling, the combustion performance is shown in Table 1;

[0032] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth and fatty alcohol polyoxyethylene ether according to a mass ratio of 3:1.8:0.85:0.62, and then ball milling for 20min with steel balls with a diameter of 2-3mm; and the combustion improver is obtained by mixing potassium permanganate, nano-bamboo powder and nano-carbon powder according to a mass ratio of 1:5.6:2.2, and then ball milling for 35min with steel balls with a diameter of 2-3mm.

[0033] Example 2

[0034] A preparation method of an anti-slagging biomass pellet fuel, the specific steps are as follows:

[0035] (1) The agricultural and forestry waste is cleaned, impurities are removed, and it is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core according to a mass ratio of 55:27:18:12:28:23;

[0036] (2) The biomass powder is sent into a spiral extrusion expander to be extruded and expanded, heated to a temperature of 230℃ and pressurized to a pressure of 3Mpa at the same time, kept for 8min, and then released to normal pressure instantaneously, so that the biomass powder is formed to be porous, and porous biomass powder is obtained;

[0037] (3) After 90 parts of porous biomass powder, 4.5 parts of anti-slagging agent, 4 parts of combustion improver and 1 part of silane coupling agent are uniformly mixed, they are sent into an extruder to be extruded and granulated at a temperature of 90℃ and a pressure of 85MPa, the particle size is kept at 6-8mm, the length is kept at 2-3cm, and the anti-slagging biomass pellet fuel is obtained after cooling, the combustion performance is shown in Table 1;

[0038] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth and fatty alcohol polyoxyethylene ether according to a mass ratio of 3:1.8:0.85:0.62, and then ball milling for 15min with steel balls with a diameter of 2-3mm; and the combustion improver is obtained by mixing potassium permanganate, nano-bamboo powder and nano-carbon powder according to a mass ratio of 1:5.6:2.2, and then ball milling for 30min with steel balls with a diameter of 2-3mm.

[0039] Example 3

[0040] A preparation method of an anti-slagging biomass pellet fuel, the specific steps are as follows:

[0041] (1) The agricultural and forestry waste is cleaned, crushed and powdered to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core in a mass ratio of 55:27:18:12:28:23;

[0042] (2) The biomass powder is sent into a spiral extrusion expander to be extruded and expanded, heated to a temperature of 240 DEG C and pressurized to a pressure of 3.5 MPa at the same time, kept for 5 min, and then released to normal pressure instantaneously, so that the biomass powder is formed into porous, and porous biomass powder is obtained;

[0043] (3) 93 parts of the porous biomass powder, 3.5 parts of the anti-slagging agent, 2.5 parts of the combustion-supporting agent and 1 part of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 95 DEG C and a pressure of 90 MPa, with the particle size kept at 6-8 mm and the length kept at 2-3 cm, and then cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0044] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano diatomite and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.8:0.85:0.62, and then ball milling with steel balls with a diameter of 2-3 mm for 25 min; and the combustion-supporting agent is obtained by mixing potassium permanganate, nano bamboo powder and nano carbon powder in a mass ratio of 1:5.6:2.2, and then ball milling with steel balls with a diameter of 2-3 mm for 40 min.

[0045] Example 4

[0046] A preparation method of anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0047] (1) The agricultural and forestry waste is cleaned, crushed and powdered to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core in a mass ratio of 55:27:18:12:28:23;

[0048] (2) The biomass powder is sent into a spiral extrusion expander to be extruded and expanded, heated to a temperature of 240 DEG C and pressurized to a pressure of 3.5 MPa at the same time, kept for 5 min, and then released to normal pressure instantaneously, so that the biomass powder is formed into porous, and porous biomass powder is obtained;

[0049] (3) 93 parts of the porous biomass powder, 3.5 parts of the anti-slagging agent, 2.5 parts of the combustion-supporting agent and 1 part of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 95 DEG C and a pressure of 90 MPa, with the particle size kept at 6-8 mm and the length kept at 2-3 cm, and then cooled to obtain anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0050] Wherein, the dicalcium phosphate, nano-porous powder quartz, nanometer diatomite and fatty alcohol polyoxyethylene ether are mixed according to the mass ratio of 3:1.8:0.85:0.62, then a steel ball with a diameter of 2-3mm is used for ball milling for 20min to obtain the anti-slagging agent; the potassium permanganate, nano-bamboo powder and nano-carbon powder are mixed according to the mass ratio of 1:5.6:2.2, then a steel ball with a diameter of 2-3mm is used for ball milling for 35min to obtain the combustion improver.

[0051] Example 5

[0052] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0053] (1) The agricultural and forestry waste is cleaned and impurities are removed, and is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core according to the mass ratio of 55:25:15:10:25:20;

[0054] (2) The biomass powder is sent into a spiral extrusion expander for extrusion expansion, heated to a temperature of 220℃ and pressurized to a pressure of 3Mpa at the same time, maintained for 5min, and then released to normal pressure instantaneously, so that the biomass powder is formed into pores to obtain porous biomass powder;

[0055] (3) 90.3 parts of the porous biomass powder, 5.4 parts of the anti-slagging agent, 3.5 parts of the combustion improver and 0.8 parts of the silane coupling agent are uniformly mixed and then sent into an extruder for extrusion granulation at a temperature of 90℃ and a pressure of 85MPa, the particle size is kept at 6-8mm, the length is kept at 2-3cm, and the anti-slagging biomass pellet fuel is obtained after cooling, and the combustion performance is shown in Table 1;

[0056] Wherein, the dicalcium phosphate, nano-porous powder quartz, nanometer diatomite and fatty alcohol polyoxyethylene ether are mixed according to the mass ratio of 3:1.8:0.85:0.62, then a steel ball with a diameter of 2-3mm is used for ball milling for 20min to obtain the anti-slagging agent; the potassium permanganate, nano-bamboo powder and nano-carbon powder are mixed according to the mass ratio of 1:5.6:2.2, then a steel ball with a diameter of 2-3mm is used for ball milling for 35min to obtain the combustion improver.

[0057] Example 6

[0058] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0059] (1) The agricultural and forestry waste is cleaned and impurities are removed, and is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core according to the mass ratio of 55:30:20:15:30:25;

[0060] (2) the biomass powder is sent into a spiral extrusion expander to be extrusion expanded, heated to a temperature of 220°C while being pressurized to a pressure of 3Mpa, maintained for 5min, and then instantaneously released to normal pressure to make the biomass powder porous, to obtain porous biomass powder;

[0061] (3) 90.3 parts of the porous biomass powder, 5.4 parts of the anti-slagging agent, 3.5 parts of the combustion-supporting agent, and 0.8 parts of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 90°C and a pressure of 85MPa, with a particle size maintained at 6-8mm and a length maintained at 2-3cm, to obtain anti-slagging biomass pellet fuel, with combustion performance as shown in Table 1;

[0062] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth, and fatty alcohol polyoxyethylene ether according to a mass ratio of 3:2:0.9:0.65, and then ball-milling with steel balls with a diameter of 2-3mm for 20min; and the combustion-supporting agent is obtained by mixing potassium permanganate, nano-bamboo powder, and nano-carbon powder according to a mass ratio of 1:6:2.5, and then ball-milling with steel balls with a diameter of 2-3mm for 35min.

[0063] Example 7

[0064] A preparation method of anti-slagging biomass pellet fuel, with specific steps as follows:

[0065] (1) agricultural and forestry waste is cleaned to remove impurities, and then crushed into powder to obtain biomass powder; the agricultural and forestry waste is obtained by mixing straw, rice straw, nut shell, oil tea shell, wood chips, and wood core according to a mass ratio of 55:30:20:15:30:25;

[0066] (2) the biomass powder is sent into a spiral extrusion expander to be extrusion expanded, heated to a temperature of 220°C while being pressurized to a pressure of 3Mpa, maintained for 5min, and then instantaneously released to normal pressure to make the biomass powder porous, to obtain porous biomass powder;

[0067] (3) 89.7 parts of the porous biomass powder, 5 parts of the anti-slagging agent, 4.5 parts of the combustion-supporting agent, and 0.8 parts of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 90°C and a pressure of 85MPa, with a particle size maintained at 6-8mm and a length maintained at 2-3cm, to obtain anti-slagging biomass pellet fuel, with combustion performance as shown in Table 1;

[0068] The calcium hydrogen phosphate, nano-porous powder quartz, nanometer diatomite and fatty alcohol polyoxyethylene ether are mixed according to the mass ratio of 3:1.5:0.8:0.6, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 20 min to obtain the anti-slagging agent; the potassium permanganate, nanometer bamboo powder and nanometer carbon powder are mixed according to the mass ratio of 1:5:2, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 35 min to obtain the combustion improver.

[0069] Example 8

[0070] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0071] (1) The agricultural and forestry wastes are cleaned, impurities are removed, and the agricultural and forestry wastes are crushed into powder to obtain biomass powder; the agricultural and forestry wastes are composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core according to the mass ratio of 55:25:15:10:25:20;

[0072] (2) The biomass powder is sent into a spiral extrusion expander for extrusion expansion, heated to a temperature of 220 DEG C, and pressurized to a pressure of 3 Mpa at the same time, and kept for 5 min, and then released to normal pressure instantaneously, so that the biomass powder is formed into pores to obtain porous biomass powder;

[0073] (3) 91.5 parts of the porous biomass powder, 4.5 parts of the anti-slagging agent, 3.2 parts of the combustion improver and 0.8 parts of the silane coupling agent are uniformly mixed and then sent into an extruder for extrusion granulation at a temperature of 90 DEG C and a pressure of 85 MPa, and the particle size is kept at 6-8 mm and the length is kept at 2-3 cm, and then cooled to obtain the anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0074] The calcium hydrogen phosphate, nano-porous powder quartz, nanometer diatomite and fatty alcohol polyoxyethylene ether are mixed according to the mass ratio of 3:1.5:0.8:0.6, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 20 min to obtain the anti-slagging agent; the potassium permanganate, nanometer bamboo powder and nanometer carbon powder are mixed according to the mass ratio of 1:5:2, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 35 min to obtain the combustion improver.

[0075] Example 9

[0076] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0077] (1) The agricultural and forestry wastes are cleaned, impurities are removed, and the agricultural and forestry wastes are crushed into powder to obtain biomass powder; the agricultural and forestry wastes are composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core according to the mass ratio of 55:25:15:10:25:20;

[0078] (2) the biomass powder is sent into a spiral extrusion expander to be extruded and expanded, heated to a temperature of 220 DEG C while being pressurized to a pressure of 3Mpa, maintained for 5 min, and then instantaneously released to normal pressure to make the biomass powder porous, thereby obtaining porous biomass powder;

[0079] (3) 90.3 parts of the porous biomass powder, 5.4 parts of the anti-coking agent, 3.5 parts of the combustion-supporting agent, and 0.8 parts of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 90 DEG C and a pressure of 85 MPa, with the particle size being kept at 6-8 mm and the length being kept at 2-3 cm, and then cooled to obtain anti-coking biomass pellet fuel, and the combustion performance is shown in Table 1;

[0080] The anti-coking agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano diatomite, and fatty alcohol polyoxyethylene ether according to a mass ratio of 3:1.5:0.8:0.6, and then ball-milling with steel balls with a diameter of 2-3 mm for 20 min; and the combustion-supporting agent is obtained by mixing potassium permanganate, nano bamboo powder, and nano carbon powder according to a mass ratio of 1:6:2.5, and then ball-milling with steel balls with a diameter of 2-3 mm for 35 min.

[0081] The anti-coking biomass pellet fuel of the embodiments 1-9 of the present application has lower coking and higher combustion heat value during combustion, and the amount of smoke during combustion is very small, so that the biomass pellet fuel has higher calorific value, combustion efficiency, and anti-coking property; at the same time, the calorific value and coking rate of the biomass pellet fuel of the embodiments 1-9 of the present application are relatively stable, which improves the product performance and quality and is helpful for large-scale production of the biomass pellet fuel.

[0082] Comparative Example 1

[0083] A preparation method of anti-coking biomass pellet fuel, and the specific steps are as follows:

[0084] (1) agricultural and forestry waste is cleaned, impurities are removed, and the waste is crushed into powder to obtain biomass powder; the agricultural and forestry waste is obtained by mixing straw, rice straw, nut shell, oil tea shell, wood chips, and wood core according to a mass ratio of 55:27:18:12:28:23;

[0085] (2) 93 parts of the biomass powder, 3.5 parts of the anti-coking agent, 2.5 parts of the combustion-supporting agent, and 1 part of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 95 DEG C and a pressure of 90 MPa, with the particle size being kept at 6-8 mm and the length being kept at 2-3 cm, and then cooled to obtain anti-coking biomass pellet fuel, and the combustion performance is shown in Table 1;

[0086] The calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth and fatty alcohol polyoxyethylene ether are mixed according to the mass ratio of 3:1.8:0.85:0.62, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 25 min to obtain the anti-slagging agent; the potassium permanganate, nano-bamboo powder and nano-carbon powder are mixed according to the mass ratio of 1:5.6:2.2, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 40 min to obtain the combustion improver.

[0087] Comparative Example 2

[0088] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0089] (1) The agricultural and forestry waste is cleaned and impurities are removed, and then is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chip and wood core according to the mass ratio of 55:27:18:12:28:23;

[0090] (2) The biomass powder is sent into a spiral extrusion expander for extrusion expansion, heated to a temperature of 240 DEG C and pressurized to a pressure of 2 Mpa at the same time, and kept for 20 min, and then released to normal pressure instantaneously, so that the biomass powder is formed into pores to obtain porous biomass powder;

[0091] (3) 93 parts of the porous biomass powder, 3.5 parts of the anti-slagging agent, 2.5 parts of the combustion improver and 1 part of the silane coupling agent are uniformly mixed, and then sent into an extruder for extrusion granulation at a temperature of 95 DEG C and a pressure of 90 MPa, and the particle size is kept at 6-8 mm and the length is kept at 2-3 cm, and then cooled to obtain the anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0092] The calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth and fatty alcohol polyoxyethylene ether are mixed according to the mass ratio of 3:1.8:0.85:0.62, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 25 min to obtain the anti-slagging agent; the potassium permanganate, nano-bamboo powder and nano-carbon powder are mixed according to the mass ratio of 1:5.6:2.2, and then a steel ball with a diameter of 2-3 mm is used for ball milling for 40 min to obtain the combustion improver.

[0093] Comparative Example 3

[0094] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0095] (1) The agricultural and forestry waste is cleaned and impurities are removed, and then is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chip and wood core according to the mass ratio of 55:27:18:12:28:23;

[0096] (2) the biomass powder is sent into a spiral extrusion expander to be extrusion expanded, heated to a temperature of 240°C while being pressurized to a pressure of 4 MPa, maintained for 2 min, and then instantaneously released to normal pressure to make the biomass powder porous, to obtain porous biomass powder;

[0097] (3) 93 parts of the porous biomass powder, 3.5 parts of the anti-slagging agent, 2.5 parts of the combustion-supporting agent, and 1 part of the silane coupling agent are uniformly mixed and then sent into an extruder to be extruded and granulated at a temperature of 95°C and a pressure of 90 MPa, with the particle size being maintained at 6-8 mm and the length being maintained at 2-3 cm, to obtain anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0098] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth, and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.8:0.85:0.62, and then ball-milling with steel balls with a diameter of 2-3 mm for 25 min. The combustion-supporting agent is obtained by mixing potassium permanganate, nano-bamboo powder, and nano-carbon powder in a mass ratio of 1:5.6:2.2, and then ball-milling with steel balls with a diameter of 2-3 mm for 40 min.

[0099] Compared with Comparative Examples 1-3, the biomass powder can be made porous by extrusion expansion under suitable extrusion expansion conditions. The mutual combination of the biomass powder particles is more uniform, which helps the biomass powder particles to be tightly combined to form a more uniform, more stable, and suitably porous structure, thereby effectively improving the combustion efficiency of the biomass pellet fuel, increasing the overall calorific value of the fuel, making the fuel combustion more complete, greatly reducing slagging, and making the combustion more stable, and enhancing the applicability of the biomass pellet fuel. However, if the pressure is too small and the time is too short, the combination of the particles is insufficient, and a stable porous structure cannot be formed. If the pressure is too large and the time is too long, the combination of the particles is too dense, and the porosity is reduced, which affects the combustion of the biomass pellet fuel, reduces the combustion efficiency, and increases the slagging rate.

[0100] Comparative Example 4

[0101] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0102] (1) The agricultural and forestry waste is cleaned, and then crushed into powder to obtain biomass powder. The agricultural and forestry waste is a mixture of straw, rice straw, nut shells, oil tea shells, wood chips, and wood cores in a mass ratio of 55:27:18:12:28:23.

[0103] (2) The biomass powder is sent into a spiral extrusion expander to be extrusion expanded, heated to a temperature of 240°C while being pressurized to a pressure of 3.5 MPa, maintained for 5 min, and then instantaneously released to normal pressure to make the biomass powder porous, to obtain porous biomass powder.

[0104] (3) After 93 parts of porous biomass powder, 3.5 parts of anti-slagging agent, 2.5 parts of combustion improver, 1 part of silane coupling agent are uniformly mixed, they are sent into an extruder to be extruded and granulated at a temperature of 95℃ and a pressure of 90MPa, the particle size is kept at 6-8mm, the length is kept at 2-3cm, and then cooled to obtain anti-slagging biomass pellet fuel, the combustion performance is shown in Table 1;

[0105] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz and nano diatomite according to a mass ratio of 3:1.8:0.85, and then ball milling with steel balls with a diameter of 2-3mm for 25min; the combustion improver is obtained by mixing potassium permanganate, nano bamboo powder and nano carbon powder according to a mass ratio of 1:5.6:2.2, and then ball milling with steel balls with a diameter of 2-3mm for 40min.

[0106] Compared with Comparative Example 4, the anti-slagging agent by adding suitable fatty alcohol polyoxyethylene ether can promote calcium hydrogen phosphate, nano-porous powder quartz and nano diatomite to form a more uniform anti-slagging layer during fuel combustion, thereby effectively improving the anti-slagging property of biomass pellet fuel.

[0107] Comparative Example 5

[0108] (1) The agricultural and forestry waste is cleaned, impurities are removed, and then is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core according to a mass ratio of 55:27:18:12:28:23;

[0109] (2) The biomass powder is sent into a spiral extrusion expander to be extruded and expanded, heated to a temperature of 220℃ while pressurized to a pressure of 2.5Mpa, kept for 10min, and then released to normal pressure instantaneously, so that the biomass powder is formed to be porous to obtain porous biomass powder;

[0110] (3) After 88 parts of porous biomass powder, 6.5 parts of anti-slagging agent, 5 parts of combustion improver and 0.5 part of silane coupling agent are uniformly mixed, they are sent into an extruder to be extruded and granulated at a temperature of 85℃ and a pressure of 80MPa, the particle size is kept at 6-8mm, the length is kept at 2-3cm, and then cooled to obtain anti-slagging biomass pellet fuel, the combustion performance is shown in Table 1;

[0111] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano diatomite and fatty alcohol polyoxyethylene ether according to a mass ratio of 3:1.8:0.85:0.62, and then ball milling with steel balls with a diameter of 2-3mm for 20min; the combustion improver is obtained by mixing potassium permanganate and nano bamboo powder according to a mass ratio of 1:5.6, and then ball milling with steel balls with a diameter of 2-3mm for 35min.

[0112] Comparative Example 6

[0113] (1) The agricultural and forestry wastes were cleaned, impurities were removed, and were crushed into powder to obtain biomass powder; the agricultural and forestry wastes were composed of straw, rice straw, nut shell, oil tea shell, wood chips, and wood core in a mass ratio of 55:27:18:12:28:23;

[0114] (2) The biomass powder was sent into a spiral extrusion expander to perform extrusion expansion, was heated to a temperature of 220°C while being pressurized to a pressure of 2.5 MPa, was maintained for 10 min, and was then instantaneously released to normal pressure to make the biomass powder porous to obtain porous biomass powder;

[0115] (3) 88 parts of the porous biomass powder, 6.5 parts of an anti-slagging agent, 5 parts of a combustion-supporting agent, and 0.5 parts of a silane coupling agent were uniformly mixed and then were sent into an extruder to perform extrusion granulation at a temperature of 85°C and a pressure of 80 MPa, the particle size was maintained at 6-8 mm, the length was maintained at 2-3 cm, and cooling was performed to obtain anti-slagging biomass pellet fuel, and the combustion performance was as shown in Table 1;

[0116] The anti-slagging agent was obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth, and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.8:0.85:0.62, and then performing ball milling with steel balls with a diameter of 2-3 mm for 20 min; and the combustion-supporting agent was obtained by mixing potassium permanganate and nano-carbon powder in a mass ratio of 1:2.2, and then performing ball milling with steel balls with a diameter of 2-3 mm for 35 min.

[0117] Compared with Comparative Examples 5 and 6, the combustion-supporting agent in Example 1 is obtained by adding appropriate potassium permanganate, nano-bamboo powder, and nano-carbon powder, 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 preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0120] (1) The agricultural and forestry wastes were cleaned, impurities were removed, and were crushed into powder to obtain biomass powder; the agricultural and forestry wastes were composed of straw, rice straw, nut shell, oil tea shell, wood chips, and wood core in a mass ratio of 55:27:18:12:28:23;

[0121] (2) The biomass powder was sent into a spiral extrusion expander to perform extrusion expansion, was heated to a temperature of 220°C while being pressurized to a pressure of 2.5 MPa, was maintained for 10 min, and was then instantaneously released to normal pressure to make the biomass powder porous to obtain porous biomass powder;

[0122] (3) 95 parts of the porous biomass powder, 2.5 parts of the anti-slagging agent, 2 parts of the combustion-supporting agent, and 0.5 part of the silane coupling agent are uniformly mixed and then fed into an extruder to be extruded and granulated at a temperature of 85°C and a pressure of 80 MPa, with the particle size being kept at 6-8 mm and the length being kept at 2-3 cm, to obtain the anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0123] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth, and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.8:0.85:0.62, and then ball-milling with steel balls of 2-3 mm in diameter for 20 min; and the combustion-supporting agent is obtained by mixing potassium permanganate, nano-bamboo powder, and nano-carbon powder in a mass ratio of 1:5.6:2.2, and then ball-milling with steel balls of 2-3 mm in diameter for 35 min.

[0124] Comparative Example 8

[0125] A preparation method of an anti-slagging biomass pellet fuel, and the specific steps are as follows:

[0126] (1) The agricultural and forestry waste is cleaned and impurities are removed, and then is crushed into powder to obtain biomass powder; the agricultural and forestry waste is composed of straw, rice straw, nut shell, oil tea shell, wood chips, and wood core in a mass ratio of 55:27:18:12:28:23;

[0127] (2) The biomass powder is fed into a spiral extrusion expander to be extruded and expanded, heated to a temperature of 220°C while being pressurized to a pressure of 2.5 MPa, and kept for 10 min, and then released to normal pressure instantaneously, so that the biomass powder is formed to be porous to obtain the porous biomass powder;

[0128] (3) 86 parts of the porous biomass powder, 7.5 parts of the anti-slagging agent, 6 parts of the combustion-supporting agent, and 0.5 part of the silane coupling agent are uniformly mixed and then fed into an extruder to be extruded and granulated at a temperature of 85°C and a pressure of 80 MPa, with the particle size being kept at 6-8 mm and the length being kept at 2-3 cm, to obtain the anti-slagging biomass pellet fuel, and the combustion performance is shown in Table 1;

[0129] The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz, nano-diatomic earth, and fatty alcohol polyoxyethylene ether in a mass ratio of 3:1.8:0.85:0.62, and then ball-milling with steel balls of 2-3 mm in diameter for 20 min; and the combustion-supporting agent is obtained by mixing potassium permanganate, nano-bamboo powder, and nano-carbon powder in a mass ratio of 1:5.6:2.2, and then ball-milling with steel balls of 2-3 mm in diameter for 35 min.

[0130] Compared with Comparative Examples 7 and 8, the suitable porous biomass powder cooperates with the corresponding anti-slagging agent and combustion-supporting agent, which is conducive to reducing the slagging rate of the biomass pellet fuel.

[0131] Comparative Example 9

[0132] A preparation method of an anti-coking biomass pellet fuel, and the specific steps are as follows:

[0133] (1) The agricultural and forestry wastes are cleaned, impurities are removed, and are crushed into powder to obtain biomass powder; the agricultural and forestry wastes are composed of straw, rice straw, nut shell, oil tea shell, wood chips and wood core, and the mass ratio is 55:27:18:12:28:23;

[0134] (2) 88 parts of porous biomass powder, 6.5 parts of anti-coking agent, 5 parts of combustion-supporting agent and 0.5 parts of silane coupling agent are uniformly mixed, heated to a temperature of 220 DEG C and pressurized to a pressure of 2.5 MPa at the same time, kept for 10 min, and then released to normal pressure instantaneously to obtain a porous mixture;

[0135] The calcium hydrogen phosphate, nano-porous powder quartz, nano diatomite and fatty alcohol polyoxyethylene ether are mixed according to a mass ratio of 3:1.8:0.85:0.62, and then ball-milled with a steel ball with a diameter of 2-3 mm for 20 min to obtain the anti-coking agent; the potassium permanganate, nano bamboo powder and nano carbon powder are mixed according to a mass ratio of 1:5.6:2.2, and then ball-milled with a steel ball with a diameter of 2-3 mm for 35 min to obtain the combustion-supporting agent;

[0136] (3) The porous mixture is sent into a spiral extrusion expander for extrusion expansion, and is sent into an extruder for extrusion and granulation at a temperature of 85 DEG C and a pressure of 80 MPa, the particle size is kept at 6-8 mm, the length is kept at 2-3 cm, and then cooled to obtain the anti-coking biomass pellet fuel, and the combustion performance is shown in Table 1.

[0137] Compared with Comparative Example 9, the biomass powder is first extruded and expanded, and then combined with the anti-coking agent and the combustion-supporting agent, so that the improvement of the anti-coking property of the biomass pellet fuel is promoted.

[0138] Table 1 Combustion performance of biomass pellet fuel

[0139] Combustion heat value (MJ / Kg) Smoke amount Sag 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 Large 2.65 Comparative Example 2 32.9 Less 1.35 Comparative Example 3 33.3 Less 1.31 Comparative Example 4 31.2 Small 1.68 Comparative Example 5 32.1 Less 1.65 Comparative Example 6 30.3 Small 1.98 Comparative Example 7 32.5 Less 1.65 Comparative Example 8 31.5 Small 1.83 Comparative Example 9 32.3 Less 1.67

[0140] The combustion values in Table 1 are tested according to GB / T 30727-2014 and NB / T 34025-2015.

[0141] As can be seen from the above, the biomass pellet fuel has good anti-coking property and calorific value, high combustion efficiency and good combustion effect.

[0142] It is apparent for a person skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that it can be implemented in other concrete forms without departing from the spirit and essential characteristics of the application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the application being defined by the appended claims rather than the above description, and all changes falling within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0143] Furthermore, it should be understood that although the present specification describes exemplary embodiments, the present specification does not limit the application to these embodiments alone. The present specification describes the embodiments with enough details to enable those skilled in the art to practice the application. However, it should be understood that the description is not intended to limit the application to one or more specific examples, and that the specification can include and be practiced with other systems, components, compositions of matter, and methods. Such other systems, components, compositions of matter, and methods used in the practice of the present application, while not specifically described herein, are well within the scope of the present application.

Claims

1. A method of producing an anti-caking biomass particulate fuel, characterized by, The method comprises the following steps: (1) cleaning and removing impurities from the agricultural and forestry wastes, crushing them into powder to obtain biomass powder; The agricultural and forestry wastes include straw, rice straw, nut shell, oil tea shell, wood chips and wood core; (2) sending the biomass powder into a spiral extrusion expander to perform extrusion expansion, so that the biomass powder is porous to obtain porous biomass powder; (3) mixing the porous biomass powder, anti-slagging agent, combustion improver and silane coupling agent uniformly, and then sending the mixture into an extruder to perform extrusion granulation, so that the particle size is 6-8 mm and the length is 2-3 cm, and then cooling to obtain anti-slagging biomass pellet fuel; The anti-slagging agent is obtained by mixing calcium hydrogen phosphate, nano-porous powder quartz and nano-diatomic earth in a mass ratio of 3:1.5-2:0.8-0.9:0.6-0.65 and then ball milling; The combustion improver is obtained by mixing potassium permanganate, nano-bamboo powder and nano-carbon powder in a mass ratio of 1:5-6:2-2.5 and then ball milling; In step (2), the extrusion expansion conditions are as follows: heating to a temperature of 220-240 DEG C while pressurizing to a pressure of 2.5-3.5 MPa, maintaining for 5-10 min, and then releasing to normal pressure instantaneously to make the biomass powder expand to be porous; In step (3), the anti-slagging biomass pellet fuel is prepared from the following raw materials in terms of weight parts: 88-93 parts of porous biomass powder, 3.5-6.5 parts of anti-slagging agent, 2.5-5 parts of combustion improver, and 0.5-1.2 parts of silane coupling agent; and the sum of the weight parts of the porous biomass powder, anti-slagging agent, combustion improver and silane coupling agent is 100 parts.

2. A method of producing an anti-caking biomass pellet fuel according to claim 1, characterized by, The anti-slagging biomass pellet fuel is prepared from the following raw materials in terms of weight parts: 90.3 parts of porous biomass powder, 5.4 parts of anti-slagging agent, 3.5 parts of combustion improver, and 0.8 parts of silane coupling agent.

3. A method of producing an anti-caking biomass pellet fuel according to claim 1, characterized by, In step (3), the extrusion granulation conditions are as follows: extrusion temperature is 85-95 DEG C, and extrusion pressure is 80-90 MPa.

4. The method of claim 1, wherein the anti-caking biomass pellet fuel is prepared by adding the anti-caking agent to the biomass pellet fuel. The agricultural and forestry wastes are obtained by mixing straw, rice straw, nut shell, oil tea shell, wood chips and wood core in a mass ratio of 55:25-30:15-20:10-15:25-30:20-25.

5. The method of claim 1, wherein the anti-caking biomass pellet fuel is prepared by adding the anti-caking agent to the biomass pellet fuel. The ball milling conditions are as follows: the ball milling medium is steel ball, and the diameter of the steel ball is 2-3 mm.