Biomass pellet fuel and preparation method thereof

Abstract

The invention discloses a biomass pellet fuel and a preparation method thereof, and belongs to the technical field of biomass pellet fuels, the biomass pellet fuel comprises the following raw materials by weight: 68-77% of a biomass raw material, 15-22% of a tea seed cake, 2-4.5% of a moisture-proof agent, 1.5-2.5% of a combustion improver and 3-4% of an adhesive. The structure of the biomass pellet fuel is optimized, the biomass pellet fuel has a higher heat value and a more excellent moisture-proof effect, and the quality is improved.

Description

Technical Field

[0001] The invention relates to a biomass pellet fuel and a preparation method thereof, belonging to the technical field of biomass pellet fuel. Background Art

[0002] With the environmental pressure and carbon emission problems brought by the consumption of coal resources, biomass fuel has gradually entered the public's field of vision. Biomass fuel is made of agricultural and forestry wastes such as straw, husks, corn cobs, nut shells, flowers, tea residues, and domestic garbage. It is made into strips and granules through processes such as crushing, extrusion, and drying. It is a new type of clean fuel that can be directly burned, which can alleviate pollution. It has efficient combustion characteristics and can reduce dependence on traditional energy sources such as coal. The calorific value of existing biomass pellet fuels is still not ideal, and some biomass pellet fuels deliquesce due to long-term storage, which reduces the combustion quality and affects its calorific value, thus limiting the potential for widespread application of biomass pellet fuels. Summary of the invention

[0003] In order to solve at least one problem existing in the above-mentioned prior art, the present invention provides a biomass pellet fuel and a preparation method thereof. The structure of the biomass pellet fuel is optimized, and it has a higher calorific value and a better moisture-proof effect, and the quality is improved.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a biomass pellet fuel, comprising the following raw materials, calculated by weight percentage: 68-77% biomass raw material, 15-22% tea seed cake, 2-4.5% moisture proof agent, 1.5-2.5% combustion aid and 3-4% adhesive.

[0005] Preferably, the biomass raw materials include the following raw materials, calculated by weight: 30-50 parts of corn cobs, 15-25 parts of corn stalks, and 35-45 parts of cotton stalks.

[0006] Preferably, the sum of the weight parts of the corn cob, corn stalks and cotton stalks is 100 parts.

[0007] Preferably, the combustion improver consists of potassium permanganate, magnesium oxide and aluminum oxide.

[0008] Preferably, the combustion aid is composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1-2:1:2-3.

[0009] Preferably, the moisture-proofing agent consists of montmorillonite and ethyl cellulose.

[0010] Preferably, the moisture-proof agent is composed of montmorillonite and ethyl cellulose in a mass ratio of 1:1.5 to 2.5.

[0011] Preferably, the adhesive consists of rosin and tower bottom heavy oil.

[0012] Preferably, the adhesive is composed of rosin and tower bottom heavy oil in a mass ratio of 3 to 4:1.

[0013] The tower bottom heavy oil of the present invention is a heavy component obtained by vacuum distillation in the process of biodiesel production.

[0014] The present invention also provides a method for preparing biomass pellet fuel, comprising the following steps:

[0015] (1) crushing corn cobs, corn stalks, cotton stalks, and tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0016] (2) calcining the montmorillonite under high-temperature and high-speed airflow, stirring and mixing with deionized water and performing high-pressure homogenization to form a montmorillonite dispersion, adding ethyl cellulose for ultrasonic dispersion, and stirring and mixing for 20 to 30 minutes to obtain a moisture-proofing agent dispersion;

[0017] (3) During the stirring process, spraying a moisture-proof agent dispersion onto the crushed solid powder, stirring evenly, drying, adding a combustion aid, mixing evenly, and then subjecting the crushed solid powder to a steam explosion treatment to obtain a steam explosion solid powder;

[0018] (4) The steam explosion solid powder and the adhesive are stirred and mixed evenly, and then heated and stirred in a vacuum, and then pressed and formed by a molding machine to obtain biomass pellet fuel.

[0019] Preferably, in step (2), calcination treatment is carried out at a temperature of 1100 to 1150° C., a gas flow rate of 5 to 10 m / s, and a time of 15 to 25 min.

[0020] Preferably, in step (2), high pressure homogenization treatment: the pressure is 150 to 200 MPa, and the treatment is circulated 10 to 15 times.

[0021] Preferably, in step (2), the amount of deionized water used is 20-30% of the weight of the crushed solid powder.

[0022] Preferably, in step (2), ultrasonic treatment: the ultrasonic power is 400-500W, and the time is 20-30min.

[0023] Preferably, step (3), steam explosion treatment: heat and pressure treatment at a temperature of 135-145° C. and a pressure of 1.8-2.2 MPa for 8-10 min, and then unloading to normal temperature and pressure within 25-30 s.

[0024] Preferably, in step (4), vacuum heating: the vacuum degree is 0.02-0.03 MPa, the temperature is 120-130° C., and the time is 1-2 h.

[0025] Preferably, step (4) is compression molding: extruding into a cylindrical shape of 5 to 6 cm at a temperature of 125 to 135° C. and a pressure of 65 to 70 MPa.

[0026] The beneficial effects of the present invention are as follows: 1. The present invention uses corn cobs, corn stalks and cotton stalks as biomass raw materials, mixes the biomass raw materials, moisture-proofing agents, combustion aids, adhesives and rapeseed cakes, optimizes the biomass pellet fuel composition system, and effectively solves the problem of low combustion calorific value of biomass pellet fuel; 2. At the same time, the present invention uses steam explosion treatment on the mixed system of biomass raw materials, rapeseed cakes, moisture-proofing agents and combustion aids, and then heats them with adhesives in a vacuum, and then presses them into shape, so that the structure of the biomass pellet fuel is optimized and has a higher calorific value; 3. The present invention uses a moisture-proofing agent composed of montmorillonite and ethyl cellulose. The montmorillonite is calcined with high-temperature and high-speed airflow, homogenized under high pressure, and then mixed with ethyl cellulose for ultrasonic treatment. Then the moisture-proofing agent is mixed with the biomass raw materials and rapeseed cakes, which has better barrier properties and makes the biomass pellet fuel have better Good moisture-proof effect, fuel quality is improved, and montmorillonite is mixed in the biomass raw materials, which can promote the expansion of the particles and improve the combustion efficiency. At the same time, ethyl cellulose and adhesives work together to promote the raw materials to be more compact during combustion, the raw materials are not easy to disperse, and the combustion is more complete, thereby improving the fuel stability and calorific value; 4. The present invention adopts a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide, so that the biomass pellet fuel has higher combustion efficiency and stability, and its overall calorific value is also improved; the present invention adopts an adhesive composed of rosin and tower bottom heavy oil, so that the biomass particles can be closely combined together during the molding process to form a molded pellet fuel with a stable structure, which also promotes the improvement of the moisture resistance of the biomass pellet fuel, and the rosin and tower bottom heavy oil can also work together to improve the calorific value and combustion performance of the biomass pellet fuel. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the implementation of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without 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 conventional conditions or the conditions recommended by the manufacturer.

[0028] Example 1

[0029] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are as follows:

[0030] (1) crushing 40 parts of corn cobs, 20 parts of corn stalks, 40 parts of cotton stalks, and 32.3 parts of tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0031] (2) 1.96 parts of montmorillonite were calcined at a temperature of 1120° C. and a high-temperature, high-speed airflow of 8 m / s for 20 min, then mixed with 33 parts of deionized water and subjected to high-pressure homogenization at a pressure of 180 MPa, and the mixture was circulated for 13 times to form a montmorillonite dispersion, and 3.92 parts of ethyl cellulose were added, and ultrasonic dispersion was performed at an ultrasonic power of 450 W for 25 min, and then stirred and mixed for 25 min to obtain a moisture-proof agent dispersion;

[0032] (3) During the stirring process, spray a moisture-proof agent dispersion onto the crushed solid powder, stir evenly and dry, then add 2.94 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1.5:1:2.5, mix evenly, and then steam explode at a temperature of 140° C. and a pressure of 2 MPa for 9 minutes, and then discharge to room temperature and pressure within 25 to 30 seconds to obtain steam-exploded solid powder;

[0033] (4) The steam explosion solid powder and 5.88 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1.5 hours at a vacuum degree of 0.025 MPa and a temperature of 125° C., and then pressed into a cylindrical structure of 5 to 6 cm by a molding machine at a temperature of 130° C. and a pressure of 67.5 MPa to obtain a biomass pellet fuel;

[0034] The bottom heavy oil in this embodiment is a heavy component obtained by vacuum distillation during the production of biodiesel.

[0035] Example 2

[0036] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are as follows:

[0037] (1) crushing 40 parts of corn cobs, 20 parts of corn stalks, 40 parts of cotton stalks, and 26.4 parts of tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0038] (2) 2.08 parts of montmorillonite were calcined at a temperature of 1100° C. and a high-speed airflow velocity of 10 m / s for 25 min, then mixed with 37.9 parts of deionized water and subjected to high-pressure homogenization at a pressure of 150 MPa, and the mixture was circulated for 15 times to form a montmorillonite dispersion, and 4.16 parts of ethyl cellulose were added, and ultrasonic dispersion was performed at an ultrasonic power of 400 W for 30 min, and then stirred and mixed for 20 min to obtain a moisture-proof agent dispersion;

[0039] (3) During the stirring process, spray a moisture-proof agent dispersion onto the crushed solid powder, stir evenly and dry, then add 2.1 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1.5:1:2.5, mix evenly, and then steam explode for 10 minutes at a temperature of 135° C. and a pressure of 1.8 MPa, and then discharge to room temperature and pressure within 25 to 30 seconds to obtain steam-exploded solid powder;

[0040] (4) The steam explosion solid powder and 4.2 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1 hour at a vacuum degree of 0.03 MPa and a temperature of 130° C., and then pressed and formed by a molding machine at a temperature of 135° C. and a pressure of 65 MPa, and extruded into a cylindrical structure of 5 to 6 cm to obtain a biomass pellet fuel;

[0041] The bottom heavy oil in this embodiment is a heavy component obtained by vacuum distillation during the production of biodiesel.

[0042] Example 3

[0043] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are as follows:

[0044] (1) crushing 40 parts of corn cobs, 20 parts of corn stalks, 40 parts of cotton stalks, and 19.5 parts of tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0045] (2) 0.87 parts of montmorillonite was calcined at a temperature of 1500° C. and a high-temperature, high-speed airflow of 5 m / s for 15 min, then mixed with 23.9 parts of deionized water and subjected to high-pressure homogenization at a pressure of 200 MPa, and the mixture was circulated for 10 times to form a montmorillonite dispersion, and then 1.73 parts of ethyl cellulose was added, and ultrasonic dispersion was performed at an ultrasonic power of 500 W for 20 min, and then stirred and mixed for 30 min to obtain a moisture-proof agent dispersion;

[0046] (3) During the stirring process, spray a moisture-proof agent dispersion onto the crushed solid powder, stir evenly and dry, then add 3.24 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1.5:1:2.5, mix evenly, and then steam explode at a temperature of 145° C. and a pressure of 2.2 MPa for 8 minutes, and then discharge to room temperature and pressure within 25 to 30 seconds to obtain steam-exploded solid powder;

[0047] (4) The steam explosion solid powder and 4.54 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1 hour at a vacuum degree of 0.03 MPa and a temperature of 130° C., and then pressed and formed by a molding machine at a temperature of 135° C. and a pressure of 70 MPa, and extruded into a cylindrical structure of 5 to 6 cm to obtain a biomass pellet fuel;

[0048] The bottom heavy oil in this embodiment is a heavy component obtained by vacuum distillation during the production of biodiesel.

[0049] Example 4

[0050] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are as follows:

[0051] (1) crushing 30 parts of corn cobs, 25 parts of corn stalks, 45 parts of cotton stalks, and 22.9 parts of tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0052] (2) 1.9 parts of montmorillonite were calcined at a temperature of 1130° C. and a high-temperature, high-speed airflow of 7 m / s for 20 min, then mixed with 27 parts of deionized water and subjected to high-pressure homogenization at a pressure of 180 MPa, and the mixture was circulated for 12 times to form a montmorillonite dispersion, and then 2.8 parts of ethyl cellulose were added, and ultrasonic dispersion was performed at an ultrasonic power of 450 W for 25 min, and then stirred and mixed for 25 min to obtain a moisture-proof agent dispersion;

[0053] (3) During the stirring process, spray a moisture-proof agent dispersion onto the crushed solid powder, stir evenly and dry, then add 2.7 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1:1:2, mix evenly, and then steam explode at a temperature of 140° C. and a pressure of 2 MPa for 9 minutes, and then discharge to room temperature and pressure within 25 to 30 seconds to obtain steam-exploded solid powder;

[0054] (4) The steam explosion solid powder and 4.7 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3:1 were stirred and mixed evenly, and then stirred for 1.5 hours at a vacuum degree of 0.025 MPa and a temperature of 125° C., and then pressed by a molding machine at a temperature of 130° C. and a pressure of 67.5 MPa to extrude into a cylindrical structure of 5 to 6 cm to obtain a biomass pellet fuel;

[0055] The bottom heavy oil in this embodiment is a heavy component obtained by vacuum distillation during the production of biodiesel.

[0056] Example 5

[0057] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are as follows:

[0058] (1) crushing 50 parts of corn cobs, 15 parts of corn stalks, 35 parts of cotton stalks, and 29.5 parts of tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0059] (2) 1.25 parts of montmorillonite were calcined at a temperature of 1120° C. and a high-temperature, high-speed airflow of 8 m / s for 20 min, then mixed with 32 parts of deionized water and subjected to high-pressure homogenization at a pressure of 170 MPa, and the mixture was circulated for 12 times to form a montmorillonite dispersion, and 3.05 parts of ethyl cellulose were added, and ultrasonic dispersion was performed at an ultrasonic power of 450 W for 25 min, and then stirred and mixed for 25 min to obtain a moisture-proof agent dispersion;

[0060] (3) During the stirring process, spray a moisture-proof agent dispersion onto the crushed solid powder, stir evenly and dry, then add 2.15 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 2:1:3, mix evenly, and then steam explode for 10 minutes at a temperature of 140° C. and a pressure of 2 MPa, and then discharge to room temperature and pressure within 25 to 30 seconds to obtain steam-exploded solid powder;

[0061] (4) The steam explosion solid powder and 4.9 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 4:1 were stirred and mixed evenly, and then stirred for 1.5 hours at a vacuum degree of 0.025 MPa and a temperature of 125° C., and then pressed by a molding machine at a temperature of 130° C. and a pressure of 67.5 MPa to extrude into a cylindrical structure of 5 to 6 cm to obtain a biomass pellet fuel;

[0062] The bottom heavy oil in this embodiment is a heavy component obtained by vacuum distillation during the production of biodiesel.

[0063] Example 6

[0064] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are as follows:

[0065] (1) crushing 35 parts of corn cobs, 20 parts of corn stalks, 35 parts of cotton stalks, and 22.2 parts of tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder;

[0066] (2) 1.9 parts of montmorillonite were calcined at a temperature of 1120° C. and a high-temperature, high-speed airflow of 8 m / s for 20 min, then mixed with 28 parts of deionized water and subjected to high-pressure homogenization at a pressure of 190 MPa, and the mixture was circulated for 15 times to form a montmorillonite dispersion, and then 3 parts of ethyl cellulose were added, and ultrasonic dispersion was performed at an ultrasonic power of 450 W for 25 min, and then stirred and mixed for 25 min to obtain a moisture-proof agent dispersion;

[0067] (3) During the stirring process, spray a moisture-proof agent dispersion onto the crushed solid powder, stir evenly and dry, then add 2.5 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 2:1:2, mix evenly, and then steam explode for 10 minutes at a temperature of 140° C. and a pressure of 2.1 MPa, and then discharge to room temperature and pressure within 25 to 30 seconds to obtain steam-exploded solid powder;

[0068] (4) The steam explosion solid powder and 3.7 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1.5 hours at a vacuum degree of 0.028 MPa and a temperature of 130° C., and then pressed by a molding machine at a temperature of 130° C. and a pressure of 68 MPa to extrude into a cylindrical structure of 5 to 6 cm to obtain a biomass pellet fuel;

[0069] The bottom heavy oil in this embodiment is a heavy component obtained by vacuum distillation during the production of biodiesel.

[0070] Comparative Example 1

[0071] A biomass pellet fuel and a preparation method thereof, the specific steps of the preparation process are different from those of Example 2 in that: no rapeseed cake is added, wherein 40 parts of corn cobs, 20 parts of corn stalks, 40 parts of cotton stalks, 1.65 parts of a combustion aid, 3.3 parts of an adhesive, and a moisture-proof agent: 1.65 parts of montmorillonite and 3.29 parts of ethyl cellulose; the rest are exactly the same.

[0072] Comparative Example 2

[0073] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: a moisture-proof agent is composed of montmorillonite, ethyl cellulose and lignin, wherein the moisture-proof agent dispersion of step (2) is: 1.57 parts of montmorillonite is subjected to a calcination treatment for 25 minutes under a high-temperature, high-speed airflow at a temperature of 1100°C and an airflow velocity of 10 m / s, then stirred and mixed with 37.9 parts of deionized water and subjected to a high-pressure homogenization treatment at a pressure of 150 MPa, and the treatment is circulated for 15 times to form a montmorillonite dispersion, then 3.12 parts of ethyl cellulose is added, ultrasonic dispersion is carried out at an ultrasonic power of 400 W for 30 minutes, then stirring and mixing for 20 minutes, then 1.56 parts of lignin is added, and stirring and mixing for 20 minutes to obtain a moisture-proof agent dispersion; the rest are exactly the same.

[0074] Comparative Example 3

[0075] A biomass pellet fuel and a preparation method thereof. The specific steps of the preparation process are different from those of Example 2 in that methyl cellulose is used instead of ethyl cellulose; the rest are exactly the same.

[0076] Comparative Example 4

[0077] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: the desiccant is only ethyl cellulose, wherein the desiccant dispersion of step (2) is: 3.12 parts of ethyl cellulose and 37.9 parts of deionized water are stirred and mixed for 20 minutes, ultrasonically dispersed at an ultrasonic power of 400 W for 30 minutes, and then stirred and mixed for another 20 minutes to obtain a desiccant dispersion; the rest are exactly the same.

[0078] Comparative Example 5

[0079] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: the moisture-proofing agent is only montmorillonite, wherein the moisture-proofing agent dispersion of step (2) is: 1.57 parts of montmorillonite is calcined for 25 minutes under a high-temperature, high-speed airflow at a temperature of 1100°C and an airflow velocity of 10 m / s, then mixed with 37.9 parts of deionized water and subjected to high-pressure homogenization treatment at a pressure of 150 MPa, and the treatment is circulated for 15 times to form a montmorillonite dispersion, and then ultrasonically dispersed for 30 minutes at an ultrasonic power of 400 W, and then stirred and mixed for 20 minutes to obtain a moisture-proofing agent dispersion; the rest is exactly the same.

[0080] Comparative Example 6

[0081] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: no adhesive is added, wherein the rapeseed cake is 30.6 parts, and the steam explosion solid powder of step (4) is pressed and formed by a molding machine at a temperature of 135° C. and a pressure of 65 MPa, and extruded into a cylindrical structure of 5 to 6 cm to obtain a biomass pellet fuel; and the rest are exactly the same.

[0082] Comparative Example 7

[0083] A biomass pellet fuel and a preparation method thereof, the specific steps of the preparation process are different from those of Example 2 in that: only rosin is contained in the adhesive; the rest are exactly the same.

[0084] Comparative Example 8

[0085] A biomass pellet fuel and a preparation method thereof, the specific steps of the preparation process are different from those of Example 2 in that: the adhesive contains only tower bottom heavy oil; the rest are exactly the same.

[0086] Comparative Example 9

[0087] A biomass pellet fuel and a preparation method thereof, the specific steps of the preparation process are different from those of Example 2 in that: the combustion aid is composed of magnesium oxide and aluminum oxide; the rest are exactly the same.

[0088] Comparative Example 10

[0089] A biomass pellet fuel and a preparation method thereof. The specific steps of the preparation process are different from those of Example 2 in that the combustion aid is composed of potassium permanganate and aluminum oxide; the rest are exactly the same.

[0090] Comparative Example 11

[0091] A biomass pellet fuel and a preparation method thereof, the specific steps of the preparation process are different from those of Example 2 in that: the combustion aid is composed of magnesium oxide and potassium permanganate; the rest are exactly the same.

[0092] Comparative Example 12

[0093] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: (3) the crushed solid powder is mixed evenly with 2.1 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1.5:1:2.5, and then subjected to steam explosion treatment, and heat-maintained and pressure-maintained treatment at a temperature of 135° C. and a pressure of 1.8 MPa for 10 minutes, and then discharged to normal temperature and pressure within 25 to 30 seconds to obtain steam explosion solid powder;

[0094] (4) The steam explosion solid powder and 4.2 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1 hour at a vacuum degree of 0.03 MPa and a temperature of 130°C. After that, they were pressed into a cylindrical structure of 5 to 6 cm at a temperature of 135°C and a pressure of 65 MPa. Then, the moisture-proof agent dispersion was sprayed on the cylindrical structure through a spraying process. After the spraying was completed, it was dried to obtain biomass pellet fuel; the rest was exactly the same.

[0095] Comparative Example 13

[0096] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: (3) during the stirring process, spraying a moisture-proof agent dispersion onto the crushed solid powder, stirring evenly and drying, then adding 2.1 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1.5:1:2.5, mixing evenly, and obtaining a mixed solid powder;

[0097] (4) The mixed solid powder and 4.2 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1 hour at a vacuum degree of 0.03 MPa and a temperature of 130°C. After that, it was pressed into a cylindrical structure of 5 to 6 cm by a molding machine at a temperature of 135°C and a pressure of 65 MPa to obtain biomass pellet fuel; the rest were exactly the same.

[0098] Comparative Example 14

[0099] A biomass pellet fuel and a preparation method thereof, wherein the specific steps of the preparation process are different from those of Example 2 in that: (1) 40 parts of corn cobs, 20 parts of corn stalks, 40 parts of cotton stalks, and 26.4 parts of tea seed cakes are crushed to pass through a 200-mesh sieve to obtain crushed solid powder, which is then subjected to steam explosion treatment, and heat-preserved and pressure-maintained for 10 minutes at a temperature of 135° C. and a pressure of 1.8 MPa, and then discharged to room temperature and pressure within 25 to 30 seconds to obtain steam explosion solid powder;

[0100] (3) During the stirring process, spray the moisture-proof agent dispersion onto the steam explosion solid powder, stir evenly and dry, then add 2.1 parts of a combustion aid composed of potassium permanganate, magnesium oxide and aluminum oxide in a mass ratio of 1.5:1:2.5, mix evenly to obtain a mixed solid powder;

[0101] (4) The mixed solid powder and 4.2 parts of an adhesive composed of rosin and tower bottom heavy oil in a mass ratio of 3.5:1 were stirred and mixed evenly, and then stirred for 1 hour at a vacuum degree of 0.03 MPa and a temperature of 130°C. After that, it was pressed into a cylindrical structure of 5 to 6 cm by a molding machine at a temperature of 135°C and a pressure of 65 MPa to obtain biomass pellet fuel; the rest were exactly the same.

[0102] Performance test: The biomass pellet fuels prepared in Examples 1 to 6 and Comparative Examples 1 to 12 were subjected to performance tests, and the moisture content of the biomass fuels was measured under a relative humidity of 80%. The results are shown in Table 1.

[0103] Table 1 Biomass pellet fuel properties

[0104]

[0105]

[0106] It can be found from Table 1 that in Example 2 of the present invention, compared with Comparative Example 1, the use of rapeseed cake can optimize the composition system of biomass pellet fuel and improve the calorific value and combustion efficiency of biomass pellet fuel; compared with Comparative Examples 2 to 5, the use of montmorillonite and lignin can further optimize the composition system of biomass pellet fuel. Montmorillonite is calcined by high-temperature and high-speed airflow, homogenized by high pressure, and then mixed with ethyl cellulose for ultrasonic treatment. Then, the moisture-proof agent is mixed with the biomass raw material and rapeseed cake, which has better barrier properties, so that the biomass pellet fuel has better moisture-proof effect, and the fuel quality is improved. In addition, montmorillonite is mixed in the biomass raw material to promote the expansion of the particles, improve the combustion efficiency, and have high thermal efficiency. At the same time, ethyl cellulose and adhesives work together to promote the raw materials to be more compact during combustion, the raw materials are not easy to disperse, and the combustion is more complete, thereby improving the fuel stability and calorific value; compared with Comparative Examples 6 to 8, the adhesive used is composed of rosin and The composition of the heavy oil at the bottom of the tower further optimizes the composition system of the biomass pellet fuel, so that the biomass particles can be closely combined together during the molding process to form a molded pellet fuel with a stable structure, and the presence of rosin further improves the moisture resistance of the biomass pellet fuel, and the synergy of the rosin and the heavy oil at the bottom of the tower further improves the calorific value and combustion performance of the biomass pellet fuel; compared with comparative examples 9 to 11, the combustion aid used is composed of potassium permanganate, magnesium oxide and aluminum oxide, which further improves the composition system of the biomass pellet fuel, so that the biomass pellet fuel has higher combustion efficiency and stability, and improves the overall calorific value of the biomass pellet fuel; compared with comparative examples 12 to 14, the biomass raw material, rapeseed cake, moisture-proof agent and flame retardant are mixed together and then subjected to steam explosion treatment, so that the biomass pellet fuel has more excellent combustion efficiency and high thermal efficiency, and at the same time improves the overall calorific value of the biomass pellet fuel.

[0107] In summary, the biomass pellet fuel composition system is optimized in Examples 1 to 6 of the present invention, using corn cobs, corn stalks, and cotton stalks as biomass raw materials, mixing the biomass raw materials, moisture-proof agents, combustion aids, adhesives, and rapeseed cakes, and effectively solving the problem of low combustion calorific value of biomass pellet fuels. The biomass pellet fuels have a more excellent moisture-proof effect, thereby improving the quality of the biomass pellet fuels.

[0108] 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.

[0109] 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 biomass pellet fuel, characterized in that: The invention comprises the following raw materials, calculated by weight percentage: 68-77% of biomass raw materials, 15-22% of tea seed cakes, 2-4.5% of moisture-proof agent, 1.5-2.5% of combustion aid and 3-4% of adhesive.

2. A biomass pellet fuel according to claim 1, characterized in that: The biomass raw materials include the following raw materials, calculated by weight: 30-50 parts of corn cobs, 15-25 parts of corn stalks, and 35-45 parts of cotton stalks.

3. The biomass pellet fuel according to claim 1, characterized in that: The combustion improver consists of potassium permanganate, magnesium oxide and aluminum oxide.

4. The biomass pellet fuel according to claim 1, characterized in that: The moisture-proof agent consists of montmorillonite and ethyl cellulose.

5. The biomass pellet fuel according to claim 1, characterized in that: The adhesive consists of rosin and tower bottom heavy oil.

6. A method for preparing biomass pellet fuel according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) crushing corn cobs, corn stalks, cotton stalks, and tea seed cakes until they pass through a 200-mesh sieve to obtain crushed solid powder; (2) calcining the montmorillonite under high-temperature and high-speed airflow, mixing with deionized water and subjecting to high-pressure homogenization to form a montmorillonite dispersion, adding ethyl cellulose to perform ultrasonic dispersion treatment, and stirring to obtain a moisture-proofing agent dispersion; (3) During the stirring process, spray the desiccant dispersion onto the crushed solid powder, stir evenly, dry, add a combustion aid, mix evenly, and then perform steam explosion treatment to obtain steam explosion solid powder; (4) The steam explosion solid powder and the adhesive are stirred and mixed, and then heated and stirred under vacuum, and then pressed and formed by a molding machine to obtain biomass pellet fuel.

7. The method for preparing biomass pellet fuel according to claim 6, characterized in that: In step (2), the calcination treatment is carried out at a temperature of 1100 to 1150° C., a gas flow rate of 5 to 10 m / s, and a time of 15 to 25 min; the high-pressure homogenization treatment is carried out at a pressure of 150 to 200 MPa and the treatment is circulated for 10 to 15 times.

8. The method for preparing biomass pellet fuel according to claim 6, characterized in that: In step (2), the ultrasonic treatment is carried out at an ultrasonic power of 400 to 500 W and for a time of 20 to 30 min.

9. The method for preparing biomass pellet fuel according to claim 6, characterized in that: In step (3), the steam explosion treatment is carried out at a temperature of 135-145° C. and a pressure of 1.8-2.2 MPa for 8-10 minutes, and then the steam is discharged to normal temperature and pressure within 25-30 seconds.

10. The method for preparing biomass pellet fuel according to claim 6, characterized in that: In step (4), the vacuum heating: the vacuum degree is 0.02-0.03 MPa, the temperature is 120-130° C., and the time is 1-2 h; Pressing: Extruding into a 5-6 cm cylindrical shape at a temperature of 125-135°C and a pressure of 65-70 MPa.

Images