A high-calorific-value biomass fuel from agricultural waste and its preparation method

Abstract

This invention provides a high-calorific-value biomass fuel made from agricultural waste and its preparation method, belonging to the field of biomass energy utilization technology. The biomass fuel comprises agricultural waste and cellulase or lignin; the amount of cellulase or lignin added is 0.5%-1.0% of the agricultural waste. The preparation method is as follows: the agricultural waste is dried and coarsely crushed, then sieved, magnetically separated, and air-separated before fine crushing to obtain powdered raw material; cellulase or lignin is added to the powdered raw material, mixed evenly, and then extruded to obtain the high-calorific-value biomass fuel. The preparation method of this invention employs a combination of two-stage crushing, multi-stage sieving, intelligent magnetic separation, and air separation, as well as multi-stage drying, intelligent moisture control, and dry-wet material ratio. The prepared biomass fuel has a stable calorific value and high energy density, significantly reduced pollutant emissions, strong agricultural waste digestibility, low raw material cost, and stable supply, thus promoting energy structure transformation.

Description

Technical Field

[0001] This invention belongs to the field of biomass energy utilization technology, and in particular relates to a high-calorific-value biomass fuel from agricultural waste and its preparation method. Background Technology

[0002] Biomass energy, as a clean and renewable energy source, is an important alternative to fossil fuels. Agricultural waste, as one of the core raw materials for biomass energy, is widely available and abundant. Its resource utilization is of great significance for reducing carbon emissions and realizing a circular economy in agriculture. Preparing agricultural waste into high-calorific-value biomass fuel is the mainstream method for achieving its efficient resource utilization. However, many technical bottlenecks still exist in the current preparation and application of agricultural waste biomass fuel, severely restricting its industrial development and efficient promotion.

[0003] On the one hand, the natural characteristics of agricultural waste raw materials bring multiple challenges to fuel preparation: the moisture content of agricultural waste raw materials is generally in the range of 30%-50%, far exceeding the 10%-15% required for biomass fuel pelleting. High moisture content not only leads to loose and unformed pellets during pelleting, resulting in insufficient strength and easy breakage of the finished product, but also makes the fuel extremely prone to mold and deterioration during storage, while directly reducing fuel combustion efficiency. On the other hand, agricultural waste raw materials are easily mixed with various impurities such as mud, sand, stones, and metals during collection, and the particle size distribution of the raw materials themselves is uneven. Untreated raw materials are directly fed into the process. The pelleting process significantly impacts the stability of the pelleting process. Different types of agricultural waste exhibit significant differences in fiber structure, fiber toughness, and other characteristics. Traditional pelleting equipment has fixed process parameters and structural designs, making it difficult to adapt to agricultural waste raw materials with different fiber characteristics, easily leading to inconsistent pelleting results. High-hardness impurities such as stones and metals contained in the raw materials will generate severe friction with core pelleting components such as ring dies and pressure rollers during the pelleting process, greatly accelerating the wear rate of these components. This results in a high frequency of replacement of core components, significantly increasing the equipment cost and production and maintenance cost of fuel preparation.

[0004] On the other hand, agricultural waste raw materials have a high ash content, with straw-type agricultural waste generally having an ash content exceeding 5%. Biomass fuel prepared from such raw materials is prone to coking and blockage in combustion equipment such as boilers and household stoves during the combustion application stage. This not only reduces the heat exchange efficiency of the combustion equipment and increases the difficulty of maintenance, but also directly leads to low fuel combustion efficiency, with the combustion efficiency of household stoves even being less than 60%. To achieve the same heating effect, the consumption of agricultural waste biomass fuel is 30% higher than that of coal, resulting in poor energy utilization economy. Furthermore, due to incomplete combustion, it produces harmful pollutants such as carbon monoxide and nitrogen oxides, causing both energy waste and environmental pollution problems, which does not meet the requirements for the application of clean energy.

[0005] In summary, the existing technology for preparing agricultural waste biomass fuel is unable to solve the problems of pelleting and equipment wear caused by the characteristics of raw materials. Moreover, the finished fuel has defects such as low combustion efficiency, high consumption, and high pollutant emissions. There is an urgent need to develop a high-calorific-value biomass fuel and its preparation method that are suitable for the characteristics of agricultural waste raw materials, break through the existing technological bottlenecks, and achieve efficient, low-cost preparation and clean and efficient combustion of agricultural waste biomass fuel. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies, this invention provides a high-calorific-value biomass fuel made from agricultural waste and its preparation method. This invention involves sequentially drying and crushing agricultural waste, then subjecting the crushed material to low-temperature fusion and granulation to obtain high-calorific-value pellet fuel. The prepared biomass fuel can be applied to biomass direct-fired power plants and combined heat and power projects, blended with coal, and used in steam boilers and hot water boilers in industries such as textiles, dyeing, chemicals, and food processing to replace coal and heavy oil. The combustion efficiency reaches over 85%, meeting environmental policy requirements. Furthermore, the core process of this invention has been domestically produced, resulting in low equipment failure rates and controllable maintenance costs. Compared to traditional incineration and landfill methods, this invention achieves resource recovery from agricultural waste, and pollutant emissions during combustion are significantly lower than those from coal.

[0007] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of the present invention: This invention provides a high-calorific-value biomass fuel made from agricultural waste, wherein the biomass fuel comprises agricultural waste and cellulase or lignin; The amount of cellulase or lignin added is 0.5%-1.0% of the agricultural waste.

[0008] The second technical solution of the present invention: The present invention also provides a method for preparing high-calorific-value biomass fuel from agricultural waste, comprising the following steps: (1) After drying, agricultural waste is coarsely crushed, then screened, magnetically separated and air-separated before fine crushing to obtain powdered raw materials; (2) Add cellulase or lignin to the powdered raw material, mix evenly and then extrude to obtain the high-calorific-value biomass fuel from agricultural waste.

[0009] Further, in step (1), the agricultural waste is mixed with the wet material at a mass ratio of 1:5; The moisture content of the wet material is >20%.

[0010] Furthermore, the drying in step (1) is carried out in a multi-stage drying process using a three-pass rotary drum or airflow dryer to reduce the moisture content of the agricultural waste from 30%-50% to 12%-15%; during the drying process, the moisture content of the agricultural waste is monitored in real time and linked with the three-pass rotary drum or airflow dryer to control the output moisture fluctuation to ≤2%.

[0011] Beneficial effects: This invention combines intelligent moisture monitoring and wet-dry ratio technology, and multi-stage drying avoids the damage to raw material fibers caused by single high-temperature drying. Intelligent monitoring provides real-time feedback of moisture data, and the linkage with wet-dry ratio technology can dynamically adjust the ratio of wet and dry materials to ensure the stability of raw material moisture content before molding.

[0012] Furthermore, the process of real-time detection of the moisture content of agricultural waste is achieved using an intelligent monitoring system, including sensors and control mechanisms; The sensor is a microwave moisture sensor (model MS-600), which is installed at the drying inlet, intermediate section, outlet, and raw material silo before forming. The monitoring locations are the drying inlet, the middle drying section, the drying outlet, and the raw material silo before molding; The control mechanism is a PLC control system (Siemens S7-200), with a data acquisition interval of 2 seconds and a response delay of ≤3 seconds; The specific implementation of the intelligent monitoring system is as follows: the sensor transmits the moisture data to the PLC control system in real time. When the moisture content is higher than 15%, the system automatically increases the drying temperature or reduces the feeding speed. When the moisture content is lower than 12%, the system automatically increases the wet material ratio or reduces the drying temperature. The system's response speed (such as data acquisition interval and adjustment delay time) and control accuracy experimental data are supplemented to verify the feasibility of moisture content fluctuation ≤2%. Preferably, when the moisture content of agricultural waste is >15%, the temperature is raised to 85 ℃ and the feeding speed is reduced to 1.0 t / h; when the moisture content is <12%, the wet-dry material ratio is adjusted to wet material:dry material = 1:5 and the temperature is lowered to 75 ℃.

[0013] Furthermore, the dried agricultural waste is stored in an intelligent warehousing system, which is designed to be moisture-proof, mildew-proof, and well-ventilated to ensure stable raw material quality.

[0014] Further, the coarse crushing in step (1) is to crush the particles to a particle size of ≤50mm at a rotation speed of 1450 rpm.

[0015] Further, the magnetic field strength of the magnetic separator in step (1) is 1000-1500 G, the operating speed is 0.5-1 m / s, and it removes hard impurities such as metal and sand, with an impurity removal rate of ≥95%. The blade gap and rotation speed are automatically adjusted according to the characteristics of the raw materials. The wind speed for the air separation is 8-15 m / s.

[0016] Furthermore, when the magnetic separation uses a drum-type magnetic separator (model CXG-800), the magnetic field strength is 1200 G, the drum speed is 30 rpm, and the belt running speed is 0.8 m / s; When the magnetic separation uses a suspended magnetic separator, the magnetic field strength is 1200 G and the belt speed is 0.8 m / s; The air separator uses a horizontal air separator (model FX-1200) with PLC automatic speed control (9 m / s for straw and 13 m / s for fruit pomace), and can run continuously for 72 hours without failure.

[0017] Further, the fine crushing in step (1) is to crush the particles to a particle size ≤ 6 mm at a rotation speed of 3000 rpm, with a fine crushing stator and rotor gap of 1 mm.

[0018] Beneficial Effects: This invention employs a combination of two-stage crushing, multi-stage screening, intelligent magnetic separation, and air separation. The two-stage crushing lays the foundation for subsequent impurity removal and drying. Coarse crushing reduces the raw material size to ≤50 mm, preventing excessively large materials from clogging the magnetic separator. Fine crushing ensures the raw material particle size is ≤6 mm, increasing the drying contact area and improving drying efficiency. The synergy between intelligent magnetic separation, air separation, and crushing processes is crucial because crushing exposes hidden metallic impurities. Magnetic separation removes these impurities promptly, preventing them from entering the fine crusher and exacerbating equipment wear. Air separation removes light impurities and sand generated during crushing, improving raw material purity and reducing the risk of clogging in subsequent forming molds.

[0019] Furthermore, the extrusion molding pressure in step (2) is 80-100 MPa, and the temperature is 100-120 ℃, ensuring that the particle density reaches 1.2-1.3 g / cm³. 3 Hardness ≥90%.

[0020] Furthermore, the extrusion molding process of this invention is carried out in a special mold, and the compression ratio is customized for different raw materials. The volume compression ratio is 1:8 for straw and 1:10 for fruit pomace. The diameter of the die hole is 8 mm. The special mold is a wear-resistant mold, preferably a 42CrMo alloy steel ring mold, equipped with a fully automatic lubrication system (lubricating oil type: L-AN46), and the ring mold life is ≥1500 hours.

[0021] Beneficial effects: In this invention, a special mold is combined with a pretreatment process. The pretreated raw material has uniform particle size and fewer impurities, which can make the mold bear force evenly and avoid excessive local wear. At the same time, the customized compression ratio is adapted to the fiber characteristics of different pretreated raw materials, which improves the molding rate. The wear-resistant mold can withstand the long-term wear of a small number of hard particles in the raw material, ensuring the stability of equipment operation and effectively extending the service life of the whole machine.

[0022] Furthermore, the product after extrusion molding in step (2) needs to be cooled and screened to ensure that the particle temperature is ≤35℃, and biomass fuel is obtained through screening.

[0023] The beneficial effects of this invention compared to the prior art are as follows: The biomass fuel prepared by this invention has a stable calorific value and high energy density: after compression molding, the pellet density reaches 1.1-1.3 g / cm³. 3 The pellet forming rate is ≥97%, an improvement of 9%-25% compared to existing technologies (72%-88%). The calorific value is stable at 3800-4200 kcal / kg, far exceeding that of loose agricultural waste (1500-2500 kcal / kg). The combustion efficiency is increased to over 85% (compared to only 30%-50% for traditional loose agricultural waste burning). Ease of use is improved: compared to loose agricultural waste, the pellet volume is reduced by 60%-80%, saving over 70% of storage space. The impurity removal rate is ≥95%, an improvement of 15%-35% compared to existing technologies (60%-80%). The moisture content fluctuation range is ≤1.5%, a reduction of 3.5%-6.5% compared to existing technologies (5%-8%). The ring die life is ≥1500 hours, an improvement of 2-4 times compared to existing technologies (300-500 hours).

[0024] This invention has a strong agricultural waste digestion capacity: 1 ton of straw can be made into 0.7-0.8 tons of biomass pellets. A pellet plant with an annual output of 10,000 tons can digest about 12,000-15,000 tons of agricultural waste annually. It can effectively solve the problem of open burning and random dumping of agricultural waste such as wheat and corn straw and fruit and vegetable processing residue in Shandong Province. The resource utilization rate of agricultural waste has been increased from 30% in the traditional treatment mode to more than 95%.

[0025] The biomass fuel prepared by this invention has significantly reduced pollutant emissions: compared to coal combustion, SO2 emissions during pellet combustion are ≤50 mg / m³. 3 (Coal combustion concentration: approximately 800-1500 mg / m³) 3 NO x Emissions ≤150 mg / m³ 3 (Coal combustion concentration: approximately 600-1000 mg / m³) 3 Dust emissions ≤30 mg / m³ 3 (Coal combustion concentration: approximately 300-500 mg / m³) 3 It contains no heavy metals or other harmful substances and meets the requirements of the national "Emission Standard for Air Pollutants from Boilers" (GB 13271-2014).

[0026] The process of this invention is adaptable to various agricultural wastes: through standardized processes such as pretreatment (crushing, impurity removal, drying), molding (extrusion / ring die granulation), cooling and screening, it can process a variety of agricultural wastes such as straw, rice husks, peanut shells, fruit pomace, and sawdust, with a raw material adaptability rate of over 90%. Furthermore, by adjusting parameters such as compression ratio and temperature, it can be adapted to the characteristics of different raw materials.

[0027] The raw materials for this invention are inexpensive and have a stable supply: agricultural waste resources are abundant, with straw, rice husks, and other raw materials purchased for approximately 200-400 yuan / ton, far lower than coal (800-1200 yuan / ton) and natural gas (3-4 yuan / m³). 3 Raw material costs account for 55%-65% of the total cost of pelleted materials, ensuring a stable supply of raw materials, further reducing procurement costs, solving the problem of agricultural waste pollution, replacing traditional agricultural waste incineration and landfill disposal methods, reducing emissions of pollutants such as PM2.5 and VOCs from open burning, and avoiding soil and water pollution caused by agricultural waste dumping, thus improving the rural ecological environment. Furthermore, it can promote energy structure transformation, serving as a renewable and clean energy source to replace fossil fuels, alleviating dependence on non-renewable resources such as coal and natural gas, and contributing to energy diversification, especially suitable for the clean energy substitution needs of industrial enterprises and industrial parks. In addition, this invention can promote synergistic soil improvement; the ash from pelleted material combustion is rich in minerals such as potassium, calcium, and phosphorus, which can be used as organic fertilizer (after harmless treatment) to improve soil fertility and realize a circular agricultural model of agricultural waste-energy-fertilizer. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0031] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0032] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0033] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0034] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0035] Example 1 A method for preparing high-calorific-value biomass fuel from agricultural waste includes the following steps: (1) Agricultural and forestry waste, urban greening waste and livestock and poultry manure (moisture content ≥20%) are fed into a three-pass rotary drum for multi-stage drying. The temperature gradient is controlled as follows: inlet 60 ℃, middle section 80 ℃ and outlet 70 ℃. During the drying process, an intelligent monitoring system is used to detect the moisture content of agricultural waste in real time and control the output moisture fluctuation ≤2%. After drying, the moisture content of the raw materials is reduced to below 12%-15%. The dried agricultural waste is stored in an intelligent storage system for later use.

[0036] (2) The dried raw material is fed into the feeding belt and sent to the coarse crusher. It is crushed by the hammer at a speed of 1450 rpm to a particle size of ≤50 mm. Then it is conveyed to the drum magnetic separator (model CXG-800) by the first belt conveyor. The belt running speed is 0.8 m / s. Magnetic separation is carried out at a magnetic field strength of 1200 G and a drum speed of 30 rpm. Metal impurities in the raw material are removed by adsorption. Then the magnetically separated raw material is sent into the air separation device. The air speed is adjusted to 10 m / s to separate and remove non-metallic impurities such as sand and gravel. After the air separation is completed, the raw material is fed into the fine crusher. The gap between the stator and the rotor is adjusted to 1 mm. After crushing at a speed of 3000 rpm, it passes through a sieve with a aperture of 6 mm to obtain powdered raw material with a particle size of ≤6 mm.

[0037] (3) Lignin was added to the above powdered raw materials at a rate of 0.8% of the total mass of the raw materials. After mixing evenly, the mixture was fed into a fuel pellet mill for extrusion pelleting. The low-temperature fusion temperature was 120 ℃, and the molding pressure was 80 MPa. The pellets were then fed into the molding host and extruded through an 8 mm die under the pushing and compression action of the screw. The finished pellets had a diameter of 8 mm and a length of 30 mm. Finally, the extruded finished products were fed into a cooler for cooling and screening to ensure that the pellet temperature was ≤35℃, thus obtaining high-calorific-value biomass fuel from agricultural waste. During the extrusion molding process, the pellet forming rate was 97%. The prepared biomass fuel was then burned, and its calorific value was 4000 kcal / kg, with an SO2 emission of 15 mg / m³. 3 .

[0038] Example 2 A method for preparing high-calorific-value biomass fuel from agricultural waste differs from Example 1 in that agricultural waste is replaced with 100 kg of corn stalks. The remaining preparation methods are the same as in Example 1. The calorific value of the prepared biomass fuel is 4120 kcal / kg.

[0039] Example 3 A method for preparing high-calorific-value biomass fuel from agricultural waste differs from Example 1 in that: the agricultural waste is replaced with a mixture of 150 kg of wheat straw with a moisture content of 35%, 42% corn straw, and 48% fruit pomace (the mass ratio of the three components is 1:1:1). The remaining preparation methods are the same as in Example 1. The calorific value of the prepared biomass fuel is 4080 kcal / kg.

[0040] Example 4 A method for preparing high-calorific-value biomass fuel from agricultural waste differs from Example 1 in that: the agricultural waste is replaced with a mixture of 120 kg of wheat straw with a moisture content of 35% and 48% fruit pomace (the mass ratio of the two is 2:3). The remaining preparation methods are the same as in Example 1. The calorific value of the prepared biomass fuel is 4100 kcal / kg.

[0041] Example 5 A method for preparing high-calorific-value biomass fuel from agricultural waste includes the following steps: (1) Agricultural and forestry waste, urban greening waste and livestock and poultry manure (moisture content ≥20%) are sent into the airflow drying equipment for multi-stage drying. The temperature gradient is controlled as follows: inlet 70 ℃, middle section 85 ℃ and outlet 80 ℃. During the drying process, an intelligent monitoring system is used to detect the moisture content of agricultural waste in real time and control the output moisture fluctuation ≤2%. After drying, the moisture content of the raw materials is reduced to below 15%. The dried agricultural waste is stored in the intelligent storage system for later use.

[0042] (2) The dried raw material is fed into the feeding belt and sent to the coarse crusher. It is crushed by the hammer at a speed of 1450 rpm to a particle size of ≤50 mm. Then it is conveyed to the suspended magnetic separator by the first belt conveyor. The belt running speed is 0.7 m / s. Magnetic separation is carried out under a magnetic field strength of 1300 G. Metal impurities in the raw material are removed by adsorption. Then the magnetically separated raw material is sent into the air separation device. The air speed is adjusted to 12 m / s to separate and remove non-metallic impurities such as sand and gravel. After the air separation is completed, the raw material is fed into the fine crusher. The gap between the stator and the rotor is adjusted to 1 mm. After crushing at a speed of 3000 rpm, it is passed through a sieve with a aperture of 6 mm to obtain powdered raw material with a particle size of ≤6 mm.

[0043] (3) Cellulase was added to the above-mentioned powdered raw materials at a rate of 1.0% of the total mass of the raw materials. After mixing evenly, the mixture was fed into a fuel pellet mill for extrusion pelleting. The low-temperature fusion temperature was 100 ℃, and the forming pressure was 90 MPa. The pellets then entered the forming host and were extruded through an 8 mm die under the pushing and compression action of the screw. The diameter of the finished pellets was 8 mm and the length was 30 mm. Finally, the extruded finished products were fed into a cooler for cooling and screening to ensure that the pellet temperature was ≤35 ℃, thus obtaining high-calorific-value biomass fuel from agricultural waste. During the extrusion molding process, the pellet forming rate was 96.5%. The prepared biomass fuel was burned, and its calorific value was 4050 kcal / kg, with an SO2 emission of 48 mg / m³. 3 .

[0044] Effect verification: (1) Effects of impurity removal rate, ash content and calorific value The impurity removal rate, particle ash content, and calorific value during the biomass fuel preparation process in Example 2 were tested. Simultaneously, 100 kg of corn stalks were treated using a combination of traditional single crushing, single drying, and non-magnetic air separation (as a control group). Before treatment, the corn stalks contained 0.8% metallic impurities and 2.3% sand and gravel impurities. After coarse crushing, magnetic separation, air separation, and fine crushing, tests showed that the total impurity removal rate was 95.7%, the particle ash content was 4.2%, and the calorific value of the prepared biomass fuel was 4120 kcal / kg. In contrast, the control group had an impurity removal rate of 72.1%, a particle ash content of 12.5%, and a calorific value of 3800 kcal / kg.

[0045] (2) Effects of moisture content control, molding rate and mold rate The moisture content, molding rate, and mold rate during the biomass fuel preparation process in Example 3 were tested. Simultaneously, a control group was prepared by treating 150 kg of a mixture of agricultural waste (wheat straw with a moisture content of 35%, corn straw with a moisture content of 42%, and fruit pomace with a mass ratio of 1:1:1) using a traditional single drying method without intelligent moisture monitoring and a proper wet-dry ratio. The results showed that the final raw material obtained using the method in Example 3 had a moisture content of 13.2%-14.5% (fluctuating by 1.3%), a molding rate ≥97%, and showed no mold growth after 3 months of storage. In contrast, the control group had a molding rate of 72%-88% and a mold rate of 15% after 3 months of storage.

[0046] (3) Verification of equipment stability and lifespan The stability and lifespan of the biomass fuel preparation process in Example 4 were verified. Simultaneously, a conventional pelleting method (control group) without a dedicated wear-resistant die and an automatic lubrication system was used to process 120 kg of mixed agricultural waste (wheat straw with a moisture content of 35%, fruit pomace with a moisture content of 48%, and a mass ratio of 2:3) of wheat straw and fruit pomace. The results showed that the equipment using the method in Example 4, after combining magnetic separation and air separation, operated without failure, with ring die wear ≤0.2 mm, reducing equipment maintenance frequency to 0.5 times per month. In contrast, the control group required equipment maintenance 2-3 times per month.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high calorific value biomass fuel from agricultural waste characterized in that, The biomass fuel comprises agricultural waste and cellulase or lignin; The cellulase or lignin is added in an amount of 0.5%-1.0% of the agricultural waste.

2. The method of claim 1, wherein the agricultural waste high-calorific value biomass fuel is prepared by the steps of: The method comprises the following steps: ​ (1) drying the agricultural waste, then coarsely crushing, screening, magnetic separation and air separation, and finely crushing to obtain a powder-like raw material; (2) adding cellulase or lignin to the powder-like raw material, uniformly mixing, and extruding to obtain the high-calorific-value biomass fuel.

3. The method for producing a high-calorific-value biomass fuel from agricultural waste according to claim 2, characterized by, In step (1), the wet material and the dry material are mixed at a mass ratio of 1:

5. The moisture content of the wet material is >20%.

4. The method of claim 2, wherein the agricultural waste high-calorific-value biomass fuel is prepared by the steps of: In step (1), the drying is carried out by using a three-return roller or air flow drying for multi-stage drying, so that the moisture content of the agricultural waste is reduced from 30%-50% to 12%-15%; the moisture content of the agricultural waste is detected in real time during the drying process, and the three-return roller or air flow drying is linked to control the moisture fluctuation of the discharged material to be ≤2%. ​ 5. The method of claim 2, wherein the agricultural waste high-calorific-value biomass fuel is prepared by the steps of: In step (1), the coarse crushing is carried out at a rotation speed of 1450 rpm to a particle size of ≤50 mm. ​ 6. The method of claim 2, wherein the agricultural waste high-calorific-value biomass fuel is prepared by the steps of: In step (1), the magnetic field strength of the magnetic separation is 1000-1500 G, and the running speed is 0.5-1 m / s. ​ The air speed of the air separation is 8-15 m / s.

7. The method of claim 2, wherein the agricultural waste high-calorific value biomass fuel is prepared by the steps of: In step (1), the fine crushing is carried out at a rotation speed of 3000 rpm to a particle size of ≤6 mm. ​ 8. The method of claim 2, wherein the agricultural waste high-calorific value biomass fuel is prepared by the steps of: In step (2), the pressure of the extrusion molding is 80-100 MPa, and the temperature is 100-120 ℃. ​

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