Eucommia ulmoides-wood tar biomass pellet fuel and preparation method thereof

Abstract

The invention discloses eucommia ulmoides-wood tar biomass pellet fuel and a preparation method thereof, and belongs to the technical field of biomass fuels, 54-86% by mass of eucommia ulmoides wood particles, 2-8% by mass of wood tar and 10-40% by mass of eucommia ulmoides wood charcoal are pressed at room temperature, and the purpose of preparing high-calorific-value pellet fuel with eucommia ulmoides wood as a base material is achieved. The prepared eucommia ulmoides-wood tar biomass fuel has a higher heat value, lower hygroscopicity and good mechanical strength during combustion, by adding the wood tar and the eucommia ulmoides wood charcoal, the physical stability of the eucommia ulmoides wood pellet fuel is remarkably improved, the high energy density of the biomass pellet fuel is ensured, and the biomass pellet fuel is suitable for industrial production. Therefore, the requirements of combustion application are met.

Description

Technical Field

[0001] The invention relates to the technical field of biomass fuels, and in particular to an eucommia-wood tar biomass particle fuel and a preparation method thereof. Background Art

[0002] Biomass energy is sustainable and has a broad resource base. The use of biomass fuel can reduce carbon dioxide emissions and is of great significance to alleviating the greenhouse effect and environmental pollution. However, when untreated biomass is used directly as fuel, it often has disadvantages such as low energy density, susceptibility to moisture, and inconvenient storage and transportation. Therefore, it is very important to properly pretreat and modify biomass.

[0003] Eucommia ulmoides is a common agricultural and forestry waste. Its wood is rich in cellulose and lignin. However, due to its loose original structure and high moisture content, its direct use as fuel has limitations. Wood tar is a liquid byproduct of biomass pyrolysis, usually rich in organic compounds such as phenols, aldehydes, acids, etc., with high calorific value and viscosity. However, due to the high oxygen content and high moisture content of wood tar, there are problems of incomplete combustion and low combustion efficiency when using it as fuel. In addition, wood tar has high chemical activity and complex composition, which makes it easy to deteriorate during storage and transportation.

[0004] The molding process of biomass pellet fuel is an effective way to increase the energy density of biomass, which can significantly improve the physical properties and combustion characteristics of the fuel. In the preparation process of pellet fuel, the molding pressure, temperature, and the type and amount of additives have a significant impact on the density, strength, and moisture resistance of the pellets. Through reasonable formulation optimization, the compressive strength, drop durability, and energy density of the pellet fuel can be greatly improved, making it more suitable for industrial applications and long-term storage. However, the existing biomass pellet fuel still has problems such as insufficient mechanical strength, poor durability, and the inability to further improve the calorific value. Summary of the invention

[0005] In view of the above problems, the present invention provides a eucommia-wood tar biomass pellet fuel and a preparation method thereof, which effectively solves the limitations of using eucommia wood as a fuel due to its loose original structure and high moisture content; the incomplete combustion and low combustion efficiency due to the high oxygen content and high moisture content of wood tar as a fuel; and the technical problems that existing biomass pellet fuels have low calorific value, durability and mechanical strength. At the same time, a eucommia-wood tar biomass fuel with high energy density, good moisture resistance, high durability and mechanical strength is provided.

[0006] The first object of the present invention is to provide a method for preparing eucommia-wood tar biomass pellet fuel, comprising the following steps: The following raw materials were weighed in percentage by mass: 54% to 86% of Eucommia ulmoides wood particles, 2% to 8% of wood tar, and 10% to 40% of Eucommia ulmoides wood charcoal, totaling 100%.

[0007] The eucommia wood particles, wood tar and eucommia wood charcoal in the above mass percentages are mixed at room temperature to obtain a mixture, and the mixture is pressurized to 60MPa-65MPa, pressed and dried to obtain eucommia-wood tar biomass pellet fuel.

[0008] As a preferred embodiment, the size of the Eucommia ulmoides wood particles is 0.1 mm to 0.3 mm, and the moisture content is 5% to 8%.

[0009] As a preferred embodiment, the pH value of the wood tar is 2-4 and the viscosity is 50 mm 2 / s~90mm 2 / s.

[0010] As a preferred embodiment, the preparation method of the Eucommia wood charcoal is: in a protective atmosphere with a flow rate of 100mL / min~120mL / min, the temperature of the Eucommia wood stem is raised to 480℃~500℃, and sintered for 1h~1.5h.

[0011] As a preferred embodiment, the pressing time is 1.3 min to 2.0 min.

[0012] As a preferred embodiment, the drying is performed at 50° C. to 60° C. for 4 h to 6 h.

[0013] As a preferred embodiment, the moisture content of the Eucommia ulmoides-wood tar biomass pellet fuel is 4% to 10%.

[0014] As a preferred embodiment, the pressure is increased to 60 MPa-65 MPa at a rate of 0.2 kN / s-0.3 kN / s.

[0015] The second object of the present invention is to provide an eucommia-wood tar biomass pellet fuel prepared by the above-mentioned preparation method of eucommia-wood tar biomass pellet fuel.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for preparing eucommia-wood tar biomass pellet fuel, which achieves the goal of preparing high calorific value pellet fuel using eucommia wood as a base material by pressing 54% to 86% eucommia wood particles, 2% to 8% wood tar and 10% to 40% eucommia wood charcoal at room temperature. The eucommia-wood tar biomass pellet fuel prepared by the present invention has higher calorific value, lower moisture absorption rate and good mechanical strength when burned. The present invention significantly improves the physical stability of the eucommia wood pellet fuel by adding wood tar and eucommia wood charcoal, ensures the high energy density of the biomass pellet fuel, and thus meets the needs of combustion applications.

[0017] The present invention is suitable for application scenarios such as clean energy production, industrial boiler combustion and household heating, and can achieve efficient utilization of biomass resources, providing a feasible and practical solution for the development and application of biomass fuels. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a comparison chart of the anti-drop resistance of the Eucommia-wood tar biomass pellet fuel prepared in Examples 1 to 8 of the present invention.

[0019] Figure 2 This is a density comparison chart of the Eucommia-wood tar biomass pellet fuel prepared in Examples 1 to 8 of the present invention and the pellet fuel prepared in Comparative Examples 1 to 3.

[0020] Figure 3 This is a comparison chart of the total calorific value of the Eucommia-wood tar biomass pellet fuel prepared in Examples 1 to 8 of the present invention and the pellet fuel prepared in Comparative Examples 1 to 3.

[0021] Figure 4 This is a comparison chart of the energy densities of the Eucommia-wood tar biomass pellet fuels prepared in Examples 1 to 8 of the present invention and the pellet fuels prepared in Comparative Examples 1 to 3.

[0022] Figure 5 This is a durability comparison chart of the Eucommia-wood tar biomass pellet fuel prepared in Examples 1 to 8 of the present invention and the pellet fuel prepared in Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is further described below in conjunction with specific examples, but the examples are not intended to limit the present invention. The following test methods and detection methods, unless otherwise specified, are conventional methods; the reagents and raw materials, unless otherwise specified, are commercially available.

[0024] In view of the above-mentioned technical problems when using Eucommia wood and wood tar as fuel, the direct use of Eucommia wood as fuel has limitations. Second, wood tar is a liquid byproduct of biomass pyrolysis, which has high calorific value and viscosity. However, due to the high oxygen content and high water content of wood tar, it will cause incomplete combustion and low combustion efficiency when used as fuel. Third, the existing biomass fuel particles have low calorific value, durability and mechanical strength. Based on the technical problems existing when using Eucommia wood and wood tar as fuel, the present invention provides an Eucommia-wood tar biomass pellet fuel and a preparation method thereof.

[0025] The technical solution of the present invention is described in detail below.

[0026] The present invention first provides a method for preparing eucommia-wood tar biomass pellet fuel, comprising the following steps: The following raw materials are weighed in mass percentage: 54% to 86% of eucommia wood particles, 2% to 8% of wood tar, and 10% to 40% of eucommia wood charcoal, totaling 100%. The physicochemical properties of the eucommia wood particles used in the present invention and the prepared eucommia wood charcoal are shown in Table 1.

[0027] The above mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal are mixed at room temperature to obtain a mixture, the mixture is pressurized to 60MPa-65MPa, pressed, and dried at 50°C-60°C for 4h-6h to obtain Eucommia-wood tar biomass pellet fuel.

[0028] Regarding the amount of the above raw materials, when the mass percentage of Eucommia wood particles is less than 54%, although the calorific value can be increased, it mainly affects the combustion stability and the physical properties of the particles. Too much wood tar may cause the particles to be too sticky, and too much charcoal may cause the combustion rate to be too fast or incomplete combustion. When the proportion of Eucommia wood particles is greater than 86%, the calorific value of the fuel may decrease and the combustion stability will also be affected. Lack of sufficient wood tar and charcoal will result in poor adhesion of the particles, resulting in poor particle formation and combustion efficiency.

[0029] For the above 60MPa~65MPa, if the pressure is less than 60MPa, the particles are poorly formed, have low density, are fragile, and burn incompletely; if the pressure is greater than 65MPa, the particles are too dense, have poor combustion performance, increase mechanical energy consumption, and increase particle brittleness.

[0030] Table 1 Physical and chemical properties of Eucommia ulmoides particles and Eucommia ulmoides biochar

[0031] In order to ensure the stability and complete combustion of pellet fuel, the size of the Eucommia wood particles is 0.1mm~0.3mm, and the moisture content is 5%~8%. If the size of the Eucommia wood particles is too large or too small, it will affect the molding, combustion and storage, resulting in unstable particles or incomplete combustion. If the moisture content is too low or too high, it will affect the adhesion and drying effect of the particles, and then affect the molding quality, combustion efficiency and storage stability.

[0032] It should be noted that the pH value of the wood tar is 2-4 and the viscosity is 50 mm 2 / s~90mm 2 / s. If the pH value of wood tar is less than 2 or greater than 4, it will affect the stability and combustion efficiency of the fuel. Too low a pH value will cause the chemical substances in the fuel to be unstable, affecting the energy release efficiency of the fuel. Too high a pH value will change the bonding properties of the fuel, reduce the strength of the particles, and thus affect the continuity and thermal efficiency of combustion. For the above-mentioned viscosity values, the viscosity is less than 50. Too low a viscosity will cause the particles to be not formed tightly enough and easily broken, affecting the combustion time and heat release of the particles. The viscosity is greater than 90. Too high a viscosity will cause the particles to be difficult to ignite during the combustion process, or to burn incompletely, resulting in more harmful emissions.

[0033] It should be noted that the preparation method of the Eucommia wood charcoal of the present invention is: in a protective atmosphere with a flow rate of 100mL / min~120mL / min, the temperature of the Eucommia wood stem is raised to 480℃~500℃, and sintered for 1h~1.5h.

[0034] It should be emphasized that the pressing time is 1.3min~2.0min. When the pressing time is controlled to 1.5min, the prepared Eucommia-wood tar biomass pellet fuel has better physical stability, high energy density, good moisture resistance, and higher durability and mechanical strength.

[0035] It should be noted that the moisture content of the Eucommia-wood tar biomass pellet fuel prepared by the present invention is 4% to 10%. If the moisture content is lower than 4%, the pellets will be brittle and the mechanical strength will be reduced, but the energy density will be higher, and the moisture resistance and durability will be better. If the moisture content is higher than 10%, the pellets will swell, deform, and mold, the combustion efficiency will be reduced, the moisture resistance and durability will be weakened, and the mechanical strength will be reduced.

[0036] In order to improve the molding strength and combustion characteristics of the Eucommia-wood tar biomass pellet fuel of the present invention, the pressure is increased to 60MPa~65MPa at a rate of 0.2kN / s~0.3kN / s. If the pressure increase rate is too slow, the fuel particles will be loose and the strength will be insufficient. The loose particles are easy to break, resulting in a decrease in the overall quality of the fuel particles and impaired fuel performance; if the pressure increase rate is too fast, there are fewer gaps between the raw materials in the fuel particles, and the combination is too tight. When the particles are burning, it is difficult for oxygen to enter the interior, resulting in incomplete combustion of the fuel particles, thereby generating less heat and even increasing the emission of harmful gases.

[0037] The technical effects of the present invention are described below through embodiments and comparative examples.

[0038] Example 1 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1.5 h to obtain Eucommia wood charcoal.

[0039] The following raw materials were weighed in mass percentage: 68% Eucommia wood particles, 2% wood tar, and 30% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles was 0.1 mm to 0.3 mm, and the moisture content was 6.6%. The pH value of the wood tar was 3.6, and the viscosity was 62 mm 2 / s.

[0040] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 60 MPa at a pressure increase rate of 0.25 kN / s, pressed for 1.5 min, and dried at 50° C. for 4 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 5.00%.

[0041] Example 2 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0042] The following raw materials were weighed in mass percentage: 58% Eucommia wood particles, 2% wood tar, and 40% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles was 0.1 mm to 0.3 mm, and the moisture content was 6.6%. The pH value of the wood tar was 3.6, and the viscosity was 62 mm 2 / s.

[0043] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 63 MPa at a pressure increase rate of 0.2 kN / s, pressed for 1.5 min, and dried at 55° C. for 5 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 4.45%.

[0044] Example 3 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0045] The following raw materials were weighed in mass percentage: 86% Eucommia wood particles, 4% wood tar, and 10% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles was 0.1 mm to 0.3 mm, and the moisture content was 6.6%. The pH value of the wood tar was 3.6, and the viscosity was 62 mm 2 / s.

[0046] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 60 MPa at a pressure increase rate of 0.3 kN / s, pressed for 1.5 min, and dried at 60° C. for 4 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 6.11%.

[0047] Example 4 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0048] Weigh the following raw materials in mass percentage: 76% Eucommia wood particles, 4% wood tar, and 20% Eucommia wood charcoal, a total of 100%; the size of the Eucommia wood particles is 0.1 mm to 0.3 mm, the moisture content is 6.6%, the pH value of the wood tar is 3.6, and the viscosity is 62 mm 2 / s.

[0049] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 64 MPa at a pressure increase rate of 0.2 kN / s, pressed for 1.5 min, and dried at 60° C. for 5 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 5.57%.

[0050] Example 5 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0051] The following raw materials were weighed in mass percentage: 64% Eucommia wood particles, 6% wood tar, and 30% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles was 0.1 mm to 0.3 mm, and the moisture content was 6.6%. The pH value of the wood tar was 3.6, and the viscosity was 62 mm 2 / s.

[0052] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 64 MPa at a pressure increase rate of 0.2 kN / s, pressed for 1.5 min, and dried at 60° C. for 5 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 5.05%.

[0053] Example 6 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0054] The following raw materials were weighed in mass percentage: 54% Eucommia wood particles, 6% wood tar, and 40% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles was 0.1 mm to 0.3 mm, and the moisture content was 6.6%. The pH value of the wood tar was 3.6, and the viscosity was 62 mm 2 / s.

[0055] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 64 MPa at a pressure increase rate of 0.2 kN / s, pressed for 1.5 min, and dried at 60° C. for 5 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 4.51%.

[0056] Example 7 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0057] The following raw materials were weighed in mass percentage: 82% Eucommia wood particles, 8% wood tar, and 10% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles was 0.1 mm to 0.3 mm, and the moisture content was 6.6%. The pH value of the wood tar was 3.6, and the viscosity was 62 mm2 / s.

[0058] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 64 MPa at a pressure increase rate of 0.2 kN / s, pressed for 1.5 min, and dried at 60° C. for 5 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 6.17%.

[0059] Example 8 A method for preparing eucommia-wood tar biomass pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1 h to obtain Eucommia wood charcoal.

[0060] Weigh the following raw materials in mass percentage: 72% Eucommia wood particles, 8% wood tar, and 20% Eucommia wood charcoal, totaling 100%; the size of the Eucommia wood particles is 0.1 mm to 0.3 mm, and the moisture content is 6.6%. The pH value of the wood tar is 3.6, and the viscosity is 62 mm 2 / s.

[0061] The above-mentioned mass percentages of Eucommia wood particles, wood tar and Eucommia wood charcoal were mixed at room temperature to obtain a mixture, and the mixture was pressurized to 64 MPa at a pressure increase rate of 0.2 kN / s, pressed for 1.5 min, and dried at 60° C. for 5 h to obtain Eucommia-wood tar biomass pellet fuel with a moisture content of 5.62%.

[0062] In order to further illustrate the effect of the present invention, the present invention also provides a comparative example, which is as follows: Comparative Example 1 Compared with Example 1, the difference is that no wood tar and Eucommia ulmoides wood charcoal are added, and only Eucommia ulmoides wood particles are used.

[0063] A method for preparing eucommia wood pellet fuel comprises the following steps: Weigh the same mass of eucommia wood particles as the total mass of wood tar, eucommia wood charcoal and eucommia wood particles in Example 1. The eucommia wood particles have a size of 0.1 mm to 0.3 mm and a moisture content of 6.6%.

[0064] The eucommia wood particles were pressurized to 60 MPa at a pressure increase rate of 0.25 kN / s at room temperature, pressed for 1.5 minutes, and dried at 50° C. for 4 hours to obtain eucommia wood pellet fuel with a moisture content of 5.00%.

[0065] Comparative Example 2 Compared with Example 1, the difference is that no wood tar and Eucommia ulmoides wood particles are added, and only Eucommia ulmoides wood charcoal is used.

[0066] A method for preparing eucommia wood charcoal pellet fuel comprises the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1.5 h to obtain Eucommia wood charcoal.

[0067] Weigh the same mass of eucommia wood charcoal as the total mass of wood tar, eucommia wood charcoal and eucommia wood particles in Example 1, pressurize the eucommia wood charcoal to 60 MPa at a pressurization rate of 0.25 kN / s at room temperature, press for 1.5 min, and dry at 50° C. for 4 h to obtain eucommia wood charcoal pellet fuel with a moisture content of 5.00%.

[0068] Comparative Example 3 Compared with Example 1, the difference is that no wood tar is added, and only Eucommia ulmoides wood particles and Eucommia ulmoides wood charcoal are used.

[0069] A method for preparing eucommia wood particles-eucommia wood charcoal particle fuel, comprising the following steps: In a protective atmosphere with a flow rate of 100 mL / min, the temperature of the Eucommia wood stem was raised to 500° C. and sintered for 1.5 h to obtain Eucommia wood charcoal.

[0070] The following raw materials were weighed in mass percentage: 90% of Eucommia ulmoides wood particles and 10% of Eucommia ulmoides wood charcoal, which totaled 100%; the Eucommia ulmoides wood particles had a size of 0.1 mm to 0.3 mm and a moisture content of 6.6%.

[0071] The above mass percentages of eucommia wood particles and eucommia wood charcoal were mixed at room temperature to obtain a mixture, which was pressurized to 60 MPa at a pressure increase rate of 0.25 kN / s, pressed for 1.5 min, and dried at 50° C. for 4 h to obtain eucommia wood particles-eucommia wood charcoal pellet fuel with a moisture content of 5.00%.

[0072] The performances of the Eucommia ulmoides-wood tar biomass pellet fuel provided in Examples 1 to 8, the Eucommia ulmoides wood pellet fuel of Comparative Example 1, the Eucommia ulmoides wood charcoal pellet fuel of Comparative Example 2, and the Eucommia ulmoides wood pellet-Eucommia ulmoides wood charcoal pellet fuel provided in Comparative Example 3 were tested respectively, and the results are shown in Table 2.

[0073] Table 2 Performance comparison of the pellet fuels of the embodiments of the present invention and the comparative examples

[0074] “-” means it cannot be measured.

[0075] From Table 1 and Figure 1~Figure 5It can be seen that the Eucommia-wood tar biomass pellet fuel prepared in the embodiment of the present invention has a better energy density, good moisture absorption rate, high durability and mechanical strength. The density of the Eucommia-wood tar biomass pellet fuel obtained in Examples 1 to 8 of the present invention can reach 0.91 g / cm 3 , anti-drop resistance can reach 82.47%, heat can reach 20.54MJ / kg, energy density can reach 18.96GJ / m 3 , the durability can reach 96.20%. The present invention significantly improves the physical stability of single Eucommia wood particles as fuel by adding wood tar and Eucommia wood charcoal to Eucommia wood particles, ensuring the high energy density of biomass pellet fuel, while Comparative Examples 1 to Comparative Examples 3 are pellet fuels prepared by using only Eucommia wood particles, only Eucommia wood charcoal, and only Eucommia wood particles and Eucommia wood charcoal, respectively, and their performance has certain deficiencies in some aspects, and the specific reasons are analyzed as follows.

[0076] The performance of the Eucommia wood pellet fuel of Comparative Example 1, the Eucommia wood charcoal pellet fuel of Comparative Example 2 and the Eucommia wood pellet-Eucommia wood charcoal pellet fuel provided in Comparative Example 3 is poor, and the main reasons are: In comparative example 1, pure Eucommia ulmoides wood particles are used, and the raw materials are not carbonized, and the natural lignin is retained to play a bonding role, making the particle structure stable and durable. Moreover, it cannot be fully burned during combustion, resulting in low calorific value and limited combustion release energy, which is difficult to meet the demand for efficient fuel.

[0077] In Comparative Example 2, pure Eucommia ulmoides carbon particles were used. The raw materials were carbonized at high temperature to significantly increase the calorific value, but all the lignin was lost, the natural bonding effect was lost, the particles were brittle, the mechanical strength was greatly reduced, and the durability was reduced.

[0078] In Comparative Example 3, a mixture of Eucommia ulmoides particles and Eucommia ulmoides charcoal is used, aiming to take into account both calorific value and particle adhesion. However, due to the lack of wood tar assistance, the combustion is not fully achieved. Compared with Comparative Example 3, the purpose of adding wood tar is to improve combustion efficiency and increase adhesion.

[0079] In summary, the eucommia-wood tar biomass pellet fuel prepared by the present invention has higher calorific value, lower moisture absorption rate and good mechanical strength when burned. The present invention significantly improves the physical stability of the eucommia wood pellet fuel by adding wood tar and eucommia wood charcoal, ensures the high energy density of the biomass pellet fuel, thereby meeting the needs of combustion applications and having strong practicality.

[0080] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing Eucommia ulmoides-wood tar biomass pellet fuel, characterized in that: The following steps are involved: Weigh the following raw materials in percentage by mass: 54% to 86% of Eucommia wood particles, 2% to 8% of wood tar, and 10% to 40% of Eucommia wood charcoal, a total of 100%; The eucommia wood particles, wood tar and eucommia wood charcoal are mixed at room temperature to obtain a mixture, and the mixture is pressurized to 60MPa-65MPa, pressed, and dried to obtain eucommia-wood tar biomass pellet fuel.

2. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The pH value of the wood tar is 2-4 and the viscosity is 50 mm 2 / s~90mm 2 / s.

3. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The preparation method of the Eucommia ulmoides wood charcoal is as follows: in a protective atmosphere with a flow rate of 100 mL / min to 120 mL / min, the temperature of the Eucommia ulmoides wood stem is raised to 480° C. to 500° C., and the charcoal is sintered for 1 h to 1.5 h.

4. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The size of the Eucommia ulmoides wood particles is 0.1 mm to 0.3 mm, and the moisture content is 5% to 8%.

5. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The pressing time is 1.3min~2.0min.

6. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The drying is carried out at 50° C. to 60° C. for 4 h to 6 h.

7. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The moisture content of the Eucommia ulmoides-wood tar biomass pellet fuel is 4% to 10%.

8. The method for preparing the Eucommia ulmoides-wood tar biomass pellet fuel according to claim 1, characterized in that: The pressure is increased to 60MPa~65MPa at a rate of 0.2kN / s~0.3kN / s.

9. Eucommia ulmoides-wood tar biomass pellet fuel prepared by the preparation method according to any one of claims 1 to 8.

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