A kind of civil biomass charcoal and its preparation method

Abstract

The present invention relates to a kind of civil biomass charcoal and its preparation method, specifically to the technical field of biomass charcoal preparation. The civil biomass charcoal uses biomass as raw material, first obtains carbide through catalytic conversion, then forms the carbide into charcoal rods, and finally mixes the charcoal rods with a tar cracking agent and obtains the product after treatment by microwave, ultrasonic and electric assisted heating. Among them, the tar cracking agent is any one of bagasse biochar, reed biochar or coconut shell biochar. The biomass charcoal prepared by the present invention has low volatile content and good product quality, and can be used as barbecue charcoal. In addition, in terms of the preparation method, the present invention uses the synergistic deep processing of microwave heating, electric assisted heating and ultrasonic to prepare biomass charcoal from carbide, which is different from traditional earth kiln production and fixed bed pyrolysis carbonization technology, and has the advantages of high-efficiency heating, enhanced reaction efficiency, improved product yield and quality, energy conservation and environmental protection, etc., and has good application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass carbon preparation, and particularly relates to a civilian biomass carbon and a preparation method thereof. Background Art

[0002] Biomass carbon is a carbon-rich solid material made from carbon-containing substances, such as biomass materials like wood chips, straws or bamboos, through carbonization pyrolysis under anaerobic or low-oxygen conditions. Currently, the carbonization process of biomass carbon mostly adopts traditional earth kiln production or fixed-bed pyrolysis carbonization technology.

[0003] Traditional earth kiln carbonization furnaces have very strict requirements for fire control during the combustion process. And since the kiln bodies are mostly made of red bricks and generally have a large volume, hard logs are mostly used for charcoal burning, which not only causes serious waste of resources, but also has poor labor conditions, high intensity, long production cycles, and serious pollution during the production process. It is impossible to pyrolyze and carbonize the abundant biomass raw materials such as a large amount of rural waste straws and rice straws. The fixed-bed pyrolysis carbonization technology arranges different numbers of high-temperature heat pipes at different positions and uses the isothermal property of the heat pipes to achieve the purpose of carbon production. However, due to the generation of a large amount of tar and the escape of volatile gases, the biochar yield is low, the pipes are easily blocked, and the process implementation is difficult and thus it is difficult to promote. It can be seen that the current biomass carbon preparation process has problems such as low yield, poor carbonization quality, low calorific value of combustion, high energy consumption and environmental pollution caused by traditional methods.

[0004] Currently, biomass carbon is widely used in fields such as civilian fuels, soil improvement, pollution plasmid and energy storage. Among them, biomass carbon can be used as barbecue charcoal in the civilian fuel field. Barbecue charcoal has relatively strict standards in terms of calorific value, safety, combustion characteristics such as smokeless and odorless, and stable and lasting combustion compared with other civilian fuels, which also puts forward more stringent requirements for the biomass carbon preparation process. Summary of the Invention

[0005] The purpose of the present invention is to provide a civilian biomass carbon and a preparation method thereof in order to solve the above problems.

[0006] The present invention realizes the above purpose through the following technical solutions:

[0007] In the first aspect of the present invention, a civilian biomass carbon is provided. The civilian biomass carbon uses biomass as a raw material, first undergoes catalytic conversion to obtain a carbide, then forms the carbide into a carbon rod, and finally mixes the carbon rod with a tar cracking agent and obtains it after being treated by microwave, ultrasonic and electric auxiliary heating.

[0008] As a further optimized scheme of the present invention, the biomass is any one of bamboo blocks, wood blocks, corn straws or cotton straws.

[0009] As a further optimized solution of the present invention, the biochar is any one of bamboo chip biochar, wood chip biochar, bagasse biochar, reed biochar, coconut shell biochar or walnut shell biochar.

[0010] In the second aspect of the present invention, a preparation method of civil biomass carbon is further provided, including the following steps:

[0011] (1) Catalytically convert the biomass to obtain carbide;

[0012] (2) First crush the carbide obtained in step (1), and then mix and stir the crushed carbide with a binder, a surfactant and water according to the formula amount to make rods to obtain carbon rods;

[0013] (3) Under an inert gas atmosphere, mix the carbon rods obtained in step (2) with a tar cracking agent and then use three heating methods of microwave, ultrasonic and electric-assisted heating for deep processing, and then cool down to obtain civil biomass carbon.

[0014] As a further optimized solution of the present invention, step (1) is specifically: cut the biomass into sections and send it into a carbonization furnace, heat the temperature in the carbonization furnace to 200-300 °C by steam heating, then add a catalyst, and carbonize for 2h-3h under an inert gas atmosphere to obtain carbide.

[0015] As a further optimized solution of the present invention, in step (2), the mass ratio between the carbide, the binder and the surfactant is 9.2:0.3-1.0:0.1-0.3.

[0016] As a further optimized solution of the present invention, in step (3), the dosage of the tar cracking agent is determined according to the tar content to be cracked in the carbide, and the mass ratio of the tar cracking agent to the tar is 1:1-3.

[0017] As a further optimized solution of the present invention, the inert gas atmosphere is any one of nitrogen atmosphere, helium atmosphere, neon atmosphere or argon atmosphere.

[0018] As a further optimized solution of the present invention, step (3) is specifically: mix the carbon rods obtained in step (2) with a tar cracking agent and then send them into a carbonization furnace, use three heating methods of microwave, ultrasonic and electric-assisted heating to first heat the temperature in the furnace to 180-200 °C, then introduce an inert gas into the carbonization furnace to make the sealed space in the furnace in an oxygen-deficient environment, continue heating to raise the temperature in the furnace to 450-500 °C, stop heating, and cool down.

[0019] As a further optimization scheme of the present invention, the microwave power is 500W - 100KW, the ultrasonic power is 500W - 20KW, and the electric auxiliary heating power is 1KW - 100KW.

[0020] Therefore, the beneficial effects of the present invention are as follows:

[0021] The biomass charcoal provided by the present invention is obtained by first catalytically converting biomass to obtain carbide, then forming the carbide into carbon rods, and finally mixing the carbon rods with a tar cracking agent and treating them with microwave, ultrasonic and electric auxiliary heating.

[0022] First of all, by adopting the synergistic action of microwave, ultrasonic and electric auxiliary heating, the present invention can achieve the following advantages: (1) High - efficiency heating and uniformity: The combination of the rapidity and selectivity of microwave heating and the uniformity of electric auxiliary heating can further optimize the temperature field in the furnace, ensuring more uniform heating of the material; (2) Enhanced reaction efficiency: The synergistic effect of the cavitation effect of ultrasonic and the heating effect of microwave can significantly improve the heat and mass transfer efficiency, accelerate the carbonization reaction, and increase the product yield; (3) Improved product quality: Through the dispersion effect of ultrasonic and the uniform heating of microwave, not only can local overheating or over - cooling be effectively avoided, ensuring the stable quality of biomass charcoal, but also the volatile matter in biomass charcoal can be effectively reduced, enhancing the calorific value of biomass charcoal for combustion; (4) Energy conservation and environmental protection: The high efficiency of microwave heating and the rapid heating ability of electric auxiliary heating, combined with the dispersion effect of ultrasonic, can reduce energy consumption and lower production costs.

[0023] Secondly, by selecting bagasse biochar, reed biochar or coconut shell biochar as the tar cracking agent and mixing it with the carbon rods for further processing, the present invention can further reduce the volatile matter in biomass charcoal and improve the quality of biomass charcoal, making it better applicable to the field of civil fuel. Description of the Drawings

[0024] Figure 1 The civil biomass charcoal prepared from bamboo sections as raw materials provided by the embodiment of the present invention;

[0025] Figure 2 The influence of different further - processing heating treatment methods provided by the present invention on the quality performance of civil biomass charcoal. In the figure, A is the total moisture; B is the fixed carbon; C is the ash; D is the volatile matter;

[0026] Figure 3 The influence of different further - processing heating treatment methods provided by the present invention on the yield of civil biomass charcoal;

[0027] Figure 4The effects of the use of different types of tar cracking agents provided by the present invention on the quality and performance of civilian biomass charcoal. In the figure, A is the total moisture; B is the fixed carbon; C is the ash; D is the volatile matter. Detailed implementation manners

[0028] The following further describes the present application in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation manners are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0029] The civilian biomass charcoal disclosed by the present invention uses biomass as the raw material, first obtains carbide through catalytic conversion, then forms the carbide into carbon rods, and finally mixes the carbon rods with a tar cracking agent and obtains the product after treatment with microwave, ultrasonic and electric-assisted heating.

[0030] In the present invention, the biomass is selected as forest wood blocks or crop straws; the tar cracking agent is selected as any one of bamboo biochar, wood biochar, bagasse biochar, reed biochar, coconut shell biochar or walnut shell biochar.

[0031] The specific preparation method is as follows:

[0032] (1) Cut and catalytically convert the biomass to obtain carbide; specifically, cut the biomass and send it into a carbonization furnace, heat the temperature in the carbonization furnace to 200 - 300 °C through steam heating, then add a catalyst, and carbonize for 2 h - 3 h in an inert gas atmosphere. The inert gas atmosphere is any one of nitrogen atmosphere, helium atmosphere, neon atmosphere or argon atmosphere, and the catalyst is any one of polymaleic acid, hydrochloric acid, sodium hydroxide or potassium hydroxide, but not limited to this. The dosage of the catalyst accounts for 3% of the mass of the biomass raw material.

[0033] (2) First crush the carbide obtained in step (1), pass through a 100-mesh sieve, and then mix and stir the crushed carbide with an adhesive, a surfactant and water according to a mass ratio of 9.2:0.3 - 1.0:0.1 - 0.3 to make a carbon rod.

[0034] (3) Deep-process the carbon rod obtained in step (2).

[0035] Specifically, mix the carbon rod obtained in step (2) with a tar cracking agent and send it into a carbonization furnace. Use three heating methods of microwave, ultrasonic and electric-assisted heating to first raise the temperature in the furnace to 180 - 200 °C, then introduce an inert gas into the carbonization furnace to make the sealed space in the furnace in an anoxic environment, continue heating to raise the temperature in the furnace to 450 - 500 °C, stop heating, and cool down to obtain the civilian biomass charcoal.

[0036] Furthermore, the dosage of the tar cracking agent is determined according to the tar content to be cracked in the carbide, usually tar cracking agent: tar = 1: 1 - 3.

[0037] Furthermore, the microwave power is 500W - 100KW, the ultrasonic power is 500W - 20KW, and the electric auxiliary heating power is 1KW - 100KW. The magnitudes of the microwave power, ultrasonic power, and electric auxiliary heating power are adjusted according to the required heating rate and heating time of the furnace temperature. The inert gas is any one of nitrogen, helium, neon, or argon.

[0038] In the deep - processing process, firstly, microwave heating can greatly shorten the carbonization time compared with traditional kiln - type carbonization. On the other hand, microwave heating has low heat loss and high thermal energy utilization rate, enabling the heated substance to be heated from the inside and outside together, avoiding the cold - center phenomenon caused by traditional heating. Secondly, electric auxiliary heating can directly increase the temperature inside the furnace body with high thermal efficiency. In the preparation process of biomass charcoal, using an electric heating device can quickly reach the set temperature in the carbonization furnace, shorten the pre - heating time, and improve production efficiency. Electric heating can also achieve overall uniform heating or local heating according to the actual process requirements of heating. In the carbonization furnace, by reasonably arranging the electric heating elements, the materials in the furnace can be heated more evenly, avoiding inconsistent biomass charcoal quality caused by local overheating or overcooling, thereby improving the stability of product quality. Finally, the high - frequency vibration of ultrasonic waves can generate local high temperature and high pressure in the carbon material, breaking the intermolecular forces such as van der Waals forces between particles, so that the particles are more evenly dispersed, facilitating more sufficient heating during the subsequent heating process and higher carbonization efficiency.

[0039] The reference standard for the quality evaluation of biomass charcoal is the group standard "Charcoal for Barbecue" (T / CNFPIA 3025 - 2022), and the specific evaluation indicators are shown in Table 1.

[0040] Table 1. Evaluation indicators

[0041] ;

[0042] The beneficial effects of the present invention are illustrated by the following specific examples.

[0043] Example 1

[0044] The preparation method of the civil biomass charcoal provided in this example includes the following steps:

[0045] (1) Cut the moso bamboo into sections and crush them into flaky moso bamboo slices, then send them into the carbonization furnace. After closing the furnace door, set the temperature to rise to 300 °C, heat up by steam heating, and add a catalyst (dosage accounts for 3% of the mass of moso bamboo) to increase the reaction rate and reduce the heating time. After carbonizing for 2 h under a nitrogen atmosphere, cool down and take out the materials to obtain the carbide.

[0046] (2) Transfer 10 kg of the prepared carbide to a crusher, crush and sieve it into particles smaller than 100 mesh. Weigh the crushed carbide particles, water, binder, surfactant, etc. according to a mass ratio of 9.2:0.3:0.1. Pour the measured raw and auxiliary materials into a blender, set the blender frequency for stirring, put the stirred material into a rod-making machine, set the rod-making machine frequency to 45 Hz, and increase the propulsion speed of the screw propeller to make the carbon rod more compact after rod forming.

[0047] (3) Mix the carbon rod obtained in step (2) with bamboo chip biochar and send it into a carbonization furnace. The dosage of bamboo chip biochar is determined according to the tar content to be cracked in the carbide. Bamboo chip biochar:tar = 1:1. Use three heating methods of microwave, ultrasonic and electric-assisted heating to first raise the temperature in the furnace to 180 °C, then introduce nitrogen into the carbonization furnace to make the sealed space in the furnace in an oxygen-deficient environment, eliminate the interference of oxygen, continue heating to raise the temperature in the furnace, the heating-up time is 1 h, after raising the temperature to 450 °C and stabilizing, stop heating and cooling to obtain civilian biomass carbon, as Figure 1 shown.

[0048] Example 2

[0049] The preparation method of the civilian biomass carbon provided in this example includes the following steps:

[0050] (1) Cut the wooden blocks into sections and send them into a carbonization furnace. After closing the furnace door, set the temperature to rise to 200 °C, heat up by steam heating, and add a catalyst (the dosage accounts for 3% of the mass of the wooden blocks) to increase the reaction rate and reduce the heating-up time. Carbonize for 3 h under a nitrogen atmosphere, then cool down and take out the material to obtain carbide.

[0051] (2) Take 10 kg of the prepared carbide and transfer it to a crusher to crush and sieve it into particles smaller than 100 mesh. Weigh the crushed carbide particles, water, binder, surfactant, etc. according to a mass ratio of 9.2:1.0:0.3. Pour the measured raw and auxiliary materials into a blender, set the blender frequency for stirring, put the stirred material into a rod-making machine, set the rod-making machine frequency to 45 Hz, and increase the propulsion speed of the screw propeller to make the carbon rod more compact after rod forming.

[0052] (3) Feed the carbon rods and wood chip biochar obtained in step (2) into a carbonization furnace. The dosage of wood chip biochar is determined according to the tar content to be cracked in the carbonized product. Wood chip biochar:tar = 1:2. Use three heating methods, namely microwave, ultrasonic and electric-assisted heating, to first raise the temperature in the furnace to 200 °C, then introduce nitrogen into the carbonization furnace to make the sealed space in the furnace in an anoxic environment, eliminate the interference of oxygen, continue heating to raise the temperature in the furnace, with a heating-up time of 1 h. After stabilizing at 500 °C, stop heating and cool down to obtain civil biomass charcoal.

[0053] Example 3

[0054] The preparation method of the civil biomass charcoal provided in this example includes the following steps:

[0055] (1) Cut the corn straw into sections and feed it into a carbonization furnace. After closing the furnace door, set the temperature to rise to 200 °C, heat up by steam, and add a catalyst (the dosage accounts for 3% of the mass of the corn straw). Carbonize for 3 h under a nitrogen atmosphere, then cool down and take out the material to obtain the carbonized product.

[0056] (2) Take 10 kg of the prepared carbonized product and transport it to a crusher to crush and sieve it into particles smaller than 100 mesh. Weigh the crushed carbonized product particles, water, binder, surfactant, etc. according to a mass ratio of 9.2:0.6:0.2. Pour the measured raw and auxiliary materials into a mixer, set the mixer frequency for stirring, and put the stirred material into a rod-making machine. Set the rod-making machine frequency at 45 Hz and increase the propulsion speed of the screw propeller to make the carbon rods more compact after rod forming.

[0057] (3) Mix the carbon rods obtained in step (2) with bagasse biochar and feed them into a carbonization furnace. The dosage of bagasse biochar is determined according to the tar content to be cracked in the carbonized product. Bagasse biochar:tar = 1:3. Use three heating methods, namely microwave, ultrasonic and electric-assisted heating, to first raise the temperature in the furnace to 190 °C, then introduce nitrogen into the carbonization furnace to make the sealed space in the furnace in an anoxic environment, eliminate the interference of oxygen, continue heating to raise the temperature in the furnace, with a heating-up time of 1 h. After stabilizing at 470 °C, stop heating and cool down to obtain civil biomass charcoal.

[0058] Example 4

[0059] The difference between the preparation method of the civil biomass charcoal provided in this example and Example 1 is that the biomass raw material used is cotton straw and the tar cracking agent used is reed biochar.

[0060] Verification test

[0061] 1. Influence of different deep processing heating methods on the quality performance of civil biomass charcoal.

[0062] According to the method for preparing civil biomass charcoal disclosed in Example 1, biomass charcoal was prepared by adjusting different deep-processing heating treatment means according to Table 2.

[0063] Table 2. Different deep-processing heating treatment methods

[0064] ;

[0065] Note: "+" indicates that this treatment was carried out; "-" indicates that this treatment was not carried out.

[0066] The industrial analysis of the biomass charcoal prepared from treatment groups A-1 to A-7 was carried out with reference to the group standard of "Charcoal for Barbecue" (T / CNFPIA 3025-2022). The industrial analysis data of the biomass charcoal prepared from treatment groups A-1 to A-7 are shown in Table 3, Figure 2 as shown below.

[0067] Table 3. Statistical table of industrial analysis data

[0068] ;

[0069] As can be seen from Table 3, different deep-processing heating treatment methods have an impact on the quality of the prepared biomass charcoal. By comparing treatment groups A-1 with A-3, A-4, A-4, and A-5, it can be seen that microwave heating treatment and ultrasonic heating treatment have a positive effect on reducing the volatile matter in the biomass charcoal. By comparing treatment group A-1 with A-2, it can be seen that although the electric-assisted heating treatment has no significant effect on reducing the content of volatile matter in the biomass charcoal, it has a certain positive effect on reducing the total moisture in the biomass charcoal.

[0070] In addition, the present invention further statistically analyzed the yields of the biomass charcoal of treatment groups A-1 to A-7. The yield of the biomass charcoal was calculated by dividing the difference between the mass of the biomass and the mass of the finally prepared biomass charcoal by the mass of the biomass. The results are shown in Table 4, Figure 3 as shown below.

[0071] Table 4. Yield statistics of treatment groups A-1 to A-7

[0072] ;

[0073] As can be seen from Table 4, in the A-1 treatment group, the yield of biochar treated by microwave heating, ultrasonic heating, and electro-assisted heating can be increased to more than 55%. The combination of the rapidity and selectivity of microwave heating and the uniformity of electro-assisted heating can further optimize the temperature field in the furnace, ensure more uniform heating of the material, and cooperate with the cavitation effect of ultrasonic waves and the heating effect of microwaves to significantly improve the heat and mass transfer efficiency, accelerate the carbonization reaction, and further increase the yield of biochar.

[0074] 2. The influence of the use of different types of tar cracking agents on the quality performance of civil biochar.

[0075] According to the method for preparing civil biochar disclosed in Example 1, adjust the use of different types of tar cracking agents according to Table 5.

[0076] Table 5. Use of different types of tar cracking agents

[0077] ;

[0078] For the biochar obtained by preparing the B-1 to B-8 treatment groups, industrial analysis was carried out with reference to the group standard of "Charcoal for Barbecue" (T / CNFPIA3025-2022). The industrial analysis data is shown in Table 6, Figure 4 as shown.

[0079] Table 6. Statistical table of industrial analysis data

[0080] ;

[0081] As can be seen from Table 6, in the process of deep processing of the carbide, selecting different types of biochar has different degrees of influence on reducing the volatile matter in the civil biochar. Selecting reed biochar has the best effect on reducing the volatile matter in the final biochar. The lower the volatile matter, the higher the calorific value of the biochar, and the less harmful gases are generated during combustion, which has a positive significance for improving the quality of the biochar and can be better used as barbecue charcoal.

[0082] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A kind of civilian biomass charcoal, characterized in that, The civilian biomass charcoal is used as barbecue charcoal. The civilian biomass charcoal uses biomass as raw material, first obtains carbide through catalytic conversion, then forms the carbide into carbon rods, and finally mixes the carbon rods with a tar cracking agent and obtains the product after treatment with microwave, ultrasonic and electric-assisted heating; wherein, the tar cracking agent is reed biochar.

2. The civil biomass charcoal according to claim 1, characterized in that, The biomass is any one of bamboo blocks, wood blocks, corn straws or cotton straws.

3. A preparation method of the civilian biomass charcoal according to any one of claims 1-2, characterized in that, The preparation method includes the following steps: (1) Obtain carbide by catalytic conversion of biomass; (2) First crush the carbide obtained in step (1), then mix, stir and form the crushed carbide with an adhesive, a surfactant and water according to the formula amount to obtain carbon rods; (3) Under an inert gas atmosphere, mix the carbon rods obtained in step (2) with a tar cracking agent and carry out deep processing using three heating methods of microwave, ultrasonic and electric-assisted heating, and then obtain civilian biomass charcoal after cooling.

4. The preparation method of a kind of civil biomass charcoal according to claim 3, characterized in that, Step (1) is specifically: cut the biomass into sections and send it into a carbonization furnace, heat the carbonization furnace to 200-300 °C through steam heating, then add a catalyst, and carbonize for 2h-3h under an inert gas atmosphere to obtain carbide.

5. The preparation method of a kind of civil biomass charcoal according to claim 3, characterized in that, In step (2), the mass ratio between the carbide, the adhesive and the surfactant is 9.2:0.3-1.0:0.1-0.

3.

6. The preparation method of a kind of civil biomass carbon according to claim 3, characterized in that, In step (3), the dosage of the tar cracking agent is determined according to the tar content to be cracked in the carbide, and the mass ratio of the tar cracking agent to the tar is 1:1-3.

7. The preparation method of a kind of civil biomass carbon according to claim 3, characterized in that, The inert gas atmosphere is any one of nitrogen atmosphere, helium atmosphere, neon atmosphere or argon atmosphere.

8. The preparation method of a kind of civil biomass charcoal according to claim 3, characterized in that, Step (3) is specifically: mix the carbon rods obtained in step (2) with a tar cracking agent and send them into a carbonization furnace. Use three heating methods of microwave, ultrasonic and electric-assisted heating to first heat the temperature in the furnace to 180-200 °C, then introduce an inert gas into the carbonization furnace to make the sealed space in the furnace in an oxygen-deficient environment, continue heating to raise the temperature in the furnace to 450-500 °C, stop heating, and cool down.

9. The preparation method of a kind of civil biomass charcoal according to claim 3, characterized in that, In step (3), the microwave power is 500W-100KW, the ultrasonic power is 500W-20KW, and the electric-assisted heating power is 1KW-100KW.

Images