Plant fuel charcoal prepared from wormwood residues and method thereof

Abstract

The invention discloses plant fuel charcoal prepared from wormwood residues and a preparation method of the plant fuel charcoal. The method comprises the following steps of: drying and crushing residues obtained after deep processing of wormwood serving as main raw materials, plasticizing, bonding and forming lignin of the residues under the high temperature of 150-250 DEG C and the high pressure of 10-30MPa under the condition of not adding any chemical adhesive, and carbonizing at low temperature in an oxygen-limited environment of 300-500 DEG C, thereby obtaining the product. The density of the obtained fuel carbon is 0.8-1.2 g / cm < 2 >, the compressive strength is 5-15 MPa, the combustion heat value is 4500-5800 kcal / kg, the ash content is 3%-8%, the volatile component content is 15%-25%, and the fixed carbon content is 70%-80%. High-valued utilization of wormwood waste is achieved, the obtained fuel charcoal emits fresh wormwood fragrance during combustion, has the auxiliary effects of repelling mosquitoes and purifying air, is little in combustion smoke and stable in heat value, and is suitable for various scenes such as family barbecue, surrounding furnace tea boiling, outdoor camping and atmosphere building. The method is simple in process, low in cost and easy to industrialize, and has good economic and social benefits.

Description

Technical Field

[0001] This invention relates to the field of comprehensive utilization of biomass resources, specifically to a method for preparing plant-based fuel char from Artemisia argyi residue. Background Technology

[0002] Artemisia argyi is a traditional Chinese medicinal herb widely used in the processing and production of products such as moxibustion, moxa sticks, artemisia essential oil, and artemisia extract. Statistics show that my country's artemisia planting area exceeds 1 million mu (approximately 66,667 hectares), with the related industries generating nearly 30 billion yuan in annual output value, growing at a rate of 30% to 50% annually. During the deep processing of artemisia, after extracting essential oils, flavonoids, and moxa floss, a large amount of artemisia residue (mainly stems and leaves) is generated, accounting for approximately 60% to 80% of the total raw materials. Currently, most of this residue is directly discarded, landfilled, or simply incinerated, causing not only serious resource waste but also potential environmental pollution.

[0003] On the other hand, with the improvement of people's living standards, outdoor barbecues, tea gatherings, camping and other leisure activities are becoming increasingly popular, and the demand for fuel charcoal is increasing year by year. At present, most barbecue charcoal and heating charcoal on the market are made from wood and coal, or with the addition of chemical binders (such as sodium carboxymethyl cellulose, starch, bentonite, etc.). These traditional fuel charcoal have the following problems: (1) using wood as raw material leads to the consumption of forest resources; (2) burning coal as raw material produces harmful gases such as sulfur dioxide and nitrogen oxides; (3) fuel charcoal with added chemical binders may produce odors and harmful smoke when burning; (4) ordinary fuel charcoal has a single function, only providing a heat source and has no added value.

[0004] In recent years, researchers have attempted to prepare fuel char from biomass waste. For example, CN104498126A discloses a type of machine-made char and its preparation method, using traditional Chinese medicine residue (including Artemisia argyi) and biomass waste as raw materials, but 6-10 parts of binder need to be added for molding. Another patent, CN104741202A, discloses a biomass carbonization raw material molding unit, but it still requires mixing materials through a mixer, failing to solve the problem of molding without binder. A research team from Zhengzhou University disclosed a method and application for preparing char materials using Artemisia argyi as raw material under low-temperature air atmosphere (CN113415802A), but this method is used to prepare adsorbent materials and requires the addition of... The activator is used for wastewater treatment rather than fuel. Another patent discloses a natural biofuel containing artemisia, but with the addition of 10-30 parts coal, it still cannot avoid the polluting gases produced by coal combustion.

[0005] Therefore, how to utilize the residue of Artemisia argyi in a resource-efficient and high-value manner, and develop a clean, safe, chemical-free, and uniquely value-added plant-based fuel charcoal, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a plant-based fuel charcoal prepared from Artemisia argyi residue and a method thereof, in order to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A plant-based fuel charcoal prepared from Artemisia argyi residue and its method thereof is prepared by the following method: using the plant residue after deep processing of Artemisia argyi as the main raw material, after drying and crushing, the residue is plasticized and bonded by high temperature and high pressure without adding any chemical binders, and then carbonized at low temperature in a limited oxygen environment.

[0009] Preferably, the mugwort residue includes one or more of the following: mugwort essential oil, mugwort flavonoids, mugwort floss processing, or stem and leaf residue remaining after extraction of other effective components of mugwort.

[0010] Preferably, the high-temperature high-pressure molding temperature is 150℃~250℃, the pressure is 10MPa~30MPa, and the holding time is 5~20 minutes.

[0011] Preferably, the low-temperature carbonization is carried out in an oxygen-limited environment protected by nitrogen or inert gas, with a carbonization temperature of 300℃ to 500℃, a heating rate of 5 to 10℃ / minute, and a holding time of 1 to 3 hours.

[0012] Preferably, the plant-based fuel char has a density of 0.8–1.2 g / cm³, a compressive strength of 5–15 MPa, and a calorific value of 4500–5800 kcal / kg.

[0013] Preferably, the plant-based fuel charcoal is in any one of the following shapes: rod-shaped, spherical, cake-shaped, block-shaped, or incense-shaped.

[0014] Preferably, the surface or interior of the plant-based fuel charcoal is further loaded with mugwort hydrosol or natural plant essential oils, with the loading amount being 0.1% to 0.5% of the weight of the fuel charcoal.

[0015] Preferably, the mugwort residue is also mixed with fruit wood chips, and the weight ratio of mugwort residue to fruit wood chips is 9:1 to 7:3.

[0016] Preferably, the ash content of the plant-based fuel charcoal is 3% to 8%, the volatile matter content is 15% to 25%, and the fixed carbon content is 70% to 80%.

[0017] This invention also provides a method for preparing the above-mentioned Artemisia argyi residue plant fuel charcoal, comprising the following steps:

[0018] (1) Pretreatment: Dry the residue of Artemisia argyi after deep processing until the moisture content is less than 15%, and pulverize it to 20-60 mesh to obtain Artemisia argyi residue powder;

[0019] (2) Adhesive-free molding: Place the Artemisia argyi residue powder obtained in step (1) into a molding mold, press it at 150℃~250℃ and 10MPa~30MPa, and hold the pressure for 5~20 minutes to obtain the molded blank;

[0020] (3) Carbonization: The shaped blank obtained in step (2) is placed in a carbonization furnace and heated to 300℃ to 500℃ under the protection of nitrogen or inert gas at a rate of 5 to 10℃ / min. The temperature is maintained for 1 to 3 hours and then naturally cooled to room temperature to obtain the Artemisia argyi fuel carbon matrix.

[0021] (4) Optional aroma enhancement treatment: Spray mugwort hydrosol or natural plant essential oil evenly onto the surface of the mugwort fuel charcoal matrix obtained in step (3). The amount of spraying is 0.1% to 0.5% of the weight of the fuel charcoal. After drying, the aroma-enhanced mugwort fuel charcoal is obtained.

[0022] Preferably, in step (1), the mugwort residue is washed and cleaned before drying to remove mud, sand and metal impurities.

[0023] Preferably, in step (2), the temperature of the molding die is controlled at 180℃~220℃, the pressure is controlled at 15MPa~25MPa, and the pressure holding time is 8~15 minutes.

[0024] Preferably, in step (3), the carbonization process adopts a segmented heating process: first, the temperature is raised to 200℃ to 250℃ at 5 to 8℃ / minute and held for 30 to 60 minutes, then the temperature is raised to 300℃ to 500℃ at 3 to 5℃ / minute and held for 1 to 3 hours.

[0025] Technical Principles

[0026] This invention is based on the following principle: Artemisia argyi residue contains abundant lignin (approximately 20%–30%), cellulose (approximately 35%–45%), and hemicellulose (approximately 20%–25%). Lignin is a natural polymer with a three-dimensional network structure, and its glass transition temperature is approximately 130°C–170°C. When the temperature rises above 150°C, lignin undergoes a glass transition, changing from a glassy state to a highly elastic state, and the molecular chain segments begin to move. Under pressure, the softened lignin permeates and diffuses between cellulose and hemicellulose, forming physical cross-linking points upon cooling, thus acting as an adhesive. This invention utilizes this characteristic to plasticize the lignin in Artemisia argyi residue into a natural adhesive through high temperature and high pressure without adding any chemical binders, achieving self-adhesive molding. Subsequently, low-temperature carbonization under limited oxygen conditions releases some volatiles, increasing the fixed carbon content and calorific value; on the other hand, it retains some active substances and aromatic precursors, allowing the product to emit the unique fragrance of Artemisia argyi when burned.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention transforms the waste residue from deep processing of Artemisia argyi into high-value-added plant-based fuel charcoal, realizing the resource utilization of waste and conforming to the concept of a circular economy. By utilizing the lignin of the Artemisia argyi residue itself for plasticization and bonding under high temperature and pressure, no chemical binders are added throughout the process. There is no chemical odor during combustion, and CO and NOx emissions are significantly lower than traditional products (CO average 76-82 ppm), making it healthier and more environmentally friendly. The resulting fuel charcoal continuously releases the unique aroma of Artemisia argyi during combustion, possessing unique functions such as assisting in mosquito repellent and air purification. It also boasts a high calorific value of 4500-5800 kcal / kg and a compressive strength of 5-15 MPa, exhibiting excellent performance. The process of this invention is simple and controllable, allowing for the production of various shapes suitable for various scenarios such as barbecuing, tea brewing, and mosquito repellent. The aroma can be adjusted by adding fruitwood chips or spraying Artemisia argyi hydrosol, demonstrating good industrialization and market prospects. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Source of raw materials

[0031] The mugwort residue used in this invention was obtained from a mugwort processing enterprise in Nanyang, Henan Province. It consisted of residues after extracting essential oil, flavonoids, and mugwort floss. The fruit sawdust was purchased from a wood processing plant in Hebei Province and was a mixture of apple and pear sawdust. The mugwort hydrosol was prepared in the laboratory and extracted from fresh mugwort using steam distillation.

[0032] Detection methods

[0033] (1) Moisture content: determined according to GB / T211-2017 "Determination of total moisture in coal".

[0034] (2). Ash, volatile matter and fixed carbon: determined according to GB / T212-2008 "Industrial Analysis Methods for Coal".

[0035] (3) Calorific value: determined according to GB / T213-2008 "Method for determination of calorific value of coal" using an oxygen bomb calorimeter.

[0036] (4) Compressive strength: Using an electronic universal testing machine, apply axial pressure to the shaped fuel carbon sample, record the maximum pressure when the sample breaks, and divide by the cross-sectional area to calculate the strength.

[0037] (5) Density: determined by water displacement method.

[0038] (6) Combustion time: Take the same mass (50g) of fuel char sample, ignite it in a windless environment, and record the duration from ignition to flame extinguishing.

[0039] (7) Flue gas composition: The emission concentrations of CO, NOx and SO2 during the combustion process are detected using a flue gas analyzer.

[0040] Example 1

[0041] This embodiment provides a plant-based fuel charcoal prepared from Artemisia argyi residue and its preparation method.

[0042] (1) Raw material processing: Take 10 kg of dried residue after extracting flavonoids from Artemisia argyi, pick out obvious impurities, wash twice with clean water to remove surface mud and sand, and dry in an oven at 80℃ until the moisture content is 12%. Crush the dried residue with a pulverizer and pass it through a 40-mesh sieve to obtain Artemisia argyi residue powder.

[0043] (2) Composition analysis: A small amount of powder was taken for composition analysis. The results showed that the lignin content was 26.3%, the cellulose content was 42.1%, the hemicellulose content was 21.5%, and the remainder was ash and a small amount of residual flavonoids.

[0044] (3) Adhesive-free molding: The above powder is loaded into a cylindrical stainless steel mold with an inner diameter of 50 mm, with each mold containing approximately 80 g of material. The mold is placed on a flat vulcanizing machine, and the heating temperature is set to 200℃ and the pressure to 20 MPa. After reaching the set temperature, the timer is started, and the pressure is maintained for 15 minutes. After the pressure is maintained, the mold is naturally cooled to below 80℃ to obtain a disc-shaped blank with a diameter of 50 mm and a height of 28–32 mm. The density of the blank is measured to be 1.12 g / cm³, and the compressive strength is 8.7 MPa.

[0045] (4) Carbonization: Place the shaped blank in a tubular carbonization furnace, and first purge with nitrogen (flow rate 0.5 L / min) for 15 minutes to remove air. Then, under nitrogen protection, heat to 400°C at 8°C / min and hold for 2 hours. After the holding period, turn off the heating power, continue to purge with nitrogen to cool to room temperature, and remove to obtain the Artemisia argyi fuel char matrix.

[0046] (5) Product performance testing: The obtained fuel char is black, with a smooth surface and no obvious cracks, and a hard texture. Testing showed that the product density was 0.96 g / cm³, compressive strength was 11.3 MPa, ash content was 5.2%, volatile matter content was 19.8%, fixed carbon content was 75.0%, and calorific value was 5360 kcal / kg. A 50g sample was ignited, and the combustion time was approximately 98 minutes. During combustion, the flame was pale blue, with no obvious black smoke. The average CO concentration in the flue gas was 82 ppm, the average NOx concentration was 35 ppm, and SO2 was not detected. It emitted a distinct mugwort fragrance during combustion, without any irritating odor.

[0047] Example 2

[0048] This embodiment provides a method for preparing Artemisia argyi fuel charcoal with added fruitwood chips.

[0049] (1) Raw material processing: Take 7 kg of dried residue after processing mugwort into mugwort floss and 3 kg of apple wood chips, and mix them evenly. Dry the mixture in an oven at 80℃ until the moisture content is 10%. Crush the dried mixture with a pulverizer and pass it through a 30-mesh sieve to obtain mixed powder.

[0050] (2) Composition analysis: The lignin content in the mixed powder was measured to be 24.8%, the cellulose content was 44.3%, and the hemicellulose content was 22.1%.

[0051] (3) Adhesive-free molding: The above powder is loaded into a spherical molding mold, with an amount of about 15g per mold. The molding temperature is set to 180℃, the pressure is 25MPa, and the pressure is held for 10 minutes. After demolding, a spherical blank with a diameter of about 20mm is obtained. The density of the blank is measured to be 1.08g / cm³, and the compressive strength is 7.9MPa.

[0052] (4) Carbonization: The shaped blank is placed in a carbonization furnace, nitrogen gas is introduced for protection, the temperature is raised to 350°C at 6°C / min, the temperature is held for 2.5 hours, and then it is naturally cooled to room temperature to obtain the Artemisia argyi fuel carbon matrix.

[0053] (5) Fragrance enhancement treatment: Take mugwort hydrosol and spray it evenly on the surface of the cooled fuel charcoal with a sprayer. The amount of spray is 0.3% of the weight of the fuel charcoal. Let it air dry in a ventilated place for 24 hours to obtain the fragrance-enhanced mugwort fuel charcoal.

[0054] (6) Product performance testing: The obtained fuel char has a density of 0.92 g / cm³, a compressive strength of 10.5 MPa, an ash content of 4.8%, a volatile matter content of 21.2%, a fixed carbon content of 74.0%, and a calorific value of 5240 kcal / kg. A 50 g sample was ignited, and the combustion time was approximately 105 minutes. During combustion, it exhibited a complex aroma of fruit and wood with a hint of mugwort fragrance, and the smoke was odorless. Testing revealed an average CO concentration of 76 ppm and an average NOx concentration of 31 ppm in the smoke.

[0055] Example 3

[0056] This embodiment provides a cone-shaped artemisia fuel charcoal and its preparation method.

[0057] (1) Raw material processing: Take 8 kg of dried residue after extracting essential oil from Artemisia argyi and dry it in an oven at 80℃ until the moisture content is 13%. Crush the dried residue with a pulverizer and pass it through a 50-mesh sieve to obtain Artemisia argyi residue powder.

[0058] (2) Composition analysis: The lignin content was 27.1%, the cellulose content was 41.5%, and the hemicellulose content was 20.8%.

[0059] (3) Adhesive-free molding: The above powder is loaded into a special incense cone-shaped mold (bottom diameter 10mm, top diameter 5mm, height 40mm), with an amount of about 8g per mold. The molding temperature is set to 220℃, the pressure to 15MPa, and the pressure is held for 8 minutes. After demolding, an incense cone-shaped blank is obtained. The density of the blank is measured to be 1.15g / cm³.

[0060] (4) Carbonization: The shaped blank is placed in a carbonization furnace and a segmented heating process is adopted: first, the temperature is raised to 220°C at 5°C / min and held for 40 minutes to allow internal moisture and low-boiling-point substances to slowly escape; then the temperature is raised to 450°C at 4°C / min and held for 1 hour. After the holding period, the blank is cooled to room temperature in a nitrogen atmosphere.

[0061] (5) Product performance testing: The obtained fuel charcoal has a density of 0.98 g / cm³, a compressive strength of 12.7 MPa, an ash content of 5.5%, a volatile matter content of 18.3%, a fixed carbon content of 76.2%, and a calorific value of 5510 kcal / kg. A 30g sample (approximately 8-10 pieces) was ignited, and the burning time was approximately 65 minutes. Due to its unique shape, it forms a spiral-shaped rising flame during combustion, making it visually appealing and producing a rich aroma. In a trial, burning two incense-shaped fuel charcoal cones in a 15m² room resulted in a significant mosquito-repelling effect after 30 minutes (based on mosquito trap counting, mosquito activity was reduced by approximately 70%).

[0062] Example 4

[0063] This embodiment examines the impact of different molding process parameters on product performance.

[0064] (1) The pressure was fixed at 20 MPa and the holding time was 15 minutes. The effect of different molding temperatures was investigated. The results are shown in Table 1.

[0065] Table 1. Effect of molding temperature on product performance

[0066]

[0067] As shown in Table 1, when the molding temperature is below 150℃, lignin plasticization is insufficient, resulting in poor molding performance; excessively high temperatures (>250℃) may lead to the pyrolysis of some organic matter, producing a burnt smell. The preferred temperature is 170℃~230℃.

[0068] (2) The temperature was fixed at 200℃ and the holding time was 15 minutes. The effect of different molding pressures was investigated. The results are shown in Table 2.

[0069] Table 2. Effect of molding pressure on product performance

[0070]

[0071] As shown in Table 2, the molding effect is poor when the pressure is below 10 MPa; within the range of 10–30 MPa, the product density and strength increase with increasing pressure; above 30 MPa, the performance improvement is not significant, but equipment wear increases. The preferred pressure is 15–25 MPa.

[0072] Example 5

[0073] This embodiment examines the impact of different carbonization process parameters on product performance.

[0074] Uniform blanks were prepared using the same molding process as in Example 1 (200℃, 20MPa, 15 minutes), and then treated under different carbonization conditions to investigate the effects of carbonization temperature, holding time, and heating rate.

[0075] (1) The heat preservation time was fixed for 2 hours and the heating rate was 8℃ / minute. The effect of carbonization temperature was investigated. The results are shown in Table 3.

[0076] Table 3. Effect of carbonization temperature on product performance

[0077]

[0078] As shown in Table 3, with increasing carbonization temperature, the fixed carbon content and calorific value increase, and the combustion time prolongs, but the ash content also increases. Above 500℃, the increase in calorific value slows down, but the aroma of Artemisia argyi weakens significantly. Considering both combustion performance and aroma retention, a temperature range of 300℃ to 500℃ is optimal.

[0079] (2) The carbonization temperature was fixed at 400℃ and the heating rate was 8℃ / minute. The effect of the holding time was investigated. The results are shown in Table 4.

[0080] Table 4. The impact of heat preservation time on product performance

[0081]

[0082] As shown in Table 4, within the heat preservation time range of 1 to 3 hours, carbonization becomes more complete and product performance improves with longer time. After 2.5 hours, the performance improvement decreases. A heat preservation time of 1 to 3 hours is preferred, balancing efficiency and performance.

[0083] Example 6

[0084] This embodiment examines the effect of different ratios of Artemisia argyi residue to fruit wood chips on the flavor of the product.

[0085] According to the proportions shown in Table 5, Artemisia argyi residue and fruit wood chips were mixed and fuel charcoal was prepared using the same process as in Example 2 (180℃, 25MPa, 10 minutes; carbonization at 350℃ for 2.5 hours; spraying with 0.3% Artemisia argyi hydrosol). Ten sensory evaluators were organized to score the aroma of the burning charcoal (1-5 points, with 5 points being the best). The results are shown in Table 5.

[0086] Table 5. Effects of different formulation ratios on the combustion aroma of the product.

[0087]

[0088] As shown in Table 5, the fuel charcoal prepared from pure Artemisia argyi residue has a rich Artemisia argyi aroma, but the flavor is somewhat monotonous. After adding an appropriate amount of fruitwood chips, a complex aroma is formed, and the overall acceptance is higher. When the ratio of Artemisia argyi residue to fruitwood chips is 9:1 to 7:3, the overall acceptance score is above 4.5, which is the optimal ratio.

[0089] Comparative Example 1

[0090] This comparative example uses the traditional method of adding chemical binders to prepare Artemisia argyi fuel charcoal.

[0091] Take the same Artemisia argyi residue powder as in Example 1, add 10% sodium carboxymethyl cellulose (CMC) as a binder, mix evenly, add an appropriate amount of water to make a wet material, press it into shape at room temperature under a pressure of 20 MPa (without heating), demold and dry in an oven at 80°C for 12 hours. Then, carbonize the dried green body at 400°C for 2 hours under nitrogen protection by raising the temperature at 8°C / min.

[0092] The obtained fuel char has a density of 0.81 g / cm³, a compressive strength of 6.5 MPa, and a calorific value of 5180 kcal / kg. A slight chemical odor is present in the initial ignition stage (first 5 minutes), possibly due to gases produced by CMC decomposition. The combustion time is approximately 85 minutes. Compared to Example 1, the product has lower strength and an odor in the initial combustion stage.

[0093] Comparative Example 2

[0094] This comparative example uses conventional biomass carbonization process, without the high-temperature and high-pressure molding step.

[0095] The same Artemisia argyi residue as in Example 1 was dried, pulverized, and directly loaded into a carbonization furnace for carbonization under the same conditions (400°C, 2 hours, nitrogen protection). The resulting product was a loose, powdery substance, unsuitable for direct use as fuel charcoal, requiring the addition of a binder for reshaping. The calorific value of the powdery product was measured to be 4890 kcal / kg.

[0096] Comparative Example 3

[0097] This comparative example refers to the formulation in CN104498126A to prepare multi-component machine-made charcoal with added binder.

[0098] Take 40 parts of Artemisia argyi residue, 30 parts of corn stalks, 15 parts of sawdust, 10 parts of bentonite (as a binder), and 5 parts of combustion aid (sodium nitrate). Mix them evenly, add water to moisten, press them into shape under 20 MPa pressure, dry them at 80℃, and then carbonize them at 400℃ for 2 hours.

[0099] The obtained fuel char has a density of 0.95 g / cm³, a compressive strength of 9.2 MPa, and a calorific value of 5120 kcal / kg. It burns stably after ignition, but the NOx concentration in the flue gas is high (approximately 128 ppm), possibly due to the decomposition of the combustion aid. The aroma during combustion is faint, lacking obvious characteristics of artemisia.

[0100] Table 6 summarizes the performance comparison between Examples 1-3 and Comparative Examples 1-3.

[0101] Table 6. Performance Comparison of Each Example and Comparative Example

[0102]

[0103] As shown in Table 6, the Artemisia argyi fuel charcoal prepared in the embodiments of the present invention has higher compressive strength, fixed carbon content and calorific value without the need for chemical binders, longer burning time, no odor, unique aroma, and better overall performance than the comparative example.

[0104] Product application trial

[0105] Application Example 1: Home Barbecue Application

[0106] Two kg of the spherical mugwort charcoal prepared in Example 2 was used in a home charcoal grill. It ignited in 12 minutes (using a dedicated igniter) and reached stable combustion after 15 minutes, with a moderate flame height. There was no noticeable smoke during grilling, the food had no chemical odor, and possessed a faint, complex aroma of fruit, wood, and mugwort. The continuous burning time was approximately 3.5 hours, meeting the needs of home grilling. After grilling, there was little ash residue, making cleaning easy.

[0107] Application Example 2: Tea Brewing Around a Fire

[0108] Take 1 kg of the cake-shaped mugwort charcoal prepared in Example 1 and use it in a charcoal stove for brewing tea. After ignition, it reaches the suitable tea-brewing temperature (the surface temperature of the charcoal fire is approximately 450-500℃) in about 10 minutes. During the tea-brewing process, the charcoal fire is stable, requiring no frequent addition of fuel. During the tea-brewing process, the tea leaves absorb the aroma of mugwort, resulting in a unique taste. Continuous burning for about 2 hours is sufficient to boil 3-4 pots of water.

[0109] Application Example 3: Indoor Mosquito Repellent Application

[0110] Five cones (approximately 15g) of the incense-shaped mugwort fuel charcoal prepared in Example 3 were lit in a 15m² room. After 30 minutes of lighting, mosquito activity was reduced by approximately 70% using a mosquito trap; after 60 minutes, mosquito activity was reduced by approximately 90%. There was no noticeable smoke in the room, only a faint mugwort fragrance. No one in the room experienced significant discomfort.

[0111] Industrial applicability assessment

[0112] An economic evaluation was conducted on a production line with an annual output of 1,000 tons of Artemisia argyi fuel charcoal.

[0113] Raw material cost: Artemisia argyi residue is waste, and the cost of collection and transportation is only about 200 yuan / ton;

[0114] Processing costs: Energy and labor costs for drying, crushing, molding, carbonization, etc., are approximately 600 yuan / ton;

[0115] Equipment depreciation: approximately 100 yuan / ton;

[0116] The total cost is approximately 900 yuan per ton;

[0117] Market price: Ordinary machine-made charcoal is about RMB 2,500 to 3,500 per ton. This product has added value and unique aroma, and the estimated price is RMB 3,500 to 4,500 per ton.

[0118] Annual profit: 1000 tons × (3500-900) = 2.6 million yuan, with significant economic benefits.

[0119] Analysis shows that this application has the following advantages:

[0120] Turning waste into treasure, circular economy: Transforming the waste residue of the Artemisia argyi industry into high value-added products, realizing full utilization of resources, solving the waste disposal problem of Artemisia argyi processing enterprises, and conforming to the concept of circular economy.

[0121] Healthy and environmentally friendly, with no chemical additives: No chemical binders are added throughout the entire process. The lignin of Artemisia argyi itself is plasticized and bound under high temperature and pressure, resulting in safer combustion products with no chemical odor. Compared with traditional fuel charcoal containing binders, the product of this invention emits lower CO and NOx emissions during combustion (CO average 76-82ppm vs. 128ppm).

[0122] Unique Functions and Long-Lasting Aroma: When burned, it continuously releases the distinctive aroma of mugwort, providing multiple benefits including creating ambiance, assisting in mosquito repellency, and purifying the air. Compared to existing technologies that add mugwort as a raw material, this invention uses mugwort residue, resulting in lower costs and achieving resource reuse.

[0123] Technological innovation with high barriers to entry: Utilizing the glass transition properties of lignin to achieve self-adhesive molding, eliminating the need for additional adhesives, the process is simple but technically demanding. Compared to conventional biomass carbonization processes, this invention integrates two key steps: high-temperature, high-pressure molding and oxygen-limited carbonization, resulting in superior product performance.

[0124] Excellent performance and wide application: The product density is 0.8~1.2g / cm³, compressive strength is 5~15MPa, and calorific value is 4500~5800kcal / kg, meeting or even exceeding the standards of ordinary machine-made charcoal. It can be designed into various shapes such as sticks, balls, cakes, and incense cones, suitable for various life scenarios such as barbecuing, heating, tea brewing, mosquito repellent, and aromatherapy.

[0125] The aroma is adjustable and can be customized: By adding different proportions of fruitwood chips (9:1 to 7:3), the burning flavor can be adjusted to meet the preferences of different consumers; by spraying mugwort hydrosol or natural essential oil afterward, the aroma concentration and persistence can be further enhanced.

[0126] The preparation method is controllable and suitable for industrialization: The preparation method provided by this invention has clear process parameters, strong controllability of each step, and is easy to achieve large-scale and continuous production, and has good prospects for industrial application.

[0127] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A plant-based fuel charcoal prepared from Artemisia argyi residue, characterized in that, It is prepared by the following method: using the plant residue after deep processing of Artemisia argyi as the main raw material, after drying and crushing, it is plasticized and bonded by high temperature and high pressure without adding any chemical binders, and then carbonized at low temperature in a limited oxygen environment.

2. The plant-based fuel charcoal prepared from Artemisia argyi residue according to claim 1, characterized in that, The mugwort residue includes one or more of the following: mugwort essential oil, mugwort flavonoids, mugwort floss processing, or stem and leaf residue remaining after extraction of other effective components of mugwort.

3. The plant-based fuel charcoal prepared from Artemisia argyi residue according to claim 1, characterized in that, The high-temperature, high-pressure molding process is carried out at a temperature of 150℃~250℃, a pressure of 10MPa~30MPa, and a holding time of 5~20 minutes; the low-temperature carbonization is conducted in an oxygen-limited environment protected by nitrogen or inert gas, at a carbonization temperature of 300℃~500℃, a heating rate of 5~10℃ / min, and a holding time of 1~3 hours; the density of the plant-based fuel charcoal is... It has a compressive strength of 5-15 MPa and a calorific value of 4500-5800 kcal / kg.

4. The plant-based fuel charcoal prepared from Artemisia argyi residue according to claim 1, characterized in that, The plant-based fuel charcoal may be in any of the following shapes: rod-shaped, spherical, cake-shaped, block-shaped, or incense-shaped.

5. The plant-based fuel charcoal prepared from Artemisia argyi residue according to claim 1, characterized in that, The plant-based fuel charcoal is also loaded with mugwort hydrosol or natural plant essential oil on its surface or inside, with a loading amount of 0.1% to 0.5% of the weight of the fuel charcoal; the mugwort residue is also mixed with fruitwood chips, with a weight ratio of mugwort residue to fruitwood chips of 9:1 to 7:

3.

6. The plant-based fuel charcoal prepared from Artemisia argyi residue according to claim 1, characterized in that, The plant-based fuel char has an ash content of 3%–8%, a volatile matter content of 15%–25%, and a fixed carbon content of 70%–80%.

7. A method for preparing plant-based fuel charcoal from Artemisia argyi residue as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step (1) Pretreatment: Dry the residue of deep-processed Artemisia argyi to a moisture content of less than 15%, and pulverize it to 20-60 mesh to obtain Artemisia argyi residue powder; Step (2) Adhesive-free molding: Place the Artemisia argyi residue powder obtained in step (1) into a molding mold, press it at 150℃~250℃ and 10MPa~30MPa, and hold the pressure for 5~20 minutes to obtain the molded blank; Step (3) Carbonization: Place the shaped blank obtained in step (2) in a carbonization furnace, and under the protection of nitrogen or inert gas, heat it to 300℃ to 500℃ at 5 to 10℃ / min, keep it at the temperature for 1 to 3 hours, and then cool it naturally to room temperature to obtain the Artemisia argyi fuel carbon matrix. Step (4) Optional aroma enhancement treatment: Spray mugwort hydrosol or natural plant essential oil evenly onto the surface of the mugwort fuel charcoal matrix obtained in step (3). The amount of spraying is 0.1% to 0.5% of the weight of the fuel charcoal. After drying, the aroma-enhanced mugwort fuel charcoal is obtained.

8. The method for preparing plant-based fuel charcoal from Artemisia argyi residue according to claim 7, characterized in that, In step (1), the mugwort residue is washed and cleaned before drying to remove mud, sand and metal impurities.

9. The method for preparing plant-based fuel charcoal from Artemisia argyi residue according to claim 7, characterized in that, In step (2), the temperature of the molding die is controlled at 180℃~220℃, the pressure is controlled at 15MPa~25MPa, and the holding time is 8~15 minutes.

10. The method for preparing plant-based fuel charcoal from Artemisia argyi residue according to claim 7, characterized in that, In step (3), the carbonization process adopts a segmented heating process: first, the temperature is raised to 200℃ to 250℃ at 5 to 8℃ / minute and held for 30 to 60 minutes, then the temperature is raised to 300℃ to 500℃ at 3 to 5℃ / minute and held for 1 to 3 hours.

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