Biochar derived from chicken manure, method for producing same, and apparatus for producing same

Abstract

[Problem] To provide: biochar as a sustainable alternative fertilizer that serves as a plant nutrient capable of being utilized in a recyclable manner in agriculture; a method for producing the biochar; and an apparatus for producing the biochar. [Solution] Provided is an apparatus for producing biochar using chicken manure as a raw material, the apparatus being characterized by comprising: a drying chamber for drying the chicken manure; a pulverization unit for pulverizing the dried chicken manure; a sieve unit for adjusting the grain size to a predetermined grain size; a carbonization furnace for heating the chicken manure after adjustment of the grain size to 250°C or higher but lower than 320°C under an oxygen-restricted atmosphere; an atmosphere control unit for controlling the atmosphere in the carbonization furnace; and a cooling unit for cooling the biochar after carbonization. The biochar obtained by the production apparatus is obtained by thermally decomposing a chicken manure fertilizer at a low temperature. Since nitrogen can be recovered from nutrient-rich biomass and carbon can be retained and isolated, the biochar is effective as a nutrient source to be applied to soil, can make recycling of biological resources and waste management efficient, and is superior to those obtained by conventional composting and hydrothermal carbonization.

Description

Biochar Derived from Chicken Manure, Its Manufacturing Method, and Manufacturing Apparatus 【0001】 The present invention relates to biochar derived from chicken manure that can be used as an organic fertilizer and a method for manufacturing the same. The present invention also relates to a manufacturing apparatus and a manufacturing method for efficiently manufacturing chicken manure biochar of stable quality by providing drying, pulverization, sieving, and a low-temperature carbonization furnace when manufacturing biochar using chicken manure as a raw material. 【0002】 With the increase in the world's population and the reduction of arable land area, the demand for food production is driving modern agriculture towards intensive cultivation. In intensive cultivation, chemical fertilizers are applied to the soil for high yields. For example, the application rate of nitrogen fertilizers as chemical fertilizers has doubled in just 40 years (1979 - 2018). However, such chemical fertilizers are limited in the amount that can be used in the future, and due to recent price hikes and various impacts on the environment, it has become essential to find a sustainable source of plant nutrients as an alternative fertilizer. Producing organic fertilizers using livestock manure, which is nutrient-rich waste biomass, can be a reasonable alternative. Effectively circulating such nutrient-rich biomass in agriculture not only reduces chemical fertilizers but also contributes to ensuring the sustainability of modern agriculture. 【0003】 Chicken manure is one of the most nutrient-rich wastes among waste biomass. Since such nutrient-rich chicken manure contains excessive amounts of soluble nutrients, pesticides, antibiotics, and pathogenic bacteria, it is regarded as hazardous waste, and thus has the potential to cause nutrient pollution in the surrounding environment and eutrophication of adjacent waters. It must not be discarded without proper treatment and should not be used as an organic fertilizer for agriculture. 【0004】 Night soil has conventionally been treated by composting, but this technique has a high moisture content, a low porosity, requires a bulking agent, has a long aging time, and results in a significant loss of nitrogen, so it is not very effective for treating night soil. Furthermore, the produced compost is often not very stable in the soil and may contain a significant amount of soluble nutrient salts, residual antibiotics, phytotoxic substances, and pathogenic bacteria, and a more effective treatment method is needed. 【0005】 In recent years, the carbonization of waste biomass has attracted attention because it can stabilize the feedstock, produce refractory carbon, reduce the solubility of nutrients, and remove pathogens (Non-Patent Documents 1 and 2). The carbonization of livestock manure has been confirmed to significantly reduce (95 - 100%) the pollution risk due to residual antibiotics compared to composting technology (Non-Patent Document 3). Thus, producing biochar from chicken manure can be an environmentally friendly management method, and it has been confirmed that chicken manure biochar produced at 500°C or lower releases a large amount of nutrients (NPK) necessary for sweet corn production (Non-Patent Document 4). 【0006】 Biochar obtained from the carbonization process is also a major concern because it is convenient for wet chicken manure and needs to be cost-effective for producing organic fertilizers. On the other hand, hydrothermal carbonization is another option suitable for composts containing a large amount of moisture and can eliminate the need for pre-drying before carbide production. However, although hydrochar obtained from the hydrothermal carbonization process needs to be systematically compared with existing technologies such as composting and with biochar obtained from the carbonization process for better nutrient utilization efficiency, there is no prior research on nutrient recovery rates and the possibility of subsequent release into the soil. 【0007】 On the other hand, the stability of organic matter improvers in soil is also an important factor that affects the suitability as organic fertilizers and the sustainability of agro-ecosystems. Refractory organic fertilizers may increase the carbon storage in soil and bring long-term benefits to the soil environment. The stability in soil is also related to the nutrient release ability of organic fertilizers. Generally, carbides are expected to be more stable in soil than composts, release nutrients slowly, and bring long-term benefits. For example, biochar (550°C) produced in Kansas has a high fixed carbon content (63.6% and 1.9% respectively) and is more stable in soil than food waste compost (Non-Patent Document 5). However, most prior studies comparing the persistence of biochar in soil have been those of lignocellulosic materials with low nutrients, produced at high temperatures (300°C or higher), and with a high C / N ratio (Non-Patent Document 6). 【0008】On the other hand, nutrient-rich carbonized materials such as biochar produced at low temperatures have a low C / N ratio and a high content of decomposable organic matter, so they decompose quickly in the soil environment, releasing nutrients and CO2. ２ The discharge of these materials may be increasing rapidly (Non-Patent Literature 7). However, the aromaticity of chars obtained by thermochemical conversion may play an important role in their resistance to biological or chemical decomposition. Furthermore, the stability of mainly aliphatic hydrochar (usually produced below 300°C) has never been compared to that of low-temperature (300°C) biochar. Therefore, it is of great interest to investigate whether nutrient-rich biochar and hydrochar applied as organic fertilizer are relatively more stable than composted manure. 【0009】Lehmann,J., Rondon,M., 2006. Bio-char soil management on highly weathered soils in the humid tropics. Biological approaches to sustainable soil systems 113, e530.Lehmann, Johannes, Abiven, S., Kleber, M., Pan, G., Singh, B.P., Sohi, S.P., Zimmerman, A.R., Lehmann, J, Joseph, S., 2015. Persistence of biochar in soil. Biochar for environmental management: Science, technology and implementation 2, 233-80.Zhou, H., Cao, J., Luo, J., Xu, R., Fu, B., 2023. Removal Rule, Ecological Risk, and Full-Scale Assessment of Antibiotics in Three Organic Fertilizer Production Methods. Journal of Environmental Engineering 149, 04023039.Piash,M.I., Iwabuchi,K., Itoh,T., Uemura,K., 2021. Releas of essential plant nutrients from manure-and wood-based biochars. Geoderma 397, 115100. https: / / doi.org / 10.1016 / j.geoderma.2021.115100.Aubertin, M.-L., Girardin, C., Houot, S., Nobile, C., Houben, D., Bena, S., Brech, Y.L., Rumpel, C., 2021.Biochar-compost interactions as affected by weathering: Effects on biological stability and plant growth. Agronomy 11, 336.Wang, J., Xiong, Z., Kuzyakov, Y., 2016. Biochar stability in soil: meta‐analysis of decomposition and priming effects. Gcb Bioenergy 8, 512-523.Piash, MI, Iwabuchi, K., Itoh, T., Uemura, K., 2021. Release of essential plant nutrients from manure-and wood-based biochars. Geoderma 397, 115100. https: / / doi.org / 10.1016 / j.geoderma.2021.115100. 【0010】 To address the aforementioned conventional concerns, the inventors have applied chicken manure-derived biochar, hydrochar, and composted chicken manure to soil and are conducting systematic comparative studies, comparative studies with biochar obtained through carbonization processes, studies on nutrient recovery rates and the possibility of subsequent release into the soil, and studies on stability. 【0011】 The present invention is based on the findings of the above research, and its objective is to provide biochar as a sustainable alternative fertilizer that serves as a plant nutrient that can be recycled in agriculture, and a method for producing the same. Furthermore, the present invention provides a manufacturing apparatus and method for efficiently producing chicken manure biochar of stable quality, equipped with drying, crushing, sieving, and a low-temperature carbonization furnace when producing biochar from chicken manure as a raw material. 【0012】(1) The biochar production apparatus according to the present invention is an apparatus for producing biochar using chicken manure as a raw material, and is characterized by comprising: (1) a drying chamber for drying chicken manure; (2) a grinding section for grinding the dried chicken manure; (3) a sieving section for adjusting the particle size to a predetermined particle size; (4) a carbonization furnace for heating the chicken manure after particle size adjustment to 250 to 320°C under an oxygen-restricted atmosphere; (5) an atmosphere control unit including (a) a nitrogen supply line, (b) an exhaust control valve, and (c) a multi-point temperature sensor for controlling the atmosphere inside the carbonization furnace; and (6) a cooling section for cooling the biochar after carbonization. In this invention, each of these components may be an integrated apparatus, a connected apparatus, or an apparatus that is not integrated or connected but is arranged in a continuous manner. 【0013】 Traditionally, the production of nutrient-rich biochar from chicken manure had not been carried out, and therefore, relatively small furnaces were used for the drying process. Furthermore, various types of chicken manure exist, differing in origin, farm, season, chicken breed, moisture content, and the nutrients contained in the manure. However, there was no equipment available to produce biochar in a stable and homogeneous state when using such diverse types of manure as raw materials. As a result, there were challenges in homogenizing the carbonization process and stabilizing the carbonization quality. In addition, some types of chicken manure have a high moisture content (60-80%) and are highly viscous, which can lead to temperature variations and localized accumulation of volatile components during carbonization. This resulted in inconsistent properties of the biochar obtained even when carbonized at around 300°C. This invention solves the problems of the past, as it includes a drying, crushing, sieving, and low-temperature carbonization furnace for producing biochar from chicken manure as a raw material. This stabilizes the drying process, enables continuous crushing and sieving, and reduces temperature unevenness inside the carbonization furnace through atmospheric treatment in the atmosphere control unit (furnace temperature control, atmosphere adjustment including volatile components inside the furnace, etc.) to stabilize carbonization under an oxygen-restricted atmosphere. As a result, stable quality chicken manure biochar can be efficiently produced even with relatively simple pretreatment. 【0014】 In the biochar production apparatus according to the present invention, the drying chamber is equipped with a stirring device for stirring the chicken manure and a heat generator for suppressing uneven drying of the chicken manure. 【0015】 According to this invention, chicken manure can be dried evenly and uniformly using an agitator such as an agitation tray and a heat generator. In this case, by also arranging a moisture sensor to detect the degree of dryness, the output of the agitator and heat generator can be adjusted according to the signal information from the moisture sensor. The moisture sensor is not particularly limited, but may be a weight-sensing type or an infrared type. The agitator is not particularly limited, but preferably a tray type, screw type, rod agitator type, or slanted drum type like a washing machine can be applied to arrange the chicken manure on the tray with a relatively uniform thickness by vibration. The heat generator is not particularly limited, but preferably one that generates hot air to blow onto the chicken manure, for example, a hot air circulation duct is preferred. 【0016】 In the biochar production apparatus according to the present invention, the pulverization section includes a hammer mill, a roller mill, and other pulverizing devices for pulverizing the dried chicken manure. 【0017】 According to this invention, chicken manure that has been dried until it can be crushed can be crushed. As a result, most of the chicken manure is sieved in the subsequent sieving section before being fed into the carbonization furnace, so that the carbonization state of the chicken manure supplied to the carbonization furnace can be made uniform or homogeneous. 【0018】 In the biochar production apparatus according to the present invention, the sieving section classifies the pulverized chicken manure into a predetermined size range (for example, 0.5 to 3 mm) to obtain a biochar precursor. 【0019】 According to this invention, since dried chicken manure, which is a biochar precursor of a predetermined size, can be supplied to the carbonization furnace, homogeneous biochar can be produced. Here, the biochar precursor is dried chicken manure that is in a state in which biochar can be homogeneously produced in the carbonization furnace, and specifically, the degree of dryness (moisture content), moisture unevenness, and particle size are within a predetermined range. 【0020】 In the biochar production apparatus according to the present invention, the atmosphere control unit controls the oxygen-restricted environment in the carbonization furnace using control elements including the nitrogen supply line, the exhaust control valve, and the multi-point temperature sensor. 【0021】 According to this invention, each control element can adjust the environment in the carbonization furnace to facilitate the production of biochar. As a result, biochar with uniform and stable properties can be produced. Furthermore, a nitrogen supply line and exhaust control valve can maintain a low-oxygen atmosphere in the carbonization furnace by nitrogen purging. In addition, it is preferable that the carbonization furnace is equipped with an exhaust structure for separating and discharging volatile gases (e.g., ammonia, volatile organic compounds (VOCs), sulfur compounds, etc.) generated in the carbonization furnace. The exhaust structure may be a single-stage exhaust structure or a two-stage exhaust structure that allows for gradual exhaust. The multi-point temperature sensor is a temperature sensor that measures the temperature at multiple points (upper, middle, lower, etc.) inside the carbonization furnace, and based on the results of the multi-point temperature sensor, a local heater can be activated to keep the temperature as constant as possible to prevent local temperature differences. These components allow for control over the carbonization temperature and gas environment within the carbonization furnace for chicken manure-derived biochar. Therefore, even if there are variations in the properties of the incoming chicken manure (depending on the origin, season, farmer, etc.), controlling various conditions makes it possible to stably produce biochar with the desired properties in high yield. 【0022】 The cooling section is responsible for cooling the high-temperature, carbonized biochar, and can be cooled using methods such as jacket cooling or dry air cooling. The amount of volatile gases varies depending on the type of chicken manure used, but in any case, a considerable amount of volatile gases are generated in the carbonization furnace, and these volatile gases can be effectively discharged. This exhaust structure, along with the nitrogen supply line described above, allows for oxygen restriction within the carbonization furnace, enabling control of the furnace atmosphere to one suitable for carbonization. 【0023】 In the biochar production apparatus according to the present invention, it is preferable that the temperature of the carbonization furnace is controlled based on temperature sensors installed at multiple locations within the carbonization furnace. Furthermore, it is preferable that the exhaust structure includes a filter unit to suppress dust diffusion. The apparatus may also include a PLC control unit that controls the entire apparatus. The PLC control unit controls the temperature of the dry material and carbonization furnace, drying time, carbonization time, nitrogen flow rate, and exhaust volume. 【0024】In the biochar production apparatus according to the present invention, the biochar production apparatus is controlled by an AI control system, which includes a cloud server that receives the required specifications for the biochar input from a user terminal and transmits the production conditions generated based on the required specifications to the biochar production apparatus, and the biochar production apparatus automatically controls the drying time in the drying chamber, the carbonization temperature in the carbonization furnace, the carbonization holding time, and the opening degree of the exhaust control valve according to the received production conditions. 【0025】 (2) A method for producing biochar by drying, crushing, sieving, and carbonizing chicken manure, equipped with an AI unit control mechanism, characterized in that the AI ​​control unit performs the following (a) to (d) control based on data obtained from a plurality of sensors installed in the drying chamber, carbonization furnace and exhaust line: (a) Automatic correction of drying temperature and drying time based on moisture sensor values; (b) Local temperature control of the carbonization furnace based on multi-point temperature sensors; (c) Control of exhaust valve opening degree based on volatile gas concentration; (d) Correction of stirring rod rotation speed based on raw material viscosity and particle size. 【0026】 (3) The biochar according to the present invention is characterized by being obtained by low-temperature thermal decomposition of chicken manure fertilizer using the biochar production apparatus or biochar production method according to the present invention described above. 【0027】 The resulting biochar can recover nitrogen from biomass and retain and sequester carbon, making it effective as a nutrient source for application to soil. It also streamlines the recycling of biological resources and waste management, and is superior to conventional composting (composting, CP production) and hydrothermal carbonization (HTC). 【0028】 In the biochar according to the present invention, the temperature of the low-temperature pyrolysis is 250 to 350°C. 【0029】 In the biochar according to the present invention, the nitrogen recovery rate from chicken manure compost is 70-80%, the nitrogen release rate into the soil is 90-100%, and the carbon emission rate into the soil is 20% or less. 【0030】According to this invention, the nitrogen recovery rate from chicken manure compost is 70-80%, the nitrogen release rate into the soil is 90-100%, and the carbon emission rate into the soil is 20% or less. As described above, nutrients can be efficiently recovered from chicken manure fertilizer, and it has the advantageous characteristics of having an extremely high nitrogen release rate into the soil and an extremely low carbon emission rate into the soil. The nitrogen recovery rate is the percentage of nitrogen retained from chicken manure compost to prevent it from escaping into the air, and the nitrogen release rate is the percentage of nitrogen released into the soil that can be used by crops and plants. A high nitrogen recovery rate is effective in utilizing the nitrogen nutrients in the raw material chicken manure fertilizer. A high nitrogen release rate leads to an improvement in the utilization rate of nitrogen nutrients by crops and plants. 【0031】 The biochar and its manufacturing method according to the present invention provide biochar as a sustainable alternative fertilizer that can be used cyclically as plant nutrients in agriculture, and a method for producing the same. The biochar according to the present invention can recover nitrogen from nutrient-rich biomass and retain and sequester carbon, making it effective as a nutrient source to be applied to soil, and it can streamline the recycling of biological resources and waste management, making it superior to conventional composting and hydrothermal carbonization (HTC) methods. 【0032】 Furthermore, the biochar production apparatus according to the present invention includes drying, crushing, sieving, and a low-temperature carbonization furnace for producing biochar from chicken manure as a raw material. This stabilizes the drying process, enables continuous crushing and sieving, and reduces temperature unevenness inside the carbonization furnace through atmosphere control in the atmosphere control unit to stabilize carbonization under an oxygen-restricted atmosphere. As a result, even with relatively simple pretreatment, stable quality chicken manure biochar can be efficiently produced. 【0033】(a) is a graph showing the nitrogen recovery rate, phosphorus recovery rate, and potassium recovery rate from chicken manure raw material for each of the following: biochar (a), hydrochar (b), and composted chicken manure (c). The FTIR spectral results are for chicken manure raw material, biochar, hydrochar, and chicken manure compost. (b) is the XPS spectral result for chicken manure raw material, (c) is the XPS spectral result for biochar, (d) is the XPS spectral result for hydrochar, and (e) is the XPS spectral result for chicken manure compost. The first value in parentheses in (b) to (e) indicates the percentage of that fraction in the total N peak. The graph shows the change in soil pH over time after applying chemical fertilizer (Control), chicken manure raw material, biochar, hydrochar, and chicken manure compost. This shows the time course of total available nitrogen (a) and nitrogen release rate (b) in soils treated with chemical fertilizer (Control), chicken manure raw material, biochar, hydrochar, and chicken manure compost, respectively. This shows the time course of total available phosphorus (a) and phosphorus release rate (b) in soils treated with chemical fertilizer (Control), chicken manure raw material, biochar, hydrochar, and chicken manure compost, respectively. This shows the time course of total available potassium (a) and potassium release rate (b) in soils treated with chemical fertilizer (Control), chicken manure raw material, biochar, hydrochar, and chicken manure compost, respectively. This shows the time course of cumulative CO2 in soils treated with chemical fertilizer (Control), chicken manure raw material, biochar, hydrochar, and chicken manure compost, respectively. ２ This shows the time course of emissions (a) and apparent carbon emission rate (b). This shows the time course of dissolved organic carbon (DOC) in soils treated with chemical fertilizer (Control), chicken manure raw material, biochar, hydrochar, and chicken manure compost, respectively. This is an overall configuration diagram showing an example of a biochar production apparatus according to the present invention. This is a configuration diagram showing an example of a drying chamber. This is a structural diagram showing an example of a carbonization furnace. This is an example of a control system for a biochar production apparatus. This is a system diagram showing an example of a biochar production apparatus using an AI control unit. This is an example of an AI control system equipped in a biochar production apparatus. This is an overall configuration diagram showing an example of an order-linked biochar production system. 【0034】The biochar and its production method according to the present invention will be described in detail based on its embodiments. Furthermore, the biochar production apparatus according to the present invention will be described in detail with reference to the drawings. Note that the following examples and embodiments are preferred examples of the present invention and should not be interpreted as limiting the scope to these embodiments. 【0035】 [Biochar and Method for Producing the Same] The biochar and method for producing the same according to the present invention are characterized by being obtained by low-temperature thermal decomposition of chicken manure fertilizer. In this way, it is possible to produce biochar that can recover nitrogen from nutrient-rich biomass and retain and sequester carbon. Such biochar is effective as a nutrient source to be applied to soil, and can improve the efficiency of biological resource recycling and waste management, and has been found to be superior to conventional composting and hydrothermal carbonization (HTC) biochar. Such biochar can be produced, for example, by the production apparatus shown in Figures 10 to 16, and the production apparatus is equipped with drying, crushing, sieving and a low-temperature carbonization furnace when producing biochar from chicken manure as a raw material, so that the drying process can be stabilized, the crushing and sieving can be made continuous, and temperature unevenness in the carbonization furnace can be reduced by atmosphere treatment in the atmosphere control unit to stabilize carbonization under an oxygen-restricted atmosphere. As a result, even if only relatively simple pretreatment is performed, chicken manure biochar of stable quality can be produced efficiently. 【0036】 This invention is based on findings obtained from the following experiments. Unless otherwise specified, "%" in the following refers to "weight % (mass %)". 【0037】 [Sample Preparation] <Materials and Methods> (Collection of raw materials and production of organic fertilizer) Fresh, wet chicken manure (hereinafter sometimes abbreviated as "CM" (Fresh chicken manure)) was collected from an egg production company located in central Hokkaido. The collected CM was transferred to the laboratory, and a portion of it was dried in an oven at 105°C for 24 hours to remove moisture. The dried CM was crushed, sieved through a 2 mm sieve, and then stored as a CM sample for analysis and use. 【0038】(Biochar Production) Biochar (hereinafter sometimes abbreviated as "BC") was produced by heating the stored CM sample. The heating was carried out by placing the stored CM sample in a crucible, transferring it to a muffle furnace, covering it, setting the initial heating rate to 10°C / min, and heating it at 300°C for 1 hour under oxygen-limited conditions in the muffle furnace. Biochar was produced in this way. After the produced biochar was cooled to room temperature, it was placed in a sealed plastic bag and stored as a BC sample. 【0039】 (Production of Hydrochar) Hydrochar (hereinafter sometimes abbreviated as "HC") was produced by mixing a fresh, wet CM sample with distilled water in a 70 mL stainless steel container in a 1:5 ratio. The container was then sealed, oxygen was removed using pure nitrogen, and it was placed in a reactor. A proportional-integral-derivative (PID) controller was used to reach the desired temperature of 260°C. The process was started at atmospheric pressure, and the mean pressure (autologous) rise in the reactor was approximately 5.4 MPa. After heating at 260°C for 1 hour, the reaction was terminated. The reactor was rapidly cooled by placing it in cold water. When the reactor reached room temperature, the pressure relief valve was opened to exhaust the gaseous product. To prevent the loss of water-soluble nutrients, the recovered HC-water mixture (slurry) was directly dried in an oven at 105°C for 24 hours. The dried HC sample was crushed, sieved through a 2 mm sieve, and stored in a sealed bag. 【0040】(Compost Production) Using fresh CM with a known moisture content, compost (also called compost; hereinafter sometimes abbreviated as "CP" (Biochar)) was produced in a laboratory-scale 1.7L stainless steel composting container. Approximately 3.66 kg of fresh CM with a moisture content of 71.6% was used in the composting (CP) process. The CP container was sealed with a lid and placed inside an insulated chamber. A thermometer capable of monitoring the sample and chamber temperatures was installed in the chamber. The chamber temperature was controlled to be 0.3°C lower than the sample temperature to reproduce full-scale CP in the laboratory. 0.4 L / min / kg of air, on a dry, ashless basis, was supplied to the CP container. Every week, the CP container was removed from the chamber, the raw materials inside were thoroughly rotated and mixed, and then returned to the chamber while maintaining the same conditions. CP was carried out for 28 days. During that time, the maximum temperature rose to approximately 70°C, and after 28 days it had dropped to room temperature. After 28 days, the CP was removed from the CP container, its moisture content was measured, and it was stored in a sealed bag. 【0041】 (Soil Collection and Processing) The soil used in the two cultivation tests was collected from the Hokkaido University experimental farm (43°04′24.2′N, 141°20′13.2′E). The average annual rainfall at this farm is 1106 mm, and the average annual temperature is 8.9°C. The collected soil was typical Japanese brown lowland soil, and was collected from the bottom 15 cm using a plow. It was then transported to a greenhouse, air-dried, crushed, and sieved through a 2 mm sieve. The basic characteristics of the soil are that it is a clayey soil consisting of 26.27% sand, 37.76% silt, and 35.95% clay. The soil was slightly acidic with a pH of 6.05, containing 1.91% carbon, 0.026% nitrogen, 0.11% phosphorus, and 0.14% potassium, and had a cation exchange capacity of 31.5 (me / 100g). 【0042】 [Test Method] Two different cultivation experiments (Experiment 1 and Experiment 2) were conducted to compare the release of nutrients and dissolved organic carbon (DOC) and carbon dioxide emissions from the produced organic fertilizer and the recommended chemical fertilizer. 【0043】 (Nutrient release test) To investigate the dynamics of nutrient release, a volume of 300 cm³ was used. ３Using the glass pots (Experiment 1). The treatment groups were the control group (without soil conditioner added), the soil treated with the recommended chemical fertilizers, and the soils with the application rates of BC, HC, and CP varied to supply the same amount of nitrogen as the chemical fertilizers (see Table 1). In the chemical fertilizer treatment, for 100 m ２ per area of soil for sweet corn production in Hokkaido, 12 kg of N was supplied as NH ４ SO ４ and 15 kg of P ２ O was supplied as Ca(H ５ PO ２ and 13 kg of K ４ ) ２ O was supplied as K ２ SO ２ SO ４ . To supply the same amount of nitrogen in the soil, BC, HC, and CP were applied at the amounts of 1.46 t / ha, 3.10 t / ha, and 2.8 t / ha, respectively. Each treatment was replicated 3 times. A total of 15 pots (5 treatments × 3 replications) were used for measuring the nutrient release amount. 100 g of dry soil and the necessary improvement materials were put into the pots, and finally distilled water was irrigated to maintain 60% of the maximum water holding capacity. The pots were sealed with a semi-transparent plastic sheet that allows air to pass through but not water, and were stored in a 20°C dark incubator during the culture period. On each sampling day, sub-samples of soil were collected from specific glass pots and the available nutrients were measured. If necessary, water was added for each soil sampling to maintain the moisture. 【0044】 【0045】 (CO ２Emission Test) To evaluate the stability of each organic fertilizer in soil, another culture test was conducted. A similar experimental plan was developed based on the same fertilization criteria as the nutrient culture experiment (Experiment 1) described above (Experiment 2, Table 1). Air-dried soil (15 g) and the appropriate fertilizer were placed in 100 mL glass vials and thoroughly mixed. Three vials were prepared for each treatment. The soil moisture content in each vial was adjusted to 60% of its maximum water retention capacity. The vials were sealed with rubber stoppers and plastic caps to restrict gas exchange. The vials were stored in a 20°C incubator. After each gas analysis, the rubber stoppers were opened for 20 minutes in a place with free air movement to replace the air in the vials with atmospheric air. The moisture content of the vials was also measured, and CO2 was used for CO2 analysis. ２ After measurement, the results were checked, and adjustments were made if necessary. 【0046】 [Analysis Method] (Analysis of Soil and Organic Fertilizer) The solid content yields of BC, HC, and CP were calculated by multiplying the ratio of the dry mass of the produced organic fertilizer (hereinafter sometimes abbreviated as "OF" (Organic Ferilizer)) to the mass of the dry biomass by 100. The pH of the soil and OF samples was measured using solid-liquid ratios of 1:2.5 and 1:5, respectively, after shaking at 120 rpm for 30 minutes. The total C, H, and N content of the soil and BC samples was measured using a CHN analyzer (CE440). The ash content (750°C) and volatile matter (950°C) of the BC samples were measured using the method of Singh et al. (Singh, B., Camps-Arbestain, M., Lehmann, J., 2017. Biochar: a guide to analytical methods. Csiro Publishing.) Total P, K, Ca, Mg, and Na in soil and BC were measured using ICP-OES (ICPE-9000, SHIMADZU) after digestion with a nitrate system. Nutrient recovery rate in the production process (the nutrient recovery rate [%] in the manufacturing process of each organic fertilizer, "R") nutirient The value was calculated using the following formula. 【0047】 【0048】 Here, SY (%) is the solids yield [NC ＯＦ (mg / kg) and NC feedstock[(mg / kg)] represents the nutrient content of the organic fertilizer and CM raw materials, respectively. 【0049】 (Extraction and Quantification of Nutrients) Soil was collected from culture pots, and pH and plant resources were measured on days 0, 3, 7, 14, 21, 28, 45, 60, 100, and 140 of cultivation. The pH of the culture soil was measured after shaking with distilled water in a 1:10 ratio at 120 rpm for 30 minutes, followed by 10 minutes of standing. Ammonium and nitrate nitrogen were extracted by adding 1 mol / L potassium chloride (KCl) solution and distilled water in a 1:10 ratio, respectively, and shaking at 120 rpm for 30 minutes. The distilled water extracts from days 28, 60, and 140 were also used to measure dissolved organic carbon (DOC). Ammonium-N extracted with KCl was distilled after extraction to remove interference from other cations during quantification. The concentrations of ammonium and nitrate nitrogen in these solutions were measured using a capillary electrophoresis system (Agilent 7100). Available phosphorus and potassium were extracted using Mehlich-3 extractant. The phosphorus and potassium concentrations in the extract were 61% (w / v) HNO ３ Acid decomposition was performed using [a specific method], and the results were measured using an inductively coupled plasma emission spectrometer (ICP-OES, ICPE-9000, manufactured by Shimadzu). The apparent amount of nutrients (N) released into the soil from each fertilizer was measured. released The percentage (%) was calculated using the following formula. 【0050】 【0051】 Here, SNC soil and of (mg / kg) and SNC soil (mg / kg) represents the extractable nutrients in the mixture (soil and OF) and soil (control), respectively, and ANC OF (mg / kg) represents the applicable nutrient amount according to OF. 【0052】 (Fourier Transform Infrared Spectroscopy: FTIR) FTIR analysis of each organic fertilizer (sometimes abbreviated as "OFs") was performed using a spectrometer (IRT-3000N, manufactured by JASCO) equipped with an ATR (Attenuated Total Reflectance) device. For the analysis, the generated BC, HC, and CP were dried at 105°C, homogenized, pulverized, and sieved through a 0.5 mm mesh. The FTIR spectrum was obtained from 4000 to 550 cm⁻¹.－１ Measurements were taken 128 times within the range, with a resolution of 4 cm. －１ The effects of ambient humidity and carbon dioxide were eliminated by subtracting the background spectrum within the detection chamber from the spectrum of each sample. Each sample was analyzed multiple times to obtain uniform spectral data. Peaks were then identified by comparison with the reference (Tipson, RS, 1968. Infrared spectroscopy of carbohydrates. US Dept. of Commerce, National Bureau of Standards.). 【0053】 (X-ray photoelectron spectroscopy: XPS) For XPS analysis, the same sample as for FTIR described above was used. The sample was prepared by wrapping the powder in indium foil using a hydraulic press (THM017), and the outer surface (~6 nm) of the CM and OF was analyzed using an X-ray photoelectron spectroscopy analyzer (JPS-9200, JEOL). A monochromatic Mg-Kα X-ray source (output 10 kV / 10 mA, spot size approximately 3 mmφ) was used as the X-ray source. The number of integrations was 3 for wide scan, 40 for the N1s orbital, and 20 for the C1s orbital. The charge shift of the sample particle surface due to X-rays was calibrated using a C1s binding energy of 285.0 eV. The obtained spectra were processed and peak split using the analysis software SPECSURF Analysis (JEOL). Polynomial fitting (Savitzky-Golay) was used for spectrum smoothing. Background correction was performed using the Shirley method to remove noise. A mixture function of Gaussian and Lorentz functions was used to separate each peak. The spectral peaks were identified according to the following literature. 【0054】 (DOC analysis) The dissolved organic carbon (DOC) in the treatment areas (28 days, 60 days, 140 days) was found in the above distilled water extracted soil solution (NO ３ -N) was determined by measuring it with a TOC meter (TOC-L CPH, manufactured by Shimadzu Corporation). 【0055】 (CO ２Emission Analysis) The carbon dioxide concentration in the vial was analyzed using a GC4000 gas chromatograph (GL Sciences). At 1, 3, 7, 14, 21, 28, 42, 56, 77, 98, 119, and 140 days after the start of culture, 1 mL of gas was extracted from the headspace of the vial using a syringe, and CO2 was processed. ２ The concentration was measured. After that, this CO ２ By multiplying the concentration by the total headspace volume, the amount of CO2 emitted from the treatment process within a specific period can be calculated. ２ The cumulative CO2 from a certain day's processing was calculated. ２ Emissions were the same as before. ２ This is the total amount of emissions. The apparent carbon emission rate (mg / g fertilizer - carbon) is the amount of CO2 released from the treatment. ２ -Calculated by subtracting the amount of control released from the total amount of C and dividing by the amount of C applied by the OF treatment. 【0056】 (Statistical Analysis) Significant differences between treatment groups were quantified using one-way ANOVA. Tukey's test (5% level) was performed to quantify significant differences between treatments. Statistical analysis of the data was performed using R statistical software (version 4.3.2). 【0057】 [Results] (Characteristics of biochar, hydrochar, and compost) The characteristics of the produced organic fertilizers are shown in Table 2. The amount of organic fertilizer (BC, HC, CP) produced from CM was similar across all processing methods, ranging from 64% to 69%. The pH was highest for CP at 8.97, while BC and HC were almost the same, slightly exceeding 7.5. HC had the highest ash content, while CP had 60% volatile content. HC had the highest carbon content at 38.7%, followed by BC and then CP. However, the fixed carbon content of BC (19.2%) was about twice that of HC and about four times that of CP. BC also had the highest nitrogen content at 8.2%, almost twice that of HC (4.3%) and CP (3.9%). On the other hand, CP had the highest concentrations of P (4.2%) and K (3.4%). The C / N ratio of BC was the lowest at 4.6, followed by HC at 9.0 and CP at 8.1. The H (hydrogen) / C (carbon) molar ratio was lowest for BC (0.95), with the highest aromaticity, followed by HC (1.17) and CP (1.54). 【0058】 【0059】 (Nutrient Recovery) The nitrogen content of BC was higher than that of other OFs, and the solids yield (%) was relatively similar, resulting in a remarkably high nitrogen recovery rate for BC (Figure 1(a)). Surprisingly, BC was able to retain 76.4% of the nitrogen, compared to the much lower recovery rates of HC (37.4%) and CP (36.2%). This means that most of the N in CM was lost during the HTCT hydrothermal carbonization and CP conversion processes. No statistically significant difference was observed between the two. 【0060】 The recovery rate of P and K by pyrolysis slightly exceeded 100%, indicating that almost no P and K were lost during the production process (Figure 1(b)(c)). Also, as shown in Figure 1, in the production of CP, almost 100% of the nutrients could be recovered (P: 100.7%, K: 101%). On the other hand, in the production of HC (HTC process), 100% of P was recovered, but some K (~8%) was lost. Overall, the recovery rates indicate that even if HC and CP lose a considerable amount of nitrogen (more than 60%), almost 100% of P and K in CM can be recovered. 【0061】 (Surface properties of OF) As shown in Figure 2, the FTIR analysis results showed that CP exhibited a spectral pattern most similar to that of raw CM. For example, 1650 cm⁻¹ represents N-C=O. －１ The peak is common to both samples. This peak is represented by protein, amine, and amide-N. However, after thermal decomposition or hydrothermal carbonization, this peak was not as pronounced. Rather, BC was 1684 cm⁻¹. －１ The strongest nitrogen peak was observed in the amide group, with HC at 1584 cm⁻¹. －１ to C=N(+C=C) / NH ３ ＋ A small peak representing (pyrimidine or amine salt) was observed. Unprocessed CM, CP, HC at 1415 cm⁻¹. －１ The aliphatic C-C bond was suppressed in BC. Rather, at 1500-1600 cm －１ The small peaks in between may be evidence of multiple double bonds in aromatic rings such as C=C or C=N. All samples showed values ​​of 1000–1030 cm⁻¹.－１ The strongest peak at 860–930 cm² indicates the presence of C–O and / or Si–O, which originates from the quartz fraction in the manure given with poultry feed. －１ The calcium phosphate peak is at 1236 cm. －１ An ester peak (-C=O) was observed. 【0062】 XPS data from raw material CM and CP clearly showed that the N-I fraction (Protein-N, Amino-N, Amide-N, Nitrile; 89.9%) of raw material CM remained largely unchanged after composting (Figure 3(b)(e)). N remained the dominant form in CP as well (399.7±0.1eV, 65.1%). However, some of the readily soluble nitrogen (N-I) was converted to pyridine nitrogen (N-II, 15.3%) and pyrrole nitrogen (N-III, 19.6%). On the other hand, when raw material CM was thermally decomposed, the relatively stable pyridine nitrogen (N-II) became the most dominant nitrogen fraction (38.2%), followed by readily soluble N-I (35.3%) (Figure 3(c)). The HC recovered after HTC treatment consisted mainly of relatively stable pyrrolic-N (N-III, 43.7%), followed by N-I at 34.6% (Figure 3(d)). Correlation between the relative proportions of N compounds and the total elemental N content of each OF was examined. The readily soluble N-I fraction of BC was the most abundant (2.88% of total mass), followed by CP (2.52%) and HC (1.47%). Relatively stable forms of N (pyridine N and pyrrolic N) were dominant in the HC fraction (2.8% of total mass), accounting for the highest relative proportion (65.4%) among the OFs. The N-II and N-III fractions combined accounted for 64.7% of BC and 34.9% of CP. 【0063】 (Changes in soil pH) Chemical fertilizer treatment (also known as "CF treatment") significantly lowered the soil pH (Figure 4). The average soil pH in the control group was 6.2, while in the CF-treated group it was 5.7. None of the OF treatments significantly altered the average soil response. At the end of the cultivation period, the pH of the control soil was 6.0, while the pH of BC, HC, and CP were 5.9, 6.0, and 6.0, respectively. 【0064】 (Nitrogen Release) Of all the OFs, biochar treatment (also called "BC treatment") released the most available nitrogen, which was closest to the available nitrogen of the recommended amount of CF treatment (Figure 5(a)). After 100 days of cultivation, the available nitrogen was highest for the recommended CF treatment at 179 mg / kg compared to 159 mg / kg for the BC treatment. This suggests that the application rate of BC (1.46 t / ha) can meet 88% of the recommended N supply for optimal sweet corn production. CP released the second most N among the OFs, followed by HC, which released the least. Figure 5(b) shows that the apparent nitrogen releases from BC, HC, and CP were 100%, 33%, and 85%, respectively. Nitrogen release from HC was significantly lower than that from the other OFs. The total nitrogen releases from BC and CP were not significantly different, but the initial release from BC was much higher than that from CP (Figure 5(b)). BC released a large amount of nitrogen between days 0 and 3, while CP released the most significant amount between days 46 and 60. 【0065】 Figures 5(a) and 5(b) show nitrogen release from OF and conversion of ammonium to nitrate nitrogen. All OF initially released nitrogen as ammonium, which was gradually converted to nitrate nitrogen. The ammonium content of CF, BC, and CP peaked within 3 days and continued to be released until day 21. After that, no significant ammonium content was observed in any of the treatments except for the one at day 100. The converted nitrate initially reached its maximum within 28 days, and then reached its maximum point after 100 days of incubation. The nitrate content in all treatment groups showed a decrease between days 100 and 140. 【0066】(Phosphorus Release) Comparing the available phosphorus in the soil, all OF treatments were able to increase the available phosphorus to nearly the maximum level achievable with recommended chemical fertilizers (195.3 mg / kg) (Figure 6(a)). CF treatment rapidly released phosphorus immediately after soil application, but the available amount decreased gradually until 7 days later, after which it increased again. The available phosphorus content reached its maximum level (195.3 mg / kg) with CF treatment after 45 days of cultivation. The available phosphorus content in the soil was similar with HC treatment (197.4 mg / kg) after 45 days, BC treatment (192.4 mg / kg) after 60 days, and CP treatment (195.4 mg / kg) after 100 days, but CP showed the highest available phosphorus content after 3 days of cultivation (210.1 mg / kg). With CP treatment, much of this phosphorus became unavailable after 7 days, and then, after many fluctuations, the available amount began to increase, peaking at 100 days. This data suggests that even if the phosphorus content of organic fertilizers is much lower than that of carbon dioxide (CF), it may still be possible to meet the phosphorus requirements of plants. 【0067】 Regarding the apparent release rate of plant-available phosphorus (P) from each fertilizer, BC and HC both released their maximum amounts of P after 45 days of cultivation, at approximately 100% and 78%, respectively (Figure 6(b)). In contrast, P release from CP was quite gradual, except for a rapid release three days after the start of cultivation (~123%) (average of ~38% up to 60 days). The amount of P released from CF in a plant-available form was even lower, with a maximum release of only 45.8%. This suggests that OF may release more P than CF, or create more favorable conditions for P to be available in the soil. 【0068】(Potassium Release) Initially, the K content in the soil was highest in the CF-treated group and remained higher than most other treatment groups except for HC and CP throughout the cultivation period (Figure 7(a)). After 3 days of cultivation, the available K content in the CO-treated group (757 mg / kg) exceeded that of the CF-treated group. Similarly, on day 14, the available K content in the HC group (751 mg / kg) exceeded that of the CF-treated group. The available K content in the BC-treated soil did not reach the recommended OF level. The available K content in the CF-treated group was relatively stable, but in the organic treatments, the available K content in the soil peaked in the first 14 days, then decreased sharply, and rose again by the end of the cultivation period. On average, the available K was 22 mg / (kg-soil) less than the recommended amount in the HC and CP groups, compared to 34 mg / (kg-soil) less in the BC-treated group. When examining the amount of potassium released from each treatment, all synthetic and chemical fertilizers released 100% of their original potassium within the first 14 days (Figure 7(b)). The apparent potassium release data for organic fertilizers fluctuated more significantly than that of the relatively stable CF treatment. 【0069】 (Stability of biochar, hydrochar, and compost in soil) After application to soil, organic fertilizers normally undergo decomposition. This includes physicochemical decomposition and microbial decomposition, resulting in CO2 decomposition. ２ CO is released and organic carbon dissolution occurs. Below, CO from OF ２ This section explains the release of [substance A] and the release of [substance B]. 【0070】 (CO2 from fertilizer) ２ Emissions) When applied as OF, CP releases the maximum amount of CO2 from the soil. ２ It emitted CO2 (Figure 8(a)). CF emissions were the lowest, and decreased even further from the control group. Among OFs, BC application was more CO2 than CP. ２ Emissions were significantly lower. During the first two weeks, CO2 emissions from HCs were reduced. ２ Although the cumulative emissions of BC were lower, after 21 days of culture, the cumulative emissions of HC exceeded those of BC, and after 140 days of culture, emissions were 9.4% higher. Data analysis showed that CO2 emissions within 28 days after application of OF were lower. ２Initially, the excretion rates were much higher for CP and BC. Subsequently, the excretion rates decreased considerably and followed a relatively stable trend (Figure 8(b)). However, the C excretion rate for HC was relatively gradual in the early stages and showed a gradual increasing trend towards the end of the culture. 【0071】 As is clear from Figure 8(b), the carbon of BC (CO ２ The apparent degradation rate of ) is slower than any other OF within 140 days. By the end of the culture, 267 mg / (g-C) of CP is CO ２ CO2 was emitted as [amount omitted], while the amount emitted from BC was less than half of that, at 116 mg / (g-C). ２ Initially, the carbon emission rate of BC was considerably slower than that of CP and BC. However, after 77 days, the cumulative carbon emissions exceeded those of BC. After 140 days of cultivation, the decomposition rate of BC was only 11.6%, proving that BC was the most stable organic fertilizer treatment, followed by HC (14.9%) and CP (26.7%). Furthermore, a slight decrease in the cumulative apparent carbon emissions from BC was observed after 21 days. Note that the apparent carbon emissions are calculated by subtracting the emissions from the control group. The significant increase in carbon emissions from the control group compared to BC after 21 days may have caused this trend. 【0072】 (Release of dissolved organic carbon) The amount of water-soluble organic carbon released by various treatments was investigated over a cultivation period of 28, 60, and 140 days. As a result, the dissolved organic carbon (DOC) content was found to be the same as the amount of CO2 emitted. ２- It was found to be considerably lower than C. In all observation intervals, HC consistently showed the highest level of DOC (Figure 9). In Figure 9, three bar graphs are touching for each organic treatment, such as BC, HC, and CP, with the left graph showing the results after 28 days of culture, the middle graph after 60 days of culture, and the right graph after 140 days of culture. After 140 days of culture, HC measured 49 mg / kg, particularly in dry soil, which was the highest DOC concentration. At 28 and 60 days, BC's DOC concentration was the second highest among all organic treatments. In contrast, CP had a significantly lower DOC concentration compared to the control, recording 29 mg / kg in dry soil after 28 days. Nevertheless, after 140 days of culture, CP released DOC content significantly faster than the other treatments, ultimately resulting in the second highest DOC concentration (46 mg / kg dry soil). 【0073】 (Total amount of carbon emitted from OF) Emitted CO ２ The total amount of carbon released from OF was calculated by adding -C (mg / g OF-C) and DOC (mg / g OF-C) released into the soil after 140 days of cultivation. As a result, BC was the most stable OF, and the amount of released carbon (CO) was calculated. ２ The total amount of carbon (as DOC) was lowest for BC-C (127 mg / g), followed by HC (169 mg / g HC-C) and CP (282 mg / g CP-C). This composite analysis of apparent released carbon shows that the degradation rate of HC is significantly higher than that of BC (33%), but significantly lower than that of CP (40%). 【0074】 [Review of Results] (Nutrient Recovery) The results above confirmed that BC effectively retains nitrogen despite being produced at low temperatures, compared to HC and CP. The loss of nitrogen during the OF production process is undesirable because it disrupts the nutrient cycle in agricultural ecosystems and leads to the emission of nitrogen-containing greenhouse gases. An investigation into the reasons for the significant nitrogen loss from the hydrothermal carbonization (HTC) and CP processes revealed different mechanisms. 【0075】Firstly, readily soluble proteins are the dominant form of nitrogen in CM, and therefore can easily undergo a deamination process in HTC to form independent ammonia. In the hydrothermal decomposition process of HTC, reactions occur with subcritical water. Ammonia is the main byproduct of the hydrolysis of various nitrogen-containing substances in CM, including amines, proteins, and amino acids, and it has been reported that more than 80% of the constituent nitrogen in CM is converted to ammonia in HTC at 300°C and 350°C. In HTC at 240°C and 270°C, the movement of sewage sludge-N involves a conversion from liquid to gas, which is also called deamination of low molecular weight amines, amino acids, and nitriles, and is converted to gaseous-N. It is thought that some of this ammonia leaked out as gas when the HTC container was opened in this experiment, and that most of the dissolved nitrogen in the liquid was subsequently lost by volatilization during drying at 105°C. Increasing the temperature for HC production accelerates deamination and promotes the conversion of nitrogen between the liquid and gas phases, which is thought to further decrease the nitrogen recovery rate. Therefore, the HTC process is not very effective for nitrogen recovery. 【0076】 Secondly, the biological depolymerization and ammoniaization processes of CP formation cause nitrogen loss from CM. Depolymerization breaks down long protein chains and nucleic acids into amino acids, amino sugars, and nucleotides. These ammoniaizations then produce ammonium, and under high temperature (~60°C) and alkaline pH conditions, NH ３ It is released as a gas. Furthermore, the volatilization loss of ammonia during CP formation is accelerated when the C / N ratio is low, the temperature of the CP formation pile is high, and the pH exceeds 7. Since the C / N ratio was low at 5.2 and the temperature during the CP formation process was approximately 70°C, it is thought that the loss of nitrogen due to volatilization was accelerated in this experiment. 【0077】On the other hand, during the pyrolysis process, the deamination by subcritical water and the biological degradation of protein-N did not occur. Therefore, the loss of N due to low-temperature biochar production was much less. Furthermore, nitrogen loss from biomass during pyrolysis usually begins at around 200°C. However, generally, the loss is small up to 300°C. During pyrolysis, inorganic N functional groups begin to decompose at 200°C, nitriles at 250°C, amides at 400°C, and pyrrolic-N and pyridine-N at 500°C. Amides are one of the main forms of N in CM-BC and decompose at high temperatures such as 400°C, so in the BC production at 300°C for 1 hour in this experiment, amides could not be decomposed, resulting in a high retention rate of N. At temperatures above 320°C, decomposition begins, and biomass-N becomes N ２ NH ３ HCN, NO ｘ This process involves conversion to other substances, resulting in losses. In the thermal decomposition of pig manure, only 6% of nitrogen is lost when treated at 300°C, compared to 19% when treated at 500°C. Therefore, the high nitrogen recovery rate achieved by low-temperature (300°C) thermal decomposition is an innovative and interesting method that retains 76% of the nitrogen from CM, opening up an effective way to reuse this valuable biological resource in agricultural ecosystems. 【0078】 As a result, most of the phosphorus (P) and potassium (K) in compost can be recovered using any processing method. During carbonization and composting, organic phosphorus (P) is converted to inorganic phosphorus (P) by thermal decomposition or enzymatic activity. These compounds are usually not easily lost by volatilization at such low temperatures (~300°C). Therefore, almost no P was lost. The volatilization temperature of potassium (K) and its by-products is also very high (~760°C). Therefore, most of the potassium (K) was retained. From the perspective of hydrothermal carbonization (HTC), if only solid HC is recovered after hydrothermal carbonization, most of the potassium may be lost because it remains in a highly water-soluble form. In this experiment, the liquid portion was dried together with the solid HC, so the recovery rate of potassium (K) was relatively high (~92%). Considering the high nitrogen recovery rate by low-temperature (300°C) thermal decomposition and the nearly 100% retention rate of phosphorus (P) and potassium (K), BC production from compost can be said to be the most appropriate option for nutrient recovery and recycling. 【0079】(Persistence of Organic Fertilizers in Soil) BC has been repeatedly reported to be more stable than conventional compost and can be used for carbon sequestration in soil. Therefore, it was essential to compare the carbon stability of BC, HC, and CP derived from nutrient-rich CM, which have potential for use as organic fertilizers. Initially, considering the final carbon content and yield, BC (67.6%) had the highest carbon retention (recovery) capacity, followed by HC (64.9%). This recovery rate of BC is even higher than that of BC from corn silage produced at 500°C (44.9%), and it is expected to be an energy-efficient carbon recovery method. After application to soil, CM-BC (lowest C / N ratio) had the lowest CO2 emissions among all organic matter treatments. ２ It released CO2. CP and HC released 19% and 9.5% more CO2 than BC within 140 days of culture. ２ It released CO2 (Figure 8(a)). This indicates that even if nutrient-rich BC is used as organic fertilizer, it releases more CO2 than conventional OFs such as CP and compost. ２ This suggests that emissions may be low. 【0080】 Regarding relative carbon stability, approximately 12% of BC-carbon was mineralized within 140 days of cultivation, making it 15% more stable than CP-carbon and 3.5% more stable than HC-carbon (Figure 8(b)). This relatively slow decomposition rate is primarily due to the high fixed carbon content of BC. The fixed carbon content of BC was almost twice that of HC (approximately 19%) and about four times that of CP (Table 1). Secondly, the lowest H / C ratio of BC (0.95) indicates high aromaticity of its carbon structure. The aromaticity of BC, as seen in FTIR spectral results, suggests that the initial mineralization rate of BC may exceed the overall mineralization rate throughout its lifecycle due to the rapid decomposition of the non-aromatic carbon fraction. As a result, BC may persist in the soil for longer periods than suggested by short-term cultivation tests. However, compared to standard wood biochar produced at high temperatures, manure biochar produced at low temperatures has a higher VM and N content, resulting in more CO2. ２ It can be said that it may release [something]. 【0081】 From the DOC content in the treated material, CO2 was determined to be produced by HC treatment. ２Despite the initial lowest release of CO2, it was revealed that DOC release was highest with this treatment (within 28 days). Previous studies have reported that after hydrothermal treatment at 160°C, 220°C, and 250°C, the carbon solubilization rate increased from 4.6% in raw sewage digestate to 31.7%, 32.6%, and 30.5%, respectively. DOC is easily decomposed by microorganisms, and CO2 ２ It is expected to be released as CO2 or lost through leaching. Some of the dissolved organic carbon in the HC liquid slurry remains loosely bound to its surface and is thought to be rapidly released when applied to soil. On the other hand, the carbon in mineralized BC and CP is directly released as CO2 by microbial respiration. ２ It was converted to DOC released from HC, but the apparent emission C (CO) from HC was the highest among OFs. ２ The contribution rate to the sum of -C and DOC was low, at only 6.7% at the end of the culture period. 【0082】 FTIR and XPS analysis revealed that CM-CP has a similar composition to the raw material CM (N-C=O and C-C stretchable, protein or amide 399.7 eV; Figures 2(a) and 3(e)). On the other hand, the composition of thermochemically treated BC and HC changed significantly. It was found that BC and HC contain many C=C structures (pyrimidine, aromatic C=C) that are difficult to decompose. This is consistent with the stability experiment (CO) conducted in this experiment. ２ The results were found to be consistent with those of emission. It has been reported that HC contains more aliphatic carbon than BC, which has lower thermal and chemical stability. In addition, the aliphatic peak of HC (1415 cm) was observed. －１ ) is a more stable C=C structure in BC (1500-1600 cm －１ It was found that it had changed to ). Therefore, BC has higher persistence in the soil than high-concentration hydrocarbon treatment, and CO ２ Furthermore, the emission of dissolved organic carbon was low. Therefore, CM-BC is expected to be more effective than HC and CP in sequestrating recalcitrant organic matter (carbon) in the soil. 【0083】(Nutrient Release) Compared to the recommended CF, BC was the most effective in meeting the N requirements of sweet corn (88%). This suggests that even when supplying the same amount of N with different organic fertilizers, the N release rate from pyrolysis CM is the highest. In the inventors' previous research, CM-BC produced at 300°C also released a considerable amount of N (49% at 40 ton / ha) (Non-Patent Literature 4). However, the apparent release rate from CMB300 (100% from 1.46 ton / ha) is much higher in this study. This high N release may be attributed to the relatively low application rate of BC (0.07% on a dry basis), which is almost half that of HC and CP. 【0084】 FTIR and XPS analysis were used to further understand the chemical forms of nitrogen in organic fertilizers and to clarify the reason for the high nitrogen release of CM-BC. XPS analysis revealed that CM-BC contained the most readily soluble protein-N, amino-N, amide-N, and nitrile (N-I fraction, 2.8% of total mass) compared to HC (1.47%) and CP (2.52%). However, in this experiment, the same amount of organic fertilizer was not applied to the soil; rather, the same amount of nitrogen was applied. Therefore, it was expected that compost, where 65% of the N is readily soluble protein-N, amino-N, amide-N, and nitrile-N, would release far more N than BC (where N in this form is 35%). Nevertheless, the release of N from BC was rapid and slightly higher than that from CP. This high nitrogen release is thought to be due to two factors. 【0085】 Firstly, BC contains a large amount of readily soluble nitrogen, particularly amides as seen in the FTIR spectrum. The amides in BC are primary amides (1684 cm²) bonded to the surface. －１ ) whereas the nitrogen compounds of CP are structurally bonded secondary amides (1650 cm²). －１) required depolymerization and a long decomposition process to release nitrogen. Secondly, BC produced at 300°C usually contains all forms of nitrogen in biomass, as well as the nitrogen forms of BC produced below 500°C. In this experiment, no very stable forms of nitrogen (pyridine oxide or quaternary nitrogen) were observed. Therefore, thermal decomposition at 300°C produces intermediate forms of N in BC that are either soluble (usually contained in biomass or other soluble forms) or decompose in soil (pyridine-N or pyrroline-N). On the other hand, the N in CP (Figure 2) had already undergone microbial decomposition and was not decomposed within 140 days. Thus, CP released N more slowly and in slightly less quantities than BC. 【0086】 Interestingly, the amount of nitrogen released by HTC (HC treatment) was the lowest, at only 33%. This can be attributed to the fact that the releaseable N (in CM) dissolved during the manufacturing process and was lost during subsequent drying (volatilization). The remaining N in HC may be structurally bound or aromatic. The results of XPS analysis support this consideration, and HC had the highest proportion of relatively stable pyridine-N and pyrroline-N compared to BC and compost (65.4% and 2.8% of the total mass). 1584 cm －１ The presence of a strong peak nearby is also evidence that HC contains stable pyrimidine-N (FTIR, Figure 2). Therefore, the amount of nitrogen released by HC treatment is small and may not be effective in meeting the nitrogen requirements of crops. To overcome the loss of N in HC and the low release into the soil, the HC slurry can be applied directly to the soil without drying or freeze-dried before use. However, such a large amount of dissolved ammonium suddenly released into the field may result in losses and reduce nutrient utilization efficiency. 【0087】Data on the availability of phosphorus (P) in the soil suggest that even when organic fertilizers were applied at doses that met the crop's nitrogen (N) requirements, all of them were sufficient to make enough P available to the sweet corn (at least once during the growing period). All OF treatments had lower intrinsic P content than CF (75.0 mg / kg). CP treatment added 41.2 mg of P per kg of soil, while HC treatment added 41.2 mg and BC treatment added only 19.9 mg. This suggests that OF may be advantageous for P utilization even with lower P inputs. In particular, BC significantly increased the amount of P available in the soil and demonstrated the ability to create favorable conditions for soil-specific P release. The ability of BC to increase soil-available P is thought to be due to 1) changes in soil pH and the resulting dissolution of fixed Ps, and 2) the release of phosphate ions from the soil through substitution with anions introduced by BC. 【0088】 Most of the potassium in CM typically remains in potassium feldspar, which can be converted to diphosphate or silvite after thermal decomposition. When potassium feldspar is converted to silvite, KNO3, or diphosphate, the solubility of potassium increases. However, in this experiment, the amount of potassium released from BC was never sufficient. Since the process water of HC was not discarded, most of the potassium was retained and eventually released. However, the overall data trends (especially after 21 days) suggest that none of the organic fertilizer application rates may be sufficient to meet the potassium requirements of the plants. Furthermore, the unavailability of the potassium initially released from OFs in the later stages of cultivation may hinder potassium uptake during the plant's growth phase. 【0089】 Overall, BC treatment releases enough nitrogen for plants to absorb, and can potentially meet phosphorus requirements with roughly half the application rates of HC and CP. Furthermore, a slight increase in application rate could potentially meet most of the potassium requirements. Therefore, considering the combined nutrient (NPK) release potential of these three organic fertilizers, producing BC from CM by thermal decomposition is economically feasible, as it can meet the requirements for one crop cycle with a reasonable application rate. 【0090】(Relationship between OF decomposition and nutrient release) The decomposition rates of BC, HC, and CP are expected to correlate with the release of nutrients from them. In that case, CP should release far more NPKs than BC. However, the decomposition rate of BC (CO ２ Even though BC released the most nitrogen (including CO2) for the same amount of N applied, it released the most N. This is thought to be because the aromatic structure of BC carbon (lowest H / C ratio) is resistant to decomposition, and the nitrogen in CM-BC may not be structurally bonded. The nitrogen in CM-BC is not structurally bonded, but dissolves as an amide and is adsorbed (or bonded) to the surface of BC. On the other hand, the nitrogen in CP is structurally bonded by a long aliphatic carbon chain, and the carbon chain must first be cleaved in order to release nitrogen. Therefore, BC releases more nitrogen than CP through decomposition and CO2. ２ It can be released with minimal release of other substances. The release rates of P and K in BC were also the highest, which is likely because the solubility of P is high in BC treatment where the soil pH is low. 【0091】 As described above, pyrolysis of potentially harmful chicken manure at low temperatures (300°C) and its application to soil as a nutrient source can be a more efficient method of biological resource recycling and waste management. This technology is superior to conventional composting and hydrothermal carbonization in that it recovers nitrogen and sequesters carbon from nutrient-rich biomass. It can retain nitrogen from chicken manure (preventing it from escaping into the air) (nitrogen recovery rate). Furthermore, contrary to predictions, it improves crop nutrient utilization by accelerating the release of nitrogen available to plants. By producing nutrient-rich biochar-based organic fertilizer, the present invention could help achieve several Sustainable Development Goals. It can achieve food safety and provide solutions for waste management, pollution prevention, and GHG mitigation (SDGs 2, 6, 13). 【0092】 [Biochar Production Apparatus] The biochar production apparatus according to the present invention is capable of efficiently producing biochar of stable quality by low-temperature thermal decomposition of chicken manure fertilizer. The biochar production apparatus according to the present invention will be described in detail with reference to Figures 10 to 16. 【0093】 Traditionally, the production of nutrient-rich biochar from chicken manure had not been carried out, and therefore, relatively small furnaces were used for the drying process. Furthermore, various types of chicken manure exist, differing in origin, farm, season, chicken breed, moisture content, and the nutrients contained in the manure. However, there was no equipment available to produce biochar in a stable and homogeneous state when using such diverse manure as a raw material. As a result, there were challenges in homogenizing the carbonization process and stabilizing the carbonization quality. In addition, some chicken manure has a high moisture content (60-80%) and is highly viscous, which can lead to temperature unevenness and localized accumulation of volatile components during carbonization. This resulted in inconsistent properties of the biochar obtained even when carbonized at around 300°C. 【0094】 The biochar production apparatus 1 according to the present invention solves the problems of the conventional method and is an apparatus for producing the biochar according to the present invention using chicken manure as a raw material. Specifically, as shown in Figure 10, the biochar production apparatus 1 comprises (1) a drying chamber 20 for drying chicken manure, (2) a grinding section 30 for grinding the dried chicken manure, (3) a sieving section for adjusting the particle size to a predetermined size, (4) a carbonization furnace 41 for heating the chicken manure after particle size adjustment to 250 to 320°C under an oxygen-restricted atmosphere, (5) an atmosphere control unit 60 including (a) a nitrogen supply line, (b) an exhaust control valve, and (c) a multi-point temperature sensor for controlling the atmosphere inside the carbonization furnace, and (6) a cooling section 50 for cooling the biochar after carbonization. Each of these components may be an integrated apparatus, a connected apparatus, or an apparatus that is not integrated or connected but is arranged continuously. 【0095】 This apparatus 1 solves the problems of conventional methods and is equipped with a drying chamber 20, a crushing section, a sieving section 30, and a low-temperature carbonization furnace 41 for producing biochar from chicken manure as a raw material. This stabilizes the drying process, enables continuous crushing and sieving, and reduces temperature unevenness inside the carbonization furnace through atmospheric treatment in the atmosphere control unit (furnace temperature control, atmosphere adjustment including volatile components inside the furnace, etc.) to stabilize carbonization under an oxygen-restricted atmosphere. As a result, stable quality chicken manure biochar can be efficiently produced even with relatively simple pretreatment. 【0096】 The drying chamber 20 may not have an agitator, as shown in Figure 11, but it is preferable to have an agitator for agitating the chicken manure, as shown in Figure 10. Furthermore, it is preferable to have a heat generator (e.g., a hot air circulation duct 21) to suppress uneven drying of the chicken manure. The agitator, such as an agitation tray, and the heat generator allow for uniform and even drying of the chicken manure. In this case, by also arranging a moisture sensor to detect the degree of dryness, the output of the agitator and heat generator can be adjusted according to the signal information from the moisture sensor. The moisture sensor is not particularly limited, but may be a weight-sensing type or an infrared type. The agitator is not particularly limited, but tray type, screw type, rod agitator type, or slanted drum type like a washing machine can be preferably applied to arrange the chicken manure on the tray in a relatively uniform thickness by vibration. The heat generator is not particularly limited, but it is preferable to have one that generates hot air to blow onto the chicken manure, for example, a hot air circulation duct 21. 【0097】 As shown in Figure 13, the crushing section 25 is configured to include a hammer mill, roller mill, and other crushing devices for pulverizing dried chicken manure. This crushing section allows for the crushing of chicken manure that has been dried to a pulverizable state. As a result, most of the chicken manure is sieved in the subsequent sieving section before being fed into the carbonization furnace, thus ensuring that the carbonization of the chicken manure supplied to the carbonization furnace is uniform or homogeneous. 【0098】 As shown in Figure 10, the sieving section 30 classifies the crushed chicken manure into a predetermined size range (for example, 0.5 to 3 mm) to obtain a biochar precursor. By sieving in the sieving section, dried chicken manure, which is a biochar precursor of a predetermined size range, can be supplied to the carbonization furnace, thereby enabling the production of homogeneous biochar. Here, the biochar precursor is in a state where it can be homogeneously produced as biochar in the carbonization furnace, and specifically, it is dried chicken manure in a state where the degree of dryness (moisture content), moisture unevenness, and particle size are within a predetermined range. 【0099】The carbonization processing unit 40 includes, for example, a carbonization furnace 41, a rotary stirring rod 42, a hopper 43, a nitrogen supply line 44, an exhaust control valve 45, and a multi-point temperature sensor 46, as shown in Figures 10 and 12. The carbonization furnace 41 is a container for carbonizing sieved dried chicken manure and is made of a heat-resistant container that can be used for heating treatment at around 300°C. Multiple multi-point temperature sensors 46 are provided at arbitrary locations in the carbonization furnace 41. In the example in Figure 12, they are provided at three locations: the top, the middle, and the bottom. Furthermore, the carbonization furnace 41 is equipped with a nitrogen supply line 44 and an exhaust control valve 45. These allow the oxygen inside the carbonization furnace 41 to be purged with nitrogen, creating a low-oxygen state. In Figure 10, a rotary stirring rod 42 is provided, which stirs the dried chicken manure introduced into the carbonization furnace 41, allowing the dried chicken manure, a precursor to biochar, to be heated evenly. As a result, it is possible to suppress nitrogen loss due to localized overheating, for example, exceeding 320°C. 【0100】 It is preferable that the temperature of the carbonization furnace is controlled based on temperature sensors installed at multiple locations within the carbonization furnace. The temperature of the carbonization furnace is preferably in the range of 250°C or higher and less than 320°C, and more preferably in the range of 280°C or higher and 300°C or lower. In the above-described embodiment, it was found that the N retention rate was high at low carbonization temperatures (300°C or lower), and that decomposition progressed and N loss increased at temperatures of 320°C or higher. 【0101】The atmosphere control unit controls the oxygen-restricted environment inside the carbonization furnace using control elements including a nitrogen supply line 44, an exhaust control valve 45, and a multi-point temperature sensor 46. Each control element adjusts the environment inside the carbonization furnace to facilitate biochar production. As a result, biochar with uniform and stable properties can be produced. The nitrogen supply line 44 and exhaust control valve 45 maintain a low-oxygen atmosphere by purging nitrogen inside the carbonization furnace. Furthermore, it is preferable that the carbonization furnace 41 is equipped with an exhaust structure for separating and discharging volatile gases (e.g., ammonia, volatile organic compounds (VOCs), sulfur compounds, etc.) generated inside the carbonization furnace. The exhaust structure may be a single-stage exhaust structure or a two-stage exhaust structure that allows for gradual exhaust. The multi-point temperature sensor 46 is a temperature sensor that measures temperature at multiple points inside the carbonization furnace (upper, middle, lower, etc.), and based on the results of the multi-point temperature sensor 46, local heaters can be activated to keep the temperature as constant as possible to prevent local temperature differences. These components allow for control over the carbonization temperature and gas environment within the carbonization furnace for chicken manure-derived biochar. Therefore, even if there are variations in the properties of the incoming chicken manure (depending on the origin, season, farmer, etc.), controlling various conditions makes it possible to stably produce biochar with the desired properties in high yield. 【0102】 The exhaust structure preferably includes a filter unit to suppress dust diffusion. It may also include a PLC control unit to control the entire apparatus. The PLC control unit controls the temperature of the dry material and carbonization furnace, drying time, carbonization time, nitrogen flow rate, and exhaust volume. 【0103】 As shown in Figures 10 and 13, the cooling section 50 is the part that cools the carbonized biochar in a high-temperature state, and cooling methods such as jacket cooling or dry air cooling can be applied. Although it is difficult to generalize as the amount of volatile gases varies depending on the chicken manure, in any case, a considerable amount of volatile gases are generated in the carbonization furnace, so these volatile gases can be effectively discharged. With this exhaust structure and the nitrogen supply line described above, oxygen can be limited in the carbonization furnace, and the furnace atmosphere can be controlled to be suitable for carbonization. 【0104】(AI Control) The biochar production apparatus according to the present invention preferably includes an AI control unit, as shown in Figure 14. Data from various sensors shown in Figure 14 is sent to this AI control unit, and the processing unit can be controlled based on this data. In other words, the sensors can capture the variable factors specific to biochar production, and the carbonization conditions can be dynamically corrected. More specifically, the AI ​​control unit performs control based on information obtained from multiple sensors installed in the drying chamber, carbonization furnace, and exhaust treatment device. Such control includes (a) a control step of automatically adjusting the drying temperature and drying time based on the input value from the moisture sensor, (b) a control step of locally controlling the heating heater output based on temperature gradient information from multi-point temperature sensors in the carbonization furnace, and (c) a control step of adjusting the exhaust valve opening based on the ammonia and VOC concentrations in the exhaust gas. 【0105】 These control steps enable the use of an AI model to predict the next drying time based on the moisture content history, to optimize the carbonization holding time based on the particle size distribution of the precursor, and to automatically increase the rotation speed of the stirring rod when the VOC concentration increases. 【0106】 (AI Control System) The biochar production apparatus according to the present invention is used as equipment owned by the biochar manufacturer in a system between chicken manure suppliers (poultry farmers, poultry farms), biochar manufacturers (individuals or businesses), and chicken manure consumers (farmers, agricultural farms). The biochar production apparatus may be owned by the chicken manure supplier, thereby enabling them to produce biochar from chicken manure generated in their own chicken coop using their own production apparatus. 【0107】The biochar production apparatus according to the present invention is controlled by an AI control system 100 illustrated in Figure 15. In this AI control system 100, the biochar requirement specifications 102 input from a user terminal 101 are sent to a cloud server 103, and the cloud server 103 generates production conditions 107 based on the requirement specifications 102. The generated production conditions 107 are sent to an AI control unit 104, which automatically controls the drying process 111, the crushing process 112, the carbonization process 113, and the cooling process (not shown). In other words, the AI ​​control system 100 includes a cloud server 103 that receives a biochar requirement specification 102 input from a user terminal 101 and transmits the manufacturing conditions 107 generated based on the requirement specification 102 to the biochar production apparatus 105. The biochar production apparatus 105 is characterized by its ability to automatically control the drying time in the drying chamber 111, the carbonization temperature in the carbonization furnace 113, the carbonization holding time, and the opening degree of the exhaust control valve according to the received manufacturing conditions 107. 【0108】 Furthermore, the system can obtain moisture information from chicken manure suppliers (poultry farmers, poultry farms) via IoT. It can also automatically create a carbonization schedule based on user order quantities. Additionally, it can automatically generate shipment decisions with attached product inspection data as needed. 【0109】 The production of biochar involves physical changes in process control, as the production conditions are reflected in each control unit of the manufacturing equipment. Therefore, it's not simply a matter of "order → production," but rather a process that requires physical changes in process control. 【0110】 Because the moisture content, viscosity, and volatile components of chicken manure vary greatly from batch to batch, conventional technologies have resulted in low reproducibility of carbonization quality. In this invention, information from multiple sensors installed in the drying chamber, crushing section, sieving section, carbonization furnace, cooling section, and exhaust line is collected in real time, and an AI control unit dynamically adjusts (1) drying conditions, (2) carbonization temperature distribution, (3) exhaust valve opening, (4) stirring rod rotation speed, and (5) input amount. This control reduces fluctuations in carbonization quality due to variations in the physical properties of chicken manure, making it possible to ensure stable biochar quality. 【0111】The AI ​​control system can handle data from drying process sensors, moisture sensors (infrared / gravimetric), temperature sensors, and dry air flow rate sensors. Furthermore, for the crushing and sieving processes, it can handle data from particle size distribution sensors (image analysis or vibrating sieve feedback, etc.), flow rate sensors, carbonization furnace sensors, multi-point temperature sensors (at predetermined locations such as the upper, middle, and lower parts of the carbonization furnace), stirring load torque sensors (viscosity indicators), furnace pressure sensors, nitrogen flow rate sensors, and exhaust gas sensors (e.g., NH4). ３ Concentration (electrochemical formula), VOC concentration sensor (PID formula), CO ２ Examples include concentration, etc. 【0112】 The AI ​​control unit's calculations include, for the drying correction algorithm, correction of the estimated drying completion time based on moisture history, and optimization of the next drying step based on the degree of concentration. Furthermore, correction of temperature unevenness during carbonization can be performed by estimating the temperature gradient from multiple points (T1, T2, T3) and controlling the local heater output to minimize ΔT at ΔT = T1 - T3. In addition, for volatile gas control, when VOC levels rise sharply, the exhaust valve opening is automatically adjusted, and NH ３ During rising pressure, control measures such as increasing the stirring speed and exhaust can be implemented. Furthermore, for feedforward control, the carbonization holding time can be automatically calculated from the initial moisture content and particle size of the raw material, allowing for adjustments to variations in physical properties. 【0113】 The biochar production method equipped with such an AI unit control mechanism is a method for producing biochar by drying, crushing, sieving, and carbonizing chicken manure, and is a process control method in which the AI ​​control unit performs the following controls (a) to (d) based on data obtained from multiple sensors installed in the drying chamber, carbonization furnace and exhaust line: (a) automatic correction of drying temperature and drying time based on moisture sensor values, (b) local temperature control of the carbonization furnace based on multi-point temperature sensors, (c) control of exhaust valve opening based on volatile gas concentration, and (d) correction of stirring rod rotation speed based on raw material viscosity and particle size. 【0114】Figure 16 is an overall configuration diagram showing an example of an order-linked biochar production system. This biochar production system 120 shows the flow of user order 124 → quality inspection information 125 → cloud server 121 → AI control 122 → equipment group 123. The produced biochar 126 is then shipped to the user. The quality inspection information 125 includes biochar particle size, fixed carbon content target, nutritional value (nitrogen retention), shipping form (powder / fine granules), batch quantity, etc. Other data includes raw material data from chicken manure farmers, past order history, logistics information, shipping information, quality inspection data, etc. 【0115】 As explained above, the biochar production apparatus according to the present invention is highly effective in optimizing carbonization conditions through AI control. In other words, since changing the control conditions of the production apparatus (temperature, holding time, exhaust, stirring, etc.) changes the properties of the biochar (N retention rate, fixed carbon, volatile matter), the properties of the biochar can be managed by controlling them with AI. In the above-described embodiment, it was found that the N retention rate was high at low carbonization temperatures (below 300°C), and decomposition progressed and N loss increased at temperatures above 320°C. 【0116】 Here, regarding the relationship between temperature control and nitrogen retention, nitrogen compounds in chicken manure tend to volatilize rapidly at a temperature of 320°C. Therefore, if there is a large temperature unevenness within the carbonization furnace and there are parts within the furnace where the temperature exceeds 320°C locally, nitrogen loss will increase in those parts. To solve this problem, in this invention, if the temperature unevenness can be maintained within ±5°C within a temperature range of, for example, 280 to 300°C by using a multi-point temperature sensor and local heater control, biochar with a high nitrogen retention rate can be stably obtained. 【0117】 Next, regarding the relationship between exhaust valve control and N loss (volatile behavior), if the exhaust valve opens too rapidly, the negative pressure inside the furnace increases, promoting the release of volatile N compounds. In this invention, volatile organic compounds (VOCs) / NH ３ Controlling the valve opening based on sensors has the advantage of preventing excessive negative pressure and contributing to the suppression of N-loss. 【0118】Regarding the relationship between stirring control (viscosity countermeasures) and temperature uniformity, chicken manure has high viscosity, and if it is not dried sufficiently and stirred inadequately, clumps will form in the manure, and the inside will become an overheated region. For example, stirring control such as controlling the rotation speed of the stirring rod enables uniform heating, which has the advantage of preventing nitrogen decomposition due to overheating. 【0119】 Regarding the relationship between drying conditions and carbonization behavior, excessive drying (e.g., prolonged holding at 120°C or higher) imparts a thermal history to the precursor, making the N compound more susceptible to decomposition during the subsequent carbonization stage. In this invention, if drying can be controlled while measuring the moisture content, the nitrogen retention rate can be increased by minimizing the thermal history. 【0120】 The relationship between temperature control and nitrogen retention can be understood from the results of the above examples at 300°C and 320°C. Furthermore, regarding the relationship between exhaust valve control and nitrogen loss (volatilization behavior), stirring control (viscosity countermeasures) and temperature uniformity, and the relationship between drying conditions and carbonization behavior, results have already been obtained showing that there is a point beyond a threshold where nitrogen loss occurs when the control conditions are changed. Since it has been found that these various controls affect changes in physical properties (nitrogen retention, nitrogen loss), it is desirable to have a manufacturing apparatus that can perform such controls. 【0121】 As described above, the biochar and its manufacturing method according to the present invention provide biochar as a sustainable alternative fertilizer that can be used cyclically as plant nutrients in agriculture, and a method for producing the same. The biochar according to the present invention can recover nitrogen from nutrient-rich biomass and retain and sequester carbon, making it effective as a nutrient source to be applied to soil, and it can also streamline the recycling of biological resources and waste management, making it superior to conventional composting and hydrothermal carbonization (HTC) biochar. 【0122】Furthermore, the biochar production apparatus according to the present invention includes drying, crushing, sieving, and a low-temperature carbonization furnace for producing biochar from chicken manure as a raw material. This stabilizes the drying process, enables continuous crushing and sieving, and reduces temperature unevenness inside the carbonization furnace through atmosphere control in the atmosphere control unit to stabilize carbonization under an oxygen-restricted atmosphere. As a result, even with relatively simple pretreatment, stable quality chicken manure biochar can be efficiently produced. 【0123】 1 Biochar production equipment 20 Drying chamber (drying section) 21 Hot air circulation duct 30 Sieving section 40 Carbonization section 41 Carbonization furnace 42 Rotary stirring rod 43 Hopper 44 Nitrogen supply line 45 Exhaust control valve 46 Multi-point temperature sensor 50 Cooling section 60 Control unit 61 AI control unit 62 Data storage 63 Sensor 100 AI control system 101 User terminal 102 Biochar requirements 103 Cloud server 104 AI control unit 105 Biochar production equipment 106 Control signal transmission 107 Production conditions 111 Drying process (drying chamber) 112 Grinding process (grinding section) 113 Carbonization process (carbonization furnace) 120 Biochar production system 121 Cloud server 122 AI control 123 Quality inspection information 124 User Orders 125 Quality Inspection Information 126 Biochar

Claims

1. A biochar production apparatus for producing biochar using chicken manure as a raw material, comprising: (1) a drying chamber for drying chicken manure; (2) a grinding section for grinding the dried chicken manure; (3) a sieving section for adjusting the particle size to a predetermined size; (4) a carbonization furnace for heating the chicken manure after particle size adjustment to 250 to 320°C under an oxygen-restricted atmosphere; (5) an atmosphere control unit including (a) a nitrogen supply line, (b) an exhaust control valve, and (c) a multi-point temperature sensor for controlling the atmosphere inside the carbonization furnace; and (6) a cooling section for cooling the biochar after carbonization.

2. The biochar production apparatus according to claim 1, wherein the drying chamber is equipped with a stirring device for stirring the chicken manure and a heat generator for suppressing uneven drying of the chicken manure.

3. The biochar production apparatus according to claim 1 or 2, wherein the grinding section includes a hammer mill, a roller mill, and other grinding devices for pulverizing the dried chicken manure.

4. The biochar production apparatus according to claim 1 or 2, wherein the sieving section classifies the pulverized chicken manure into a predetermined size range to obtain a biochar precursor.

5. The biochar production apparatus according to claim 1 or 2, wherein the atmosphere control unit controls the oxygen-restricted environment in the carbonization furnace using control elements including the nitrogen supply line, the exhaust control valve, and the multi-point temperature sensor.

6. The biochar production apparatus according to claim 1 or 2, wherein the temperature of the carbonization furnace is controlled based on temperature sensors installed at multiple locations within the carbonization furnace.

7. The biochar production apparatus according to claim 1, wherein the biochar production apparatus is controlled by an AI control system, the AI ​​control system includes a cloud server that receives the required specifications for the biochar input from a user terminal and transmits the production conditions generated based on the required specifications to the biochar production apparatus, and the biochar production apparatus automatically controls the drying time in the drying chamber, the carbonization temperature in the carbonization furnace, the carbonization holding time, and the opening degree of the exhaust control valve according to the received production conditions.

8. A method for producing biochar, comprising an AI unit control mechanism, for drying, crushing, sieving, and carbonizing chicken manure, characterized in that the process control method includes the AI ​​control unit performing the following controls (a) to (d) based on data obtained from a plurality of sensors installed in the drying chamber, carbonization furnace, and exhaust line: (a) Automatic correction of drying temperature and drying time based on moisture sensor values; (b) Local temperature control of the carbonization furnace based on multi-point temperature sensors; (c) Control of exhaust valve opening degree based on volatile gas concentration; (d) Correction of stirring rod rotation speed based on raw material viscosity and particle size.

9. A biochar characterized by being obtained by low-temperature thermal decomposition of chicken manure fertilizer using the biochar production apparatus described in claim 1 or the biochar production method described in claim 8.

10. The biochar according to claim 9, wherein the temperature of the low-temperature pyrolysis is 250 to 350°C.

11. The biochar according to claim 9, wherein the nitrogen recovery rate from chicken manure compost is 70-80%, the nitrogen release rate to the soil is 90-100%, and the carbon emission rate to the soil is 20% or less.

Images