Method for producing immediately effective organic fertilizer from organic waste

Abstract

To provide a pretreated product for fermentation-producing an organic fertilizer from organic waste, and a treatment method therefor.SOLUTION: Organic waste including sludge, garbage, and animal or human excrement blended with a vegetative cellulose substrate material as a superheated steam reaction decomposition promoting agent which contains, as a main component, crushed powder having an average particle diameter of 10 mm±5 mm in length including sawdust, wood dust, straw, chaff, branches, bark, wood chips, and dried grass is decomposition-treated by superheated steam reaction at a low temperature of 300°C or less, giving superheated steam-pretreated organic waste having a carbon ratio of not more than 50%. This causes fermentation time for producing an immediately effective organic fertilizer by aerobic fermentation to be half or less of fermentation time for a non-pretreated product.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a method for producing a fast-acting organic fertilizer by fermenting organic waste pretreated using a superheated steam reaction. [Background technology]

[0002] Organic fertilizers are not immediately effective after application, and most of them are slow-acting, beginning to work after 30 to 40 days due to decomposition by microorganisms in the soil. In recent years, due to the soaring prices of chemical fertilizers, there is a demand for the production of fast-acting organic fertilizers by effectively utilizing the organic waste that is increasing in the city. A technology has been proposed in which an approximately equal amount of cellulose substrate material such as sawdust, straw, rice husks, etc. is added to the organic waste, and microorganisms that ferment and decompose the organic matter are added to this, and fermentation treatment is carried out while adjusting the moisture content (Patent Document 1), and organic fertilizer is produced from food waste and sludge discharged from sewage treatment facilities. However, this method requires time for the fermentation and decomposition of organic waste, so it takes as long as four months to obtain organic fertilizer. In addition, this long fermentation treatment causes the emission of foul odors, which is a problem in terms of its impact on the environment, and therefore cannot be processed in urban areas.

[0003] Therefore, the present inventors have proposed a method of performing subcritical treatment at high temperatures and high pressures of 15 to 40 atmospheres and 200 to 250°C in order to decompose polymeric compounds such as proteins and cellulose in organic waste and to rapidly carry out the subsequent fermentation treatment (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] PCT / JP98 / 02655 publication [Patent Document 2] JP 2018-70386 A [Patent Document 3] JP 2010-216748 A [Patent Document 4] JP 2015-223542 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned reaction in subcritical conditions, sludge is converted into particulate low-molecular-weight organic matter suitable for fermentation by useful microorganisms at only 150°C, 15 atm, and a treatment time of 20 minutes. However, it was found that when the reaction temperature exceeds 200°C, the decomposition of the organic matter proceeds too much, and the carbonization rate of the organic matter increases. Furthermore, subcritical water reaction equipment is expensive, and a batch system must be adopted, which limits the treatment capacity. In other words, a single pretreatment facility in subcritical conditions can treat sludge at most 5 tons / day, which is far from the recent demand of treating 100 tons / day at one facility with 8-hour operation.

[0006] The present inventors have found that organic waste treated with a superheated steam reaction at low temperatures has properties that are favorable for promoting fermentation. That is, 1) in order to be suitable for the subsequent fermentation process, it is necessary to control the decomposition of the organic matter to an appropriate level while suppressing the carbonization rate to 50% or less. On the other hand, 2) they have found that treatment in a batch-type subcritical pressure vessel is not suitable for fermentation treatment in combination with a cellulose substrate material because decomposition proceeds too much in the subcritical reaction. Based on this knowledge, the present invention is a result of intensive research and an objective of the present invention to provide organic waste treated with a treatment method that is an alternative to the subcritical pretreatment method and that can promote fermentation, and a treatment method that can shorten the time required for fermentation production of organic fertilizer using the organic waste. [Means for solving the problem]

[0007] As a result of intensive research conducted by the present inventors in order to meet the above requirement 1), they found that organic waste treated at low temperatures using superheated steam is more suitable for promoting fermentation treatment in combination with a cellulose substrate than batch-type pre-treated waste in a subcritical state under high temperature and high pressure. Conventionally, superheated steam has only been used as a drying means and carbonization means for high-water content sludge at high temperatures exceeding 300°C, and has not been used as a pre-treatment for fermentation treatment (Patent Document 3, Patent Document 4). However, when one focuses on the reaction mechanism (Figs. 4 and 5), it is surprising that, unlike the reaction of subcritical water under high pressure in a pressure vessel, in the superheated steam reaction temperature range of 150°C to 300°C depending on the water content, a moderate low-temperature decomposition treatment of organic waste can be realized by the superheated steam reaction, and that it is suitable for pre-treatment of decomposition of organic matter in combination with a cellulose substrate while suppressing the carbonization rate as a pre-treatment for fermentation treatment. In other words, they discovered that when a superheated steam reaction is carried out in a steam reactor while stirring the superheated steam and organic waste and keeping the internal temperature of the organic waste below 300°C, not only is dehydration carried out efficiently and the carbonization rate of the organic waste kept to 50% or less, but the fermentation process is accelerated when used in combination with a cellulose substrate material, and a deodorized, sterilized, and harmless organic fertilizer is produced in less than half the time required for conventional fermentation processes.

[0008] The present invention was made in view of the discovery that it is possible to achieve a treatment suitable for fermentation treatment in combination with a cellulose substrate material by using superheated steam, which is inexpensive and has a large treatment capacity compared to subcritical water treatment, which is expensive and has a small treatment capacity. The present invention relates to a pretreatment material that can shorten the fermentation treatment time, which is: Organic waste, including sludge, food waste, and animal or human excrement, is decomposed at a low temperature of 300°C or less in a superheated steam reaction with a mixture of a plant-based cellulose substrate material, the main component of which is crushed powder with an average particle size of 10 mm ± 5 mm including sawdust, wood chips, straw, rice husks, branches, bark, wood chips, and dried grass, as a superheated steam reaction decomposition accelerator, to provide pretreated organic waste with a carbon content of not more than 50% (Figure 8).

[0009] The fermentation time required for the pretreated organic waste of the present invention to produce an appropriate organic fertilizer varies depending on the superheated steam reaction treatment conditions. Therefore, it is appropriate to determine the number of treatments depending on the treatment capacity of the reactor or the intended use (when used as a cowshed flooring material, it is preferable to treat once or twice, and to prepare organic fertilizer, it is preferable to repeat the treatment three or more times). The treated organic waste can be repeatedly used as a superheated steam reaction promoter.

[0010] Next, the present invention also provides a method for producing an organic fertilizer, which is characterized in that the above-mentioned cellulose substrate material is used as a superheated steam reaction decomposition accelerator and is used to decompose pretreated organic waste having a carbon content not exceeding 50%, and the pretreated organic waste is mixed with the above-mentioned cellulose substrate material in a volume ratio of 2:1 to 1:2, and one or more microorganisms having fermentation decomposition activity are selected from the following group, and the fermentation period is half that of the conventional method: Note Bacteria: Bacillus subtilis;Bacillus stearothermophilus;Clostridium thermocellum, Mold: Aspergillus oryzae;Aspergillus niger;Aspergillus fumigatus;Chaetomium thermophile;Humicola lanuginosa;Rhizopus javanicus, Yeast: Candida glabrata;Debaryomyces hansenii;Hansenula anomala;Pichia membranaefaciens;Rhodotorula glutinis;Saccharomyces cerevisiae, Actinomycetes: Actinobifida dichotomy, Streptomyces griseus, Streptomyces thermophilus, Thermoactinomyces vulgaris, Thermomonospora glaucus and Monascus sp. Effect of the Invention

[0011] According to the present invention, a pre-treated material can be provided that can shorten the fermentation time when used in combination with a cellulose substrate material. This superheated steam reaction treated material can be repeatedly used as a superheated steam reaction promoter, reducing the amount of paid cellulose substrate material used. It can also be used as a cowshed flooring material. Furthermore, it is a versatile material that can be used as a precursor for the production of fast-acting organic fertilizer.

[0012] The organic waste treated with superheated steam in accordance with the present invention can reduce the time required for the subsequent fermentation process by half or more depending on the number of times of treatment, i.e., depending on the degree of peptide formation of proteins, which are polymeric compounds in the organic waste, and the degree of hydrolysis of cellulose. In addition, since the waste is deodorized and sterilized, the problems associated with conventional fermentation processes can be eliminated.

[0013] Furthermore, it is possible to produce an organic fertilizer obtained by fermentation treatment that has a fertilizer effect of 80 me / 100 g or more in cation exchange capacity (CEC) as determined by soil analysis. If the pretreated organic waste is made by spreading the above-mentioned cellulose substrate material on the floor of a cowshed and using cow dung collected as the raw material, the carbon rate of the obtained organic fertilizer is 50% or less, and the fertilizer effect is 100 me / 100 g or more in cation exchange capacity (CEC) as determined by soil analysis, whereas the fertilizer effect of normal cow dung fermented is about 50 me / 100 g on average, so it is clear that this is an excellent organic fertilizer. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing an entire superheated steam facility for performing pretreatment. [Diagram 2] FIG. 1 is a schematic diagram showing an example of equipment for fermenting pretreated organic waste. [Diagram 3] (a) Schematic diagram of the superheated steam reactor in Figure 1, and (b) is a schematic diagram of the inside. [Figure 4] A comparison diagram of the heat capacity of superheated steam and hot air. [Diagram 5]This is a comparison diagram of the temperature rise of superheated steam and hot air. [Figure 6] FIG. 1 is a component analysis diagram of organic waste (cow dung) before superheated steam treatment. [Figure 7] FIG. 1 is a component analysis diagram of organic waste (cow dung) after superheated steam treatment. [Figure 8] Photograph of organic waste after superheated steam treatment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The organic waste treated with superheated steam that is the subject of the fermentation treatment of the present invention has a carbon content of 50% or less and is an organic waste selected from the group consisting of sludge, food waste, fishery waste, and animal or human excrement that has been pretreated to a state that is easy to ferment with microorganisms. When pretreating organic waste with superheated steam, the pretreatment facility shown in Fig. 1 can be used. The facility in Fig. 1 has a superheated steam means for producing superheated steam at 200°C or higher, preferably 250°C to 500°C, and blowing in the superheated steam, agitation and transport means for transporting the superheated steam and organic waste from an inlet IN to an outlet OUT while agitating and mixing them in the furnace, and a reaction control means for subjecting the agitated and transported organic waste to a superheated steam reaction in a temperature range of 150°C to 300°C, and is equipped with a superheated steam reaction furnace that decomposes, deodorizes, and sterilizes the organic waste while suppressing carbonization of the organic waste at low temperatures of 150°C to 300°C.

[0016] In the above-mentioned superheated steam treatment furnace, organic waste is converted into low molecular organic waste suitable for fermentation treatment by reaction with superheated steam, and this is fermented in combination with a cellulose substrate material, so that the fermentation treatment time can be shortened to half, preferably to less than one third, of the conventional fermentation treatment, and the fermentation treatment equipment can be made compact. Moreover, since the waste is deodorized, dehydrated, and sterilized by reaction with superheated steam, there is no environmental pollution. Considering its function, superheated steam has a higher heat capacity than hot air as shown in Figure 4, and has a temperature rise efficiency as shown in Figure 5. In the superheated steam furnace, the superheated steam comes into contact with and penetrates the organic waste stirred in the furnace, so that it is thought that the organic matter can be efficiently heated at a low temperature, decomposing the polymeric substances, and dehydrating and deodorizing them.

[0017] In the present invention, for mass production, organic waste can be continuously treated, and 100 tons / day of pretreated material can be provided in 8 hours at one facility. In addition, compared to high-temperature, high-pressure subcritical treatment of organic waste, the carbonization rate of the organic matter does not exceed 50%, so the efficiency of the subsequent fermentation treatment is not reduced. In order to increase the reaction efficiency with superheated steam, the pretreated organic waste is preferably treated by containing a pretreatment promoter containing a cellulose-containing base material selected from the following group in a volume ratio of 2:1 to 1:3 relative to the organic waste. A plant-based cellulose substrate material including sawdust, wood chips, straw, rice husks, branches, bark, wood chips, and dried grass, crushed powder with an average length of 10±5 mm. In the case of cow manure, these cellulose substrate materials are laid in the cowshed, so there is no need to mix any cellulose substrate material into the manure collected from the cowshed.

[0018] The above-mentioned superheated steam reactor is provided with an agitation means consisting of a ribbon blender as an agitation and transport means, and the reactor is provided with a superheated steam space of 50% or more, but this is not limited to this. Here, a ribbon blender is usually formed with two ribbon blades in the horizontal direction as shown in Figure 3 (b), and the agitated material flows inward due to the outer blade close to the case, and strong collisions occur repeatedly, while the agitated material flows outward due to the inner blade close to the main shaft, and hits the side case and moves to the outer blade, repeating the agitation motion, so that the contact reaction with the superheated steam occurs efficiently. By devising the ribbon shape, the agitation motion of the front, back, inside and outside can be adjusted, and the transportation from IN to OUT can be performed while stirring, but a transport roller conveyor can also be attached to the bottom of the reactor.

[0019] The pretreated material of the present invention may be treated by connecting two or more superheated steam reactors in series depending on the reaction treatment capacity of each superheated steam reactor, or may be treated repeatedly in one reactor. The degree of treatment can be appropriately selected depending on the fermentation treatment conditions in the subsequent stage.

[0020] The organic waste to be treated by the present invention preferably includes food waste such as vegetable scraps and fish bones discharged in large quantities from food retailers such as supermarkets, sludge generated during sewage treatment discharged from sewage treatment facilities, and livestock manure discharged from poultry farms and livestock farms. These wastes have a high moisture content and have traditionally been incinerated, but by treating them with superheated steam, they become pre-treated material that can be turned into fertilizer in a short period of time.

[0021] The process of fermenting organic waste is preferably a process of piling a mixture of pretreated organic waste and wood waste, which is a cellulose substrate, and culturing it in a solid state under aerobic conditions while controlling the temperature and moisture content in combination with the cellulose substrate. This makes it possible to lower the molecular weight of the polymers contained in the organic waste, improving the fertilizer effect, and to obtain a powdered organic fertilizer that is easy to apply. This is an advantageous measure because the pretreated material that has been subjected to subcritical treatment has a high carbon content and may be overtreated, making it difficult to ferment when used in combination with the cellulose substrate.

[0022] The pretreated organic waste may be mixed with the organic waste before pretreatment, and then cultured under aerobic conditions. As described later, it is desirable to select various compositions for the pretreated material by selecting the fermentation conditions in the subsequent stage.

[0023] In an embodiment of the present invention, organic waste is pretreated by a superheated steam reaction, and then fermented by microorganisms to produce an organic fertilizer. As the raw organic waste, it is preferable to use at least one organic matter selected from the group consisting of sludge, food waste, and animal or human waste. As raw materials for pretreated materials, sludge discharged from sewage treatment facilities, which has been considered particularly difficult to treat, marine waste such as vegetable waste and fish bones discharged from food retailers such as supermarkets and homes, and animal or human waste are excellent as fertilizer components.

[0024] In the method of the present embodiment, since the moisture content can be reduced by treating the organic waste under a superheated steam reaction, even organic waste with a high moisture content can be treated without any problems to produce organic fertilizer. The moisture content of the organic waste may be, for example, 40 to 90% by mass, or 40 to 60% by mass.

[0025] In carrying out the present invention, it is preferable to provide the pretreatment facility shown in Fig. 1 and the fermentation treatment facility shown in Fig. 2, and to perform pretreatment with superheated steam before carrying out the process of fermenting the organic waste, but this is not limited to this. In the pretreatment process, the superheated steam pretreatment shown in Fig. 1 is preferable, and the pretreatment facility includes a superheated steam reactor 100, a tank 110 for supplying organic waste, and a rotor 120 for supplying organic waste to the reactor by a motor. The reactor also includes a superheated steam supply means 130, and inside the reactor is a ribbon blender 140 that conveys the organic waste and superheated steam fed therein from an inlet IN to an outlet OUT while stirring them.

[0026] As shown in Fig. 3(a), the superheated steam reactor 100 includes a superheated steam supply means 130 consisting of a boiler 131 and a superheated steam generator 132 for superheating the steam generated from the boiler 131, and a control panel 140 controls the boiler 131 and the superheated steam generator 132 to supply a predetermined amount of superheated steam to the reactor 130. The control panel 140 also controls a motor 160 for driving a ribbon blender 150 in the reactor to adjust the mixing speed.

[0027] As shown in FIG. 3(b), ribbon blender 150 provided inside reactor 130 is configured with inner blades 152 and outer blades 153 arranged around main shaft 151. The outer blades 153, which are closer to the case, cause the material to flow inward, resulting in repeated strong collisions, while the inner blades 152, which are closer to main shaft 151, cause the material to flow outward, where it collides with the side case and moves to the outer blades, repeating the stirring motion.

[0028] In the present invention, when producing a pretreated material for fermentation treatment, it is preferable to use a superheated steam reactor which has a superheated steam supplying means which produces superheated steam at 200°C or higher and injects the superheated steam into the furnace at a predetermined pressure, a stirring and transporting means which stirs and mixes the superheated steam from the superheated steam supplying means and the organic waste while transporting it into the furnace from the inlet IN to the outlet OUT, and a reaction control means which reacts the stirred and transported organic waste with the superheated steam in a temperature range of 150°C or higher and 300°C or lower, and which decomposes, deodorizes and sterilizes the organic waste while suppressing its carbonization at a low temperature of 150°C or higher and 300°C or lower, but other superheated steam low-temperature decomposition furnaces may be used as long as they perform a decomposition treatment suitable for fermenting polymer compounds at low temperatures, and are not limited to these.

[0029] Although the detailed mechanism by which the pretreated material of the present invention shortens the fermentation time by using it in combination with a cellulose substrate material is unclear, it is believed that the volume of the polymeric compounds in the organic waste is appropriately reduced by the superheated steam reaction at low temperature, which causes cracks in the organic waste particles, facilitating the growth of microorganisms. It is believed that by fermenting organic waste treated in this way, the fermentation period can be shortened compared to conventional methods.

[0030] The time for which the superheated steam reaction treatment is carried out may be determined depending on the moisture content of the organic waste, and may be, for example, until the organic waste after treatment turns brown in appearance (FIG. 8). As a further example, the heat treatment and pressure treatment are preferably carried out for 20 to 180 minutes, and more preferably for 20 to 60 minutes. By shortening the heat treatment and pressure treatment, the moisture content of the organic waste can be increased.

[0031] When fermenting organic waste, the organic waste is fermented by microorganisms. In the method of this embodiment, microorganisms capable of decomposing high molecular weight organic matter contained in the organic waste into low molecular weight organic matter are used. Examples of such microorganisms include microorganisms that grow under aerobic conditions. Examples of microorganisms that grow under aerobic conditions include bacteria: Bacillus subtilis; Bacillus stearothermophilus; Clostridium thermocellum; Mold: Aspergillus oryzae;Aspergillus niger;Aspergillus fumigatus;Chaetomium thermophile;Humicola lanuginosa;Rhizopus javanicus, Yeast: Candida glabrata;Debaryomyces hansenii;Hansenula anomala;Pichia membranaefaciens;Rhodotorula glutinis;Saccharomyces cerevisiae, Actinomycetes: At least one or more microorganisms selected from the group consisting of Actinobifida dichotomy, Streptomyces griseus, Streptomyces thermophilus, Thermoactinomyces vulgaris, Thermomonospora glaucus, and Monascus sp.

[0032] When fermenting organic waste, it is preferable to pile up the organic waste that has been treated with superheated steam, and perform solid culture under aerobic conditions while controlling the temperature and moisture content. In the method of this embodiment, the moisture content is controlled to be 40 to 75 mass%, and the temperature inside the organic waste is controlled to be 55 to 85°C. The temperature can be controlled, for example, by adjusting the fermentation heat depending on the height and width of the organic waste pile, or by the frequency of turning.

[0033] When fermenting the pretreated organic waste of the present invention, it is preferable to mix wood waste such as sawdust, wood shavings, straw, branches, bark, and wood chips with the pretreated organic waste. As fermentation progresses, the volume of the organic waste decreases, and it may become difficult to handle as an organic fertilizer. By mixing the wood waste with the pretreated organic waste, the organic waste can be attached to the surface of the wood waste, making it possible to produce an easy-to-handle powdered organic fertilizer.

[0034] If the moisture content of the organic waste after the superheated steam treatment is low, it is preferable to replenish moisture and perform solid culture under aerobic conditions. Since the moisture content of the organic waste before treatment is relatively high, it is possible to adjust the moisture content of the organic waste to a state suitable for the proliferation of microorganisms by mixing this. The fermentation equipment may be a fermentation lane as shown in Figure 2. Specifically, the organic waste treatment method can be carried out as follows using the organic waste treatment facility shown in FIG. 2. That is, before a vehicle (truck) carrying organic waste such as sewage treatment sludge arrives, a cellulose substrate material consisting of sawdust, straw, rice husk, branches, bark, wood chips, bark, etc., or a mixture selected from these, is laid out in an approximately flat state in a sludge carrying yard in an amount equal to the amount of organic waste loaded on the truck (weight ratio). An active mixed microorganism (obtained from Fukunaga Microorganism Laboratory Co., Ltd. (Address: 2705 Funatsu-cho, Himeji City, Hyogo Prefecture)) is added to this cellulose substrate material at a ratio of approximately 100 g per ton of the material to be treated. Then, the vehicle carrying the organic waste discharges the organic waste in a state of spreading it on the carbonaceous substrate. Next, the cellulose substrate material, organic waste, and active mixed microorganisms are stirred so that they are roughly evenly distributed using a bucket such as a shovel loader (or other device such as a crane bucket), and then water is sprayed to adjust the moisture content so that the overall moisture content is about 65 to 75% (preferably 70%). The pretreated material is then loaded into the fermentation lane 200 using a bucket such as the shovel loader. When the material is loaded into the fermentation lane 200, fresh air is supplied from the bottom side by an aeration device into the material (referred to as the material to be treated) in which the cellulose substrate material, organic waste, and active mixed microorganisms are stirred. In this embodiment, the turning device M is remotely operated by an operator once a day to bring the material into contact with fresh air and to turn the material from the bottom of the fermentation lane 200 to the surface. When the material to be treated is turned over in this manner, the turning device M transports the material to be treated about 1 to 2 m toward the tip of the fermentation lane 200. When the active mixed microorganisms are performing the fermentation action in the fermentation lane 1, the temperature inside the fermentation lane 1 is approximately 75 to 85°C. In other words, it is required to set the thickness of the material to be treated so that it becomes the above-mentioned internal temperature during the fermentation process. In addition, since the heat of the fermentation action causes moisture to evaporate, the moisture content of the material to be treated is adjusted by spraying water so that the moisture content is always 65 to 75% (preferably 70%).The moisture adjustment may be configured to be performed by spraying using a spray nozzle, or by providing the turning device M with a spray nozzle and a water tank (or a water source and a piping such as a hose may be connected to supply water). Then, as described above, aeration, moisture adjustment, and turning are performed, and the fermentation treatment is performed in the fermentation lane 200 for about two months. During this time, the active mixed microorganisms decompose the organic waste and the cellulose substrate material into useful organic matter. In this embodiment, the material to be treated is forwarded to the end of the 45 m long fermentation lane 1 by the turning device M for about two months. In the present invention, the fermentation time is reduced to at least half, preferably one third. In addition, the organic waste that had a foul odor can be deodorized by pretreatment. In the fermentation lane 200, the active mixed microorganisms perform organic decomposition, so there is almost no foul odor. The pre-treated material that has been sent to the end of the fermentation lane 200 is transported by a shovel loader to an aging yard, where the moisture is adjusted to about 50-65% (preferably about 60%) and the shovel loader is used to turn the material over once every 10-20 days. The material is aged in the aging yard to become an organic fertilizer that can be used for agriculture or horticulture.

[0035] The nutrient retention capacity of organic fertilizers can be evaluated by their cation exchange capacity (CEC value), because soil retains nutrients through cation exchange. EXAMPLES

[0036] The method for producing an organic fertilizer of the present invention will be described in more detail below with reference to examples. A mixture of manure and sawdust was collected from a cowshed where sawdust was laid to a thickness of 15 to 20 cm, and used as organic waste. Manure and sawdust were mixed in a volume ratio of 50:50 or less, with a moisture content of 87% and other component ratios as shown in Figure 6. This organic waste was treated for 30 to 60 minutes in a pretreatment facility equipped with a superheated steam reactor as shown in Figure 1, resulting in the state shown in the photograph in Figure 8. The component analysis values ​​were as shown in Table 2 in Figure 7, with a moisture content of 57%. Comparing the components in Tables 1 and 2, it is noted that the nitrogen content decreased with the decrease in moisture content, and as a result, it is believed that amino acids were sublimated with the peptide formation of high molecular weight proteins. Although the hydrolysis results of cellulose are not clear from a comparison of Tables 1 and 2, it can be seen that the fermentation treatment time in the subsequent fermentation facility is at least half, making it a preferable material for fermentation treatment.

[0037] After pretreatment, sawdust was added as a cellulose substrate to the organic waste, and the moisture content of the organic waste was adjusted to 60% by mass. Microorganisms were added to the waste, which was then placed in a fermentation tank for solid-state cultivation. The microorganisms used were Bacillus subtilis, Lactobacillus sp.1, and Aspergillus oryzae.

[0038] Solid culture was carried out for one month while controlling the moisture content of the organic waste piled up in the culture tank to be 40-75% by mass and the temperature inside the organic waste to be 55-85°C. The moisture content was adjusted by adding sludge with a high moisture content. The temperature was adjusted by changing the frequency of turning. Below, the fertilizer efficacy of the organic fertilizer obtained by the pretreatment conditions and fermentation treatment was compared in terms of cation exchange capacity.

[0039] In Example 1, cow dung pretreated in the superheated steam reactor shown in Figure 1 in the temperature range of around 200°C, in Example 2 in the temperature range of around 250°C, and in Example 3 in the temperature range of around 300°C was used, while in Comparative Example 1, cow dung without pretreatment was used. The fermentation conditions were the same.

[0040] In the methods of Examples 1 to 3, the organic waste after pretreatment turned blackish brown, as shown in the photograph in Figure 8. The organic fertilizer fermented using this as a raw material had sufficient microorganisms propagating despite the fermentation period of only one month, which is shorter than conventional fermentation periods, and had a cation exchange capacity of around 100 me / 100 g, demonstrating excellent fertilizer effectiveness, whereas in Comparative Example 1, even with a fermentation period of more than two months, the general average value was around 50 me / 100 g.

[0041] The cation exchange capacity (CEC) of soil by grain size is usually 7-12 me / 100g for coarse soil, 12-25 me / 100g for medium soil, and 26-35 me / 100g for fine soil. While general organic fertilizers are effective at around 50 me / 100g, organic fertilizers pretreated with the equipment of the present invention not only have a fermentation time that is less than half, but also have a cation exchange capacity of around 100 me / 100g, demonstrating excellent nutrient retention. [Explanation of symbols]

[0042] 100 Superheated Steam Reactor 200 Fermentation Lane 201 Running rail 300 Running gear M Turning device

Claims

1. Organic waste including sludge, food waste, and animal or human excrement is decomposed at a low temperature of 300°C or less by a superheated steam reaction in the presence of a plant-based cellulose substrate material mainly composed of crushed powder having an average particle size of 10 mm±5 mm including sawdust, wood chips, straw, rice husks, branches, bark, wood chips, and dried grass as a superheated steam reaction decomposition accelerator, and the organic waste is characterized in that it has been pretreated with superheated steam and has a carbon ratio of not more than 50%.

2. 2. The organic waste according to claim 1, wherein the pretreatment step of the superheated steam reaction treatment is repeated a number of times depending on the treatment capacity of the reactor to decompose the polymer compounds in the organic waste and the cellulose substrate material.

3. 3. A method for producing an organic fertilizer, comprising: mixing the cellulosic substrate material with the superheated steam pretreated material according to claim 1 or 2 in a volume ratio of 2:1 to 1:2; selecting one or more microorganisms having a fermentation / decomposition activity from the group below; and fermenting the mixture for a period of 20 to 45 days depending on the number of times of the superheated steam reaction treatment. Note Bacteria: Bacillus subtilis; Bacillus stearothermophilus; Clostridium thermocellum, Mold: Aspergillus oryzae; Aspergillus niger; Aspergillus fumigatus; Chaetomium thermophile; Humicola lanuginosa; Rhizopus javanicus, Yeast: Candida glabrata; Debaryomyces hansenii; Hansenula anomala; Pichia membranaefaciens; Rhodotorula glutinis; Saccharomyces cerevisiae Actinomycetes: Actinobifida dichotomy; Streptomyces griseus; Streptomyces thermophilus; Thermoactinomyces vulgaris; Thermomonospora glaucusglaucus and Monascus sp.

4. 2. The method for producing an organic fertilizer according to claim 1, wherein the superheated steam reaction treatment in the pretreatment step is repeated a number of times according to the processing capacity of the reactor, thereby enhancing the fermentation decomposition properties of the high molecular weight proteins and cellulose substrate materials in the organic waste, and shortening the fermentation time to half or less compared to non-pretreated organic waste.

5. 2. The method for producing an organic fertilizer according to claim 1, wherein the organic fertilizer obtained by the fermentation treatment has a fertilizing effect of 80 me / 100 g or more as determined by a soil analysis method.

6. 3. The method for producing an organic fertilizer according to claim 1 or 2, wherein the pretreated organic waste is cow dung collected by spreading the cellulose substrate material on the floor of a cowshed, the cow dung has a carbon content of 50% or less, and the fertilizer efficacy of the obtained organic fertilizer is 100 me / 100 g or more in terms of cation exchange capacity (CEC) as determined by soil analysis.

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