WO2024048531A1

WO2024048531A1 - Compost production method and compost

Info

Publication number: WO2024048531A1
Application number: PCT/JP2023/031023
Authority: WO
Inventors: 一成謝花; 拓人南出; 薫大嶺; 翔菊池; 美登志望月; 浩一渕上
Original assignee: 株式会社リュウクス
Priority date: 2022-08-30
Filing date: 2023-08-28
Publication date: 2024-03-07
Also published as: JP2024033352A; JP7296000B1

Abstract

The present invention can provide: a compost production method by which workability can be improved; and compost. A compost production method according to the present invention is a compost production method in which compost is produced through a mixing step for mixing an animal-derived nitrogen source material with a plant-derived carbon source material. The compost production method according to the present invention involves: performing a nitrogen source modifying step for mixing biomass combustion ash, which is combustion ash discharged by thermal power generation using a combusted plant-based biomass fuel, with the nitrogen source material to obtain a modified nitrogen source material; and mixing the modified nitrogen source material with the carbon source material as the mixing step after the nitrogen source modifying step.

Description

Compost production method and compost

The present invention relates to a compost using biological waste as a raw material and a method for producing compost.

Conventionally, a compost production method has been proposed in which livestock manure, such as cow manure, pig manure, and chicken manure, which is discharged as waste from livestock facilities, is used as a raw material and is subjected to appropriate treatments such as anaerobic treatment and drying treatment, thereby producing compost. (See Patent Document 1).

However, in the conventional compost production method as proposed in Patent Document 1, there is a problem that livestock manure, which is a nitrogen source material, is easily putrefied. For this reason, it is necessary to perform a mixing operation with the carbon source material before the nitrogen source material spoils, and there is a problem in that the mixing operation occurs frequently. In other words, there is room for improvement in terms of workability.

Japanese Patent Application Publication No. 2004-051474

In view of the above-mentioned problems, it is an object of the present invention to provide a compost manufacturing method and compost that can improve workability.

The present invention provides a compost production method for producing compost through a mixing step of mixing a nitrogen source material and a carbon source material, the nitrogen source material being a reformed nitrogen source material by mixing biomass combustion ash with the nitrogen source material. The present invention is characterized by a method for producing a compost, and a compost, in which a reforming step is performed, and the modified nitrogen source material and the carbon source material are mixed in the mixing step after the nitrogen source reforming step.

According to the present invention, it is possible to provide a compost manufacturing method and compost that can improve workability.

1 is a schematic configuration diagram showing the configuration of a circulating fluidized bed boiler. FIG. 1 is a schematic configuration diagram showing the configuration of a stoker boiler. A flow diagram for producing compost from biomass combustion ash derived from vegetable biomass fuel. The flow diagram for producing compost from biomass combustion ash derived from vegetable biomass fuel in a modified example.

Traditionally, fossil fuels such as coal, oil, and natural gas have been used extensively in thermal power generation from the viewpoint of energy efficiency. However, fossil fuels produce a large amount of carbon dioxide when burned, which could contribute to global warming, so other fuels with a lower environmental impact have been considered. Among these, biomass power generation uses plants, etc. (plant-based materials) as fuel (vegetable biomass fuel), in which the carbon dioxide absorbed during the growth process of plants is greater than the carbon dioxide generated when burning the fuel. Based on the concept of carbon neutrality, thermal power generation with a low environmental impact is becoming increasingly popular.

However, since biomass power generation uses plants as fuel, a certain amount of combustion ash is generated. The generated combustion ash is treated as industrial waste and is generally disposed of in a landfill, but there is a problem in that it requires securing a large amount of land for landfill, and the effectiveness of combustion ash as a byproduct of biomass power generation as a resource is limited. Its use has been considered.

The applicant has conducted extensive research into the effective use of combustion ash generated in such biomass power generation. Then, we invented compost and a method for producing compost using biomass combustion ash (vegetable biomass combustion ash) discharged from thermal power generation using fuel made from plants (hereinafter referred to as "vegetable biomass fuel"). did.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The compost of the present invention contains, as raw materials, biomass combustion ash including at least combustion ash of burned vegetable biomass fuel, a nitrogen source material, a carbon source material, and an active material.

Biomass combustion ash is produced by burning and ashes vegetable biomass fuel, and is mainly produced as a byproduct of thermal power generation (biomass power generation) that uses vegetable biomass fuel as fuel. Plant biomass fuel can also be called biological waste.

As a raw material for vegetable biomass fuel, plants of the Poaceae family can be used. For example, as raw materials for vegetable biomass fuel, it is possible to use plants belonging to the Poaceae family, such as bagasse (residue after sugarcane juice extraction), sorghum, rice husk, and wheat straw. These Gramineae plants have a wide range of cultivation applications, have a large yield, and can be stably obtained as fuel, so they are suitable as vegetable biomass fuels.

In addition to substances derived from plants of the Poaceae family, palm shells, wood chips, wood pellets, and the like can also be used as raw materials for vegetable biomass fuel. Palm shell is the seed shell of a coconut called palm palm, and is a residue generated during the process of producing palm oil. Palm shells contain calcium components and a trace amount of palm oil that remains unextracted, so they have high combustion efficiency and are suitable as a vegetable biomass fuel. Wood chips are artificially manufactured by crushing wood such as logs, bark, branches and leaves, and scraps generated during lumbering into granules. It is made by compression molding the resulting wood-derived material. Both wood chips and wood pellets are suitable as vegetable biomass fuels because they are easy to produce and obtain, and can be stably obtained as fuel.

Note that the vegetable biomass fuel may be made of a single substance (plant) or may be a mixture of multiple types (two or more types) of substances (plants). For example, a mixture of palm shells and wood pellets can be used as a vegetable biomass fuel.

Each of the nitrogen source material and carbon source material is a material (organic material) derived from living things (animals, plants, etc.). More specifically, each of the nitrogen source material and the carbon source material is composed of animal or plant-derived waste (biological waste). Therefore, the nitrogen source material can also be called an organic nitrogen source material, and the carbon source material can also be called an organic carbon source material.

Nitrogen source materials are materials that contain at least nitrogen, and include livestock manure such as cow manure, pig manure, chicken manure, horse manure, sheep manure, and animal manure such as sewage sludge (sludge discharged from wastewater treatment facilities, etc.). or a mixture of two or more of these materials. Further, livestock manure such as cow manure, pig manure, chicken manure, horse manure, sheep manure, etc., which also contains urine, may be used as livestock manure such as cow manure, pig manure, chicken manure, horse manure, sheep manure, etc.

Carbon source materials are materials that contain at least carbon, such as sawdust, chips, bagasse, waste fungal beds, grass clippings, bamboo, bark, rice husks, wheat straw, rice straw, pruned branches, bark, tree leaves, and phytoplankton. It is composed of plant-derived materials such as algae and algae, or a mixture of two or more of these materials.

The active material is a fermenting bacteria or an active liquid containing fermenting bacteria. As the fermentation bacteria, for example, bacteria such as Bacillus microorganisms, actinomycetes, filamentous bacteria, nitrite bacteria, nitrate bacteria, cellulose-degrading bacteria, etc. can be used.

The boiler (combustion furnace) used for thermal power generation using vegetable biomass fuel is not limited to any type and can be of various types as long as it can be used for biomass power generation. For example, a fluidized bed boiler, a stoker boiler, or the like can be used as a boiler for burning vegetable biomass fuel (hereinafter referred to as a "biomass combustion boiler").

Briefly, a fluidized bed boiler is a boiler equipped with a fluidized bed (bed) that uses sand as a fluidizing medium. A stoker-type boiler incinerates vegetable biomass fuel on a plurality of stokers arranged in a stepped manner.

The fluidized bed boiler is more preferably a circulating fluidized bed boiler equipped with a mechanism (circulation mechanism) for forcibly circulating sand as a fluidized medium. FIG. 1 is a schematic configuration diagram showing the configuration of a circulating fluidized bed boiler 10. As shown in FIG. The configuration of the circulating fluidized bed boiler 10 will be described below with reference to FIG.

As shown in FIG. 1, the circulating fluidized bed boiler 10 includes a furnace body 10a, a fuel supply port 11, a bed material 12, a furnace 13, an air inflow path 14 for introducing air into the furnace 13, and a furnace 13. The furnace outlet 15 communicates with the side surface of the upper space of the furnace 13, the ash (biomass combustion ash) contained in the combustion gas generated by combustion in the furnace 13, and some of the bed material 12 that has flowed together with the biomass combustion ash. A cyclone 16 that collects and separates the combustion gas, an exhaust passage 17 that exhausts the combustion gas in the cyclone 16 together with fine powder (fine biomass combustion ash) to the outside of the furnace body 10a, and a bottom of the cyclone 16 and a lower side of the furnace 13. The ash return pipe 18 is connected to the ash return pipe 18.

The fuel supply port (fuel input part) 11 communicates with the inside of the furnace body 10a (furnace 13) and is provided to supply vegetable biomass fuel to the furnace 13 from the outside of the furnace body 10a. That is, the fuel supply port 11 communicates the external space of the furnace body 10a and the internal space of the furnace 13.

The bed material 12 is, for example, a granular member mainly composed of silica sand. The bed material 12 is located inside the furnace 13 and is mixed with vegetable biomass fuel (fuel) supplied from the fuel supply port 11 inside the furnace 13. The bed material 12 may contain limestone for flue gas desulfurization in addition to silica sand.

Although not shown in the drawings, the circulating fluidized bed boiler 10 is provided with a heating device for heating the furnace 13 at an appropriate position. The furnace 13 is heated by a heating device to a temperature (combustion temperature) for burning the vegetable biomass fuel and the bed material 12. The combustion temperature is appropriately set from the viewpoints of securing a sufficient amount of heat, the type of vegetable biomass fuel, the amount of combustion ash, etc. The lower limit of the combustion temperature in the circulating fluidized bed boiler 10 can be 600°C or higher, preferably 700°C or higher. The upper limit of the combustion temperature can be 1100°C or less, preferably 900°C or less.

The air inflow path 14 is provided at the lower part of the furnace 13. Air is supplied into the furnace 13 through the air inflow path 14 . The vegetable biomass fuel and the bed material 12 are combusted and flowed up and down in the furnace 13 by the air supplied from the air inflow path 14 to the furnace 13 from the lower part of the furnace 13 . By flowing the vegetable biomass fuel and the bed material 12 inside the furnace 13, the temperature inside the furnace 13 is made uniform, and combustion efficiency can be improved.

The furnace outlet 15 is provided so as to communicate with the side surface of the upper space of the furnace 13. By being burned in the furnace 13, the vegetable biomass fuel and the bed material 12 become biomass combustion ash, which has a smaller particle size (particle diameter) and is lighter in weight than the fuel (before combustion). The biomass combustion ash whose weight has become lighter than a predetermined weight is blown up to the height of the furnace outlet 15 together with the combustion gas generated by combustion, and moves through the furnace outlet 15 to the communicating cyclone 16. The position (height) at which the furnace outlet 15 communicates with the furnace 13 is at the upper end (the highest point) of the range where the vegetable biomass fuel and bed material 12 before combustion (before the weight becomes lighter) flow in the furnace 13. ) is preferably located above. In this way, the light biomass combustion ash reaches the height of the furnace outlet 15 and flows into the furnace outlet 15, and moves through the furnace outlet 15 to the cyclone 16, but the light biomass combustion ash is heavier than the biomass combustion ash. Since the vegetable biomass fuel and bed material 12 do not reach the height of the furnace outlet 15, they do not flow into the furnace outlet 15. That is, it is possible to efficiently move (transport) what has been burned into biomass combustion ash to the cyclone 16, and to suppress the outflow of the unburned vegetable biomass fuel and bed material 12 from the furnace outlet 15.

The cyclone 16 settles (moves downward) the biomass combustion ash that is relatively coarse-grained (large grain size and relatively heavy) transported from the furnace 13 through the furnace outlet 15. , separating coarse (heavy) biomass combustion ash and fine (light) biomass combustion ash. The coarse biomass combustion ash is returned to the bottom of the furnace 13 through an ash return pipe 18 communicating with the bottom of the cyclone 16, and is combusted again to become fine biomass combustion ash and returned to the cyclone 16. On the other hand, the fine biomass combustion ash is introduced into the exhaust passage 17 together with the combustion gas.

The combustion gas and biomass combustion ash introduced into the exhaust passage 17 are separated by an appropriate separation mechanism through a convection heat transfer section that generates steam from the heat of the combustion gas and supplies the steam to a turbine generator (not shown). separated by A bag filter or an electrostatic precipitator can be used as the separation mechanism. The combustion gas is desulfurized to remove sulfur oxides and then released into the atmosphere as flue gas. As a desulfurization treatment method, a limestone/gypsum method or the like can be used. If the bed material 12 contains limestone, the same effect as the desulfurization treatment can be obtained in the combustion stage (sulfur oxides are removed), so the desulfurization treatment of the combustion gas can be omitted. The biomass combustion ash separated from the combustion gas can be recovered by an appropriate method.

Biomass combustion ash can be obtained by the above method from a thermal power generation facility (thermal power plant) that is equipped with such a circulating fluidized bed boiler 10 and uses vegetable biomass fuel as fuel.

Next, the stoker boiler will be explained. FIG. 2 is a schematic configuration diagram showing the configuration of the stoker boiler 20. As shown in FIG. Hereinafter, a schematic configuration of the stoker boiler 20 will be described with reference to FIG. 2.

As shown in FIG. 2, the stoker boiler 20 includes a furnace body 20a, a fuel input hopper 21 communicating with the inside of the furnace body 20a, a fuel supply section 22, a stoker section 23, a stoker lower hopper 24, and an ash It includes a passage 25, a combustion chamber 26, a waste heat boiler 27, an air supply section 28, a combustion ash recovery section 29, a combustion ash conveyance section 30, and the like.

The fuel input hopper (fuel input unit) 21 is provided to communicate with the inside of the furnace body 20a and to supply vegetable biomass fuel to the fuel supply unit 22 from the outside of the furnace body 20a. That is, the fuel input hopper 21 communicates the outside of the furnace body 20a with the inside of the furnace body 20a.

The fuel supply section 22 is provided below the outlet of the fuel input hopper 21 and supplies the vegetable biomass fuel discharged from the fuel input hopper 21 to the stoker section 23. Further, the fuel supply section 22 includes a pusher that performs reciprocating motion, a drive source that operates the pusher, a control section that controls the drive source, and the like. In the fuel supply section 22, the stroke, operation speed, and operation interval of the pusher are adjusted as appropriate, and the amount (supply amount) of the vegetable biomass fuel supplied to the stoker section 23 is controlled.

The stoker portion 23 is provided so as to be inclined downward in the direction away from the fuel supply portion 22, with its base end facing toward the fuel supply portion 22. This stoker part 23 has a plurality of grate, and the plurality of grate goes from the base end (the end on the fuel supply part 22 side) to the tip part (the end on the opposite side to the fuel supply part 22). They are arranged in a stair-like manner, gradually getting lower and lower. Further, the plurality of grate includes a movable grate that reciprocates between the base end side and the distal end side of the stoker portion 23, and a fixed grate that is fixed (does not move). The movable grate and the fixed grate are alternately arranged from the base end side to the distal end side of the stoker portion 23.

The vegetable biomass fuel supplied to the stoker section 23 moves on the plurality of fire grates arranged in a stepped manner from the base end (upstream side) to the tip end (downstream side) while being heated.

The stoker lower hopper 24 is provided to cover the lower part of the stoker part 23. Air flows into the stoker lower hopper 24 from an air supply section 28 such as a blower (forced air blower) provided on the opposite side of the stoker section 23 (in this embodiment, below the stoker lower hopper 24). The air that has flowed into the stoker lower hopper 24 passes through the stoker portion 23 (fire grate) from below to above.

In addition, the stoker unit 23 includes, in order from the upstream side, a drying stoker 23a for drying the vegetable biomass fuel by evaporating moisture in the vegetable biomass fuel, and a combustion stoker for burning (main combustion) the dried vegetable biomass fuel. 23b, it has an after-combustion stoker 23c for completely burning the unburned remains of the vegetable biomass fuel after combustion. The lower stoker hopper 24 also includes a dry stoker hopper 24a that covers the lower part of the dry stoker 23a, a combustion stoker hopper 24b that covers the lower part of the combustion stoker 23b, and an after-combustion stoker hopper 24c that covers the lower part of the after-combustion stoker 23c. .

The vegetable biomass fuel heated on the stoker section 23 is blown upward by air supplied from the lower stoker hopper 24 and burns in the combustion chamber 26. The lower limit of the combustion temperature in the stoker boiler 20 can be 600°C or higher, preferably 700°C or higher. The upper limit of the combustion temperature can be 1100°C or less, preferably 900°C or less. Combustion gas generated by combustion of the vegetable biomass fuel in the combustion chamber 26 flows into a waste heat boiler 27 communicating above the combustion chamber 26 .

The waste heat boiler 27 recovers heat from the combustion gas, heats and evaporates water, further superheats the generated steam to become superheated steam, and supplies this superheated steam to a turbine generator (not shown). Further, the waste heat boiler 27 includes a radiant heat transfer chamber 27a having a radiant heat transfer surface for receiving radiant heat from the combustion gas that has passed through the combustion chamber 26 and generating steam. The inner wall of the radiant heat transfer chamber 27a is formed of a water tube wall. This water tube wall has a plurality of water tubes arranged in parallel, and a strip-shaped connecting member that connects adjacent water tubes in an airtight manner. That is, the inner surface of the water tube wall that forms the inner wall of the radiant heat transfer chamber 27a serves as a boiler radiant heat transfer surface, and the water inside the water tube is heated by the combustion gas through the radiant heat transfer surface and becomes superheated steam. Become.

As described above, the vegetable biomass fuel is burned in the stoker section 23, and becomes biomass combustion ash, which has smaller particle size and lighter weight than the fuel. Furthermore, an ash passage 25 is provided at the tip of the stoker section 23 and communicates with the combustion ash collection section 29 and extends downward, and the biomass combustion ash discharged from the stoker section 23 is transported back and forth between the movable grate. Due to the movement, the ash is guided to the ash passage 25 and moves (falls) through the ash passage 25 to the combustion ash recovery section 29 . That is, the biomass combustion ash burned in the stoker section 23 is transported to the combustion ash recovery section 29. Further, some of the biomass combustion ash may fall into the lower stoker hopper 24. Below the ash passage 25 and the lower stoker hopper 24, there is provided a combustion ash transport section 30 that includes a conveyor, an extrusion mechanism, etc., and transports the biomass combustion ash to the combustion ash recovery section 29. Therefore, the biomass combustion ash that has fallen into the stoker lower hopper 24 and the ash passage 25 is transported to the combustion ash recovery section 29 by the combustion ash transport section 30.

The biomass combustion ash transported to the combustion ash recovery section 29 can be recovered by an appropriate method. Biomass combustion ash can be obtained by the above method from a thermal power generation facility (thermal power plant) that is equipped with such a stoker boiler 20 and uses vegetable biomass fuel as fuel.

In the case of the circulating fluidized bed boiler 10 and the stoker type boiler 20, an appropriate combustion temperature is set according to the type of vegetable biomass fuel, the generation of unburned remains is suppressed, and fine particles with a large surface area (particle size will be described later) are used. biomass combustion ash can be obtained. That is, with the circulating fluidized bed boiler 10 and the stoker boiler 20, biomass combustion ash suitable as a raw material for compost can be obtained.

FIG. 3 is a flow diagram of the compost production process (compost production method) of the present invention, which produces (manufactures) compost from biomass combustion ash derived from vegetable biomass fuel. As shown in FIG. 3, in the compost production process of the present invention, vegetable biomass fuel is first burned (step S1). Here, vegetable biomass fuel as a fuel for thermal power generation is charged into a biomass combustion boiler (circulating fluidized bed boiler 10 or stoker boiler 20 as described above), and the vegetable biomass fuel is combusted.

Next, the biomass combustion ash discharged from the biomass combustion boiler is recovered by an appropriate method (step S2). At this time, it is preferable to adjust the particle size of the biomass combustion ash contained in the compost (as a raw material for the compost) using a classifier. The particle size of biomass combustion ash is defined by volume average particle size (MV), number average particle size (MN), area average particle size (MA), or cumulative average particle size (median size, D50).

The upper limit of the volume average particle diameter (MV) of biomass combustion ash as a raw material for compost is preferably 100 μm or less, more preferably 40 μm or less. Further, the upper limit of the number average particle diameter (MN) of the biomass combustion ash is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 15 μm or less. Further, the upper limit of the area average particle size (MA) of the biomass combustion ash is preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. Furthermore, the upper limit of the cumulative average diameter (median diameter, D50) of the biomass combustion ash is preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. In addition, the lower limit of the volume average particle diameter (MV), number average particle diameter (MN), area average particle diameter (MA), or cumulative average diameter (median diameter, D50) of biomass combustion ash shall be 1 μm or more. Can be done. In this way, by using biomass combustion ash having a particle size below a predetermined size as a raw material for compost, the specific surface area of the compost and the biomass combustion ash contained therein increases.

Furthermore, biomass combustion ash as a raw material for compost contains 15 to 50% by weight of calcium oxide components. Calcium oxide contained in biomass combustion ash is an oxidized substance derived from the calcium component originally contained in the vegetable biomass fuel used as fuel for thermal power generation. In addition, depending on the condition of the soil where the compost is used and the amount of calcium contained in the biomass combustion ash after combustion, calcium oxide or a substance containing calcium oxide may be added as appropriate to keep it within the above range. Also good. Examples of substances containing calcium oxide include limestone used in desulfurization treatment. In this case, calcium oxide released from the limestone used in the desulfurization process can be appropriately collected and added to the biomass combustion ash. Depending on the type of biomass combustion boiler, calcium oxide generated during desulfurization treatment is mixed in during the biomass combustion ash discharge process, so biomass combustion ash mixed with limestone-derived calcium oxide may be used as is. .

Furthermore, biomass combustion ash as a raw material for compost contains 30 to 60% by weight of silicon dioxide. For example, silicon dioxide contained in the biomass combustion ash is a component derived from silica sand, which is used as a bed material for thermal power generation when the circulating fluidized bed boiler 10 is used. The total proportion of the calcium oxide component and the silicon dioxide component contained in the biomass combustion ash can be 90% by weight or less of the entire biomass combustion ash.

Next, the biomass combustion ash collected in step S2 is added to the nitrogen source material (mixing the biomass combustion ash and the nitrogen source material) to generate a modified nitrogen source material (step S3: nitrogen source reforming step). The lower limit of the amount of biomass combustion ash added in step S3 can be 15% by mass or more, preferably 20% by mass or more, and preferably 30% by mass or more with respect to 100% by mass of the nitrogen source material. More preferred. Further, the upper limit of the amount of biomass combustion ash added in step S3 can be 45% by mass or less, preferably 40% by mass or less, and 30% by mass or less based on 100% by mass of the nitrogen source material. It is more preferable. Further, in this addition, it is preferable to thoroughly mix the nitrogen source material and the biomass combustion ash so that there is no imbalance between the nitrogen source material and the biomass combustion ash in the reformed nitrogen source material.

Next, the modified nitrogen source material, carbon source material, and active material prepared up to step S3 are mixed in appropriate amounts (step S4: mixing step), and each material is homogenized (modified nitrogen source material and The carbon source material and the active material are mixed so that they are substantially uniformly dispersed (step S5).

Next, it is determined whether the moisture content of the mixture prepared up to step S5 is within an allowable range (step S6). Here, the lower limit of the permissible moisture content of the mixture can be 40% or more, preferably 50% or more, and more preferably 55% or more. Further, the upper limit of the allowable range of the water content of the mixture can be 65% or less, preferably 60% or less, and more preferably 55% or less.

If the water content of the mixture is not within the permissible range, that is, if the water content of the mixture is outside the permissible range (step S6: NO), return to step S4, adjust the mixing ratio of each material, and adjust the mixing ratio of each material in step S5. Mix again until homogeneous. That is, if the water content of the mixture is not within the allowable range, the processes of step S4 and step S5 are repeated.

If the moisture content of the mixture is within the allowable range (step S6: YES), the mixture is fermented in step S7 (step S7), and the compost production process is ended. In step S7 (fermentation step), the mixture can be fermented in a plurality of steps (processes). For example, the mixture can be fermented in three steps: a primary fermentation step (7 to 10 days), a secondary fermentation step (7 to 10 days), and a tertiary fermentation step (7 to 10 days). . The period of each fermentation step can be changed as appropriate. Furthermore, when the tertiary fermentation step is completed, the lumps larger than a predetermined size may be returned to the beginning of the primary fermentation step. Here, the standard size (diameter) of the lump can be 10 mm, 12 mm, 15 mm, or 20 mm.

In this way, a mixture of the nitrogen source material and the modified nitrogen source material containing the biomass combustion ash discharged from the biomass combustion boiler, the carbon source material, and the active material is obtained, and this is made into compost. be able to.

According to the compost manufacturing method (compost manufacturing method) of the present invention, biomass combustion ash is added to the nitrogen source material to obtain a modified nitrogen source material. This modified nitrogen source material is less susceptible to decay than the nitrogen source material before modification (conventional), and can be stored for a longer period of time (for example, 1 week to 10 days) than conventional nitrogen source materials. Ta. Thereby, the frequency of mixing operations can be reduced, and workability during compost production can be improved (labor saving can be achieved). Furthermore, according to the method for producing compost of the present invention, the amount of modified nitrogen source material input in one mixing operation can be increased, mass production becomes possible, and the efficiency of producing compost can be improved. did it. In addition, by adding biomass combustion ash to the nitrogen source material, it has a moisture adjustment effect, stabilizes its properties, and makes it easier to handle. It also reduces odor and improves fermentation conditions. Ta.

Furthermore, by mixing 20 to 40% by mass of biomass combustion ash with respect to 100% by mass of nitrogen source material, it is possible to further enhance the decomposition suppressing effect of the modified nitrogen source material, improving workability during compost production and improving compost performance. Manufacturing efficiency can be improved.

Furthermore, the compost of the present invention uses biomass combustion ash produced by combustion of vegetable biomass fuel as a raw material. Vegetable biomass fuel is a fuel for biomass power generation, which has a small environmental impact among thermal power generation, and biomass combustion ash, which is a byproduct generated in the power generation process of biomass power generation, can be used as a raw material for the compost of the present invention. This configuration makes it possible to reduce waste and provide environmentally friendly compost.

Furthermore, since the biomass combustion ash, which is the raw material for the compost of the present invention, contains a predetermined amount of calcium oxide and silicon dioxide, it is possible to produce compost rich in calcium oxide and silicon dioxide.

Furthermore, in the process of manufacturing the compost of the present invention, each material (nitrogen source material, carbon source material, etc.) including biomass combustion ash is mixed so as to be almost uniformly dispersed, so variations in compost performance can be suppressed. Can be done.

Furthermore, in the compost production process of the present invention, the humidity control function of the biomass combustion ash makes it difficult to form lumps during the composting process, improving the yield of the compost product. That is, when a lump is formed, it is necessary to return the lump to the beginning of the fermentation process in the next compost production and process it again, but such work can be reduced and compost can be produced efficiently. In addition, since lumps are less likely to form, handling becomes easier.

Additionally, by adding or spraying the compost produced as described above to agricultural soil, water drainage was improved and plant growth was also improved.

Note that the present invention is not limited to the configuration of the above-described embodiments, and many embodiments can be obtained. For example, biomass combustion ash may be added to a carbon source material to produce a modified carbon source material, and the modified carbon source material may be mixed with a modified nitrogen source material or an active material instead of the carbon source material. . In this case, as shown in FIG. 4, after generating the reformed nitrogen source material in step S3, biomass combustion ash is added to the carbon source material (mixing the biomass combustion ash and the carbon source material) to produce the reformed carbon source. Generate a material (step S11: carbon source modification step), mix the modified nitrogen source material produced up to step S11, the modified carbon source material, and the active material (step S12: mixing step), and step S5 Proceed to. In this way, the moisture content of the reformed carbon source material can be stabilized regardless of the season or weather due to the humidity control function of the biomass combustion ash, and the fermentation conditions in the fermentation step are stabilized. As a result, the composting process, which conventionally required the experience of a skilled worker, can be made into a manual, thereby improving workability and efficiency. Further, the lower limit of the amount of biomass combustion ash added during production of the modified carbon source material can be 20% by mass or more, preferably 25% by mass or more, based on 100% by mass of the carbon source material. More preferably, the content is 30% by mass or more. Further, the upper limit of the amount of biomass combustion ash added during production of the modified carbon source material can be 40% by mass or less, preferably 35% by mass or less, based on 100% by mass of the carbon source material, More preferably, the content is 30% by mass or less. In this way, it is possible to appropriately stabilize the moisture content of the modified carbon source material, enhance the rot suppression effect, and improve workability and efficiency during compost production.

In addition, when adding biomass combustion ash to the carbon source material, it is necessary to mix the carbon source material and the biomass combustion ash well so that there is no imbalance between the carbon source material and the biomass combustion ash in the reformed carbon source material. preferable.
Further, the carbon source modification step is not limited to being performed at the time of compost creation, but may be performed before being recovered as a carbon source material. For example, when a waste bacteria bed is used as bedding in a cowshed, it is possible to create compost using this bedding as a carbon source material. This bedding is mixed with biomass combustion ash and used in the cowshed, and what is collected after use is used as a carbon source material (bedding) with biomass combustion ash already mixed therein, and this is used to make compost using the process described above. You may do so. In this case as well, the same effects as described above can be achieved.

Further, by applying the present invention, a mixture of waste bacteria bed (carbon source material) and biomass combustion ash can be used as bedding material for livestock barns (for example, cow barns). Conventionally, a mixture of waste bacteria bed and sawdust was used as bedding, but only a few of the prepared mixtures could be used as a homogeneous powder, resulting in poor yields. On the other hand, in the case of bedding made by mixing waste bacteria bed and biomass combustion ash, most of the mixture was usable as a homogeneous powder, and the yield was significantly improved. Additionally, the moisture control effect of the bedding has been improved, reducing the frequency of bedding replacement. Additionally, handling (workability) when replacing bedding has been improved. Additionally, we were able to reduce the amount of sterilizing and disinfecting slaked lime used when replacing bedding. Additionally, the odor was reduced due to the deodorizing (absorbing) effect of the biomass combustion ash. In addition, when composting the bedding after use, the number of times of turning and odor was reduced, and the fermentation state was improved.

This invention can be used in industries that produce compost using biological waste as raw material.

10...Circulating fluidized bed boiler 11...Fuel supply port 12...Bed material 13...Furnace 14...Air inflow channel 15...Furnace outlet 16...Cyclone 17...Exhaust channel 18...Ash return pipe 20...Stoker type boiler 21...Fuel input hopper 22 ... Fuel supply section 23 ... Stoker section 24 ... Stoker lower hopper 25 ... Ash passage 26 ... Combustion chamber 27 ... Waste heat boiler 28 ... Air supply section 29 ... Combustion ash collection section 30 ... Combustion ash transport section

Claims

A compost production method for producing compost through a mixing step of mixing a nitrogen source material and a carbon source material, the method comprising:
performing a nitrogen source reforming step of mixing biomass combustion ash with the nitrogen source material to obtain a reformed nitrogen source material;
A compost manufacturing method, in which the modified nitrogen source material and the carbon source material are mixed in the mixing step after the nitrogen source reforming step.
In the nitrogen source reforming step, 20 to 40% by mass of the biomass combustion ash is mixed with 100% by mass of the nitrogen source material to obtain the modified nitrogen source material;
Performing a judgment step of determining whether the moisture content of the mixture prepared in the mixing step is within the allowable range of 40 to 60%,
If it is determined in the determination step that the water content of the mixture is outside the allowable range, the mixing ratio of the modified nitrogen source material and the carbon source material is adjusted and the mixing step is repeated. ,
2. The method for producing compost according to claim 1, wherein when it is determined in the determination step that the moisture content of the mixture is within the allowable range, a fermentation step for fermenting the mixture is started.
performing a carbon source reforming step of mixing the biomass combustion ash with the carbon source material to obtain a reformed carbon source material;
The compost manufacturing method according to claim 1 or 2, wherein the modified nitrogen source material and the modified carbon source material are mixed in the mixing step after the carbon source modification step.
performing a carbon source reforming step of mixing the biomass combustion ash with the carbon source material to obtain a reformed carbon source material;
The compost manufacturing method according to claim 3, wherein the modified nitrogen source material and the modified carbon source material are mixed in the mixing step after the carbon source modification step.
The carbon source reforming step includes:
The method for producing compost according to claim 4, wherein 20 to 40% by mass of the biomass combustion ash is mixed with 100% by mass of the carbon source material.
6. The method for producing compost according to claim 5, wherein the biomass combustion ash is combustion ash obtained by combustion of plant-based materials in a thermal power plant.
A compost containing a modified nitrogen source material in which biomass combustion ash is mixed with a nitrogen source material, and a carbon source material.