Method for suppressing heat generation in carbonaceous solids

Abstract

To provide a heat generation suppression method of a carbon-based solid such as coal, biomass, and waste with a reduced cost and a low environmental impact.SOLUTION: Ozone is added to biomass chip 1, the number of viable bacteria 2 adhered to the biomass chip 1 is reduced, unstable functional groups are oxidized, and then an oxide film 3 with stable functional groups is formed, and temperature rise due to heat generation of the biomass chip 1 is suppressed with a reduced cost and a low environmental impact.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for suppressing heat generation from carbonaceous solids such as coal, biomass, and waste. [Background technology]

[0002] For example, in power plants, steel mills, paper factories, etc., coal (coal-derived materials), biomass (biomass-derived materials), waste (waste-derived materials), etc. are used as carbon-based solids, and these carbon-based solids are piled up and stored in outdoor storage areas and indoor storage areas (including silos, etc.). In utilizing carbon-based solids, it is desirable to utilize biomass-derived materials in order to reduce the amount of fossil fuels used, which contribute to the increase in greenhouse gas concentrations in the atmosphere.

[0003] In storage areas for carbonaceous solids such as coal, biomass, and waste (for example, wood chips), natural oxidation occurs when the carbonaceous solids react with oxygen, and the heat generated by natural oxidation raises the temperature of the carbonaceous solids, which may lead to spontaneous combustion. Also, attached microorganisms ferment the carbonaceous solids such as biomass and waste (including coal in some cases), generating heat and raising the temperature, which may lead to spontaneous combustion.

[0004] To suppress the temperature rise caused by heat generation in carbonaceous solids such as coal, biomass, and waste, various techniques have been proposed, including the use of a temperature rise suppressant that increases the water retention capacity of carbonaceous solids such as coal, biomass, and waste, the spraying of a film-forming liquid that suppresses contact between carbonaceous solids such as coal, biomass, and waste and oxygen, and the spraying of a bactericide that reduces the number of viable bacteria attached to carbonaceous solids such as coal, biomass, and waste (Patent Documents 1 and 2).By applying the techniques of Patent Documents 1 and 2, spontaneous combustion can be suppressed by suppressing the temperature rise caused by heat generation in carbonaceous solids such as coal, biomass, and waste.

[0005] The application of heat generation suppression techniques that involve spraying chemicals such as temperature rise suppressants, film-forming solutions, and disinfectants has not only increased the cost of chemicals but also inevitably increased the environmental impact of using chemicals. For this reason, there is a demand for the development of low-cost, environmentally friendly techniques for suppressing the heat generation of carbonaceous solids such as coal, biomass, and waste. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-194447 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-105029 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and aims to provide a method for suppressing heat generation from carbon-based solids, which can suppress heat generation from carbon-based solids such as coal, biomass, and waste, while reducing costs and impact on the environment. [Means for solving the problem]

[0008] Book The method for suppressing heat generation in a carbonaceous solid of the present invention is characterized by adding ozone to the carbonaceous solid, reducing the number of viable bacteria attached to the carbonaceous solid, and oxidizing unstable functional groups to stable functional groups.

[0009] This By adding ozone to carbonaceous solids, the sterilizing action of ozone reduces the number of attached viable bacteria, suppressing fermentation heat generation, and the oxidizing action of ozone improves the oxidation stability of the particle surface, suppressing the progression of unintended oxidation heat generation.

[0010] In other words, by reducing the number of attached viable bacteria and suppressing fermentation heat generation, the temperature rise of the carbon-based solid due to spontaneous heat is suppressed, and at the same time, sites with low oxidation stability on the solid surface (for example, unsaturated bonds, peroxide structures, aldehydes (CHO), ketones (CH2COCH2), methylene groups (CH2)) are converted into carboxyl groups with high oxidation stability, thereby suppressing the unintended progression of oxidation reactions and thereby suppressing the temperature rise of the carbon-based solid due to spontaneous heat.

[0011] Ozone can be added by spraying ozone water having a desired ozone concentration or by immersing the carbonaceous solid in ozone water.

[0012] Ozone is an oxidizing disinfectant that naturally decomposes back into oxygen. Therefore, by adding ozone to suppress the heat generation of carbonaceous solids, it is possible to suppress the heat generation of carbonaceous solids such as coal and biomass while reducing costs and environmental impact.

[0013] and , Book The method for suppressing heat generation in a carbon-based solid of the present invention comprises the steps of: the above In the method for suppressing heat generation from a carbonaceous solid, the carbonaceous solid is a material derived from biomass.

[0014] This means: The technology reduces the number of attached viable bacteria in biomass-derived materials to suppress fermentation heat generation, and improves the oxidation stability of the particle surface to suppress the heat-generating reaction.Biomass can be plant biomass such as chips and pellets, or unused biomass such as forest residues, thinnings, fruit tree prunings, rice, wheat straw, and rice husks.

[0015] Also , Book The method for suppressing heat generation in a carbon-based solid of the present invention comprises the steps of: the above In the method for suppressing heat generation from a carbonaceous solid, the carbonaceous solid is a material derived from waste.

[0016] This means:The technology reduces the number of attached viable bacteria in waste-derived materials to suppress fermentation heat generation, and improves the oxidation stability of the particle surface to suppress the heat-generating reaction. Waste materials that can be used include paper, plastics, livestock manure, construction waste, dam driftwood, kitchen waste, textiles, and sludge.

[0017] Also , Book The method for suppressing heat generation in a carbon-based solid of the present invention comprises the steps of: the above In the method for suppressing heat generation from a carbon-based solid, the carbon-based solid is a material derived from coal.

[0018] This means: The number of viable bacteria attached to coal-derived materials is reduced to suppress fermentation heat generation, and the oxidation stability of the particle surface is improved to suppress the exothermic reaction. Lignite, sub-bituminous coal, bituminous coal, etc. can be used as the coal.

[0019] Also , Book The method for suppressing heat generation from a carbon-based solid of the present invention is characterized in that, in the above-mentioned method for suppressing heat generation from a carbon-based solid, ozone is applied to the surface of the particles of the carbon-based solid to reduce the number of attached viable bacteria, thereby suppressing heat generation from fermentation (temperature rise due to fermentation).

[0020] This means: The sterilizing effect of ozone reduces the number of attached live bacteria and suppresses the rise in temperature caused by fermentation heat generated by microorganisms.

[0021] Also , Book The method for suppressing heat generation in a carbon-based solid of the present invention comprises the steps of: the above A method for suppressing heat generation in a carbon-based solid is characterized in that ozone is added to the carbon-based solid by spraying ozone-dissolved water onto the carbon-based solid.

[0022] This means: Ozone is added to the carbonaceous solid by spraying ozone-dissolved water onto the carbonaceous solid.

[0023] Also , Book The method for suppressing heat generation in a carbon-based solid of the present invention comprises the steps of: the aboveA method for suppressing heat generation in a carbon-based solid is characterized in that the ozone is added to the carbon-based solid by immersing the carbon-based solid in water containing dissolved ozone.

[0024] This means: Ozone is added to the carbon-based solid by immersing the carbon-based solid in ozone-dissolved water.

[0025] Also , Book The method for suppressing heat generation in a carbon-based solid of the present invention comprises the steps of: the above In the method for suppressing heat generation from a carbon-based solid, the ozone is obtained by electrolysis of water.

[0026] This means: Ozone obtained by electrolysis of water is added to a carbonaceous solid to suppress heat generation. The electricity used in the electrolysis can be, for example, electricity (surplus electricity) generated at power plants or electricity (surplus electricity) generated at various facilities (biomass power generation facilities, renewable energy power generation facilities, power generation facilities at steel plants, power generation facilities at paper plants, etc.).

[0027] The electrolysis equipment may be a dedicated electrolysis equipment for obtaining ozone by electrolysis at a predetermined voltage, an electrolysis equipment for producing hydrogen by adjusting the voltage to obtain ozone preferentially, or an electrolysis equipment for producing ozone from oxygen gas obtained by electrolysis of water. Also, ozone obtained from a production equipment may be used as the raw material. As a specific example of the operation of the present invention, for example, in a power plant that uses biomass as fuel, equipment for generating ozone by electrolysis is constructed near the location where the biomass is stored, and ozone is generated using electricity from the power plant.The generated ozone is then added to biomass-derived materials in the storage location (biomass-derived materials piled up indoors or outdoors, biomass-derived materials stored in a hopper, etc.), thereby suppressing the temperature rise due to heat generation in the biomass-derived materials stored near the power plant.

[0028] In order to achieve the above object, the method for suppressing heat generation of a carbon-based solid according to claim 1 of the present invention comprises: Ozone is added to the carbonaceous solids that are used as fuel for power generation and are transported to a hopper by a conveyor, reducing the number of viable bacteria attached to the carbonaceous solids, thereby suppressing fermentation heat generation and oxidizing unstable functional groups to make them stable functional groups. It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 2 is as follows: The method for suppressing heat generation in a carbon-based solid according to claim 1, The ozone is added to the carbon-based solid by spraying ozone-dissolved water onto the carbon-based solid using at least one of the conveyor and the hopper. It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 3 further comprises: Ozone is added to carbonaceous solids that are used as fuel for power generation means and are transported by conveyor and piled up, reducing the number of viable bacteria attached to the carbonaceous solids, thereby suppressing fermentation heat generation and oxidizing unstable functional groups to make them stable functional groups. It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 4 comprises: The method for suppressing heat generation in a carbon-based solid according to claim 3, The ozone is added to the carbon-based solid by spraying ozone-dissolved water onto the carbon-based solid on at least one of the conveyor and the piled portion. It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 5 further comprises: The method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 4, the power generation means has an ozone generation means, The ozone generating means generates ozone by electrolysis of water using the electricity generated by the power generating means. It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 6 comprises: The method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 5, The carbon-based solid is a material derived from biomass. It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 7 comprises: The method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 5, The carbon-based solid is a waste-derived material It is characterized by: The method for suppressing heat generation from a carbon-based solid according to claim 8 of the present invention further comprises: The method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 5, The carbon-based solid is a coal-derived material It is characterized by: The method for suppressing heat generation from a carbon-based solid according to the present invention as set forth in claim 9 comprises: The method for suppressing heat generation in a carbon-based solid according to claim 1 or 3, The carbon-based solid is immersed in ozone-dissolved water to add the ozone to the carbon-based solid. It is characterized by: [Effects of the Invention]

[0029] The method for suppressing heat generation from a carbon-based solid of the present invention suppresses heat generation from a carbon-based solid by adding ozone, making it possible to suppress heat generation from carbon-based solids such as coal, biomass, and waste while reducing costs and impact on the environment. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a conceptual diagram illustrating the action of a method for suppressing heat generation in a carbon-based solid according to the present invention. [Figure 2]FIG. 1 is a conceptual diagram illustrating the state of functional groups in the method for suppressing heat generation in a carbon-based solid according to the present invention. [Figure 3] 1 is a schematic diagram illustrating an application example of an embodiment of a method for suppressing heat generation in a carbon-based solid according to the present invention. [Figure 4] FIG. 1 is a schematic diagram illustrating an application example of another embodiment of the method for suppressing heat generation in a carbon-based solid according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention is characterized by adding ozone to a carbonaceous solid, for example, a biomass-derived material (e.g., biomass chips), to reduce the number of viable bacteria attached to the biomass chips and oxidize unstable functional groups to chemically stable groups, such as carboxyl groups. In other words, the sterilizing action of ozone reduces the number of viable bacteria attached to the biomass chips, thereby suppressing heat generation during fermentation, and the oxidizing action of ozone improves the oxidation stability of the particle surfaces, thereby suppressing the heat-generating reaction.

[0032] In other words, by reducing the number of attached live bacteria and suppressing fermentation heat generation, the temperature rise of biomass chips due to spontaneous heat generation is suppressed, and at the same time, sites with low oxidation stability on the surface of biomass chip particles (e.g., unsaturated bonds, peroxide structures, aldehydes (CHO), ketones (CH2COCH2), methylene groups (CH2)) are converted into carboxyl groups with high oxidation stability, thereby suppressing the unintended progression of oxidation reactions and thereby suppressing the temperature rise of biomass chips due to spontaneous heat generation.

[0033] Figure 1 shows the concept of the action of the method for suppressing heat generation in carbon-based solids of the present invention, with Figure 1(a) showing a state in which viable bacteria are attached to biomass chips and Figure 1(b) showing a state in which the number of viable bacteria attached to the biomass chips has decreased and the oxidation stability of the particle surface has been improved. Figure 2 also shows the concept explaining the state of functional groups in the method for suppressing heat generation in carbon-based solids of the present invention.

[0034] As shown in Fig. 1(a), live bacteria 2 are attached to biomass chips 1 in a natural state. Ozone is added to biomass chips 1 that have live bacteria 2 attached thereto and are at risk of generating heat from fermentation.

[0035] As shown in Figure 1(b), by adding ozone to biomass chips 1 that may generate fermentation heat, the sterilizing action of ozone eliminates the attached live bacteria 2, reducing the number of live bacteria (see dotted line in the figure).

[0036] Then, the portions of the particle surface of the biomass chip 1 shown in Figure 2(a) that have low oxidation stability (e.g., aldehyde groups) are converted to portions with high oxidation stability, such as carboxyl groups, as shown in Figures 1(b) and 2(b), to form a stable oxide film 3, thereby improving the oxidation stability of the particle surface.

[0037] By adding ozone to biomass chips 1, the sterilizing action of the ozone reduces the number of viable bacteria 2 attached to the biomass chips 1, thereby suppressing the generation of heat from fermentation. The oxidizing action of the ozone improves the oxidation stability of the particle surfaces of the biomass chips 1, thereby suppressing the heat-generating reaction. In other words, unstable functional groups, such as aldehyde groups, are converted into highly oxidatively stable (chemically stable) groups, such as carboxyl groups, to form a stable oxide film 3, which can suppress the reaction that leads to heat generation.

[0038] Ozone is an oxidant and disinfectant that naturally decomposes back into oxygen, so by adding ozone to suppress heat generation from biomass chips 1, it is possible to suppress heat generation from biomass chips 1 while reducing costs and impact on the environment.

[0039] Biomass-derived materials that can be used include plant biomass such as chips and pellets, and unused biomass such as forest residues, thinned wood, pruned fruit tree branches, rice, wheat straw, and rice husks.

[0040] As carbonaceous solids, waste (materials derived from waste) such as paper, plastics, livestock excrement, construction waste, dam driftwood, kitchen waste, textiles, sludge, etc. Also, as carbonaceous solids, lignite, subbituminous coal, bituminous coal, etc. (materials derived from coal) can be used.

[0041] An application example of the method for suppressing heat generation from a carbon-based solid according to the present invention will be described with reference to FIGS.

[0042] FIG. 3 shows a schematic configuration for explaining an application example of one embodiment of the method for suppressing heat generation in a carbon-based solid of the present invention, and FIG. 4 shows a schematic configuration for explaining an application example of another embodiment of the method for suppressing heat generation in a carbon-based solid of the present invention.

[0043] Figure 3 shows an example in which the method for suppressing heat generation from a carbon-based solid of the present invention is applied to a power generation facility that uses biomass chips 1 as fuel (part of the fuel) for power generation means. The same members as those shown in Figure 1 are given the same reference numerals.

[0044] As shown in the figure, power is generated using biomass chips 1 as fuel (part of the fuel) for power generation means 5. Biomass chips 1 are transported to storage area 7 by conveyor 6. The discharge section of conveyor 6 is provided with spraying means 8 for spraying ozone water (ozone-dissolved water), and ozone water 9 is sprayed (sprayed) onto biomass chips 1 at the discharge section of conveyor 6, thereby adding ozone to biomass chips 1.

[0045] It is also possible to provide the spraying means 8 above the conveyor 6 and spray the ozone water 9 onto the biomass chips 1 being transported by the conveyor 6. It is also possible to provide the spraying means 8 at any location in the storage area 7 and spray the ozone water 9 onto the biomass chips 1 discharged from the conveyor 6 and piled up.

[0046] It is also possible to configure the hopper to spray ozone water inside the hopper when biomass chips 1 are stored in it. It is also possible to generate ozone using surplus electricity at another location where biomass is used, and spray the ozone water onto the biomass being used.

[0047] Ozone water 9 is obtained by ozone generation means 11 and sprayed onto biomass chips 1. In the ozone generation means 11, ozone (ozone water 9) is obtained by electrolysis of water. The electricity used in the electrolysis is generated by power generation means 5 and part of the power supplied to the sending end is used.

[0048] In other words, in a power plant that operates using biomass chips 1 as fuel (part of the fuel), an ozone generation means 11 that generates ozone by electrolysis is installed near the location where the biomass chips 1 are stored, and ozone is generated using electricity supplied from the power plant, and the generated ozone is added to the biomass chips 1 at the storage location.

[0049] By adding ozone to biomass chips 1 at the storage location, the sterilizing action of ozone reduces the number of live bacteria 2 (see Figure 1) attached to the biomass chips 1 (see dotted line in Figure 1), suppressing fermentation heat generation, and the oxidizing action of ozone forms an oxide film 3 (see Figure 1) on the surface of the particles of biomass chips 1, improving oxidative stability and suppressing the heat-generating reaction at the storage location.

[0050] The electricity used in the ozone generation means 11 (used in electrolysis) can be electricity (surplus electricity) generated at power plants or electricity (surplus electricity) generated at various facilities (biomass power generation facilities, renewable energy power generation facilities, power generation facilities at steel plants, power generation facilities at paper plants, etc.).

[0051] The electrolysis equipment can be a dedicated electrolysis equipment for obtaining ozone by electrolysis at a predetermined voltage, an electrolysis equipment for producing hydrogen by adjusting the voltage to preferentially obtain ozone, or an electrolysis equipment for producing ozone from oxygen gas obtained by electrolysis of water.In addition to electrolysis, ozone can also be produced from oxygen obtained from production equipment.

[0052] In the above-mentioned application example, ozone, an oxidant and disinfectant that naturally decomposes back into oxygen, is added to biomass chips 1, which are transported on a conveyor 6 as fuel (part of the fuel) for the power plant. This makes it possible to suppress the heat generation of the biomass chips 1, which are fuel (part of the fuel) for the power plant, while reducing costs and impact on the environment.

[0053] Figure 4 shows an example in which the method for suppressing heat generation from a carbon-based solid of the present invention is applied to equipment in which biomass chips 1 are immersed in ozone-dissolved water. The same components as those shown in Figure 1 are given the same reference numerals.

[0054] As shown in the figure, ozone is dissolved in a solution (water) in a container 15 by an ozone supply means 16, and an ozone aqueous solution (ozone-dissolved water) 17 of a predetermined concentration is prepared. The concentration of the ozone-dissolved water 17 is confirmed by a concentration detection means 18. The ozone-dissolved water 17 is transferred to, for example, an immersion container 14, and biomass chips 1 are immersed in the ozone-dissolved water 17. By immersing the biomass chips 1 inside the immersion container 14, ozone is added to the biomass chips 1.

[0055] It is also possible to provide an ozone generating means inside the immersion vessel 14 and supply electricity to the ozone generating means to obtain water containing dissolved ozone at a predetermined concentration inside the immersion vessel 14.

[0056] The biomass chips 1 to which ozone has been added are removed from the soaking container 14 (by filtration and solid-liquid separation), and the removed biomass chips 1 are transported to a predetermined location for use or storage. In addition, the ozone-dissolved water 17 in the soaking container 14 from which the biomass chips 1 have been removed is circulated to the container 15.

[0057] By immersing biomass chips 1 in ozone-dissolved water 17 and adding ozone, it is possible to reliably add ozone to a desired amount of biomass chips 1. As a result, for a desired amount of biomass chips, the sterilizing action of ozone reduces the number of viable bacteria 2 (see FIG. 1) attached to the biomass chips 1, suppressing fermentation heat generation, and the oxidizing action of ozone forms an oxide film 3 (see FIG. 1) on the particle surface of the biomass chips 1, improving oxidation stability and reliably suppressing the heat-generating reaction of the desired amount of biomass chips 1.

[0058] By immersing a desired amount of biomass chips 1 in ozone-dissolved water 17 and adding ozone, it is possible to reliably suppress temperature rise due to spontaneous heat generation of the biomass chips 1, for example, near the place of use. [Industrial Applicability]

[0059] The present invention can be used in the industrial field of methods for suppressing heat generation in carbonaceous solids. [Explanation of symbols]

[0060] 1. Biomass chips 2 Live bacteria 3. Oxide film 5. Means of power generation 6 Conveyor 7. Storage 8 Spreading means 9. Ozone Water 11 Ozone generation means 14 Soaking vessel 15 Container 16 Ozone supply means 17 Ozone aqueous solution (ozone dissolved water) 18 Temperature detection means

Claims

1. Ozone is added to a carbonaceous solid that is used as fuel for a power generation means and is transported to a hopper by a conveyor, thereby reducing the number of viable bacteria attached to the carbonaceous solid, thereby suppressing fermentation heat generation, and oxidizing unstable functional groups to make them stable functional groups. A method for suppressing heat generation in a carbon-based solid, comprising:

2. The method for suppressing heat generation in a carbon-based solid according to claim 1, The ozone is added to the carbon-based solid by spraying ozone-dissolved water onto the carbon-based solid using at least one of the conveyor and the hopper. A method for suppressing heat generation in a carbon-based solid, comprising:

3. Ozone is added to a carbonaceous solid that is used as fuel for a power generation means and is transported by a conveyor and piled up, thereby reducing the number of viable bacteria attached to the carbonaceous solid, thereby suppressing fermentation heat generation and oxidizing unstable functional groups to make them stable functional groups. A method for suppressing heat generation in a carbon-based solid, comprising:

4. The method for suppressing heat generation in a carbon-based solid according to claim 3, The ozone is added to the carbon-based solid by spraying ozone-dissolved water onto the carbon-based solid on at least one of the conveyor and the piled portion. A method for suppressing heat generation in a carbon-based solid, comprising:

5. A method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 4, the power generation means has an ozone generation means, The ozone generating means generates ozone by electrolysis of water using the electricity generated by the power generating means. A method for suppressing heat generation in a carbon-based solid, comprising:

6. A method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 5, The carbon-based solid is a material derived from biomass. A method for suppressing heat generation in a carbon-based solid, comprising:

7. A method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 5, The carbon-based solid is a waste-derived material A method for suppressing heat generation in a carbon-based solid, comprising:

8. A method for suppressing heat generation in a carbon-based solid according to any one of claims 1 to 5, The carbon-based solid is a coal-derived material A method for suppressing heat generation in a carbon-based solid, comprising:

9. A method for suppressing heat generation in a carbon-based solid according to claim 1 or claim 3, The carbon-based solid is immersed in ozone-dissolved water to add the ozone to the carbon-based solid. A method for suppressing heat generation in a carbon-based solid, comprising:

Images