JP4377797B2 - Solid waste fuel additive and solid waste fuel - Google Patents

Description

  The present invention relates to an additive for waste solidified fuel to be added to waste solidified fuel produced from general waste or industrial waste, and waste solidification to which this waste solidified fuel is added. Regarding fuel, in detail, waste that can suppress the growth of microorganisms such as bacteria and sputum during storage due to moisture absorption of solid waste fuel and suppress the generation of flammable gas due to decay of solid waste fuel The present invention relates to a solid waste fuel additive and a solid waste fuel to which the solid waste fuel is added and which generates less combustible gas due to decay.

  A general method for producing solid waste fuel produced from general waste or industrial waste includes steps of pulverizing, selecting, drying and molding these wastes. During this process, the additive for waste solidified fuel is usually added after the moisture content of the waste solidified fuel is reduced to 10% by mass or less by the drying process in order to prevent the waste solidified fuel from being spoiled. Yes. As this waste solidified fuel additive, an alkaline inorganic substance having bactericidal properties is widely used, and as such an inorganic inorganic substance having bactericidal properties, slaked lime, quick lime, etc. are known (for example, patents). References 1-3).

  In recent years, the quality of waste solidified fuel has deteriorated as the storage tank for waste solidified fuel has become larger and the storage period has been prolonged, and spoilage due to microorganisms such as bacteria and sputum has been reported. Problems such as generation of combustible gas, heat generation, and temperature rise in the storage tank for solidified fuel have occurred. In order to prevent these problems, various monitoring and disaster prevention measures such as introducing various sensors and shutting off oxygen have been attempted.

JP-A-6-108075 JP-A-6-88083 JP-A-10-130672

  The slaked lime and quicklime, which are the conventional waste solidified fuel additives described above, show bactericidal properties at the time of producing waste solidified fuel from general waste or industrial waste. According to the above, when the water content of waste solidified fuel containing 2% by mass of slaked lime, which is made from general waste, is increased to 10% by mass or more, the growth of bacteria and soot becomes active, and the waste It has been found that combustible gas is generated by the decay of solid fuel. Moreover, if the waste solidified fuel further decays, it becomes difficult to prevent heat generation and temperature rise in the waste solidified fuel storage tank, resulting in disasters such as ignition of the solidified fuel or fire. It is also known that it may lead to

  These phenomena are suppressed by increasing the amount of slaked lime added to enhance sterilization, but increasing the amount of slaked lime increases the amount of ammonia volatilized that increases the septic odor during storage of solid waste fuel. This causes problems such as an increase in. In addition, by taking measures such as introducing various sensors and shutting off oxygen as described above, heat generation and temperature rise in the storage tank can be suppressed to some extent, but cannot be completely prevented. Not only does it require considerable equipment costs.

  In this way, disposal that does not require special equipment and can reliably suppress generation of flammable gas, heat generation, and temperature rise due to decay of solid waste fuel without increasing the odor of ammonia or the like In spite of the long-awaited demand for solidified fuel additives, no effective waste solidified fuel additive has been developed yet.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to preserve microorganisms such as bacteria and sputum during storage due to moisture absorption of solid waste fuel produced from general waste or industrial waste. Providing an additive for solid waste fuel that suppresses growth and suppresses the generation of flammable gas due to the decay of waste solidified fuel, and at the same time solidifies waste that generates less flammable gas due to decay To provide fuel.

  In order to prevent corruption, as a result of earnestly researching additives for waste solidified fuel for suppressing the decay of waste solidified fuel produced from general waste or industrial waste, the present inventors It was found that a water-absorbent resin is effective as an additive. In addition, the addition of alkaline minerals to the water-absorbing resin further increases the effect of preventing spoilage. By adding these waste solidification fuel additives, it is produced from waste solidification fuel, especially general waste. It has the effect of suppressing the decay of waste solidified fuel, and the generation of combustible gases such as methane gas can be suppressed.

The present invention has been made based on the above findings, and the additive for waste solidified fuel according to the first invention contains a water-absorbent resin and an alkaline inorganic substance , and the alkaline inorganic substance comprises light-burned dolomite, slaked lime. The blast furnace slag fine powder and the steelmaking slag are at least one selected from the group consisting of blast furnace slag fine powder and steelmaking slag .

  The additive for waste solidified fuel according to the second invention is characterized in that, in the first invention, the water absorbing performance of the water absorbent resin with respect to pure water is 100 to 1,000 g per 1 g of the water absorbent resin. To do.

In the waste solidified fuel additive according to the third invention, in the first or second invention, the ratio of the water absorbent resin and the alkaline inorganic substance is 1/100 to 2/1 in mass ratio. It is characterized by this.

In any one of the first to third inventions , the additive for a solid waste fuel according to the fourth invention has a mass average particle diameter of the water absorbent resin of 1 to 850 μm and a mass of the alkaline inorganic substance. The average particle diameter is 1 to 300 μm .

An additive for solid waste fuel according to a fifth invention is characterized in that, in any one of the first to third inventions, the surface of the alkaline inorganic substance is coated with the water-absorbent resin. is there.

A waste solidified fuel according to a sixth invention is characterized in that the additive for waste solidified fuel according to any one of the first to fifth inventions is added .

  Since the additive for waste solidified fuel according to the present invention contains a water-absorbing resin capable of absorbing a large amount of water, the waste solidified fuel necessary for the growth of microorganisms such as bacteria and sputum Moisture and moisture absorbed by the solid waste fuel during storage are quickly absorbed by the water absorbent resin, and an excellent anti-corruption effect is exhibited over a long period of time during storage of the solid waste fuel. Further, by adding an alkaline inorganic substance, a sterilizing effect by the alkaline inorganic substance is added, and the anti-corrosion effect of the solid waste fuel is further improved. As a result, the generation of combustible gas due to the decay of waste solidified fuel is suppressed, the solidified fuel can be used as a stable fuel, the effective use of waste is promoted, etc. It has a beneficial effect.

  The additive for waste solidified fuel added to waste solidified fuel for the purpose of preventing corruption according to the present invention contains a water-absorbing resin as an essential component, and from the viewpoint of enhancing the anti-corruption effect It is preferable to further contain an alkaline inorganic substance in addition to the water absorbent resin. When the alkaline inorganic substance is added in combination, even if it is added as an additive for waste solidified fuel in which the water absorbent resin and the alkaline inorganic substance are mixed in advance, the water absorbent resin is contained separately from the water absorbent resin. Either before or after the addition of the additive for waste solidified fuel, or simultaneously, the alkaline inorganic substance may be added alone. However, in order to fully demonstrate the anti-corruption effect of the waste solidified fuel additive, the waste and the added waste solidified fuel additive are mixed and stirred regardless of the addition method. It is desirable to uniformly disperse the waste solidified fuel additive. The waste solidified fuel additive according to the present invention may contain anything else as long as it contains the water-absorbing resin as an essential component, or may be only the water-absorbing resin.

  Examples of the water absorbent resin that can be used in the present invention include the following (1) to (5).

  (1): One type selected from polysaccharides (I-1) and / or monosaccharides (I-2) such as starch or cellulose, and water-soluble monomers or monomers that become water-soluble by hydrolysis This is a water-absorbent resin obtained by polymerizing the above monomer (b) and the crosslinking agent (c) as essential components and, if necessary, performing hydrolysis.

  Examples of the polysaccharide (I-1) include sucrose, cellulose, CMC, starch and the like. Examples of the monosaccharide (I-2) include pentaerythritol, diglycerin, sorbitol, xylitol, mannitol, dipentaerythritol, glucose. , Fructose and the like.

  Examples of the monomer (b) include a radical polymerizable water-soluble monomer having a carboxyl group, a radical polymerizable water-soluble monomer having a sulfonic acid group, and a radical polymerizable water-soluble monomer having a phosphate group. And a salt thereof, or a radically polymerizable water-soluble monomer having a hydroxyl group, a radically polymerizable water-soluble monomer having an amide group, a radically polymerizable water-soluble monomer having a tertiary amino group, and Examples include a radically polymerizable water-soluble monomer having a quaternary ammonium base.

  Examples of the radically polymerizable water-soluble monomer having a carboxyl group include unsaturated mono- or poly (divalent to hexavalent) carboxylic acid [(meth) acrylic acid (this is “acrylic acid and / or methacrylic acid”). And the same description is used hereinafter), maleic acid, monoalkyl maleate (1-9 carbon atoms) ester, fumaric acid, monoalkyl fumarate (1-9 carbon atoms) ester, crotonic acid, sorbic acid, Itaconic acid, itaconic acid monoalkyl (carbon number 1-9) ester, itaconic acid glycol monoalkyl (carbon number 1-9) ether, cinnamic acid, citraconic acid, citraconic acid monoalkyl (carbon number 1-9) ester, etc. And their anhydrides [maleic anhydride and the like].

  Examples of the radically polymerizable water-soluble monomer having a sulfonic acid group include aliphatic or aromatic vinyl sulfonic acids [vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid, etc.], 2-hydroxy- 3- (meth) acryloxypropylsulfonic acid, sulfoalkyl (meth) acrylate (1-9 carbon atoms) [sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, etc.], (meth) acrylamide alkyl (carbon) Numerals 1-9) sulfonic acid [2-acrylamido-2-methylpropane sulfonic acid etc.] etc. are mentioned.

  Examples of the radically polymerizable water-soluble monomer having a phosphoric acid group include hydroxyalkyl (meth) acrylate (having 1 to 9 carbon atoms) phosphoric acid monoester [2-acryloyloxyethyl (meth) phosphate, phenyl-2 -Acryloyl loxyethyl phosphate etc.] etc. are mentioned.

  Examples of salts of radically polymerizable water-soluble monomers containing a carboxyl group, a sulfonic acid group, and a phosphoric acid group include, for example, alkali metal salts [sodium salts, potassium salts, etc.], alkaline earth metal salts [calcium salts, magnesium] Salt, etc.], amine salt or ammonium salt. In addition, amide group-containing monomers [eg (meth) acrylamide etc.], tertiary amino group-containing monomers [eg dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylamide etc.], quaternary ammonium base containing monomers [eg Quaternized products of the above-mentioned tertiary amino group-containing monomers (such as those quaternized with a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, dimethyl carbonate, etc.)], epoxy group-containing monomers [for example, glycidyl (meta ) Acrylate, etc.] and other monomers [4-vinylpyridine, vinylimidazole, N-vinylpyrrolidone, etc.].

  Examples of the radically polymerizable water-soluble monomer having a hydroxyl group include hydroxyalkyl mono (meth) acrylates having 2 to 3 carbon atoms in the alkyl group, polyethylene glycol (mass average molecular weight (hereinafter referred to as “Mw”): 100-4,000) mono (meth) acrylate, polypropylene glycol (Mw: 100-4,000) mono (meth) acrylate, methoxypolyethylene glycol (Mw: 100-4,000) mono (meth) acrylate, and the like. .

  Examples of the radically polymerizable water-soluble monomer having an amide group include (meth) acrylamide, N-alkyl (C1-3) substituted (meth) acrylamide (N-methylacrylamide, N-dimethylacrylamide, etc.). It is done.

  Examples of the radically polymerizable water-soluble monomer having a tertiary amino group include dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylamide.

  Examples of the radically polymerizable water-soluble monomer having a quaternary ammonium base include, for example, quaternized products of the above-mentioned tertiary amino group-containing monomers [methyl chloride, dimethyl sulfate, benzyl chloride, dimethyl carbonate, etc. Quaternized with an agent] and the like.

  Examples of other radically polymerizable water-soluble monomers that can be used as the monomer (b) include 4-vinylpyridin, vinylimidazole, N-vinylpyrrolidone, N-vinylacetamide, and the like.

  These monomers may be used alone or in combination of two or more if necessary. Among these, preferred are a radical polymerizable water-soluble monomer having a hydroxyl group, a radical polymerizable water-soluble monomer having an amide group, a radical polymerizable water-soluble monomer having a carboxyl group, and salts thereof. More preferably, it is a radically polymerizable water-soluble monomer having an amide group, an unsaturated mono- or polycarboxylic acid and a salt thereof, and particularly preferably a radically polymerizable water-soluble monomer having an amide group, and (meta ) Acrylic acid and its salts.

  Examples of the crosslinking agent (c) include a crosslinking agent having two or more radically polymerizable unsaturated groups, a crosslinking agent having a radically polymerizable unsaturated group and a reactive functional group, and two or more reactive functional groups. A crosslinking agent etc. are mentioned.

  Specific examples of the compound having two or more radically polymerizable unsaturated groups include N, N′-methylenebis (meth) acrylamide, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth). ) Acrylate, glycerin (di or tri) acrylate, trimethylolpropane triacrylate, triallylamine, triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, pentaerythritol triallyl ether and the like.

  Polysaccharide (I-1), monosaccharide (I-2) (hereinafter, polysaccharide (I-1) and monosaccharide (I-2) are collectively referred to as “saccharide (I)”) and monomers Examples of the compound having at least one reactive functional group capable of reacting with the functional group (b) and having at least one radical polymerizable unsaturated group include, for example, hydroxyethyl (meth) acrylate and N-methylol. (Meth) acrylamide, glycidyl (meth) acrylate, etc. are mentioned.

  Specific examples of the compound having two or more reactive functional groups capable of reacting with the functional groups of saccharide (a) and monomer (b) include polyhydric alcohols [for example, ethylene glycol, diethylene glycol, glycerin, propylene. Glycol, trimethylolpropane and the like], alkanolamine [for example, diethanolamine and the like], and polyamine [for example, polyethyleneimine and the like].

  Two or more kinds of these crosslinking agents may be used in combination. Among these, preferred are copolymerizable crosslinking agents having two or more radically polymerizable unsaturated groups, and more preferably N, N′-methylenebisacrylamide, ethylene glycol diacrylate, trimethylolpropane triacrylate, Tetraallyloxyethane, pentaerythritol triallyl ether, triallylamine.

  Specific examples of the water-absorbing resin comprising the saccharide (a), monomer (b) and cross-linking agent (c) described above are disclosed in JP-A-52-25886, JP-B-53-46199, and JP-B-sho. Examples thereof are those described in Japanese Patent Publication No. 53-46200 and Japanese Patent Publication No. 55-21041.

  (2): It is a water-absorbing resin obtained by polymerizing the saccharide (a) and the monomer (b) and performing hydrolysis if necessary. Specific examples include a hydrolyzate of starch-acrylonitrile graft polymer, a hydrolyzate of cellulose-acrylonitrile graft polymer, and the like.

  (3): A water-absorbent resin comprising a cross-linked product of the saccharide (a). Specific examples include cross-linked carboxymethyl cellulose.

  (4): A water-absorbing resin comprising a copolymer of the monomer (b) and the crosslinking agent (c) and a hydrolyzate. Specific examples include crosslinked polyacrylamide partial hydrolysates, crosslinked acrylic acid-acrylamide copolymers, crosslinked polysulfonates [crosslinked sulfonated polystyrene, etc.], crosslinked polyacrylates. / Polysulfonate copolymer, vinyl ester-unsaturated carboxylic acid copolymer saponified product (such as those described in JP-A-52-14689 and JP-A-52-27455), crosslinked Polyacrylic acid (salt), cross-linked acrylic acid-acrylic ester copolymer, cross-linked isobutylene-maleic anhydride copolymer, cross-linked polyvinyl pyrrolidone, and cross-linked carboxylic acid-modified polyvinyl alcohol. .

  (5): As other water-absorbing resin, after preparing a polymer (self-crosslinking polyacrylate, etc.) of the monomer (b) having self-crosslinking property, an uncrosslinked polymer, the crosslinking agent (c) ) And, if necessary, a crosslinked product obtained by heating and a crosslinked product obtained by further thermally crosslinking an uncrosslinked polymer such as an amide polymer.

  Two or more water-absorbing resins exemplified in (1) to (5) above may be used in combination. Among these water-absorbing resins, preferred are (1), (4) and (5), more preferably a crosslinked polyacrylamide copolymer, a crosslinked polyacrylic acid (salt), Cross-linked acrylic acid (salt) -acrylamide copolymer, starch-grafted polyacrylic acid (salt), cross-linked acrylic acid-acrylic ester copolymer, and cross-linked carboxylic acid-modified polyvinyl alcohol.

  There is no particular limitation on the type of salt and the degree of neutralization in the case of a water-absorbing resin in the form of a neutralized salt, but the type of salt is preferably an alkali metal salt, more preferably a sodium salt and a potassium salt, The degree of neutralization with respect to the acid group is preferably 50 to 90 mol%, more preferably 60 to 80 mol%.

  In the case of those exemplified as (1) and (4) above, the use amount of the crosslinking agent is preferably 0.001 to 5% by mass, more preferably based on the total mass of the water-soluble monomer and the crosslinking agent. Is 0.05 to 2% by mass, particularly preferably 0.1 to 1% by mass. When the amount of the crosslinking agent is 0.001% by mass or more, the water absorption capacity of the water absorbent resin is increased. On the other hand, when the amount of the cross-linking agent is 5% by mass or less, the cross-linking does not become too strong, and the water absorption capacity is sufficient.

  In the production of the water-absorbent resin, the polymerization method is not particularly limited, and examples thereof include an aqueous solution polymerization method, reverse phase suspension polymerization method, spray polymerization method, photoinitiated polymerization method, and radiation polymerization method. A preferred polymerization method is a reverse phase suspension polymerization method. A more preferable polymerization method is a method of performing aqueous solution polymerization using a radical polymerization initiator. In this case, the type and amount of radical polymerization initiator and radical polymerization conditions are not particularly limited, and can be the same as usual. Incidentally, various additives, chain transfer agents (for example, thiol compounds) and the like may be added to these polymerization systems as necessary. The drying method after the polymerization may be a known method. For example, in the case of aqueous solution polymerization, after the polymer gel is subdivided, air drying (band drying, etc.), air drying (circulation drying, etc.), contact drying (drums) In the case of reverse phase suspension polymerization, a method of drying under reduced pressure or aeration drying after solid-liquid separation is exemplified.

  The drying temperature of the hydrogel is usually 150 ° C. or lower, preferably 130 ° C. or lower. When drying at 150 ° C. or higher for a long time, partial thermal crosslinking may start at the stage when drying is completed and water is exhausted. The obtained dried product is pulverized and powdered as necessary. The pulverization method may be a known method, for example, an impact pulverizer (pin mill, cutter mill, skiller mill, ACM pulverizer, centrifugal pulverizer, etc.) or air pulverization (jet pulverizer, etc.).

  A functional group capable of reacting with acid groups such as carboxyl groups and / or their bases in the vicinity of the surface of the particles obtained by drying the water-containing gel-like polymer of the water-absorbing resin obtained by polymerization and adjusting the particle size as necessary. It is also possible to form a water absorbent resin by surface cross-linking with at least two cross-linking agents. Such a surface-crosslinking water-absorbing resin is excellent in water absorption performance and water absorption speed not only under normal pressure but also under pressure.

  As the cross-linking agent used for this surface cross-linking, conventionally known cross-linking agents can be applied. Specific examples include polyglycidyl ether compounds having 2 to 10 epoxy groups in one molecule [ethylene glycol diglycidyl ether, glycerin-1,3-diglycidyl ether, glycerin triglycidyl ether, polyethylene glycol (degree of polymerization 2-100) diglycidyl ether, polyglycerol (degree of polymerization 2-100) polyglycidyl ether, etc.], divalent to 20-valent polyol compounds [glycerin, ethylene glycol, polyethylene glycol (degree of polymerization 2-100), etc.], 2 To 20-valent polyamine compounds [ethylenediamine, diethylenetriamine, etc.], polyamine resins having a molecular weight of 200 to 500,000 [polyamide polyamine epichlorohydrin resin, polyamine epichlorohydrin resin, etc.], alkylene carbonate Ito [ethylene carbonate, etc.], an aziridine compound, an oxazoline compound, and include polyimine compounds. Among these, polyglycidyl ether compounds, polyamine resins, and aziridine compounds are preferable because surface crosslinking can be performed at a relatively low temperature.

  The amount of the cross-linking agent in the surface cross-linking is not particularly limited because it can be variously changed depending on the type of the cross-linking agent, the cross-linking condition, the target performance, etc. The mass% is more preferably 0.01 to 2 mass%, particularly preferably 0.05 to 1 mass%. When the amount of the crosslinking agent is less than 0.001% by mass, there is no great difference in terms of water absorption and the water absorbent resin that does not perform surface crosslinking. On the other hand, if it exceeds 3% by mass, the water absorption tends to decrease, such being undesirable.

  In the thermal crosslinking of the copolymer in the above (5), before adjusting to the target particle size, the mixture is heated to a predetermined temperature and thermally crosslinked, and then pulverized as necessary to obtain the desired particle size. Although it may be adjusted, preferably, the particle size is adjusted to powder or particles having a target particle size, and then heated to a predetermined temperature for thermal crosslinking.

  The heating temperature is usually 130 to 230 ° C, preferably 150 to 210 ° C. A heating temperature of less than 130 ° C. is not preferable because the heating crosslinking does not proceed. On the other hand, when the heating temperature exceeds 230 ° C., decomposition occurs and quality deteriorates, which is not preferable. The heating time varies depending on the degree of crosslinking to be achieved, but is usually 1 to 600 minutes, preferably 5 to 300 minutes after the product temperature reaches the target temperature. When the heating time is within 1 minute, thermal crosslinking does not occur well. On the other hand, when the heating time exceeds 600 minutes, some decomposition may start depending on the heating temperature and the composition of the polymer.

  The shape of the water-absorbent resin obtained as described above is not particularly limited, and examples thereof include powder (granular, granular, granulated, pearly, flake shaped, etc.), lump, sheet, etc. Preferably, it is a powder. If it is powder, the surface area is large and the water absorption performance is good. Although there is no limitation in particular also about the mass mean particle diameter of particle | grains, Preferably it is 1-850 micrometers, More preferably, it is 1-500 micrometers. When it is larger than 1 μm, dust does not easily occur and it is easy to handle. Moreover, when smaller than 850 micrometers, it will be easy to mix with the carrier powder of an alkaline inorganic substance, and uniform dispersion | distribution and dispersion | distribution of a water absorbing resin will be attained. As for the particle size distribution, preferably used are those pulverized so that particles in the range of 1 to 1,000 μm are 95% by mass or more. Here, the mass average particle size is a plot of logarithmic probability paper in which the horizontal axis represents the particle size distribution and the vertical axis represents the mass-based content, and occupies 50% by mass of the total particle size distribution of the water absorbent resin. According to the method for determining the particle size.

  The water-absorbing performance of the water-absorbing resin with respect to pure water is 10 g to 1,000 g per 1 g of water-absorbing resin (water absorbing capacity capable of absorbing pure water having a mass 10 to 1,000 times the mass of the water-absorbing resin. ), And particularly preferably 100 g to 600 g (hereinafter referred to as “g / g”) per 1 g of the water absorbent resin. If the water absorption performance is 10 to 1,000 g / g, generation of combustible gas of the solidified fuel can be sufficiently suppressed.

  The amount of water-absorbing resin added is preferably relative to the mass of solid waste fuel produced from general waste or industrial waste when only the water-absorbent resin is added as an additive for solid waste fuel. Is 0.02% by mass to 1.0% by mass, more preferably 0.1% by mass to 0.5% by mass. When the addition amount is 0.02% by mass or more, the moisture absorption of the solid fuel is sufficient and the effect of preventing corruption is exhibited. When the addition amount is 1.0% by mass or less, the moisture absorption capacity is not excessive. Further, when used in combination with an alkaline inorganic material, it is preferably 0.01% by mass to 0.5% by mass, more preferably 0%, based on the mass of solid waste fuel produced from general waste or industrial waste. 0.05 mass% to 0.2 mass%. When the addition amount is 0.01% by mass or more, moisture absorption of the solid fuel becomes sufficient, and the effect of anti-corruption is exhibited by adding the bactericidal effect by the alkaline inorganic substance, and the addition amount is 0.5% by mass or less. Excessive moisture absorption capacity is not achieved.

On the other hand, as an alkaline inorganic material which is a preferable component to be contained in the waste solidified fuel additive according to the present invention, any alkali metal or alkaline earth metal may occupy 50% or more of the cation component. Well, for example, Ca (OH) ₂ (slaked lime), CaO (quick lime), Mg (OH) ₂ , MgO, MgO · CaCO ₃ (light calcined dolomite), NaOH, KOH, etc., blast furnace slag fine powder, steelmaking slag , Portland cement, blast furnace cement, early-strength cement, pulverized Ca-containing dust, and the like. Among these, MgO · CaCO ₃ (light calcined dolomite), Ca (OH) ₂ (slaked lime), blast furnace slag fine powder, and steelmaking slag are preferable.

  The shape of the alkaline inorganic substance is not particularly limited, and for example, there are powders (granular, granular, granulated, pearly, flakes, etc.), agglomerates, sheets, etc., like the water absorbent resin, It is a powder. When it is powder, the surface area is large, and the generation of combustible gas of the solidified fuel can be sufficiently suppressed. Although there is no limitation in particular also about the mass mean particle diameter of particle | grains, Preferably it is 1-300 micrometers, More preferably, it is 1-150 micrometers. When the particle size is 1 μm or more, dust is hardly generated and easy to handle. On the other hand, when the particle size is 300 μm or less, the dispersion into the solid waste fuel becomes good and a sufficient suppression effect is obtained.

  The addition amount of the alkaline inorganic substance is preferably 0.2% by mass to 2.0% by mass, more preferably 0.4% by mass with respect to the mass of the solid waste fuel produced from general waste or industrial waste. It is -1.0 mass%. If the added amount is 0.2% by mass or more, a bactericidal effect can be expected. If it is 2.0% by mass or less, it will not be excessively added. Especially when the alkalinity is strong like slaked lime, the volatilization amount of ammonia that increases the odor during storage of solid waste fuel increases, but if it is 2.0% by mass or less, the generation of ammonia should be suppressed. Can do. Moreover, the ratio of the addition amount of the water-absorbing resin and the addition amount of the alkaline inorganic material is preferably 1/100 to 2/1 by mass ratio, more preferably 1/20 to 1/1, and particularly preferably. 1/10 to 1/2. If this ratio is 1/100 to 2/1, generation of combustible gas from the solidified fuel can be sufficiently suppressed.

  When producing a solid waste fuel from general waste or industrial waste, the waste solid fuel additive is added to a pulverized product of these wastes and molded after the addition. When using only a water-absorbing resin without using an alkaline inorganic substance, it is desirable to mix the waste and the added water-absorbing resin to uniformly disperse the water-absorbing resin. It is preferable to stir and mix using a kneading apparatus (for example, a Henschel mixer or an Eirich mixer).

  When the water-absorbent resin and the alkaline inorganic substance are used in combination, the addition method of the water-absorbent resin and the alkaline inorganic substance is directly put into waste and mixed, and the water-absorbent resin and the alkaline inorganic substance are mixed using a mixer. There is a method of mixing in advance and adding the mixture, and a method of adding a mixture in advance is preferred from the viewpoint of enhancing the water absorption effect. As a method for premixing the water-absorbent resin and the alkaline inorganic substance, for example, a method of kneading manually with a stirring rod, spatula, etc. in an appropriate container such as a glass beaker, a can, or a plastic cup, a double helical ribbon blade, a gate There are a method of kneading with a blade or the like, a method of kneading with a planetary mixer, a bead mill or the like. When coating the surface of the alkaline inorganic particles with the water-absorbent resin, a method of pulverizing and mixing the water-absorbent resin and the alkaline inorganic material using a high fluidity mixer (for example, kneading with a high-speed rotary blade, Henschel mixer or A method using an Eirich mixer) may be used.

  When the waste solidified fuel is produced by the waste crushing, sorting, drying, and molding processes, it can be added at any time before the molding after the sorting process. Although it does not matter, it is preferable to add it after the drying step of the pulverized waste from the viewpoint of more reliably preventing the solidification of the waste solid fuel.

Solid waste fuel is a solidified solid organic waste or waste liquid, and is composed of carbohydrates, proteins, fats, and the like. The decay of waste solidified fuel occurs when carbohydrates, proteins, etc. in the solidified fuel are decomposed by microorganisms such as bacteria and sputum. When waste solidified fuel decays, a decaying odor such as ammonia and methane and flammable gases are generated. The decomposition reaction of waste solidified fuel is broadly classified into aerobic microorganisms and anaerobic microorganisms. In the degradation reaction by an aerobic microorganism, carbohydrate (C _m (H ₂ O) _n ) reacts with oxygen (O ₂ ) to generate carbon dioxide (CO ₂ ) and water (H ₂ O), and protein (C _{x Hy} N ₂ O _p ) reacts with oxygen (O ₂ ) to react with a hardly decomposable substance (C _u H _v N _w O _q ), carbon dioxide (CO ₂ ), water (H ₂ O), and ammonia (NH ₃ ) Is generated. In addition, since the decomposition reaction by anaerobic microorganisms involves fermentation, carbohydrates and proteins produce methane (CH ₄ ) and carbon dioxide.

  In order to grow microorganisms such as bacteria and sputum in these decomposition reactions, moisture is required in addition to carbohydrate and protein nutrients. The water-absorbent resin contained in the waste solidified fuel additive according to the present invention absorbs the moisture of the solidified fuel and the moisture absorbed by the solidified fuel during storage, and once absorbed moisture Therefore, the amount of water that can be used by microorganisms such as bacteria and sputum is reduced, so that the growth of microorganisms is suppressed, the decay of waste solidified fuel is suppressed, and the generation of ammonia and methane is suppressed.

  The operation of the waste solidified fuel additive according to the present invention will be described below. Since the water-absorbent resin has a water absorbency of 10 to 1,000 times the mass of the water-absorbent resin, the water content of the solid waste fuel necessary for the growth of microorganisms such as bacteria and sputum and during storage Waste solidified fuel absorbs moisture that has been absorbed by the microorganisms, reducing the amount of moisture that can be used by microorganisms such as bacteria and sputum. An inhibitory effect is obtained. In addition, in the additive for solid waste fuel containing an alkaline inorganic substance in addition to the water-absorbing resin, the alkaline inorganic substance exhibits sterilization property, and the solid waste fuel is stored during storage and moisture of the solid waste fuel. Since it absorbs moisture that has been absorbed slowly, it works to reduce the amount of water that can be used by microorganisms such as bacteria and sputum.

  By using this water-absorbing resin and an alkaline inorganic substance in combination, the above effect is further improved by a synergistic action. For example, the water-absorbent resin can be made uniform by mixing the water-absorbent resin powder and at least one kind of alkaline inorganic powder such as light-burned dolomite, slaked lime, fine powder of blast furnace slag, and steelmaking slag in advance. It has the function of carrier powder to be dispersed and dispersed in, and this mixing process improves the dispersibility of the water absorbent resin powder when added to the solid waste fuel and is uniform when producing the solid waste fuel. Water absorption and bactericidal properties are caused to act at the same time, and the effect of suppressing the decay of waste solidified fuel is further improved.

  Therefore, when the waste solidified fuel additive according to the present invention containing a water absorbent resin and an alkaline inorganic substance is used, this addition is performed during the production of waste solidified fuel from general waste or industrial waste as a raw material. The agent absorbs moisture in the fuel that is necessary for the growth of microorganisms such as bacteria and sputum, and it also has a bactericidal effect when it comes in contact with moisture, thereby suppressing the decay of waste solidified fuel For example, generation of methane gas due to the decay of the fuel is suppressed. In addition, even during storage of solid waste fuel, moisture due to condensation or moisture absorption is absorbed by the solid waste fuel additive according to the present invention, and generation of methane gas due to decay of solid waste fuel is suppressed. Is done.

  Hereinafter, the present invention will be described in more detail by way of examples of the present invention and comparative examples, but the present invention is not limited thereto.

  First, a water-absorbing resin constituting the waste solidified fuel additive according to the present invention was produced as follows. That is, 120 g of acrylic acid was placed in a 1 liter beaker, and 132 g of a 48% by mass aqueous sodium hydroxide solution, 548 g of water and 200 g of a 50% by mass acrylamide aqueous solution were added thereto, and cooled to 5 ° C. after the addition. This solution was put into an adiabatic polymerization tank, and the dissolved oxygen amount of the solution was adjusted to 0.1 ppm through nitrogen. Then, 0.0007 g of 35% by mass of hydrogen peroxide, 0.00025 g of L-ascorbic acid and 4,4′-azobis 0.125 g of (4-cyanovaleric acid) was added.

  About 30 minutes after the addition, the polymerization started, and after about 5 hours, the maximum temperature reached 72 ° C. and the polymerization was completed, and a hydrogel polymer was obtained. After this gel-like polymer was subdivided with a meat chopper, it was dried at 100 ° C. for 1 hour using a band dryer (air-permeable dryer, manufactured by Inoue Metal Co., Ltd.), and pulverized to have a particle size of 50 to 500 μm. An uncrosslinked dry powder was obtained. The uncrosslinked dry powder had an intrinsic viscosity [η] of 27.2. 100 g of this uncrosslinked dry powder was put into a stainless steel vat with a thickness of 3 mm, and heated for 60 minutes in a circulating dryer at 180 ° C. to thermally crosslink to obtain a water absorbent resin (a1). The water-absorbent resin (a1) had a mass average particle diameter of 230 μm and a water absorption performance with respect to pure water of 300 g / g.

  Further, a commercially available water-absorbing resin was also used as the water-absorbing resin constituting the waste solidified fuel additive according to the present invention. The water-absorbing resin (a2) used was “crosslinked polyacrylic acid soda-based water-absorbing resin” (manufactured by Sanyo Chemical Industries, Ltd., product name: Sunfresh ST-573), and the mass of the water-absorbing resin (a2) The average particle size was 350 μm, and the water absorption performance with respect to pure water was 500 g / g.

  Here, the water absorption performance of the water absorbent resin with respect to pure water was measured by the following method. That is, a tea bag and pure water made of 250 mesh nylon net, 10cm x 20cm in size and within 5mm in heat seal width are prepared, and the water-absorbing resin is sieved with a JIS standard sieve to obtain a particle size of 30-100 mesh. Was collected and used as a sample for measurement. 0.20 g of this measurement sample was put into a tea bag, and it was immersed in pure water to about 15 cm from the bottom of the tea bag. After standing for 1 hour, the tea bag was pulled up, hung vertically, drained for 15 minutes, and the mass (Ag) was measured. The same operation was performed using an empty tea bag without a measurement sample, and the mass (Bg) was measured. The measurement was performed three times each and averaged, and the water absorption performance with respect to pure water was calculated from the formula of “water absorption performance (g / g) = (A−B) /0.2”.

  A mixture of the water-absorbing resin (a1) and the water-absorbing resin (a2) prepared in this manner and an alkaline inorganic substance composed of one of lightly burnt dolomite, slaked lime, and blast furnace slag fine powder is used for solid waste fuel. As an additive, the amount of waste solid fuel additive added and the components of the waste solid fuel additive are changed and added to the solid waste fuel produced from general waste. A total of 13 tests (Invention Examples 1 to 13) were conducted to investigate the amount of gas to be used. In addition, a test using only the water-absorbent resin (a1) as an additive for waste solidified fuel was conducted once (Example 14 of the present invention).

Invention Examples 1 to 12 were performed as follows. First, water is added to 300 g of general waste (water content: about 7% by mass) after removing metals and glass from general waste and drying to 95% by mass of 50 mm or less. Was adjusted to 35% by mass. Next, waste solidified fuel comprising a mixture of any one of the water-absorbent resin (a1) or the water-absorbent resin (a2) and any one of light-burned dolomite, slaked lime, and blast furnace slag fine powder The additive was put into a 20 liter plastic cylindrical container together with general waste whose water content was adjusted to 35% by mass, and mixed on a biaxial roller at about 60 rpm for 1 minute. Thereafter, this mixture is loaded into a cylindrical mold having an inner diameter of 10 cm, a lid and a pressing mold are set, and a bulk density of a general waste solidified fuel is set to 0.5 to 1 using a uniaxial compression device. It was molded to 0.6 g / cm ³ to obtain a cylindrical body sample having a diameter of 10 cm and a height of 6 to 8 cm.

  This cylindrical sample was put in a 10 liter Tedoraba bag, and after sucking the bag, 3 liters of air was injected, sealed, and stored at 30 ° C. for 35 days. The concentration of flammable gas such as methane gas in the tedra bag after storage for 35 days was measured with a portable flammable gas detector (manufactured by Cosmos Electric Co., Ltd., XP-316A: measurement range 0 to 5% by volume). The ammonia gas concentration was measured with a gas detector tube (JIS-K0804, manufactured by Gastec Corporation).

  Invention Example 13 was carried out as follows. Invention Example 13 is a test in which light-absorbing resin (a1) was coated on the surface of lightly burned dolomite particles. First, 300 g of water-absorbing resin (a1) and 1500 g of light-burning dolomite powder are put into a 10-liter Henschel mixer and mixed for 5 minutes at a peripheral speed of 40 m / min. The additive for waste solidified fuel was manufactured. Next, remove metals and glass from general waste, add water to 300 g of general waste (moisture: approx. The moisture in the product was adjusted to 35% by mass. Thereafter, 1.8 g of additive for waste solidified fuel consisting of a mixture of 0.3 g of water-absorbing resin (a1) and 1.5 g of light-burned dolomite is mixed with 20 liters of general waste whose water content is adjusted to 35% by mass. Was put into a plastic cylindrical container and mixed on a biaxial roller at about 60 rpm for 1 minute. Thereafter, this mixture was molded under the same molding conditions as those of Invention Examples 1 to 12, and stored under the same conditions, and then the gas concentration was measured.

  Invention Example 14 was carried out as follows. Invention Example 14 is a test using only the water absorbent resin (a1). First, remove metals and glass from general waste, add water to 300 g of general waste (moisture: about 7% by mass) that is dried to 95% by mass of 50 mm or less, and dispose of general waste The water | moisture content in was adjusted to 35 mass%. General waste whose water content is adjusted to 35% by mass is put into a Henschel mixer with a capacity of 10 liters, and 0.3 g of the water absorbent resin (a1) is put in while operating at a peripheral speed of 40 m / min. did. Thereafter, this mixture was molded under the same molding conditions as those of Invention Examples 1 to 12, and stored under the same conditions, and then the gas concentration was measured.

  For comparison, a test in which the additive for waste solidified fuel is not added (Comparative Example 1), a test in which only the slaked lime is added without adding the water absorbent resin (Comparative Example 2), and the water absorbent resin A test (Comparative Example 3) in which light-burned dolomite and slaked lime were added without adding was also carried out. In Comparative Examples 1 to 3, other conditions were the same as those of the present invention. Table 1 shows the added amount of the waste solidified fuel additive and the constituents of the waste solidified fuel additive in Invention Examples 1 to 14 and Comparative Examples 1 to 3, and Table 2 shows storage for 35 days. The investigation results of the methane gas concentration and ammonia gas concentration in the later tedra bag are shown.

  As shown in Tables 1 and 2, in Examples 1 to 7 of the present invention in which the water-absorbent resin powder and light-burned dolomite were used in combination, the methane gas concentration in the tedra bag containing the waste solidified fuel was 0.10% by volume to It is 0.20 vol%, and decreases to 2/9 to 4/9 of the methane gas concentration in Comparative Example 1 in which nothing is added, and 2/7 to methane gas concentration in Comparative Example 2 in which only slaked lime is added. Reduced to 4/7. Further, in Examples 1 to 7 of the present invention, there is no generation of ammonia that increases the odor of spoilage, and anaerobic decomposition reaction is suppressed, so that generation of methane gas due to spoilage of solid waste fuel is suppressed. Was confirmed.

  In the present invention examples 8 to 10 in which the water-absorbent resin powder and slaked lime are used in combination, the methane gas concentration is 0.10 vol% to 0.20 vol%, and there is no generation of ammonia that increases the rot odor. In Invention Examples 11 to 12 in which the basic resin and the blast furnace slag fine powder were used in combination, the methane gas concentration was 0.10% by volume to 0.15% by volume, and there was no generation of ammonia that increased the rot odor. Further, in Example 13 of the present invention in which the surface of the lightly burnt dolomite was coated with a water-absorbent resin, the methane gas concentration was 0.05% by volume, no ammonia was generated to increase the odor, and only the water-absorbent resin (a1) was used. In Example 14 of the present invention, the methane gas concentration was 0.20% by volume, and there was no generation of ammonia that increased the odor of spoilage. Thus, it was confirmed that the inventive examples 8 to 14 can significantly suppress the generation of methane gas as compared with the comparative examples, similarly to the inventive examples 1 to 7.

Claims (6)

A solidified waste containing a water-absorbing resin and an alkaline inorganic substance , wherein the alkaline inorganic substance is at least one selected from light-burned dolomite, slaked lime, blast furnace slag fine powder, and steelmaking slag . Fuel additive.   The additive for solid waste fuel according to claim 1, wherein the water absorption performance of the water absorbent resin with respect to pure water is 100 to 1,000 g per 1 g of the water absorbent resin. The waste solidified fuel additive according to claim 1 or 2, wherein a ratio of the water absorbent resin to the alkaline inorganic substance is 1/100 to 2/1 in mass ratio . The mass average particle diameter of the water-absorbing resin is 1 to 850 μm, and the mass average particle diameter of the alkaline inorganic substance is 1 to 300 μm. The additive for solidification fuel of description . The waste solidified fuel additive according to any one of claims 1 to 3 , wherein the surface of the alkaline inorganic substance is coated with the water absorbent resin. A waste solidified fuel, wherein the waste solidified fuel additive according to any one of claims 1 to 5 is added .