JP2007021451A - Thermal decomposition method for combustible waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for thermal decomposition without enlarging the facility scale even in the case of thermal decomposition of combustible wastes, which cause endothermal reaction at the time of thermal decomposition reaction, with an external heating type thermal decomposition furnace, unlike conventional methods difficult to carry out thermal decomposition in that way. <P>SOLUTION: The thermal decomposition method for combustible wastes is for thermally decomposing combustible wastes in an external heating type thermal decomposition furnace and producing a thermal decomposition gas and thermal decomposition char. In the method, a metal or a metal compound causing exothermal reaction with at least one of gases selected from carbon dioxide, steam, and hydrogen is supplied to the external heating type thermal decomposition furnace and reaction of the metal or the metal compound with at least one of gases selected from carbon dioxide, steam, and hydrogen existing in the thermal decomposition gas is caused to utilize the generated reaction heat as an auxiliary heat source at the time of thermal decomposition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal decomposition treatment method for effectively using combustible waste as fuel or raw material. In particular, the present invention relates to a thermal decomposition method using an external heat type thermal decomposition furnace for thermal decomposition.

  Conventionally, combustible waste treatment of industrial waste plastic and general waste plastic has mainly focused on simple incineration and landfill, but the promotion of a recycling-oriented society has become a major social issue in recent years. There is a need for waste treatment technology that enables effective use of combustible wastes.

For example, as described in Non-Patent Document 1, as a waste disposal method for the purpose of effectively using waste plastic flammable waste, a flammable waste is pyrolyzed in a pyrolysis furnace. After making the volatile matter in the waste into pyrolysis gas, the pyrolysis gas is introduced into the reforming furnace, and the high molecular weight contained in the pyrolysis gas in a high temperature atmosphere of about 1000 to 1200 ° C. in the reforming furnace. The tar component, which is an organic compound, is subjected to partial combustion reaction and steam reforming reaction to convert it into low molecular weight reformed gas composed of CO, H ₂ , hydrocarbons having about 1 to 4 carbon atoms, etc., and cooling the reformed gas Waste gas conversion methods that produce purified gas by purification have been developed.

  In addition, for example, as described in Non-Patent Documents 2 to 3, after combustible waste is heated in a pyrolysis furnace to generate pyrolysis gas and pyrolysis residue, the pyrolysis gas is added at a later stage. Cool to separate the combustible gas component from the tar component, the combustible gas component is used as fuel gas or chemical raw material gas, the tar component is used as fuel oil, etc., and the pyrolysis residue is carbonaceous fuel or metal raw material A waste pyrolysis method has been proposed to be used as such.

  The pyrolysis furnaces used in these waste gas conversion methods and waste pyrolysis methods are represented by external thermal pyrolysis furnaces such as rotary kiln pyrolysis furnaces, fluidized bed pyrolysis furnaces, and moving bed pyrolysis furnaces. However, the externally-heated pyrolysis furnace has the features that the pyrolysis gas calories are not reduced by the partially-combusted air and fluidized gas, and the equipment is simple and easy to operate stably. It is widely used.

“Car Research” Vol. 23, No. 12, P668-673 (2001), p. 670, FIG. “The Journal of Japan Rubber Association” Vol. 59, No. 10, P565-567 (1986), p. 565, FIG. “Recycling Technology Research Presentation Papers” 6th, P89-92 (1998), p. 92, FIG. "Kyoto Graduate School of Engineering Doctoral Dissertation in 1986" Request Code New System 664, Registration No. 9487, p. 81 "Shiroishi Memorial Lecture, Japan Iron and Steel Institute" P85-P99, page 94, line 4 (1999) "Technical Information Center Workshop Text Dechlorination and Recycling Technology for Waste Plastic" P25-P35, page 31, line 8 (held on March 30, 2001) "The Chemical Society of Japan, Chemistry Handbook Revised 4th Edition Fundamentals I" I-132-16 and I-133-20 "Materia" Vol. 39, No. 4, pp. 365 (2000)

  However, one of the challenges of the pyrolysis method using an external heat pyrolysis furnace represented by a rotary kiln pyrolysis furnace is that combustible waste such as polyethylene, which has a large endotherm during pyrolysis, is used as a main component. When decomposing, the treatment capacity of the pyrolysis furnace is lowered.

  In order to maintain the processing capacity, it is necessary to increase the amount of heat input into the pyrolysis furnace. However, in order to ensure heat transfer, the external heat pyrolysis furnace is usually made of metal, which increases the mechanical strength. It is difficult to increase the amount of heat input due to the rise in the external heat temperature due to the above problem and the high temperature corrosion problem due to HCl or the like. For this reason, in the prior art, in order to increase the amount of heat input to the external heating type pyrolysis furnace, it is necessary to increase the heating area in the furnace, and increase the scale of the pyrolysis furnace, increase the number of facilities, etc. Will be invited.

  Therefore, the present invention provides a method for pyrolyzing a combustible waste that generates an endothermic reaction during a pyrolysis reaction without increasing the scale of the equipment even when pyrolyzing the combustible waste in an external thermal pyrolysis furnace. For the purpose.

  In order to solve the problem, the gist of the present invention is as follows (1) to (8).

  (1) In a method for thermally decomposing flammable waste by thermally decomposing flammable waste in an external thermal pyrolysis furnace to generate pyrolysis gas and pyrolysis char, at least one of carbon dioxide, water vapor, and hydrogen A metal or a metal compound that causes an exothermic reaction with the gas is supplied into the external heat type pyrolysis furnace, and carbon dioxide, water vapor, or water present in the metal or metal compound and the pyrolysis gas in the furnace, or A method for pyrolyzing flammable waste, comprising reacting at least one of hydrogen gas and using the generated reaction heat as an auxiliary heat source during the pyrolysis.

  (2) The method for thermal decomposition treatment of combustible waste according to (1), wherein the combustible waste is a combustible waste that generates an endothermic reaction during thermal decomposition.

  (3) The combustibility as described in (1) or (2) above, wherein at least one of carbon dioxide, water vapor, and hydrogen is further supplied into the external heat pyrolysis furnace. Waste pyrolysis method.

  (4) The exothermic reaction between at least one of the carbon dioxide, water vapor, or hydrogen gas and the metal or metal compound is an irreversible reaction below a maximum temperature in the furnace during the thermal decomposition. The method for thermally decomposing flammable waste according to any one of (1) to (3).

  (5) Any of the above (1) to (4), wherein the metal or metal compound is one or more of metal calcium, metal lithium, metal titanium, calcium oxide, and lithium oxide A method for thermal treatment of flammable waste according to any one of the above.

  (6) The method for thermally decomposing flammable waste according to any one of (1) to (5), wherein the metal or metal compound has a particle size of 0.1 to 5 cm.

  (7) An oxygen-containing gas and water vapor are supplied to the generated pyrolysis gas to react with the pyrolysis gas to produce a reformed gas mainly composed of carbon monoxide, hydrogen, carbon dioxide, and water vapor, Using the sensible heat of the reformed gas, the reaction product produced by the reaction of the metal or metal compound and at least one of carbon dioxide, water vapor, and hydrogen gas is heated to obtain the original metal or metal compound. The method for pyrolyzing flammable waste according to any one of (1) to (6), wherein the method is regenerated.

  (8) Oxygen-containing gas is supplied to the generated pyrolysis char and reacted with the pyrolysis char to generate gasified gas mainly containing carbon monoxide, hydrogen, carbon dioxide, or water vapor, and slag. Then, using the sensible heat of the gasified gas, the reaction product produced by the reaction of the solid metal or metal compound and at least one of carbon dioxide, water vapor, or hydrogen gas is heated, The method for pyrolyzing flammable waste according to any one of (1) to (7), wherein the method is regenerated into a metal or a metal compound.

  According to the present invention, even when combustible waste that undergoes an endothermic reaction during a pyrolysis reaction is pyrolyzed in an external heating type pyrolysis furnace, it is possible to treat it without increasing the equipment scale.

  The present inventor notices that, if the type of metal or metal compound is selected, there are those that generate an exothermic reaction with at least one of carbon dioxide, water vapor, and hydrogen under the thermal decomposition temperature conditions of waste. In the external heating type pyrolysis furnace, metal or metal compound reacts with these gas species to generate reaction heat, thereby raising the temperature of the generated gas and using the sensible heat to heat combustible waste. Invented this method.

  FIG. 1 is a block diagram showing an example of a process for carrying out the thermal decomposition method for combustible waste according to the present invention. An example of the first embodiment of the present invention is shown below based on FIG.

  The combustible waste 1 is supplied into an externally-heated pyrolysis furnace 3 (rotary kiln in the figure) using the waste supply device 2, and an exothermic reaction with at least one of carbon dioxide, water vapor, and hydrogen is performed. The resulting metal or metal compound 7 is supplied into the pyrolysis furnace 3 using a metal or metal compound supply device 8.

  The pyrolysis furnace 3 is indirectly heated by the heating furnace 4, and the combustible waste is heated from room temperature to the pyrolysis temperature in an atmosphere where air is cut off in the pyrolysis furnace (excluding inevitable intrusion air) and dried. And pyrolysis to produce pyrolysis gas 5 and residue 6.

  The metal or metal compound causes an exothermic reaction with at least one of carbon dioxide, water vapor, and hydrogen in the pyrolysis furnace, and the sensible heat of the generated gas is used as an auxiliary heat source for pyrolysis in the pyrolysis furnace 3. Use. That is, it is used as an aid for heating combustible waste.

  Carbon dioxide, water vapor, and hydrogen, which are gas species that cause an exothermic reaction, use the gas present in the pyrolysis gas generated during drying and pyrolysis of the combustible waste, or use the reaction gas supply device 10. Additional introduction into the pyrolysis furnace 3 is performed.

  The thermal decomposition temperature of combustible waste varies depending on the type of waste, but is generally about 400 to 600 ° C.

  The type of the metal or metal compound 7 is not particularly limited as long as it causes an exothermic reaction up to a temperature at which thermal decomposition is completed with at least one of carbon dioxide, water vapor, and hydrogen. Use of a metal or metal compound that causes an irreversible reaction below the maximum temperature in the pyrolysis furnace during decomposition (approximately equal to the heating temperature of the external heating pyrolysis furnace) makes it easier to operate the pyrolysis furnace. preferable.

  In other words, it is preferable not to cause an endothermic reaction by returning to the starting metal or metal compound in the pyrolysis furnace.

  That is, the pyrolysis rate of combustible waste depends on the heating temperature and reaction time, and the furnace temperature at the time of completion of pyrolysis differs depending on the operating conditions, so the maximum temperature in the pyrolysis furnace during pyrolysis is If a metal or a metal compound that causes an irreversible reaction is selected below, the operation constraint condition is reduced and the operation becomes easier.

  In addition, in order to prevent the trouble of adhesion | attachment and a fusion | melting in a furnace, it is preferable that said metal or metal compound is solid (a granular form and a powder form are included).

Examples of metals or metal compounds that cause an exothermic reaction with carbon dioxide include calcium oxide and oxidation represented by reaction formulas: CaO + CO ₂ → CaCO ₃ +180 kJ / mol, Li ₂ O + CO ₂ → Li ₂ CO ₃ +222 kJ / mol, respectively. Examples include lithium.

The amount of heat generated per kg of metal compound is 3 MJ / kg for CaO (molecular weight 56.7) and 5 MJ / kg for LiO ₂ (molecular weight 40.9). The amount of heat absorbed when thermally decomposing polyethylene, which is the main component of plastic, is about 1 MJ / kg as described in Non-Patent Document 4 and the like, and is generated by a chemical reaction between carbon dioxide and a metal compound. The calorific value corresponds to a significant calorific value to supplement the endothermic amount during polyethylene pyrolysis.

Examples of the metal or metal compound that causes an exothermic reaction with water vapor gas include calcium oxide represented by the reaction formula: CaO + H ₂ O → Ca (OH) ₂ +63 kJ / mol. The amount of heat generated per 1 kg of the metal compound is 1 MJ / kg, which corresponds to a significant amount of heat to supplement the endothermic amount during polyethylene pyrolysis.

Examples of metals or metal compounds that cause an exothermic reaction with hydrogen gas include metal titanium, metal calcium, metal lithium, and the like. For example, in the case of metal titanium, the reaction formula: Ti + H ₂ → TiH ₂ +142 kJ / mol (The amount of heat generated per 1 kg of metal is 3 MJ / kg), which corresponds to a significant amount of heat to supplement the endothermic amount during polyethylene pyrolysis.

  The metal compound generated after the reaction of the metal or metal compound 7 is discharged from the pyrolysis furnace 3 as a residue 6 together with the pyrolysis char. The metal or metal compound 7 after the reaction may be used as an industrial raw material, or may be regenerated into a metal or metal compound and reused in the pyrolysis furnace 3.

  In the process example shown in FIG. 1, the metal compound 14 generated after the reaction after separating the pyrolysis char 13 from the residue 6 by the pyrolysis char separator 11 is charged into the regenerator 12, and the original metal or metal compound 15 is supplied to the pyrolysis furnace 3.

  In addition, the second embodiment of the present invention is characterized in that the metal or metal compound is used as a plastic block preventive material by making the shape of the metal or metal compound granular.

  Many of plastics such as polyethylene and polypropylene are thermoplastics that exhibit fluidity at high temperatures, so they melt and soften in the process of increasing the temperature in external heat pyrolysis to form a lump. There is a problem that it is easy to lead to heat transfer inhibition and blockage trouble in the external heat type pyrolysis furnace.

  As a means for suppressing this, for example, as described in Non-Patent Documents 5 and 6, a granular material made of a non-volatile carbide or inorganic compound is used as an agglomeration preventing material for plastics in an external heating type pyrolysis furnace. Although a method of newly adding to a metal is proposed, the present invention according to the above (6) can add a function as an agglomeration preventing material substitute by granulating a metal or a metal compound.

  The particle size (particle size) of the metal or metal compound is preferably in the range of 0.1 to 5 cm. If the particle size exceeds 5 cm, the dispersion efficiency in the furnace is lowered and the function as an agglomeration preventing material is not sufficiently exhibited. If it is made smaller than 0.1 cm, it is likely to be scattered together with the pyrolysis gas, and the recovery efficiency from the residue is reduced.

  In order to obtain a particle size in the above range, it is possible by sieving, but a commercially available metal or metal compound within the particle size range can also be purchased and used.

  2 to 3 are block diagrams showing another process example for carrying out the method for thermally decomposing flammable waste according to the present invention.

  In the process example shown in FIG. 2, the pyrolysis gas 5 generated from the pyrolysis furnace 3 is introduced into a reforming furnace 16 provided at a subsequent stage, and is reacted with oxygen-containing gas and water vapor 17 in the reforming furnace. , Converted to reformed gas 18 containing hydrogen, carbon dioxide, water vapor, low molecular weight hydrocarbons as main components and other minor components (gases that vary depending on the type of waste such as HCl), and the reformed gas is an exhaust heat recovery device 19. Pass through the gas purifier 20 to remove harmful gas components such as HCl, dusts, and mists to obtain a purified gas 21.

  An oxygen-containing gas having a higher oxygen concentration requires less gas to be introduced into the reforming furnace 16 and is advantageous for increasing the temperature of the reformed gas 18. However, a high concentration of oxygen close to pure oxygen is costly to produce. Therefore, it is preferable to use an oxygen-containing gas (about 80% by volume concentration) that can be produced by a general-purpose method such as an adsorption separation method or a cryogenic separation method. What is necessary is just to set suitably the ratio of oxygen-containing gas and water vapor | steam according to conditions.

  In the process example shown in FIG. 3, the pyrolysis char 13 is blown into the gasification furnace 23 using the char supply device 22, oxygen or oxygen-enriched air 24 is blown into the gasification furnace 23, and partial combustion is performed at a high temperature. The combustible component in the pyrolysis char is converted into a low molecular weight gasification gas 25 containing carbon monoxide, hydrogen, carbon dioxide, water vapor as the main component and other minor components (depending on the type of waste), The ash content in the decomposition char 13 is melted and converted to slag 26.

  The gasified gas 25 is passed through a heat recovery device 27 and a gas purification device 28 to remove harmful gas components, dusts, and mists to obtain a purified gas 29. The oxygen-enriched air 24 is advantageous in that the higher the oxygen concentration, the smaller the amount of gas blown into the gasification furnace 23 and the higher the temperature of the gasification gas 25. However, high-concentration oxygen close to pure oxygen is produced. Since the cost is high, it is preferable to use oxygen-enriched air 24 (approximately 80% by volume concentration) that can be produced by a general-purpose method such as an adsorption separation method or a cryogenic separation method.

  In the third embodiment of the present invention, a metal or a metal compound after reaction with at least one of carbon dioxide, water vapor, and hydrogen is used, using the sensible heat of the above-described reformed gas or gasification gas. , Regenerated to the original metal or metal compound.

For example, in the case where calcium oxide is used as the metal or metal compound, the temperature required for heating regeneration is 580 ° C. or higher during Ca (OH) ₂ → CaO regeneration, as described in Non-Patent Document 7 and the like. When CaCO ₃ → CaO is regenerated, the temperature is 880 ° C. or higher. For example, when metal titanium is used as the metal or metal compound, the temperature necessary for heat regeneration is as described in Non-Patent Document 8, etc. , TiH ₂ → Ti regeneration is 700 ° C. or higher.

  On the other hand, since the required reaction temperature of the reforming furnace is about 1000 to 1200 ° C., and the required reaction temperature of the gasification furnace is about 1300 to 1500 ° C., a temperature potential that can be used for heating and regeneration of the metal or metal compound after the reaction. have.

  In addition, there is no particular limitation on the method of using the reformed gas sensible heat or the gasified gas sensible heat for heating and regeneration, and indirect heating in which the gas sensible heat generated from the reforming furnace or the gasification furnace is temporarily exchanged. Commonly used heat exchange methods such as a method and a direct heating method in which gas sensible heat generated from a reforming furnace or gasification furnace is brought into contact with a solid metal or metal compound after direct reaction can be applied.

  In the process example shown in FIG. 4, the carbonic acid compound or carbonic acid compound 14 in the heating and regenerating apparatus 12 is directly heated with the high-temperature reformed gas 18 to regenerate the solid metal or metal compound 15, and the process shown in FIG. In the example, the high-temperature gasified gas 25 is once subjected to heat exchange with the high-temperature air 30, and then used for regeneration heat of the carbonate compound or the carbonate compound 14 to the solid metal or metal compound 15.

Example 1
Using the process example shown in FIG. 4, the chemical composition mainly comprising polyethylene is C = 70 mass%, H = 10 mass%, O = 10 mass%, N = 0.5 mass%, Cl = 1.5 mass%, ash content 5 mass%, Plastic waste having a moisture content of 3 mass% and a calorific value of about 34 MJ / kg was supplied to the pyrolysis furnace 3 by the waste supply device 2 and pyrolyzed at a treatment rate of 100 t / day.

  An externally heated rotary kiln was used for the pyrolysis furnace 3, an LNG-fired hot air generator was used for the heating furnace 4, and the pyrolysis temperature was 500 ° C. The dimensions of the rotary drum of the pyrolysis furnace 3 were 2.5 m inside diameter x 25 m length. Granular calcium oxide having a particle size range of 0.1 to 5 cm was selected as a metal compound causing an exothermic reaction in the pyrolysis furnace, and 0.75 t / hr was supplied by a solid metal or metal compound supply device 8.

  In addition to about 0.13 t / hr of water vapor and about 0.03 t / hr of carbon dioxide contained in about 4 t / hr of pyrolysis gas 5 generated by drying and pyrolysis of waste, the reactive gas species with calcium oxide are: Carbon dioxide was supplied using the reaction gas supply device 10. The amount of carbon dioxide supplied by the reaction gas supply device 10 was about 0.5 t / hr.

The pyrolysis gas 5 containing the tar content generated in the pyrolysis furnace 3 is sent to the reforming furnace 16 at the subsequent stage, and is reacted with pure oxygen and water vapor 17 which are oxygen-containing gas in the reforming furnace 16, and CO, CO _2. , H ₂ , H ₂ O, CH ₄ , and other low-molecular-weight reformed gas 18 composed of a small amount of gas, and the reformed gas 18 is heat-exchanged by the exhaust heat recovery device 19 to be 200 ° C. After gas quenching, dust removal and hydrochloric acid gas removal were performed with a bag filter and an alkali scrubber as the gas purification device 20 to obtain 10,000 Nm ³ / hr of purified gas 29 having a calorific value of 11 MJ / Nm ³ .

  The residue 6 discharged from the pyrolysis furnace 3 is separated into 0.25 t / hr as the pyrolysis char 13 by the pyrolysis char separator 11, and the calcium compound which is the solid metal compound 14 after the reaction is reformed gas. The sensible heat of 18 was used to heat up to 900 ° C. in the heating / regenerating apparatus 12 to regenerate calcium oxide, and it was used again in the pyrolysis furnace 3.

  In addition, in the residue 6 discharged | emitted from a pyrolysis furnace, the undried lump of plastic waste was not seen, but it confirmed that the metal compound of the granular material by this invention functions as an agglomeration prevention material.

On the other hand, the pyrolysis char is gasified and melted at a reaction temperature of 1300 ° C. with N ₂ carrier gas into a spouted bed gasification furnace 23 blown with pure oxygen, and combustible components are CO, CO ₂ , H ₂ , H ₂ O, In addition, the ash was converted into a slag 26 while being converted to a gasified gas 25 composed of a trace amount of other gases.

The gasified gas 25 is subjected to heat exchange by a heat recovery device 27 and gas-quenched to 200 ° C., and then dust and hydrochloric acid gas are removed by a bag filter and an alkali scrubber which are gas purification devices 28 to generate a calorific value of 10 MJ / Nm. ³ purified gas 29 was obtained at 100 Nm ³ / hr.

(Comparative Example 1)
As Comparative Example 1, an example is shown in which the same waste plastic waste as in Example 1 is pyrolyzed at a treatment rate of 100 t / day without supplying a metal compound that causes an exothermic reaction and a reaction gas into the pyrolysis furnace 3.

  As in Example 1, an externally heated rotary kiln and an LNG-fired hot air generator were used for the pyrolysis furnace 3 and the heating furnace 4, and the pyrolysis temperature was 500 ° C. The pyrolysis gas 5 is introduced into the reforming furnace 16 and converted into the reforming gas 18 as in the first embodiment, and the pyrolysis char 13 is transferred to the entrained bed gasification furnace 23 as in the first embodiment. The gasification gas 25 and the slag 26 were manufactured by introducing the gas.

The amount of heat absorbed when plastic waste is thermally decomposed is 1.3 MJ / kg and 5000 MJ / hr per unit processing amount and unit time, respectively, while from the heating furnace 4 into the external heating rotary kiln. The average heat transfer amount was about 40 MJ / m ² · h, but in Comparative Example 1 in which no solid metal compound and reaction gas causing an exothermic reaction were supplied, the required heating area of the rotary kiln was about As the size of the rotating drum of the pyrolysis furnace increased by 60 m ^{2, the} inner diameter became 2.5 m and the length became 33 m, and the equipment was enlarged.

  In addition, in the residue discharged from the pyrolysis furnace, massive waste plastics that were not completely pyrolyzed were mixed.

It is a block diagram which shows an example of the process which concerns on this invention. It is a block diagram which shows another example of the process which concerns on this invention. It is a block diagram which shows another example of the process which concerns on this invention. It is a block diagram which shows another example of the process which concerns on this invention. It is a block diagram which shows another example of the process which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste 2 Waste supply apparatus 3 Pyrolysis furnace 4 Heating furnace 5 Pyrolysis gas 6 Residue 7 Solid metal or metal compound 8 Solid metal or metal compound supply apparatus 9 Carbon dioxide, water vapor, or hydrogen 10 Reaction gas supply apparatus 11 Pyrolysis char separator 12 Heating regenerator 13 Pyrolysis char 14 Metal compound after reaction 15 Solid metal or metal compound after regeneration 16 Reforming furnace 17 Oxygen-containing gas and water vapor 18 Reformed gas 19 Waste heat recovery device 20 Gas purification Equipment 21 Purified gas 22 Char supply equipment 23 Gasification furnace 24 Oxygen-containing gas 25 Gasification gas 26 Slag 27 Heat recovery equipment 28 Gas purification equipment 29 Purified gas 30 High temperature air

Claims (8)

  In a method for thermally decomposing flammable waste by pyrolyzing flammable waste in an external thermal pyrolysis furnace to generate pyrolysis gas and pyrolysis char, a gas of at least one of carbon dioxide, water vapor, and hydrogen A metal or a metal compound that generates an exothermic reaction with the pyrolysis furnace, and at least carbon dioxide, water vapor, or hydrogen present in the metal or metal compound and the pyrolysis gas in the furnace. A method for pyrolyzing flammable waste, comprising reacting with any gas and utilizing the generated reaction heat as an auxiliary heat source during the pyrolysis.   The method for pyrolyzing flammable waste according to claim 1, wherein the flammable waste is a flammable waste that generates an endothermic reaction during thermal decomposition.   The pyrolysis treatment of combustible waste according to claim 1 or 2, wherein at least one of carbon dioxide, water vapor, and hydrogen is further supplied into the external heat type pyrolysis furnace. Method.   The exothermic reaction between at least one of the carbon dioxide, water vapor, and hydrogen gas and the metal or metal compound is an irreversible reaction below a maximum temperature in the furnace during the thermal decomposition. The thermal decomposition processing method of the combustible waste of any one of 1-3.   The metal or metal compound is one or more of metal calcium, metal lithium, metal titanium, calcium oxide, and lithium oxide, according to any one of claims 1 to 4. Thermal decomposition treatment method for combustible waste.   The method for thermally decomposing flammable waste according to any one of claims 1 to 5, wherein the metal or metal compound is in the form of particles having a particle size of 0.1 to 5 cm.   The generated pyrolysis gas is supplied with an oxygen-containing gas and water vapor and reacted with the pyrolysis gas to produce a reformed gas mainly composed of carbon monoxide, hydrogen, carbon dioxide, and water vapor. Using the sensible heat of the gas, heating the reaction product produced by the reaction of the metal or metal compound and at least one of carbon dioxide, water vapor, and hydrogen gas to regenerate the original metal or metal compound The thermal decomposition processing method of the combustible waste of any one of Claims 1-6 characterized by these.   The generated pyrolysis char is supplied with an oxygen-containing gas and reacted with the pyrolysis char to generate a gasification gas mainly composed of carbon monoxide, hydrogen, carbon dioxide, or water vapor, and slag, Using the sensible heat of the gasification gas, the reaction product produced by the reaction of the solid metal or metal compound and at least one of carbon dioxide, water vapor, or hydrogen gas is heated to produce the original metal or metal. The method for thermal decomposition treatment of combustible waste according to any one of claims 1 to 7, wherein the method is regenerated into a compound.

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