JP2010106133A - Process and apparatus for making waste into fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process and apparatus for making waste into a fuel, which can suppress generation of molten salt alkali metals as causative substances corroding a furnace wall at high temperatures during the combustion. <P>SOLUTION: Organic waste containing organochlorine compounds as a raw material 20 is fed to a reactor 21 and superheated steam is fed thereto from a steam generator 41 to make the organic compounds in the raw material into low molecules by thermal reforming of the hydrothermal reaction and to release, volatilize and remove chlorine from the organochlorine compounds by nucleophilic substitution reaction by the superheated steam, and the reaction product is used as a fuel of the steam generator 41 to obtain superheated steam. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a waste fueling method and apparatus, which hydrolyzes chlorine-containing waste to lower the molecular weight, and transfers chlorine to the exhaust gas side, thereby improving the fuel value of the product of hydrolysis. It relates to the technology to be improved.

  As this type of technology, for example, there is one described in Patent Document 1. This is a device that manufactures powdered fuel from organic waste including raw garbage and plastic waste. It contains a processing container that contains waste and treats it in water, and supplies water to the inside of the processing container. A temperature-pressure control means for controlling the pressure to a treatment pressure of 1.55 MPa or more and a temperature to a treatment temperature of 200 ° C. or more, and a stirring means for stirring waste and water are provided.

  Patent Document 2 describes a fuel manufacturing method in which a hazardous substance such as dioxin is not generated and is converted to a property suitable for use as a fuel. By injecting high-pressure steam into the processing container, the pressure in the processing container is maintained at 1.96 MPa or more and the temperature is raised, so that the material part temperature in the lower part of the processing container becomes the gap part temperature in the upper part of the processing container. The injection of high-pressure steam is stopped when the values match.

  Patent Document 3 describes a method of recycling and using waste containing an organic chlorine compound. This is because waste containing organic chlorine compounds is dechlorinated by hydrothermal treatment, and the organic chlorine compounds are recovered as alcohol, organic acids and inorganic salts, and the waste from which the organic chlorine compounds have been removed is recovered and used as fuel. To do.

Patent Document 4 describes a method of accelerating the decomposition treatment of a hardly-decomposable organic halogen compound with an alkali-resistant and heat-resistant solvent against a high concentration of an alkaline substance. This is a method in which a hardly decomposable organic halogen compound is decomposed by reacting with a strongly alkaline substance and a hydrogen source compound in a reaction solvent, the reaction temperature is 160 ° C. or higher and 260 ° C. or lower, and the reaction solvent is polyethylene. Glycol dimethyl ethers, wherein the hydrogen source compound is selected from the group consisting of hydrogenated aromatic compounds, naphthenic high boiling mineral oils, and mixtures of two or more thereof.
JP 2007-112880 A JP 2006-28272 A JP 2006-327987 A JP 2007-197 A

  By the way, industrial waste and general waste containing plastic become powdery products that are easily combusted by a predetermined high-temperature and high-pressure treatment. However, since the chlorine content in the waste remains in the product, the properties of the exhaust gas at the time of combustion are the same as in the case where the waste is directly incinerated. That is, chlorine contained in the product migrates into the exhaust gas at the time of incineration, and DXN or the like that is a harmful component, or molten salt alkali metal NACL or KCL that is a causative substance of high-temperature corrosion is generated. As a result, there is a problem that corrosion due to halogen occurs.

  The organic chlorine can be removed by raising the temperature of the steam charged into the reaction apparatus to form superheated steam. However, in order to generate superheated steam, facility costs and running costs are greatly increased. In addition, when the product of the reactor is used as the fuel for the steam generator that generates superheated steam, and heat is recovered from the combustion exhaust gas to generate superheated steam, as described above, high temperature corrosion occurs. There is.

  The present invention solves the above-described problems, and an object of the present invention is to provide a waste fueling method and apparatus capable of suppressing generation of molten salt alkali metal as a causative substance that corrodes a furnace wall at high temperature during combustion. .

  In order to solve the above-described problems, the waste fueling method of the present invention supplies an organic waste containing an organic chlorine compound as a raw material to a reactor, and also supplies superheated steam from a steam generator to generate hydrothermal power. The organic compound in the raw material is reduced in molecular weight by heat denaturation treatment of the reaction, and chlorine is desorbed from the organochlorine compound by nucleophilic substitution reaction with superheated steam, volatilized and removed, and the product is used as fuel for the steam generator. It is characterized by obtaining superheated steam.

In the waste fueling method of the present invention, when the fuel is taken out from the reaction apparatus, the exhaust gas is discharged from the reaction apparatus and the fuel is discharged later.
The waste fuel of the present invention supplies an organic waste containing an organic chlorine compound as a raw material to a reactor, and supplies superheated steam from a steam generator to perform organic modification in the raw material by thermal denaturation treatment of a hydrothermal reaction. The molecular weight of the compound is reduced, and chlorine is desorbed and volatilized and removed from the organochlorine compound by a nucleophilic substitution reaction with superheated steam.

  The waste fueling device of the present invention reduces the molecular weight of organic compounds in the raw material by thermal denaturation treatment of hydrothermal reaction, and desorbs and volatilizes chlorine from organochlorine compounds by nucleophilic substitution reaction with superheated steam. And a steam generator that generates the superheated steam using the product as a fuel and supplies the superheated steam to the reaction apparatus.

  As described above, according to the present invention, since the chlorine concentration in the produced fuel is reduced, it is possible to suppress the generation of molten salt alkali metal as a causative substance that causes high temperature corrosion during combustion of the fuel, and to suppress the corrosion of the furnace wall. it can. For this reason, the product in the reactor can be used as the fuel for the steam generator that generates superheated steam, and heat can be recovered from the combustion exhaust gas to generate superheated steam.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a reaction apparatus 21 performs processing of solid organic waste, and has a double structure including a mantle container (jacket) 22 and a reaction container 23 stored in the mantle container 22. . The steam generator 41 supplies saturated steam and superheated steam to the reactor 21.

  In the reaction apparatus 21, the steps of charging, heating, reaction, decompression, drying, and discharging are performed. The raw material 20 is a solid organic waste containing an organic chlorine compound, and is combustible waste, garbage, plastic waste, food factory residue, fishery processing residue, sludge, livestock manure, or a mixture thereof.

In the charging step, the raw material 20 is charged into the reaction vessel 23 from the charging port 24. Inside the reaction vessel 23, a stirring blade 27 that is rotationally driven by a motor 26 stirs the raw material 20.
In the heating process, saturated steam is supplied at a predetermined pressure from the first steam supply port 25a to the inside of the outer casing 22, and when the container body temperature of the reaction vessel 23 reaches a predetermined temperature, the reaction is performed from the second steam supply port 25b. Superheated steam is supplied to the container 23 at a predetermined pressure, for example, 3 MPa. The superheated steam is superheated steam having a predetermined temperature within 210 ° C. to 350 ° C., and raises the temperature inside the reaction vessel 23 to a predetermined temperature, for example, 210 ° C.

  In the reaction step, the raw material 20 is stirred by the stirring blade 27, the internal temperature of the reaction vessel 23 is maintained at, for example, 210 to 220 ° C. for 5 to 15 minutes, and the organic waste is subjected to heat denaturation treatment by a hydrothermal reaction. Homogenize properties and reduce the molecular weight of organic compounds and organic chlorine compounds in raw materials. Further, chlorine is desorbed and volatilized and removed from the organochlorine compound by a nucleophilic substitution reaction with superheated steam.

In the decompression step, the supply of steam is stopped, and the exhaust steam and the exhaust gas 28 are taken out from the discharge port 29 to a deodorization facility (not shown).
In the drying step, after the internal pressure of the reaction vessel 23 reaches atmospheric pressure, the outside air 32 is supplied to the inside of the reaction vessel 23 by the blower 30, and the volatilization of the low molecular organic chlorine compound is promoted along with drying. At this time, the reaction vessel 23 is kept at a predetermined temperature or higher by saturated steam supplied from the first steam supply port 25a to the outer casing 22 and is dried into powder by indirect steam heating. The supply of the outside air can also be realized by providing a fan in the exhaust line extending from the discharge port 29 to the deodorizing equipment instead of the supply of the outside air by the blower 30.

  The exhaust gas containing the organic chlorine compound is taken out from the discharge port 29 to a deodorization facility (not shown), and the organic chlorine compound is removed from the exhaust gas by the activated carbon adsorption device. By removing the organic chlorine compound from the exhaust gas, it is possible to prevent the organic chlorine compound having a high influence on the human body from diffusing into the atmosphere. In the discharging process, the outlet 31 is opened, and the dry powdered raw material 20 is taken out from the outlet 31 as pulverized fuel. Since the chlorine concentration in the pulverized fuel is reduced, it is possible to suppress the generation of molten salt alkali metal, which is a causative substance that causes high temperature corrosion during combustion of the fuel, and to suppress corrosion of the furnace wall. The powder fuel can be formed into a solid fuel by molding.

  For this reason, since the pulverized fuel produced | generated with the reaction apparatus 21 can be used as a fuel of the steam generator 41, a part of taken-out pulverized fuel is supplied as a fuel of the steam generator 41, and the steam generator 41 is supplied. Makes it possible to burn pulverized fuel as at least part of the fuel and recover heat from the combustion exhaust gas to generate saturated steam and superheated steam.

  That is, in order to obtain superheated steam in the steam generator 41, it is necessary to burn the pulverized fuel in a temperature range of 300 ° C. or higher where high temperature corrosion due to halogen occurs. However, since the chlorine concentration in the pulverized fuel has been reduced, the pulverized fuel can suppress the generation of molten salt alkali metal, a causative substance that causes high-temperature corrosion during combustion in a temperature range of 300 ° C. or higher, and corrosion of the furnace wall Can be suppressed. Therefore, the pulverized fuel is an effective fuel not only for the steam generator 41 but also for other boilers and the like where high temperature corrosion is a concern.

The front view which shows the reaction apparatus in embodiment of this invention

Explanation of symbols

21 reactor 22 outer jacket (jacket)
DESCRIPTION OF SYMBOLS 23 Reaction container 24 Input port 25a 1st steam supply port 25b 2nd steam supply port 26 Motor 27 Stirring blade 28 Exhaust gas 29 Exhaust port 30 Blower 31 Outlet 41 Steam generator

Claims (4)

  In addition to supplying organic waste containing organic chlorine compounds to the reactor as a raw material, superheated steam is supplied from a steam generator to reduce the molecular weight of the organic compound in the raw material by thermal denaturation treatment of the hydrothermal reaction. A waste fueling method characterized in that chlorine is desorbed and volatilized and removed from an organic chlorine compound by a nucleophilic substitution reaction, and the superheated steam is obtained using the product as fuel for a steam generator.   2. The method of converting waste into fuel according to claim 1, wherein when the fuel is taken out from the reactor, the exhaust gas is discharged from the reactor and then the fuel is discharged.   In addition to supplying organic waste containing organic chlorine compounds to the reactor as a raw material, superheated steam is supplied from a steam generator to reduce the molecular weight of the organic compound in the raw material by thermal denaturation treatment of the hydrothermal reaction. A waste fuel characterized in that chlorine is desorbed and volatilized and removed from an organic chlorine compound by a nucleophilic substitution reaction.   A reactor that reduces the molecular weight of organic compounds in the raw material by thermal denaturation treatment of hydrothermal reaction and desorbs and volatilizes chlorine from organochlorine compounds by nucleophilic substitution reaction with superheated steam, and the product as fuel A waste fueling apparatus comprising: a steam generating device that generates the superheated steam and supplies the superheated steam to a reactor.

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