JP2005120210A - Waste disposal by gasification and system therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of disposing waste by gasification which is simple and good in heat efficiency and a system therefor. <P>SOLUTION: In the system, a kiln 1 as a dry distillation furnac which produces a dry distillation gas by disposing a waste by dry distillation and a kiln 2 as a heating furnace which heats a polluted soil to make it harmless, are installed, and the system is constituted so that a high temperature soil heated by the kiln 2 as a heating furnace is used as a dry distillation heat source for the kiln 1 as a dry distillation furnace and supplied to be able to come into contact with the waste, and the system is also constituted by being provided with a cooler 3 which cools the dry distillation gas produced in the kiln 1 to separate and remove water content and tar, a power generator 4 which generates power by using the dry distillation gas purified by the cooler 3 as a fuel, a pneumatic separator 6 which separates the soil component fed as heat source, from a residue received in a residue receiving part 5, and a melting furnace 7 which melts and treats the separated residue. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a waste gasification method and system for producing a dry distillation gas by subjecting a waste to a carbonization process in a carbonization furnace and effectively using the dry distillation gas.

  Conventionally, kiln furnaces, which are used as an example of a carbonization furnace for carbonizing waste, are constructed in a double-pipe structure in which the periphery of a rotating drum is covered with a heating jacket, and are produced by city gas, heavy oil, or the carbonization process. The air heated by a combustor using the dry distillation gas as fuel and the exhaust gas thereof are supplied into the heating jacket as a dry distillation heat source. Further, an oil component such as tar contained in the dry distillation gas generated in the kiln furnace has been used as a fuel for a combustion burner of a melting furnace for melting the dry distillation residue.

Furthermore, when a fluidized bed furnace is used as a dry distillation furnace, in order to make fluidized sand, which is a fluidized medium, flow, a heated gas containing air having a theoretical air ratio or less is supplied from the bottom of the furnace, It was configured to maintain the dry distillation temperature by partially combusting, but the fluidized sand was partially discharged from the furnace together with the residue, and the fluidized sand from which the residue was separated and removed was circulated into the furnace. It was.
JP 2000-297912 A JP-A-9-178138

  However, in the dry distillation process using the conventional kiln furnace described above, it is necessary to sufficiently seal the heating jacket so that the dry distillation gas and the air that is the heat source of the dry distillation contact and do not burn abnormally, and the sealing structure is complicated. There is a problem and an essential problem that the indirect heating by such a double-pipe structure has a limit in improving the thermal efficiency, and it has been desired to develop a kiln furnace having a simpler structure and higher thermal efficiency. Further, the dry distillation treatment using a fluidized bed furnace has a problem that an extra amount of heat is required to heat the low temperature fluidized sand that has been discharged out of the furnace and recirculated, and the thermal efficiency for dry distillation is reduced.

  On the other hand, environmental pollution of soil has become an important issue in recent years, and a method of detoxifying by heating in a heating furnace has been put into practical use for purification of contaminated soil, but the soil after detoxification is buried as it is. There has been a need for a method that effectively uses the thermal energy held by high-temperature soil.

  In view of the above-described problems, an object of the present invention is to provide a waste gasification method and system that are simple and heat efficient.

  In order to achieve the above-mentioned object, the first characteristic configuration of the waste gasification processing method according to the present invention is that the waste is subjected to dry distillation treatment in a dry distillation furnace as described in claim 1 of the claims. A waste gasification method for producing a dry distillation gas, which is that a contaminated soil heated in a heating furnace and detoxified is supplied as a dry distillation heat source of the dry distillation furnace so as to be in contact with the waste.

  According to the above-described configuration, the process in which waste is agitated and mixed with the high-temperature soil in the furnace by using the contaminated soil that has been detoxified by heating and maintained at a high temperature as the dry distillation heat source of the waste in the dry distillation furnace. It will be heated in the process and will be efficiently subjected to dry distillation. Moreover, the energy efficiency for dry distillation can be improved by effectively utilizing the retained heat of the contaminated soil after the detoxification treatment, which has not been used conventionally.

  As described in claim 2, the second characteristic configuration is, in addition to the first characteristic configuration described above, directly or indirectly using the heat of combustion of the dry distillation gas generated in the dry distillation process as a heat source of the heating furnace. It is in the point to supply as.

  The carbonization gas generated in the carbonization furnace is effectively used as energy for other combustion equipment and combustion furnaces, but by supplying surplus carbonization gas directly as heating fuel for the heating furnace, It is not necessary to consume other energy as a heat source, and the same effect can be obtained by indirectly or directly supplying the retained heat of the exhaust gas generated in such combustion equipment and combustion furnace to the heating furnace. .

  The first characteristic configuration of the waste carbonization treatment system according to the present invention is a waste gasification treatment system comprising a carbonization furnace for producing carbonization gas by subjecting waste to carbonization as described in claim 3. A heating furnace for detoxifying the contaminated soil by heating, and configured to supply the high-temperature soil heated in the heating furnace so as to be in contact with the waste as a dry distillation heat source of the dry distillation furnace There is a point.

  In the second feature configuration, as described in claim 4, in addition to the first feature configuration described above, the combustion heat of the dry distillation gas generated by the dry distillation furnace is directly or indirectly used as a heat source of the heating furnace. It is in the point comprised so that it may supply.

  In the third feature configuration, as described in claim 5, in addition to the first or second feature configuration described above, a melting furnace is provided for melting the dry distillation residue discharged from the dry distillation furnace, and the melting The heat stored in the high temperature exhaust gas from the furnace is supplied directly or indirectly as a heat source for the heating furnace.

  The residue after the carbonization treatment includes solid carbon components such as char and inorganic substances, and may be melted in a melting furnace to be finally disposed of. In such a case, it is not necessary to consume other energy as the heat source of the heating furnace as described above by directly or indirectly supplying the retained heat of the exhaust gas of the melting furnace as the heat source of the heating furnace. is there.

  In addition to any one of the first to third characteristic configurations described above, the fourth characteristic configuration is a sorting device that separates soil from the dry distillation residue discharged from the dry distillation furnace. It is in the point which is provided.

  Since the soil used as a heat source is mixed in the dry distillation residue, it is inefficient to treat all of them by melting or the like. Therefore, the soil can be backfilled and separated as safe soil by separating the soil and residue using a sorting device.

  The fifth characteristic configuration is that, in addition to any of the first to fourth characteristic configurations described above, the dry distillation furnace is a kiln furnace.

  When the dry distillation furnace is constituted by a kiln furnace, it can be directly heated by high-temperature soil, so that a complicated sealing function by the conventional indirect heating is not required, and the structure of the furnace can be simplified while ensuring safety.

  The sixth characteristic configuration is that, in addition to any of the first to fifth characteristic configurations described above, the heating furnace is a kiln furnace.

  As described above, according to the present invention, it is possible to provide a waste gasification method and system that are simple and heat efficient.

  Embodiments of the waste gasification method and system according to the present invention will be described below. As shown in FIG. 1, the waste gasification processing system includes a kiln furnace 1 as a dry distillation furnace that generates carbonization gas by subjecting waste to a carbonization process, and a heating furnace that heats contaminated soil and renders it harmless. A kiln furnace 2 is provided, and high temperature soil heated in the kiln furnace 2 as a heating furnace is supplied as a dry distillation heat source of the kiln furnace 1 as a dry distillation furnace so as to be in contact with waste. A cooling device 3 for separating and removing moisture and tar by cooling the produced dry distillation gas, a gas power generation device 4 for generating electricity using the dry distillation gas purified by the cooling device 3 as fuel, and a residue discharged from the kiln furnace 1 A wind power sorting device 6 that separates and sorts soil components introduced as a heat source from the residue housed in the housing portion 5 and a melting furnace 7 that melts the sorted residue are configured.

  The kiln 2 as the heating furnace is a device in which soil contaminated with highly toxic organic chemicals, oil, etc. is excavated and heated to decompose and remove the pollutants, and the axis is in a horizontal position or slightly A cylindrical rotary drum 21 placed on the rotary drive roller 22 so as to have a tilted posture, a hopper 23 provided at the base end of the rotary drum 21, and a terminal portion of the rotary drum 21. A discharge unit 24 and the like are provided. The contaminated soil charged into the hopper 23 is charged into the rotary drum 21 by a screw type conveyor (not shown) disposed at the bottom of the hopper 23, while the gas is used as a heating heat source for the kiln furnace 2. A high-temperature exhaust gas of about 700 ° C. to 800 ° C. from the power generator is directly supplied into the furnace, and the contaminated soil is heated in direct contact with the high-temperature exhaust gas in the furnace to decompose the pollutants. The rotary drum 21 may be configured in a double structure, and the exhaust gas may be supplied to the gap between the inner rotary drum and the outer rotary drum into which contaminated soil is introduced, and indirectly heated.

  The kiln furnace 1 as the carbonization furnace is similar to the kiln furnace 2 described above, and has a cylindrical rotating drum 11 placed on the rotation driving roller 12 so that the shaft center is in a horizontal posture or a slightly inclined posture, A hopper 13 provided at the base end portion of the rotary drum 11 and a discharge portion 14 provided at the terminal end of the rotary drum 11 are provided. The hopper 13 is crushed by a crusher and put into the hopper 13. Waste is charged into the rotary drum 11 by a screw conveyor (not shown) disposed at the bottom of the hopper 13.

  The base end portion of the rotary drum 11 is further provided with a screw type conveyor that heats the kiln furnace 2 and discharges contaminated soil of 500 ° C. to 600 ° C. discharged from the discharge portion 24 into the furnace. Waste, to which the soil charging device 15 is connected and charged in the furnace, is heat-treated while being stirred and conveyed toward the end portion inside the rotary drum 11, so that hydrogen, carbon monoxide, hydrocarbons, etc. In addition to pyrolysis of flammable gas, dry distillation gas mixed with other volatile components and moisture mixed with waste is generated and taken out from the discharge pipe 14A, and the pyrolyzed waste residue A certain char, an inorganic substance, and a soil component as a heating heat source are discharged from the discharge duct 14 </ b> B and stored in the residue storage unit 5.

  The waste contained in the residue container 5 is subjected to wind sorting by the wind sorting device 6 and separated and sorted into residues such as char having a small specific gravity and soil components having a large specific gravity, and the soil components are backfilled in the original land. While being regenerated as clean soil, the residue is melted by the melting furnace 7. Here, it is possible to supply the above-mentioned dry distillation gas as fuel to the burner of the melting furnace 7.

  The base end portion of the rotating drum 11 is sealed with waste put in the hopper 13 and the discharge portion 14 is heated by a suction fan (not shown) to be heated in a very low oxygen concentration state. Carbonized.

  The cooling device 3 is configured by arranging a cooling conduit for circulating cooling water in the gas flow path, and indirectly or directly cools the dry distillation gas flowing into the device, and mixes the vapor component mixed into the dry distillation gas, A tar component is condensed and separated and purified, and a corrosive gas such as hydrogen chloride gas mixed in the dry distillation gas is dissolved and removed in the condensed water.

  The gas power generation device 4 includes a gas engine 4A and a generator 4B that generates electric power using a turbine that is rotationally driven by the gas engine 4A. The burner portion 4a of the gas engine 4A is purified by the cooling device 2. The dry distillation gas is supplied as fuel, and the combustion exhaust gas is supplied through a pipe 25 as a heating heat source of the kiln furnace 2 as a heating furnace.

  Hereinafter, another embodiment will be described. In the above-described embodiment, the carbonization gas generated by the kiln furnace 2 is supplied to the gas power generation device 4 and the combustion exhaust gas is supplied to the kiln furnace 1 as a heating heat source. A combustor may be provided and dry distillation gas may be supplied to the combustor as fuel.

  As a heating heat source for the kiln furnace 1, it is possible to use the exhaust heat of the exhaust gas from the melting furnace 7, and the exhaust gas is directly or indirectly through another heating medium via a heat exchanger. You may comprise so that it may heat, and may utilize both the combustion heat of dry distillation gas, and the retained heat of the waste gas of the melting furnace 7. FIG.

  In the above-described embodiment, the kiln furnace 2 is used as the dry distillation furnace. However, the fluidized bed furnace 8 can be used as the dry distillation furnace, and the heating furnace is used as the fluidized medium of the fluidized bed furnace 8. It is possible to use soil that has been purified by heating. As shown in FIG. 2, the fluidized bed furnace 8 was purified by a flowing gas ejected upward from an air diffuser 8 b provided at the bottom of a vertical furnace body 8 a having a lower portion formed narrower than the upper portion. Waste water such as municipal waste and waste building materials pretreated so as to flow through a fluidized bed 8c using a contaminated soil to form a fluidized bed and flowable by a crusher (not shown), etc. The waste is introduced from a waste inlet 8d provided on the side wall of the body 8a, heated inside the fluidized bed and in the space above the fluidized bed, and pyrolyzed into a dry distillation gas containing hydrocarbons, hydrogen, steam and the like as components. .

  That is, the soil purified by the kiln furnace 2 is supplied as a fluid medium 8c from a soil conveyance path 8f, exhaust gas from the melting furnace 7 is supplied as a fluidizing gas, and pyrolysis residue generated in the fluidized bed furnace 8 Is discharged together with a part of the fluid medium 8c from the fluid medium discharge part 8e at the center of the air diffuser 8b, separated by the wind power sorter 6 into residues containing the fluid medium 8c and char, and the like as the fluid medium 8c. The soil component is backfilled in the original land and regenerated as clean soil, while the residue is melted by the melting furnace 7. Here, as the gas for flow, in addition to the exhaust gas supplied from the melting furnace 7, the exhaust gas from the gas engine 4A can be used. Furthermore, it is equipped with a boiler that generates steam using combustion heat of dry distillation gas, exhaust gas from the melting furnace, and a steam superheater that further superheats the generated steam, and the generated superheated steam can also be used as a flow gas. It is.

  In the above-described embodiment, the kiln furnace is used as the heating furnace for purifying the contaminated soil by heating. However, the heating furnace is not limited to this, for example, a known heating such as a vertical furnace. A furnace can be used.

  Each of the above-described embodiments is merely an example of the present invention, and the configuration can be changed as appropriate as long as the effects of the present invention are achieved.

Illustration of waste gasification system Explanatory drawing of the waste gasification processing system which shows another embodiment

Explanation of symbols

1: Kiln furnace (dry distillation furnace)
2: Kiln furnace (superheated furnace)
3: Cooling device 4: Gas power generation device 5: Residue container 6: Wind power sorting device 7: Melting furnace

Claims (8)

A waste gasification method for producing a dry distillation gas by subjecting a waste to a dry distillation process in a carbonization furnace,
A waste gasification method for supplying contaminated soil heated in a heating furnace and detoxified to be in contact with the waste as a dry distillation heat source of the dry distillation furnace.   The waste gasification method according to claim 1, wherein combustion heat of the dry distillation gas generated in the dry distillation process is supplied directly or indirectly as a heat source of the heating furnace. A waste gasification processing system comprising a carbonization furnace for generating carbonization gas by subjecting waste to carbonization,
A waste provided with a heating furnace for detoxifying by heating contaminated soil, and configured to supply high-temperature soil heated in the heating furnace as a dry distillation heat source of the dry distillation furnace so as to be in contact with the waste Gasification processing system.   The waste gasification processing system according to claim 3, wherein combustion heat of the dry distillation gas generated by the dry distillation furnace is supplied directly or indirectly as a heat source of the heating furnace.   A melting furnace for melting a carbonization residue discharged from the carbonization furnace is provided, and the retained heat of the high-temperature exhaust gas from the melting furnace is directly or indirectly supplied as a heat source of the heating furnace. The waste gasification processing system according to 3 or 4.   The waste gasification processing system according to any one of claims 3 to 5, further comprising a sorting device for separating soil from a carbonization residue discharged from the carbonization furnace.   The waste gasification processing system according to any one of claims 3 to 6, wherein the dry distillation furnace is a kiln furnace.   The waste gasification processing system according to any one of claims 3 to 7, wherein the heating furnace is a kiln furnace.

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