JP3824267B2 - Combustible gas recovery equipment from waste - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustible gas recovery device from waste that can efficiently recover combustible gas from waste such as municipal waste and sewage sludge.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-98282
The incineration method is generally used as a waste disposal method such as municipal waste, but from the viewpoint of reducing carbon dioxide emission, which is the cause of global warming, the above-mentioned Patent Document 1 has recently been disclosed. As shown, methods for recovering combustible gas from waste have been developed. This method is a method in which a pyrolysis gas containing a polymer gas generated by pyrolyzing waste is led to a gas reforming furnace, and oxygen is blown to reform the gas into a low molecular gas. In this case, as a means for reforming from a high molecular gas to a low molecular gas, it is common to use a gas reforming furnace that raises the temperature by blowing oxygen.
[0004]
FIG. 4 shows a typical conventional apparatus, in which 21 is a gasification furnace for thermally decomposing waste, 22 is a gas reforming furnace for reforming a polymer gas generated in the gasification furnace 21 to a low molecular gas, Reference numeral 23 denotes a cleaning tower for cleaning the obtained low molecular gas, and reference numeral 24 denotes a gas holder for storing the low molecular gas. Reference numeral 25 denotes a supply source for supplying oxygen and water vapor to the gas reforming furnace 22, and oxygen and water vapor are blown into the furnace as a swirling flow, and gas reforming is performed in contact with the pyrolysis gas.
[0005]
However, in the case of such a swirl type gas reforming furnace, it is necessary to increase the operating temperature to about 1200 ° C. and take a residence time, and in addition to oxygen necessary for gasification, oxygen necessary for temperature rise is necessary. Thus, there is a problem that the amount of oxygen used is increased and the running cost is increased, and at the same time, the calorific value of the resulting reformed gas is reduced. Further, since the temperature is high, the dust contained in the pyrolysis gas has a viscosity and adheres to the furnace wall, so that it is necessary to frequently perform the removing operation.
[0006]
[Problems to be solved by the invention]
The present invention solves the conventional problems as described above, can perform gas reforming at a low temperature, can reduce the amount of oxygen used, and can greatly reduce the processing cost. The present invention has been completed in order to provide an apparatus for recovering combustible gas from waste that can prevent dust from adhering to the furnace wall and reduce the size of the apparatus .
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a combustible gas recovery device from waste according to claim 1 of the present invention includes a waste gasifier and a low molecular weight polymer gas generated from the gasifier. Combustible gas recovery device from waste comprising a gas conversion catalyst reaction tower packed with a low molecular weight catalyst for reforming to a combustible gas, wherein the gas conversion catalyst reaction tower includes a low molecular weight catalyst The filter is filled with a filter . As this low molecular weight catalyst, it is preferable to use an iron compound composed of one or more of the group consisting of iron hydroxide, triiron tetroxide, and diiron trioxide.
[0008]
According to a second aspect of the present invention, there is provided an apparatus for recovering combustible gas from waste, a gasifier for waste, and a low gas reforming polymer gas generated from the gasifier to a low-molecular combustible gas. An apparatus for recovering flammable gas from waste comprising a gas conversion catalyst reaction tower filled with a molecular conversion catalyst, wherein the gas conversion catalyst reaction tower is filled with a filter molding of a low molecular weight catalyst. It is a feature .
[0009]
The other device of claim 3, the gasifier waste, particulate with the polymer gas generated from the gasification unit is carrying low molecular weight catalysts for reforming the combustible gas of the low-molecular A gas conversion catalyst reaction tower filled with a body and a sieving device for separating dust from the granular material extracted from the gas conversion catalyst reaction tower are provided. Furthermore, a regenerator that regenerates the separated granular material and returns it to the gas conversion catalyst reaction tower can be provided at the subsequent stage of the sieving device.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of an apparatus for recovering combustible gas from waste according to the present invention, wherein 1 is a waste gasifier, and 2 is a polymer gas generated in the gasifier 1 converted to a low molecular gas. The gas conversion catalyst reaction tower 3 is a washing tower for washing the obtained low molecular gas, and 4 is a gas holder for storing the low molecular gas.
[0011]
In this embodiment, a rotary kiln type pyrolysis furnace is used as the gasifier 1. Wastes such as municipal waste and sewage sludge are put into this pyrolysis furnace, and indirectly heated to 400-600 ° C. by a burner 1a in a low oxygen atmosphere to become pyrolysis gas containing polymer gas and pyrolysis residue. However, the waste gasifier 1 is not limited to the rotary kiln-type pyrolysis furnace, and uses a fluid kiln-type rotary kiln-type pyrolysis furnace or a digestion tank that digests garbage and sludge to generate biogas. You can also.
[0012]
The polymer gas generated in the gasifier 1 is mixed with oxygen and water vapor supplied from the supply source 2 a and sent to the gas conversion catalyst reaction tower 2. In this embodiment, the gas conversion catalyst reaction tower 2 is filled with a honeycomb body 5 carrying a low molecular weight catalyst as shown in FIG. As the low molecular weight catalyst, an iron compound composed of one or more members selected from the group consisting of iron hydroxide, triiron tetroxide, and diiron trioxide can be used. These are porous and exhibit an excellent catalytic reaction. In addition, zirconium oxide may be supported on or contained in the iron compound, and in this case, generation of residues due to the treatment can be reduced, which is preferable. Furthermore, even when one or more of the group consisting of zinc oxide, tin oxide, alkali metal oxides and alkaline earth metal oxides are supported or contained, the generation of residues associated with the treatment can be reduced. This is preferable.
In addition, although the thing of the slit structure was shown as the said honeycomb body 5 in FIG. 2, the thing of the grid | lattice structure in which a ventilation hole becomes polygons, such as a tetragon | quadrangle and a hexagon, and a flat plate and a corrugated sheet, Arbitrary structures, such as those in which corrugated cardboard plates bonded together are wound, or structures in which one end of the through hole end of a honeycomb structure used in a DPF (diesel engine filter) is alternately sealed Can be adopted.
[0013]
The polymer gas is reduced in molecular weight while passing through the honeycomb body 5 supporting the low molecular weight catalyst, and is reformed to a low molecular combustible gas such as CO and H ₂ . In this case, about 400-800 degreeC is enough for reaction temperature, and low temperature may be sufficient compared with the conventional gas decomposition furnace which required the operation temperature of 1200 degreeC. Thus, since the reactivity in a low temperature region is improved as compared with the conventional case, it is not necessary to burn a part of the combustible gas for the temperature rise, and the gas recovery heat generation amount can be increased. Further, since oxygen for raising the temperature is not necessary, the processing cost can be significantly reduced.
[0014]
Furthermore, since the gas conversion catalyst reaction tower 2 filled with the low molecular weight catalyst also has high contact efficiency between the gas and the catalyst, the equipment can be made compact, and the dust is the wall surface of the gas conversion catalyst reaction tower 2. It is also possible to reduce the number of incidental facilities as compared with the swirling flow type gas reforming furnace. The dust adhering to the honeycomb body 5 can be dropped and recovered.
[0015]
The low-molecular combustible gas modified in the gas conversion catalyst reaction tower 2 is washed in the washing tower 3 to remove impurities, and stored in the gas holder 4. This combustible gas can be effectively used as a heat source for gas engines, gas turbines, boilers, off-site facilities, and the like.
[0016]
FIG. 3 is a view showing an embodiment in which the gas conversion catalyst reaction tower 2 is filled with a granular material 6 to which a low molecular weight catalyst is attached. In FIG. 3, 7 is a cylindrical reaction column body, 8a is an inlet for a polymer gas to be treated, 8b is an outlet for a low molecular gas, 9a and 9b are inlets and outlets for a granular material 6, and 10 is a granular material 6 The stirring device. The granular material 6 charged from the charging port 9a is gradually moved downward while being continuously rotated by the stirring device 10, and is taken out from the discharging port 9b. On the other hand, the polymer gas enters the reaction tower main body 7 from the inlet 8a, and comes into contact with the granular material 6 to which the low molecular weight catalyst is attached, and is reduced in molecular weight. As the granular body 6, for example, a ceramic ball or the like can be used.
[0017]
In the embodiment of FIG. 3, a sieving device 11 and a regenerating device 12 are provided in the subsequent stage of the gas conversion catalyst reaction tower 2. The sieve device 11 has a function of separating dust attached to the granular material 6 extracted from the gas conversion catalyst reaction tower 2, and the granular material 6 from which the dust has been separated regenerates the separated granular material 6. 12 is sent. In this regenerator 12, the granular material 6 is regenerated by acid cleaning or heat treatment, and then returned to the inlet 9a of the gas conversion catalyst reaction tower 2. In this way, by continuously replacing and regenerating the granular material 6, continuous operation over a long period of time can be achieved while preventing a decrease in catalyst activity.
[0018]
In addition, although the honeycomb body which carried the low molecular weight catalyst and the granular material which carried the low molecular weight catalyst were demonstrated as what is filled in the gas conversion catalyst reaction tower 2, it does not carry a catalyst in addition to this. It is also possible to fill a honeycomb molded body, a filter molded body, a granular molded body, etc., of a low molecular weight catalyst produced with a catalyst and a binder. Moreover, it is possible to fill a filter carrying a low molecular weight catalyst so as to have a dust separation function.
[0019]
【The invention's effect】
As is clear from the above description, according to the present invention, the gas reforming is conventionally performed by passing the polymer gas obtained by gasifying the waste through the gas conversion catalyst reaction tower packed with the low molecular weight catalyst. Can be performed at a much lower temperature, and the amount of oxygen used can be reduced. For this reason, it is possible to increase the amount of heat recovered from the combustible gas while significantly reducing the processing cost as compared with the prior art. In addition, since dust can be prevented from adhering to the furnace wall, the interval between periodic repairs can be expanded. In addition, the apparatus can be reduced in size and incidental facilities can be reduced, so that there is an advantage that the installation space can be reduced.
[0020]
Furthermore, as in the inventions of claims 3 and 4 , if a sieve device or a regenerator for separating dust from the granular material extracted from the gas conversion catalytic reaction tower is provided, the apparatus can be used for a long period of time while preventing a decrease in catalyst activity. Continuous operation is possible.
[Brief description of the drawings]
FIG. 1 is a schematic overall view showing an embodiment of the present invention.
Fig. 2 is a perspective view showing a honeycomb body.
FIG. 3 is a schematic view showing a gas conversion catalytic reaction tower packed with granules.
FIG. 4 is a schematic overall view showing a conventional example.
[Explanation of symbols]
1 waste gasifier, 1a burner, 2 gas conversion catalyst reaction tower, 3 washing tower, 4 gas holder, 5 honeycomb body, 6 granule, 7 reaction tower body, 8a high molecular gas inlet, 8b low molecular gas Exit, 9a Granule inlet, 9b Granule outlet, 10 Stirrer, 11 Sieve device, 12 Regenerator, 21 Conventional gasifier, 22 Gas reformer, 23 Cleaning tower, 24 Gas holder, 25 Oxygen And water vapor source

Claims (4)

A waste gasifier and a gas conversion catalyst reaction tower packed with a low molecular weight catalyst that reforms the polymer gas generated from the gasifier into a low molecular weight combustible gas. A combustible gas recovery apparatus, wherein the gas conversion catalyst reaction tower is packed with a filter carrying a low molecular weight catalyst, wherein the combustible gas recovery apparatus is made from waste. A waste gasifier and a gas conversion catalyst reaction tower packed with a low molecular weight catalyst that reforms the polymer gas generated from the gasifier into a low molecular weight combustible gas. A combustible gas recovery apparatus, wherein the gas conversion catalyst reaction tower is filled with a low molecular weight catalyst filter molding. A waste gasifier, a gas conversion catalyst reaction tower filled with a granular material supporting a low molecular weight catalyst for reforming a high molecular gas generated from the gasifier into a low molecular combustible gas, and An apparatus for recovering combustible gas from waste, comprising a sieving device for separating dust from a granular material extracted from a gas conversion catalytic reaction tower. The apparatus for recovering combustible gas from waste according to claim 3, wherein a regenerator for regenerating the separated granular material and returning it to the gas conversion catalytic reaction tower is provided at the subsequent stage of the sieving apparatus.

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