JPH09263776A - Process for gasifying organic waste and fixed-bed gasification oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for gasifying a metal-contg. org. waste which process does not involve such risks as scattering of light-weight components of the waste into a gasification gas, deposition of low-melting components onto a perforated plate, and generation of dioxines and enables valuable metals to be recovered if necessary and to provide a fixed-bed gasification oven therefor. SOLUTION: In a process for gasifying a metal-contg. org. waste 2 by charging it into a fixed-bed gasification oven 4, supplying a gasifying agent 5 contg. oxygen and steam to gasify it, and discharging a gasification residue 14 through the lower part of the oven 4, the waste 2 is supplied together with the gasifying agent 5 through the upper part of the oven 4 and partially burned and gasified. A gasification gas generated is discharged through the lower part of the oven 4. A fixed-bed gasification oven used therefor is provided which has a gasifying- agent supply port at its upper part and a gasification-gas discharge port at its lower part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed bed gasification furnace suitable for gasification of organic waste including metals such as car shredder dust, municipal solid waste and various industrial wastes, and metals using the same. The present invention relates to a gasification treatment method of an organic waste containing.

[0002]

2. Description of the Related Art Conventionally, as a method for treating organic waste such as waste tires and plastics, these wastes are partially combusted and gasified in a fixed bed gasifier, and the generated gasified gas is used as fuel or carbon black. A method of using the same as a raw material of the above has been proposed, and the present inventors have also proposed an improved technique regarding the structure of the gasification furnace, the method of supplying the gasifying agent, the method of controlling the gasification reaction, etc. 6-298187-9,
Japanese Patent Application No. 7-11191). As shown in FIG. 5, basically, in these technologies, the organic waste 2 is charged from above the fixed bed gasification furnace 4, and metal or ash or the like is fed from the vicinity of the bottom plate 6 below. The gasification residue 14 is discharged, while the gasifying agent 5 is supplied from the lower part of the furnace, and the gasified gas 13 generated by gasification of organic substances is discharged from the upper part of the furnace. In the figure, reference numeral 8 indicates organic waste in the gasification furnace.

[0003]

The gasification furnaces of these prior arts have the following problems. First, since the gasification gas 13 flows upward, light components such as sponges contained in the injected organic wastes 2 and 8 may scatter along with the flow of the gasification gas 13.

Further, when metals are contained in the organic waste, lead (melting point 328 ° C.) and aluminum (melting point 66).
Low melting point metals such as (0 ° C.) once melt in the region of 700 to 1000 ° C. where partial combustion and gasification of organic substances are carried out, and fall downward due to gravity. However, since the low-temperature (usually 300 ° C. or lower) gasifying agent 5 is supplied from below the perforated plate 6, the temperature of the part of the perforated plate 6 may be lowered, and the once-melted low-melting-point metal may be fixed. . further,
The gasification furnace may have an oxidizing atmosphere locally, and since the oxidizing atmosphere becomes the oxidizing atmosphere in the vicinity of the plate to which the gasifying agent is supplied, when organic matter is partially combusted or gasified, high contents of iron, copper, etc. The melting point metal is oxidized and its value as a valuable resource is halved.

Further, since it is difficult to control the temperature inside the furnace, if the temperature inside the furnace falls for some reason, the chlorine content is contained in normal organic waste, which is a problem in terms of pollution control. May produce dioxin.

The present invention solves the above problems of the prior art,
Contains metals that can recover valuable metals if necessary without the risk of scattering of light weight components in organic waste into gasification gas, adhesion of low melting point components to the plate, formation of dioxins, etc. The present invention aims to provide a gasification treatment method for organic waste and a fixed bed gasification furnace therefor.

[0007]

The present invention adopts the following constitutions (1) to (6) as means for solving the above problems. (1) An organic material in which a metal-containing organic waste is put into a fixed-bed gasification furnace to supply a gasifying agent containing oxygen and steam to gasify it, and a gasification residue is discharged from the lower part of the gasification furnace. In the method for gasifying waste gas, the organic waste containing metal and the gasifying agent are supplied from the upper part of the gasification furnace to carry out partial combustion and gasification, and the generated gasification gas is stored in the gasification furnace. A method for gasifying organic waste containing metal, which is characterized in that it is discharged from the bottom.

(2) An organic waste containing the metal according to (1) above, characterized in that a part of the gasification gas generated in the fixed bed gasification furnace is supplied to the upper part of the gasification furnace and burned. Gasification treatment method for materials. (3) Oxygen-containing gas is supplied from the side wall of the fixed bed gasification furnace to form a partial high temperature field, and gasification treatment of the organic waste containing the metal according to (1) or (2) is performed. Method.

(4) Injecting organic waste containing metal,
In a fixed bed gasification furnace that supplies a gasifying agent containing oxygen and water vapor to perform partial combustion / gasification, a gasifying agent supply port is provided at the upper part of the gasification furnace and a gasification gas discharge port is provided at the lower part. A fixed-bed gasification furnace characterized by: (5) A gas burner is installed above the fixed bed gasification furnace, and a part of the gasification gas discharged from the gasification gas discharge port is circulated for combustion. The fixed bed gasification furnace according to (4) above. (6) The fixed bed gasification furnace according to (4) or (5), characterized in that a nozzle for supplying an oxygen-containing gas is provided on a side wall of the fixed bed gasification furnace.

The basic construction of a fixed bed gasification furnace according to the present invention is shown in FIG. The configuration of FIG. 1 corresponds to the configurations of (1) and (4) described above, in which the organic waste 2 is charged from above the fixed bed gasification furnace 4 to perform partial combustion in the temperature range of 700 to 1000 ° C. It is gasified, and the gasification residue 14 consisting of high melting point metals, glass, ash (large particle size), etc. is discharged from the lower part of the plate 6. Although not shown in FIG. 1, the low-melting point metal and ash (small particle size) are used for the plate 6 as described later.
Passes through the tank, collects at the bottom of the furnace, and is discharged separately. On the other hand, the gasifying agent 5 is supplied from the upper part of the furnace, and the gasified gas 13 generated by partial combustion and gasification of the organic waste 8 is discharged from the lower part of the furnace.

In the configurations of (2) and (5) above,
In addition to the configuration of FIG. 1, a gas burner is installed above the fixed bed gasification furnace 4 so that a part of the gasification gas 13 is circulated and burned. Further, in the above configurations (3) and (6), a nozzle for supplying an oxygen-containing gas is provided on the side wall of the fixed bed gasification furnace 4, and an oxygen-containing gas such as air is supplied to control the temperature in the gasification furnace. adjust.

The present invention can be applied to the treatment of organic wastes containing metals such as municipal solid waste and various industrial wastes, and in particular, Automobile Schredder Res (ASR).
10c after removing the idue, engine and suspension from the car
Shredded to m or less, plastics, sponges,
It is useful for the treatment of waste that contains half of inorganic substances such as iron pieces, copper wires, and glass in addition to organic substances such as rubber.

(Operation) With such a structure, the following operations and effects are obtained. Since the gas flow in the fixed bed gasification furnace goes from the upper side to the lower side, scattering of lightweight components such as sponge can be prevented.

High temperatures (700 to 10) produced by partial combustion and gasification of organic substances in the temperature range of 700 to 1000 ° C.
Since the gasification gas of (00 ° C.) flows below the gasification furnace, the atmospheric temperature in the perforated portion is sufficiently high, and the low melting point metal does not stick to the molten state. Further, since the gas flow is directed downward, not only the low melting point metal but also the ash is smoothly dropped from the perforated plate.

When organic matter is partially burned and gasified, iron,
Refractory metals such as copper are also oxidized, but when they move downward, they are reduced by CO, H _{2 and the} like contained in the gasification gas as shown in the following formula, and can be recovered as valuables.

[Chemical formula 1] MO + CO or H ₂ → M + CO ₂
or H ₂ O (MO: metal oxide, M: metal)

In the case of the present invention, since the low temperature (usually 300 ° C. or lower) gasifying agent is supplied from the upper part of the fixed bed gasification furnace, it is difficult to raise the temperature in the upper part of the furnace, and partial combustion of organic waste The gasification region may be narrowed and the gasification efficiency may be reduced. Therefore, a part of the discharged gasification gas is circulated and supplied to a gas burner installed in the upper part of the fixed bed gasification furnace to be burned, and the upper part in the gasification furnace is
By maintaining the high temperature of 700 ° C., it becomes possible to rapidly heat the organic waste.

Depending on the type of organic waste to be treated and the gasification conditions, harmful dioxins may be generated during partial combustion / gasification, but an oxygen-containing gas supply nozzle is provided on the side wall of the gasification furnace. By providing an oxygen-containing gas such as air to burn a part of the gasification gas generated in the gasification furnace, the oxygen-containing gas is partially supplied from the supply part to the gasification furnace outlet. Dioxins can be decomposed by forming a high temperature field of about 1000 ° C.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 2 is a schematic explanatory view showing the first embodiment of the present invention. In the apparatus of FIG. 2, the organic waste 2 containing the metal stored in the hopper 1 is supplied to the upper part of the fixed bed gasification furnace 4 by the feeder 3. A gasifying agent 5 containing oxygen and water vapor is supplied from a gasifying agent supply port provided in the upper part of the fixed bed gasification furnace 4. The supply amount of the gasifying agent 5 is O in an equivalent ratio.
₂ / combustibles = 0.5 to 1, H ₂ O / combustibles = 0.5-5
It is preferable to set it in the range. Fixed plate gasification furnace 4 plate 6
Is slowly rotated by the motor 7.

In the fixed bed gasification furnace 4, the combustible substances in the supplied organic waste 8 are converted into 7 in the partial combustion / gasification section 9.
Partial combustion and gasification are performed at 00 to 1000 ° C. For the remaining metal and ash content 10, the melting point (7
A low-melting point metal such as lead or aluminum having a temperature lower than 00 to 1000 ° C. and a part (small particle size) 11 of ash fall from the plate 6 to the bottom of the fixed bed gasification furnace 4. Also, the melting point is plate 6
Refractory metals such as iron and copper having a temperature higher than the nearby temperature are once oxidized in the partial combustion / gasification section 9, but the metal reduction section 1
CO in gasification gas 13 at 2, after being reduced by H _2, is taken out from the top of the perforated plate 6 as gasification residue 14 such as with large ash content of the glass and particle diameter.

The gasification gas 13 is discharged from the fixed bed gasification furnace 4 after passing through the perforated plate 6, burned by the combustion air 16 in the boiler 15, and the steam 1 by the heat exchanger 17.
Thermal energy is recovered as 8 and is emitted to the atmosphere from the chimney 20 as combustion exhaust gas 19.

FIG. 3 is a schematic explanatory view showing a second embodiment of the present invention. In the apparatus of FIG. 3, the same elements as those of FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, a part of the generated gasified gas 13 is used as the circulating recycled fuel gas 22, and a gas circulation fan (GR
It is supplied to a gas burner 24 provided above the fixed bed gasification furnace 4 via a fan 23 and burned. As a result, the gasifying agent 5 is heated to about 300 to 700 ° C., the temperature of the organic waste in the upper part of the fixed bed gasification furnace 4 due to the low temperature gasifying agent 5 is prevented from lowering, and the smooth partial combustion is achieved.・ Gasification is done.

The remaining part of the gasified gas 13 from which the circulating recycled fuel gas 22 has been separated is supplied to the boiler 15 as the fuel gas 25 for recovering heat energy, and is combusted by the combustion air 16 in the boiler 15 and then by the heat exchanger 17. The heat energy is recovered as the steam 18, and the combustion exhaust gas 19 is discharged to the atmosphere from the chimney 20 via the induction suction fan (IDF) 21.

FIG. 4 is a schematic explanatory view showing a third embodiment of the present invention. In the apparatus of FIG. 3, the organic waste 2 containing metal stored in the hopper 1 is supplied to the upper part of the fixed bed gasification furnace 4 by the feeder 3. In this embodiment, the gasifying agent 5 containing oxygen from the oxygen supply device 28 and steam 18 from the heat exchanger 17 is supplied from the gasifying agent supply port provided at the upper part of the fixed bed gasification furnace 4. It is preferable that the supply amount of the gasifying agent 5 is in the range of O ₂ / combustible content = 0.5 to 1 and H ₂ O / combustible content = 0.5 to 5 in equivalent ratio.

The combustible substances in the supplied organic waste 2 are partially combusted and gasified at 700 to 1000 ° C. in the partial combustion / gasification section 9 on the plate 6 in the fixed bed gasification furnace 4. The gasified gas 13 is discharged from the lower part of the plate 6.

Further, in this embodiment, a plurality of (two in the figure) air nozzles 27a and 27b are provided on the side wall (metal reduction section) of the fixed bed gasification furnace 4, and the air supplied from the blower 26 is supplied. Is supplied to the gasification furnace, and a partial high temperature field of about 1000 ° C. is formed by the combustion of the gasification gas generated in the gasification furnace. As a result, dioxin as a benzene ring compound that is subject to pollution control generated in the partial combustion / gasification section 9 is decomposed to react with C, H and C.
It decomposes and disappears into l. It should be noted that the portion into which air is introduced becomes an oxidizing atmosphere locally, but the amount of air introduced is an air ratio of 1 or less with respect to the gasified gas, and oxygen is immediately consumed to form a reducing atmosphere.

Regarding the metal pieces and ash, etc. remaining in the metal reducing section 12, those having a low melting point and those having a small particle size pass through the plate 6 and reach the bottom of the fixed bed gasification furnace 4 at a low melting point metal, ash content 1
It drops as 1 and is discharged to the outside of the system by opening and closing the valve 29 and the like. Further, a metal having a high melting point is temporarily oxidized in the partial combustion / gasification section 9, but is reduced by CO and H ₂ in the gasification gas 13 in the metal reduction section 12 and accumulated on the perforated plate 6 and partially melted. After the fixed-bed gasification furnace 4 including those mentioned above is cooled, or is discharged to the outside of the system by a continuous discharging device (not shown).

The gasification gas 13 generated in the partial combustion / gasification section 9 passes through the plate 6 as described above, is discharged from the fixed bed gasification furnace 4, and is sensible heat in the heat exchanger 17. After generating the steam 18 used as a component of the gasifying agent 5, it is used as a fuel in another plant or the like not shown.

[0028]

According to the present invention, the following effects can be obtained. (1) Organic wastes containing metals can be effectively partially combusted and gasified, and low melting point metals such as lead and aluminum can be separated and discharged without sticking to the eye plate, and iron, copper, etc. The high melting point metal can be recovered as an expensive substance containing no oxide. (2) Further, by burning a part of the gasification gas in the upper part of the fixed bed gasification furnace, the temperature inside the furnace can be maintained at a high temperature and uniformly, so that a smoother partial combustion / gasification can be achieved. Is possible. (3) Further, by supplying air or oxygen to the side wall of the fixed bed gasification furnace to form a high temperature field, the dioxin by-produced during partial combustion and gasification of organic waste is decomposed. Therefore, clean gasification gas can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the basic configuration of a fixed bed gasification furnace according to the present invention.

FIG. 2 is a schematic explanatory view showing a first embodiment of the present invention.

FIG. 3 is a schematic explanatory view showing a second embodiment of the present invention.

FIG. 4 is a schematic explanatory view showing a third embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the basic configuration of a conventional fixed bed gasification furnace.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayasu Sakai 1 717-5-chome, Fukahori-cho, Nagasaki-shi, Nagasaki Nagahishi Engineering Co., Ltd.

Claims (6)

[Claims] 1. A fixed bed gasification furnace is charged with an organic waste containing metal, a gasifying agent containing oxygen and water vapor is supplied for gasification, and a gasification residue is discharged from a lower portion of the gasification furnace. In the method for gasifying organic waste, the organic waste containing metal and a gasifying agent are supplied from the upper part of the gasification furnace to perform partial combustion and gasification, and the generated gasification gas is gasified. A method for gasifying organic waste containing metal, which is characterized in that it is discharged from the bottom of the furnace. 2. The organic waste containing metal according to claim 1, wherein a part of the gasification gas generated in the fixed bed gasification furnace is supplied to the upper part of the gasification furnace and burned. Gasification treatment method for materials. 3. The gasification of an organic waste containing metal according to claim 1, wherein an oxygen-containing gas is supplied from a side wall of the fixed bed gasification furnace to form a partial high temperature field. Processing method. 4. A fixed bed gasifier in which an organic waste containing a metal is charged and a gasifying agent containing oxygen and water vapor is supplied to partially combust and gasify the gas. A fixed bed gasification furnace characterized in that an agent supply port and a gasification gas discharge port are provided in the lower part. 5. A gas burner is installed above the fixed bed gasification furnace to circulate and burn a part of the gasification gas discharged from the gasification gas discharge port. The fixed bed gasifier according to claim 4. 6. The fixed bed gasification furnace according to claim 4, wherein a nozzle for supplying an oxygen-containing gas is provided on a side wall of the fixed bed gasification furnace.