JP2003320359A - Method and apparatus for pyrolyzing organic waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a fuel good in quality by pyrolyzing organic waste. <P>SOLUTION: An apparatus for pyrolyzing organic waste is composed of a rotary cylinder for pyrolysis which pyrolyzes the organic waste by indirectly heating the waste by a heating pipe set in the cylinder while the waste supplied from one end of the cylinder is discharged from the other end and a gas reforming chamber for converting the pyrolytic gas into the fuel by a high temperature water-gas reaction. In the system of the apparatus, a cyclone for dust collection is installed in the pyrolytic gas outlet part of the rotary cylinder, tar and dust collected by the cyclone are returned to the charging machine of the cylinder and mixed with organic waste to be newly charged, and the mixture is charged into the cylinder and pyrolyzed again. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing fuel gas through a process of pyrolyzing and reforming organic waste such as sewage sludge, human waste sludge, food sludge, food waste, papers, plastics and the like. It is about.

[0002]

As a method for thermally decomposing organic waste, a method for heating a pyrolysis rotary cylinder from the outside or a method for equipping the pyrolysis rotary cylinder with a heating tube, There has been a method in which a heating pipe is heated by an internal burner and the organic waste is thermally decomposed by radiant heat of the heating pipe.

However, when the pyrolysis rotary cylinder is heated from the outside, there is a problem that a gap is created in the seals provided at both ends of the rotary cylinder due to thermal strain.

If a gap is formed in the seal, if the rotary pyrolysis cylinder has a positive pressure, the pyrolysis gas may blow out from the gap, which may cause a fire or explosion. On the other hand, if the seal has a negative pressure, air may be sucked from the gap. There is a risk of fire and explosion.

Further, the method of heating from the inside by the heating tube having the burner inside the pyrolysis rotary cylinder has a problem that the fuel consumption of the burner inside the heating tube is very large.

Pyrolysis of organic waste is mainly aimed at effective use of charcoal, which is the residue after pyrolysis, as fertilizers and soil conditioners, and the effective use of pyrolysis gas is difficult to measure. Met. The reason is that the pyrolysis gas contains a large amount of tar and dust, and the pyrolysis gas of plastic contains hydrogen chloride, which is a harmful gas.

For the above reasons, the pyrolysis gas is burned in a deodorizing chamber (also referred to as a gas combustion chamber) to remove dust and hydrogen chloride, and then released into the atmosphere.

Further, when the concentration of dust and hydrogen chloride contained in the pyrolysis gas is low, a waste heat boiler, a hot water boiler, an air heater, etc. were installed downstream of the deodorizing chamber to measure heat recovery.

In any case, the pyrolysis gas generated in the pyrolysis rotary cylinder is incinerated in the deodorizing chamber, and the generation of dioxins generated by combustion is unavoidable. Therefore, the pyrolysis rotary cylinder is legally regulated within the category of an incinerator.

It is considered that the highly toxic dioxins generated by incineration are produced by the three elements of hydrogen chloride, unburned carbon and air. Therefore, as measures against dioxins, a method of removing hydrogen chloride in the pyrolysis gas, a method of removing tar, soot, and hydrocarbons, which are the main constituents of unburned carbon, have been taken.

However, there is no apparatus or method capable of completely removing dioxins. This is because the only way to suppress the generation of dioxins is to reform the pyrolysis gas into a hydrocarbon-free gas.

[0012] Therefore, an object of the present invention is to provide a method and apparatus for thermally decomposing organic waste which can solve various problems of the above-mentioned conventional examples.

[0013]

According to a first aspect of the present invention, a high temperature reformed gas reformed in a gas reforming chamber is caused to flow into a heating pipe provided inside a rotary cylinder for thermal decomposition, and the radiant heat of the heating pipe is used. It is the thermal decomposition of organic waste.

Since the high temperature reformed gas is used, the fuel consumption of the pyrolysis rotary cylinder can be reduced.

The second aspect of the present invention is directed to organic waste-
This is a device in which a heating pipe having a high-temperature reformed gas passing through is internally provided in a pyrolysis rotary cylinder which is received from the end and discharged from the other end, and radiant heat of the heating pipe is used to thermally decompose organic waste.

Since the high temperature reformed gas is used, the fuel consumption of the pyrolysis rotary cylinder can be reduced.

According to a third aspect of the present invention, a high temperature steam is produced by a waste heat boiler utilizing the waste heat of the high temperature reformed gas, and the high temperature steam is blown into the pyrolysis rotary cylinder during pyrolysis. is there.

When the high-temperature steam and the pyrolysis gas come into contact with each other, the water-gas reaction shown in Table 1 below occurs, and tar and soot are decomposed into carbon monoxide and hydrogen. Further, the pyrolysis gas has a suppressed carbon production rate, and is mainly composed of carbon oxide and hydrogen, and a hydrogen-rich lower hydrocarbon gas.

[0019]

[Table 1]

As described above, since the carbon production rate of the pyrolysis gas is suppressed, it is possible to suppress the generation of dioxins. The thermal decomposition of the organic waste occurs when the temperature inside the rotary cylinder for thermal decomposition is about 300 ° C. or higher, and thermal decomposition gas is generated. Further, high temperature steam of 400 ° C. or higher is required for the water gas reaction.

According to the fourth aspect of the present invention, the pyrolysis gas produced by the pyrolysis cylinder is passed through the inside of the heating pipe in the gas reforming chamber, and the heating pipe is heated from the outside to perform pyrolysis. It is characterized in that the gas is reformed into a higher quality gas. The pyrolysis gas that has undergone the water-gas reaction is passed through a heating pipe, and the temperature of the pyrolysis gas is raised to about 800 ° C. or higher to accelerate the water-gas reaction. As a result, the hydrocarbon is completely reformed into carbon monoxide and hydrogen.
Therefore, even if this reformed gas is burned, it becomes a high-quality fuel that does not produce dioxins at all.

The invention according to claim 4 is a method for thermally decomposing an organic waste for producing a high quality fuel from the organic waste, and the invention according to claim 5 is an apparatus for realizing the invention according to claim 4. It is a structure.

According to a sixth aspect of the invention, in the fifth aspect of the invention, the heating pipe is filled with a catalyst such as nickel. As a result, the optimum reaction temperature of water gas in the case of only the heating tube is 1300 to 1400 ° C.
The temperature can be lowered to 0 to 900 ° C., and the life of the heating tube can be extended and the energy can be saved.

The invention according to claim 7 is a rotary cylinder for pyrolysis (also referred to as a rotary pyrolysis chamber) utilizing high-temperature steam, which is the invention according to claims 1, 2 and 3, and claims 4, 5 and A method for producing hydrogen fuel from organic waste made possible by adding a carbon oxide conversion chamber (known) for converting carbon oxide to hydrogen in the gas reforming chamber of the invention described in 6.

Chlorine is often contained in the organic waste, and when the organic waste is thermally decomposed, it is converted into hydrogen chloride gas, which is contained in the thermally decomposed gas and discharged to the gas reforming chamber side. Hydrogen chloride gas has emission standards as harmful gas,
Needless to say, the concentration of hydrogen chloride gas discharged into the atmosphere needs to be below the emission standard, but hydrogen chloride gas is highly corrosive and needs to be removed at an early stage considering the life of the device. Therefore, according to the invention of claim 8, a hydrogen chloride gas removing device is provided between the rotary cylinder for pyrolysis and the gas reforming chamber, and chlorine gas generated during the pyrolysis is removed at an early stage so that the entire device can be removed. The life was extended.

Further, according to the invention of claim 8, the hydrogen chloride gas removing agent is heated by passing a heating pipe through the hydrogen chloride removing device to improve the removal efficiency, and at the same time, the rotary cylinder for pyrolysis. As a result, it becomes possible to thermally decompose the tar component that accompanies the pyrolysis gas toward the gas reforming chamber side. Furthermore, it becomes possible to capture dust.

There are many organic wastes that do not contain chlorine, and even if they contain chlorine, the trace amount is less than the emission standard and the corrosiveness does not pose any problem.
Although a hydrogen chloride removing device is not required, tar and dust entrained in the pyrolysis gas may block the heating pipe during pyrolysis in the rotary pyrolysis cylinder. According to the ninth aspect of the present invention, a dust collecting cyclone is installed at the pyrolysis gas outlet of the pyrolysis rotary cylinder, and the dahl and dust are captured before entering the heating pipe.

According to the tenth aspect of the invention, the captured tar and dust are returned to the charging machine side of the rotary cylinder for pyrolysis of the organic waste, mixed again with the organic waste to be charged again, and charged again. This is a structure of a cyclone for dust collection that achieves a significant reduction of tar and dust without removing the tar and dust captured by pyrolysis again with the rotary cylinder for pyrolysis to the outside of the system.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a flow chart showing a method and apparatus for thermally decomposing chlorine-containing organic waste according to the present invention, and FIG. 2 is an organic waste according to the present invention with a low chlorine content and dust easily scattered. It is a flowchart which shows the thermal decomposition method of an object, and its apparatus.

In FIG. 1, the organic waste placed on the conveyor 3 is thrown into the hopper 4 and dropped on the upper surface of the upper damper 5 of the double damper. At this time, the lower damper 6 is in a closed state. Open the upper damper 5,
Drop the organic waste on the upper surface of the lower damper 6, then close the upper damper 5 and open the lower damper 6,
The organic waste is dropped into the crusher 7 provided under the double damper. This double damper operation is performed for the purpose of preventing invasion of air from the outside air as much as possible. The organic waste dropped into the crusher 7 is crushed by the crusher 7 and sent to the charging screw conveyor 8 attached to the pyrolysis rotary cylinder in a state where the bulk is reduced.

Before the organic waste is charged into the pyrolysis rotary cylinder, the interiors of the pyrolysis rotary cylinder 1 and the gas reforming chamber 2 are preheated by a burner or the like, and the pyrolysis rotary cylinder is Is set to a temperature of 300 to 750 ° C., the waste heat boiler 9 is also activated, and the high temperature steam produced by the waste heat boiler 9 is already introduced into the pyrolysis rotary cylinder. The gas reforming chamber 2 is also set to 800 to 1300 ° C.

Before the organic waste enters the pyrolysis rotary cylinder, all the devices including the induction fan 10 are activated, and the organic waste thrown into the pyrolysis rotary cylinder 1 is discharged. The thing is pyrolyzed by the time it goes to the outlet end of the pyrolysis rotary cylinder,
After the pyrolysis gas leaves the rotary pyrolysis cylinder 1, the pyrolysis gas passes through the hydrogen chloride removing agent 12 of the hydrogen chloride removing apparatus 11 and enters the gas reforming chamber heating pipe 13 provided in the gas reforming chamber. It is heated to 800 ° C. or higher in the gas reforming chamber, and again passes through the pyrolysis rotary cylinder heating pipe 14 provided in the pyrolysis rotary cylinder, and is drawn to the waste heat boiler 9 side by the induced draft fan 10. .

The heating tube 13 installed in the gas reforming chamber 2 and the heating tube 14 installed in the rotary pyrolysis cylinder 1 are body tubes and are heated in the heating tube of the gas reforming chamber. The pyrolysis gas is reformed, passes through the heating pipe of the rotary pyrolysis cylinder, and is drawn to the waste heat boiler side. The heating tube of the pyrolysis rotary cylinder and the reformed gas flowing through it are at a high temperature of 800 ° C or higher, and serve as a sufficient heat source for pyrolyzing the organic waste in the pyrolysis rotary cylinder. The heat source of the rotary cylinder burner 15 is no longer needed. Therefore, the burner 16 provided in the gas reforming chamber is the only heat source at all times.

By filling the inside of the heating pipe 13 of the gas reforming chamber 1 with a catalyst 26 such as a Nikkell catalyst, the reforming temperature of the pyrolysis gas can be lowered.

The pyrolysis gas containing hydrocarbons and a small amount of tar is reformed into a gas composed mainly of carbon monoxide and hydrogen by a water gas reaction, and this reformed gas passes through a waste heat boiler 9,
The waste heat boiler 9 recovers heat, and the cooler 19 and the gas-liquid separation drum 18 cool it to remove excess water, and the mist (droplets) of water that accompanies the reformed gas is separated overnight. After being removed by the drum and stored in the end gas tank 27, it is pressurized and pressure-fed by the booster 30 to serve as a heat source for the generator 24 and the like. It can also be used as fuel for the pyrolysis rotary cylinder burner 15 and the gas reforming chamber burner 16.

Further, the reformed gas is passed through the carbon monoxide conversion chamber 23 having a catalyst containing iron oxide as a main component and chromium oxide as a promoter and the temperature is set to about 500 ° C. It can be used as hydrogen fuel for the generator 24 and the fuel cell 26 by converting carbon oxide into hydrogen and carbon dioxide, and dissolving or removing carbon dioxide with water or absorbing and removing it with an alkali, which helps prevent global warming. Becomes

Since the surplus water recovered does not contain oils and harmful substances such as hydrocarbons and tar, it is stored in the drain ram 28 and then the cooling tower 17 is supplied by the spray pump 29.
And used as cooling water for the exhaust gas of the gas reforming chamber burner.

The exhaust gas from the burner 16 in the gas reforming chamber 1 is cooled to about 200 ° C. in the cooling tower 17 and then exhausted.

In the invention of FIG. 2, the dust-collecting cyclone 20 is attached to the pyrolysis rotary cylinder 1, and the dust and tar entrained in the pyrolysis gas discharged from the pyrolysis rotary cylinder 1 is converted into a dust-collecting cyclone. To prevent blockage in the heating tube.
The dust collected by the cyclone for dust collection is returned to the screw conveyor 8 for input, mixed with the organic waste, re-input to the rotary cylinder for thermal decomposition, and again thermally decomposed to remove dust and tar. The weight was reduced.

Residue after pyrolysis in the pyrolysis rotary cylinder 1
(Carbide) is automatically discharged from the end product of the pyrolysis rotary cylinder, but this is cooled by the water-cooled conveyor 21 and the container 2
Pack it in 2 and use it effectively as fertilizer and soil conditioner.

[Brief description of drawings]

FIG. 1 is a flow chart showing a method and apparatus for thermally decomposing chlorine-containing organic waste according to the present invention.

FIG. 2 is a flow chart showing a method and apparatus for thermally decomposing an organic waste having a low chlorine content and easy dust scattering according to the present invention.

[Explanation of symbols]

1 Pyrolysis rotary cylinder 2 gas reforming room 3 Conveyor 4 hoppers 5 Upper damper 6 Lower damper 7 crusher 8 Input screw conveyor 9 Waste heat boiler 10 induction fan 11 Hydrogen chloride removal device 12 Hydrogen chloride remover 13 Gas reforming chamber heating pipe 14 Rotary tube heating tube for pyrolysis 15 Burner for rotary cylinder for pyrolysis 16 Burner for gas reforming room 17 Cooling tower 18 Gas-liquid separation drum 19 Cooler 20 Cyclone for dust collection 21 Water-cooled conveyor 22 containers 23 Carbon monoxide conversion room 24 power generation boiler 25 fuel cells 26 catalyst 27 gas tank 28 drain drum 29 Spray pump 30 boosters 31 spray nozzle

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C02F 11/10 ZAB C02F 11/10 ZABZ 4G140 C10B 53/00 C10B 53/00 A 4H012 B C10J 3/00 C10J 3/00 A F F23G 5/027 F23G 5/027 Z 5/14 5/14 F 5/20 5/20 A 5/44 5/44 Z F term (reference) 3K061 AA07 AB02 AC01 AC02 AC12 AC13 BA01 CA01 CA07 FA04 FA10 FA12 KA02 KA21 KA23 3K065 AA24 AB01 AC01 AC02 AC12 AC13 BA01 HA02 3K078 BA08 CA02 CA07 4D004 AA02 AA03 AA07 AA12 AB06 BA03 BA04 BA06 CA04 CA27 CA47 CB09 CB13 CB34 CB36 CC09 4D059 AA02 AA03 AA07 BB03 BB14 BK11 CB06 CC01 CC10 4G140 BA02 BB03 4H012 HA03 HB03 HB10

Claims (10)

[Claims] 1. A method of thermally decomposing an organic waste, which comprises heating the organic waste as it is or after drying it by radiant heat of a heating pipe having a high-temperature reformed gas passing through it, and thermally decomposing it. 2. A rotary tube for pyrolysis, which is internally equipped with a heating tube through which high-temperature gas passes, and which pyrolyzes organic waste while receiving it from one end and discharging it from the other end. Pyrolysis device for organic waste consisting of the body. 3. A boiler is heated by utilizing waste heat of a heating pipe,
Pyrolysis of organic waste, characterized in that high-temperature steam generated from the boiler is introduced into a rotary cylinder for pyrolysis to promote pyrolysis of the organic waste and produce a pyrolysis gas by a water gas reaction. Method. 4. A pyrolysis gas produced by a pyrolysis cylinder is passed through the inside of a heating pipe in a gas reforming chamber, and the heating pipe is heated from the outside so that the pyrolysis gas has a higher quality. A method for thermally decomposing organic waste, characterized by reforming into organic matter. 5. A heating pipe is provided inside a gas reforming chamber, which is a casing of a steel sheet lined with a refractory heat insulating material, and the recovered reformed gas is burned using a burner to heat the heating pipe. Thermal decomposition equipment for organic waste. 6. The apparatus for thermally decomposing organic waste according to claim 5, wherein a heating tube equipped in the gas reforming chamber is filled with a catalyst such as Nikkell. 7. A method for thermally decomposing an organic waste, wherein hydrogen gas is produced from the organic waste by a combination of a thermal decomposition chamber using high temperature steam, a gas reforming chamber and a carbon oxide conversion chamber. 8. A hydrogen chloride removing device is provided between the pyrolysis rotary cylinder and the gas reforming chamber, and a heating pipe through which high-temperature reformed gas is passed is provided in the hydrogen chloride removing device. Pyrolysis device for organic waste. 9. An apparatus for thermally decomposing organic waste, characterized in that a cyclone for collecting dust is provided at the thermally decomposing gas outlet of the rotary cylinder for thermal decomposition. 10. The tar and dust collected by the cyclone for dust collection are returned to the throwing machine of the rotary cylinder for thermal decomposition, mixed with the newly introduced organic waste, and charged into the rotary cylinder for thermal decomposition. The apparatus for thermally decomposing organic waste according to claim 9, which is a system for thermally decomposing again.