JPS5837851B2 - Pyrolysis gas cleaning method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes pyrolysis gas obtained by thermally decomposing organic matter such as urban waste, pulp sludge, pyomas, and coal.
The present invention relates to a cleaning method and apparatus for removing solid particles such as char, oil, condensed matter such as alcohol, and obtaining clean pyrolysis gas.

Conventionally, in order to collect and remove carbon particles in the gas exiting the pyrolysis furnace, a cyclone was installed in a single stage or in multiple stages to remove most of the particles, and then the gas was led to a wet gas cooling cleaning device to remove oil, oil, etc. It collects and removes condensate such as tar.

However, the collection efficiency of cyclo/ remains around 90% due to the relationship with pressure loss.

Therefore, the remaining 10 or so uncollected particles will be collected by the wet gas cooling cleaning device.

In the 10,000 wet gas cooling cleaning equipment, oil and tar contained in the gas condense and are transferred to the cleaning water and removed, but at the same time, uncollected carbon particles are also captured and mixed in the cleaning water. do.

This mixed liquid is highly sticky and adheres to devices that separate oil from cleaning water, other equipment, and pipes, causing problems.
To avoid this, equipment such as oil separation equipment has become complicated, and when supplying separated oil and carbon particles as a heat source to a heating fluidized bed for regenerating fluidized media, it has also become difficult to transport equipment and equipment. It gets complicated.

The present invention eliminates the above-mentioned drawbacks of the conventional system by forming a moving bed using a fluidized medium and making the gas exiting the cyclone pass through the moving bed before being guided to a wet gas cooling and cleaning tower. In addition, uncollected particles and condensed oil that are not collected by a cyclone are collected by adhering to a fluid medium, making them easy to handle, simplifying or omitting wet oil separation equipment, and transport equipment, The object of the present invention is to provide a highly reliable pyrolysis gas purification method and device that has a simple structure by eliminating obstacles in pipes and the like.

The present invention relates to a method for cleaning pyrolysis gas produced by pyrolysis of organic matter in a pyrolysis apparatus equipped with a fluidized bed pyrolysis furnace and a fluidized bed incinerator, in which the pyrolysis gas is passed through a cyclone. After removing most of the solid particles, the fluidized medium is passed through a moving bed to remove the remaining solid particles, and then oil and tar are condensed and removed in a wet cooling washing tower, and the fluid is extracted from the moving bed. A method for purifying pyrolysis gas, and an apparatus therefor, characterized in that the discharged fluidized medium is supplied to the fluidized bed incinerator.

To explain the present invention using an example of a two-column circulation type pyrolysis apparatus for municipal waste, the particle size is reduced by a pulverizer or the like,
supplied to

A pyrolysis gas path is formed by the fluidized bed pyrolysis furnace 1, the cyclone 2, the moving bed 17, the wet cleaning tower 7, and the pipes connecting them.

The gas produced by thermal decomposition contains solid particles such as char, but most of the char is collected by the cyclone 2, sent to the fluidized bed combustion furnace 3 via the return path 15, and combusted to become a heat source.

The gas leaving the cyclone 2 is sent to a dry desaturator 4.

The dry dust remover 4 is provided with a moving bed 17 made of a fluidized medium.

This fluidized medium is a fluidized medium extracted from the bottom of the pyrolysis furnace 1 together with foreign matter, separated by a foreign matter/sand separator 5, and sent from a conveyor 6K serving as a fluidized medium transfer path.

This is a foreign substance that has been separated into 14 parts. While the supplied gas passes through the moving bed 17, solid particles such as uncollected char adhere to the fluidizing medium (such as sand) and are removed.

Since the temperature of the moving bed 11 is lower than the internal temperature of the pyrolysis furnace 1, part of the oil contained in the gas condenses and adheres to the fluidized medium and is removed.

The fluid medium to which char oil and the like are attached is transferred to the moving bed 11.
After descending, it is discharged and supplied into the fluidized bed of the combustion furnace 3 by a screw conveyor 16 serving as a moving medium supply path.

The screw conveyor 16 may also be used in conjunction with the return path.

The combustion furnace 3 is for regenerating and heating the fluidized medium, and the char and oil adhering to the fluidized medium sent to the screw conveyor 16 are combusted and used to create a heat source for pyrolysis.

After a certain amount of heat is recovered from the gas discharged from the dry dust collector 4 by a heat exchanger 10, it is cooled and washed in a wet washing tower 7, and condensed oil and residue are washed away with washing water. It is removed and sent to the next process as a clean pyrolysis gas 12.

It is circulated and used by the cleaning water pump 9, but it is partially extracted and the oil is separated and removed by the oil-water separator 8, and then the waste water 13 is used.
The wastewater is sent to the wastewater treatment facility as a wastewater treatment facility.

Since this embodiment is constructed and operates as described above, most of the char remaining in the gas is removed by the moving bed 17 of the fluidized medium of the dry dust remover 4, and thereby the downstream Disturbances caused by the presence of char in the heat exchanger 10 and wet sintering tower 7 can be eliminated.

In addition, by using particles for the moving bed 1T as the fluidized medium that accompanies the discharge of foreign matter from the two-column fluidized bed pyrolysis device, the fluidized medium is passed through the moving bed 11 and comes into contact with the pyrolysis gas to be preheated and combusted. Since it is fed into the furnace 3, the temperature of the fluidized bed in the combustion furnace 3 can be prevented from decreasing.

In addition, although a portion of the oil is also collected in the moving bed 17, since the oil is transported along with the char while adhering to the fluidized medium, which is a solid particle, there is no problem such as adhesion to each device or pipe line.

According to the present invention, all of the char and most of the oil are removed before reaching the wet cleaning tower, so it is possible to eliminate the hindrance to the generation of sticky substances due to the coexistence of char and oil, and The fluidized medium is preheated, and the char and oil adhering to the fluidized medium serve as a heat source fuel to prevent the temperature of the fluidized bed of the combustion furnace from decreasing and ensure stable operation.
The maintenance of each device and pipeline is easy, the structure of each device is simple, and a highly reliable pyrolysis gas cleaning method and device can be provided, which has extremely great practical effects. be.

[Brief explanation of drawings]

The drawing is a flow diagram of an embodiment of the invention. 1... Pyrolysis furnace, 2... Cyclone, 3... Combustion furnace, 4... Dry dust remover, 5... Foreign matter/sand separator,
6... Conveyor, 7... Wet cleaning tower, 8... Oil/water separator, 9... Pump, 10... Heat exchanger, 11...
...Pyrolysis raw material, 12...Clean pyrolysis gas, 13...
・Wastewater, 14... Foreign matter, 15... Return route, 16.
...screw conveyor, 17...moving layer.

Claims (1)

[Claims] 1. A method for cleaning pyrolysis gas produced by pyrolysis of organic matter in a pyrolysis apparatus equipped with a fluidized bed pyrolysis furnace and a fluidized bed incinerator. After passing through a cyclone to remove most of the solid particles, the remaining solid particles are removed by passing through a moving bed of fluidized medium, and then oil and tar are condensed and removed in a wet cooling washing tower, and the transferred A method for purifying pyrolysis gas, characterized in that the fluidized medium extracted from the bed is supplied to the fluidized bed incinerator. 2. The method according to claim 1, wherein the fluidized medium of the moving bed is a fluidized medium discharged from the fluidized bed pyrolysis furnace together with foreign matter discharge. 3. A fluidized bed pyrolysis furnace that pyrolyzes organic matter to generate pyrolysis gas and discharges foreign substances, and a fluidized bed pyrolysis furnace that heats and regenerates the fluidized medium of the pyrolysis furnace to a receiver and returns to the pyrolysis furnace. The fluidized bed incinerator is equipped with a fluidized bed incinerator that circulates fM-w again, a dry desaturator in which a moving bed is formed by the fluidized medium, and a wet cooling and washing tower, and the fluidized medium discharged from the moving bed section is It is characterized by comprising a fluidized medium supply path leading to the combustion furnace, and a pyrolysis gas path leading the pyrolysis gas produced in the pyrolysis furnace to the wet cooling and cleaning tower after passing through the moving bed. Pyrolysis gas purification equipment. 4. The apparatus according to claim 3, further comprising a fluidized medium transfer path that guides the fluidized medium extracted together with the foreign matter discharged from the pyrolysis furnace to the moving bed.