JP2005048160A - Method for decomposing organic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for decomposing an organic material, capable of rapidly decomposing the organic material with a low-cost apparatus. <P>SOLUTION: This method for decomposing the organic material comprises introducing the solid or liquid organic material into a decomposing unit which has an air blower, a heater, and a stirrer and is filled with titanium oxide particles, and then decomposing the material into a gas with stirring. Further, the method preferably comprises introducing the solid or liquid organic material into a preliminary decomposing unit which has the air blower, the heater, and the stirrer and is filled with particles other than the titanium oxide particles or a catalyst, then decomposing the material into a gas with stirring, and further introducing the decomposed gas into a gas oxidation unit which is filled with the titanium oxide particles. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for decomposing organic matter.

  Recently, the treatment of organic substances such as plastics has become a major social problem. This is mainly because plastic does not decompose as it is, it cannot be solved by landfill, and the landfill site is disappearing.

  Such processing of plastics and the like has conventionally been an incineration method. Incineration is burning at high temperature in a furnace to produce carbon dioxide and other oxides.

However, in the combustion method, there is a risk that toxic gas is generated unless complete combustion is performed. Therefore, the fuel is inevitably burned at a high temperature. Therefore, since unnecessary fuel is also incinerated, the surrounding environment is heated and carbon dioxide is unnecessarily generated.
Furthermore, it is difficult to completely suppress the generation of dioxins.

  Therefore, a method is provided that can decompose organic substances such as plastics into gas in as short a time as possible.

  In view of the present situation as described above, the present inventor has completed the organic matter decomposition method of the present invention as a result of earnest research, and the feature thereof is that a solid or liquid organic substance is converted into an air introduction device, a heating device, a stirring device. The device is introduced into a decomposition apparatus filled with titanium oxide particles and decomposes into a gas while stirring. In another aspect, solid or liquid organic matter is converted into an air introduction device, a heating device, and a stirring device. And is introduced into a decomposition apparatus filled with particles other than titanium oxide and a catalyst, decomposed into a gas with stirring, and then introduced into a gas oxidation apparatus filled with titanium oxide particles.

  Solid or liquid organic substances include not only solids such as plastics and liquids such as oils and fats and organic solvents, but also toxic substances such as PCBs. The organic matter is not limited to low molecules and polymers.

The decomposition apparatus used in the method of the present invention has at least an air introduction apparatus, a heating apparatus, and a stirring apparatus, and is filled with titanium oxide particles.
The air introduction device may be a simple opening, a pipe, or anything. In short, it suffices if air can be introduced from there. You may make it introduce | transduce air in a particle layer by putting a pipe etc. inside the particle layer mentioned later. This air introduction device may be used as a stirring device by stirring particles with the air jet pressure.
Further, even if a dedicated air introduction device is not provided, it may be sufficient if sufficient air is introduced from the organic substance introduction port.

Any heating device may be used as long as the particle layer can be heated. Electric heaters, gas burners, etc. It is preferable to control the temperature by providing a temperature control device.
The heating temperature depends on the type of organic matter to be decomposed and the particles used. Usually, 250-450 degreeC is suitable. Depending on the type of organic matter, it may be lower or higher.

  The stirring device only needs to stir the titanium oxide particles. It is easy to rotate the rod and blade, but any type such as a vibration type may be used. The particle layer is agitated by this agitator to increase the contact efficiency between the titanium oxide particles and the organic matter.

As the titanium oxide, anatase type crystals are generally well known, but other types may be used. In short, any titanium oxide may be used as long as it exhibits an oxidation catalyst effect by heating.
Since titanium oxide is more efficient as its grains are smaller, usually several nm to several μm are suitable, but the special size is not limited. In addition, the fine powder soars or comes out of the system with the gas, so it may be supported on a carrier. Further, such fine particles may be granulated into a predetermined size.

The carrier to be supported may be any particle such as silica sand. Moreover, not a particle but a fibrous thing may be sufficient. The size is not particularly limited, but is preferably 10 mm or less, preferably several μm to 6 mm, and more preferably about 10 μm to 1 mm.
As a method of fixing to the carrier, adhesion may be made with a fluorine-based resin or a silicon-based resin that is not easily decomposed. It may be fixed with an inorganic adhesive.
Further, both a water-based resin (water-soluble resin or emulsion-type resin) and cement (all those cured by a hydraulic reaction) may have a photocatalyst fixed to a carrier.
In the fixing method, first, an aqueous resin is applied to the carrier, and then the cement and the photocatalyst are fixed. First, the cement or photocatalyst is fixed by the initial adhesive strength of the water-based resin. And if a cement hardens | cures, even if an aqueous resin is decomposed | disassembled by the oxidizing power by a photocatalyst, it will be hold | maintained by the cement.
The amount to be attached is arbitrary and does not depend on the method of attachment, but it is usually about 1% to 10% of the weight of the carrier due to the difference in size with the carrier.

  The granulation method may be a sintering method or a binder method. As a binder, a titanium alkoxide and an inorganic type are preferable.

  The decomposition apparatus may be provided with an electromagnetic wave irradiation device. This is because the efficiency varies depending on the presence or absence of an electromagnetic wave irradiation device (such as an ultraviolet lamp). Even if there is no electromagnetic wave irradiation device, heat alone is sufficient, but if it is irradiated, the decomposition effect is increased.

The titanium oxide particles in the decomposition apparatus can immediately introduce the organic matter if the organic matter becomes a gas when the organic matter is effectively decomposed at a high temperature in operation. However, when decomposition products adhere to the surface of the particles, it is better to reintroduce organic materials after the particles have been heated to a high temperature and sufficiently decomposed and vaporized. The temperature at this time is about 250-500 degreeC. This is called particle regeneration.
The particle regeneration time may be shorter or longer than the decomposition time. This is determined by temperature conditions and ease of organic matter decomposition.

  In order to perform the regeneration smoothly, a separate particle regeneration device may be provided in the decomposition device. Particles are discharged from the decomposition apparatus, heated by a regenerating apparatus, oxidatively decomposes organic substances on the surface, and returned to the original apparatus.

  In order to regenerate more efficiently, there is also a method in which a plurality of disassembly devices are installed and operated alternately. In other words, when one unit is in disassembly operation, the other unit is regenerated and the loss time is reduced as much as possible.

  The present invention is basically complete. That is, if it can be decomposed by this decomposition apparatus and then released into the atmosphere, it may be so, or if other processing (post-processing) is performed, it may be led to the processing step. Moreover, you may utilize if it can utilize for another thing (raw material, fuel, etc.).

Any type of post-treatment may be used. For example, the post-treatment may be introduced into a device filled with titanium oxide separately (which may or may not be heated, may or may not be irradiated with electromagnetic waves), and again An oxidation reaction with titanium oxide may be performed.
Moreover, you may make it contact with well-known oxidation catalysts, such as a platinum catalyst. This is suitable for reactions such as conversion of carbon monoxide to carbon dioxide.
Further, if there is something in the gas that cannot be released into the atmosphere even if it is oxidized or decomposed, or something that does not want to be released, these may be washed and absorbed with acid or alkali. When chlorine-based compounds, carbon monoxide, etc. still remain, other absorption devices or adsorption devices may be provided.

  Furthermore, a simple filter may be used. The structure of the filter is not particularly limited, and a normal filter such as paper, non-woven fabric, or cloth may be used, and an easily replaceable filter is preferable. Moreover, what filled many adsorbents, such as a zeolite, a silica, and Kanuma stone, may be used. In such a case, if tar or the like adheres, it can be easily recovered by heating with a burner or the like, which is convenient. You may enable it to heat without removing.

A second decomposition apparatus as an example of the post-processing apparatus will be described. This uses titanium oxide and electromagnetic waves.
This second decomposition device has at least an air introduction device, an electromagnetic wave irradiation device, and a photocatalyst carrying filter. When the air introduction device is introduced between the decomposition device and the second decomposition device for cooling or as an air component, it may be the air introduction device referred to here.
When introduced into the second decomposition apparatus, the temperature of the gas may be lowered to normal temperature or an appropriate temperature by introducing air. When the temperature is lowered to some extent, a heat insulating device (such as a quartz glass cover that air-cools the inside) is not required for the electromagnetic wave irradiation device (such as an ultraviolet lamp). Further, when the temperature of the gas from the decomposition apparatus is low and the reaction in the second decomposition apparatus is performed at a higher temperature, a heating apparatus may be provided for heating. Therefore, you may provide the temperature control apparatus which can be cooled and heated.

A photocatalyst carrying filter is a filter-like thing carrying a photocatalyst. The filter here simply means that the passage is a large number of small holes. Therefore, any material such as particles, cloth, non-woven fabric, sponge, porous material, etc. may be used.
This filter carries a photocatalyst. As a supporting method, a fluorine-based resin or a silicon-based resin which is not easily decomposed may be used, or may be fixed with an inorganic adhesive. Further, it may be fixed with both the aqueous resin and cement.

The shape can be freely selected, for example, a block or plate made of a net filled with photocatalyst-supporting particles, or a frame in which photocatalyst particles are fixed to the cloth or nonwoven fabric described above.
As long as the gas of a 2nd decomposition device passes, the place provided may be anywhere. The second decomposition apparatus may be partitioned into a plurality of rooms, and the photocatalytic filter may be provided on the intermediate wall surface. Of course, the entire wall surface may be a filter.

  The photocatalyst powder may be suspended in the space of the second decomposition apparatus. In this case, the suspended powder is carried along with the gas to the filter unit so that the filter is not clogged. This is to slow down the flow rate.

  Basically, the air introduction device is preferably in the upstream portion. This is to contribute to the reaction at the earliest possible stage.

In the second decomposition apparatus, the decomposition reaction is desirably performed at a low temperature (50 ° C. or lower), but may be performed at 50 ° C. or higher. That is, the hot gas from the first decomposition apparatus may be introduced as it is or after being cooled to 50 ° C. or higher. Moreover, you may provide a heating apparatus in a 2nd decomposition | disassembly apparatus.
In the second decomposition apparatus, the photocatalytic reaction may be performed at room temperature or at a high temperature (50 ° C. or higher).

  The post-processing apparatus and post-processing described above may or may not be performed, and a plurality of post-processing apparatuses and post-processing may be performed. Implementation may be continuous or discontinuous.

  Next, the invention of claim 6 will be described. In this case, the organic substance is first introduced into the preliminary decomposition apparatus, where it undergoes thermal decomposition, and the gas therefrom is introduced into the gas oxidation apparatus and decomposed. This preliminary decomposition apparatus is similar to the above-described decomposition apparatus, except that other particles and a catalyst are filled instead of the titanium oxide particles.

Other particles and catalysts are particles that do not react, such as mere sand, and do not melt or deform depending on the heating temperature. For example, silica sand, charcoal cal, metal particles, stone powder and the like. Furthermore, a known pyrolysis catalyst may be used.
Here, not a decomposition by titanium oxide but a normal thermal decomposition reaction takes place. Although the temperature of a preliminary decomposition apparatus is about 300-500 degreeC, it may be lower depending on the kind of organic substance, and it is the same as above that it may be higher.

The gas oxidation device is filled with titanium oxide, and may or may not have a heating device. Of course, the temperature is necessary, but it is not necessary if the gas from the preliminary decomposition apparatus has a temperature higher than necessary. It may be provided in advance.

The decomposition method of the present invention has the following great advantages.
(1) Organic substances can be easily decomposed.
(2) The device is simple and inexpensive.
(3) Any treatment may be performed after the decomposition apparatus, and it can deal with various organic substances.

  Hereinafter, the present invention will be described in more detail based on preferred examples.

FIG. 1 is a partially broken perspective view showing an example of a disassembling apparatus 1 used in the method of the present invention. An air introduction device (simple air blower, pipe and opening) 2, an organic substance introduction unit 3, and a heating device 4 are provided. The air introduction device 2 also serves as the stirring device. That is, it is agitated with the jetting air. The air introduction device 2 is divided into six legs at the distal end portion, and a number of air ejection holes are provided in each leg.
In this example, the reaction is a batch type, and when a predetermined amount of organic substance is introduced, the reaction is carried out with sealing (other than the outlet). Of course, it is also possible to operate continuously.

The lower part of the decomposition apparatus 1 is filled with titanium oxide particles 5. And the replenishment tool 6 which supplements the part discharged | emitted with the gas and air by which the organic substance was decomposed | disassembled is provided. When heated to a predetermined temperature by the heating device 4 and stirred, the organic matter is decomposed into gas by the catalytic effect of titanium oxide. Then, it is discharged from the discharge port 7. This gas may be anything. If it can be released to the atmosphere, it may be released as it is or may be sent to another processing step.
Of course, if it cannot be released into the atmosphere, further processing is necessary.

  FIG. 2 is a partially broken perspective view showing another example of the apparatus used in the method of the present invention. It comprises a decomposition apparatus 1, a second decomposition apparatus 8 that is a post-processing apparatus, and a communication pipe 9. The decomposition apparatus 1 is basically the same as that shown in FIG. Similarly, the lower part of the decomposition apparatus 1 is filled with titanium oxide particles 5.

  Below the heating device 4, a regeneration device 10 for titanium oxide particles is provided. In this method, the organic matter adhering to the particle surface is heated and decomposed and oxidized to remove it from the surface. In the method, the particles 5 are appropriately extracted from the reaction layer 11, introduced into the lower regeneration device 10, and returned to the reaction layer 11 by the return pipe 12 after regeneration. The returning method may be any method such as an air entrained conveyance method or a bucket conveyor.

  The generated gas, air, or the like is introduced from the communication pipe 9 to the second decomposition device 8. The communication pipe 9 is provided with a tar filter 13 and a cooling air introduction device 14. The tar filter 13 catches tar when it is generated in the decomposition apparatus 1. Here, zeolite particles (size, about 5 to 15 mm) are filled.

  The second decomposition apparatus 8 is separated into five chambers 15 in this example. Each wall surface is composed of a filter 16 carrying a photocatalyst powder. The filter 16 is a woven fiber, and a photocatalyst is supported on the fiber. As a loading method, the above-described aqueous resin (here, acrylic emulsion) and cement are used for adhesion. In this case, even if the resin is decomposed by the oxidation reaction of the photocatalyst, the photocatalyst is unlikely to fall and be entrained in the gas because it is fixed with cement.

  Each chamber 15 is provided with a large number of ultraviolet lamps 17. Ultraviolet light from this lamp is irradiated to the photocatalyst of the filter 16 to cause a photocatalytic reaction. As a result, the gas passing through the filter 16 undergoes an oxidation or decomposition reaction.

Further, the second decomposition device 8 is provided with an air introduction device 18. This means a further supply of oxygen for the oxidation reaction. Moreover, the temperature control apparatus 19 is provided up and down. This is a device that can be heated and cooled. It is like a combination of an air conditioner and an electric heater. Of course, a simple heating device or cooling device may be used.
Thus, it is discharged from the discharge port 20 as the smallest molecule and as the most oxidized molecule. If the introduced organic substance contains chlorine atoms and the like and chlorine molecules are generated, an absorption device may be further provided.
If the plastic is polyethylene, polypropylene, polyester, etc., there is no problem if it is released as it is.

An example of the driving | running state of the apparatus shown in FIG. 2 is shown.
About 40 kg of titanium oxide was put into the decomposition apparatus shown in FIG. 2, and about 2 kg of crushed polyethylene (about 5 mm square) was introduced therein and the lid was closed. Titanium oxide is heated to about 400 ° C. by a heating device. Air is introduced from the air blower, and the titanium oxide and the plastic piece are stirred by the injection.
The solid content almost disappeared in about 15 minutes.
The gas from the discharge port is sent to the second decomposition device 8 through the communication pipe 9. In the communication pipe, air was sufficiently introduced to cool the gas to about 40 ° C. The gas (gas generated by the decomposition of polyethylene) is oxidized and decomposed by the ultraviolet rays and the photocatalyst from the ultraviolet lamp.

  The amount of the photocatalyst powder of the entire surface filter on the wall surface that partitions each chamber of the second decomposition apparatus is about 2 kg. By slowly taking the residence time in this apparatus, it is completely oxidized and decomposed. In this example, it was completely decomposed into gas in about 1 hour. All of the gases (carbon dioxide, water, etc.) were safe and could be released without any problem.

It is the perspective view which fractured | ruptured one part which shows an example of the apparatus which implements the method of this invention. It is the perspective view which fractured | ruptured one part which shows the other example of the apparatus which enforces this invention method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Decomposition | disassembly apparatus 2 Air introduction apparatus 3 Organic substance introduction part 4 Heating apparatus 5 Titanium oxide particle 6 Replenisher 7 Outlet 8 Second decomposition apparatus 9 Communication pipe 10 Reproduction apparatus 11 Reaction layer 12 Return pipe 13 Tar filter 14 Air introduction apparatus for cooling 15 Chamber 16 Filter 17 UV lamp 18 Air introduction device 19 Temperature control device 20 Outlet

Claims (6)

  A method for decomposing an organic substance, which comprises introducing a solid or liquid organic substance into a decomposition apparatus having an air introduction device, a heating device, and a stirring device and filled with titanium oxide particles, and decomposing it into a gas while stirring.   The organic matter decomposition method according to claim 1, wherein post-treatment is performed as a post-treatment step of the method according to claim 1.   The organic matter decomposition method according to claim 2, wherein the post-treatment is to pass through a titanium oxide filling device.   The organic matter decomposition method according to claim 2, wherein the post-treatment is performed through an apparatus having a platinum catalyst.   The organic matter decomposition method according to claim 2, wherein the post-treatment is washing or absorption with an acid or an alkali. Solid or liquid organic matter is introduced into a pre-cracking device that has an air introduction device, a heating device, and a stirring device and is filled with particles and catalysts other than titanium oxide, and decomposes into a gas while stirring, and then the gas is An organic matter decomposing method comprising introducing into a gas oxidizer filled with titanium oxide particles.

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