JP2977743B2 - Plastic waste gasification gas treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention gasifies combustible substances including chlorine-based plastics, such as general waste and industrial waste, and efficiently removes corrosive gas such as HCl in the gasification gas and dust in a dry manner. It relates to a method of removing and purifying. The clean gas obtained by the method of the present invention is used for gas turbine power generation, chemical raw materials, city gas, and the like. When this clean gas is used for power generation equipment, dust and H
Since the corrosive gas such as Cl is removed, the device is not damaged and the device is not corroded.

[0002]

2. Description of the Related Art Conventionally, in order to perform denitration, dust removal, and HCl removal from exhaust gas generated from a municipal solid waste incinerator, denitration is performed by blowing urea or NH ₃ into the exhaust gas, and then in a stage before the bag filter. A method is known in which slaked lime is blown into exhaust gas to remove dust and remove HCl (see, for example, JP-A-5-220339). Japanese Patent Publication No. 59-8388 discloses that solid waste is pyrolyzed in a fluidized bed pyrolysis furnace, the obtained gas is washed, then passed through an activated carbon layer, and steam reformed. A method for producing a gas is described. In addition, Japanese Patent Publication No. 4-72878
The publication describes that a desulfurizing agent degraded in a desulfurization process is introduced into a char recycling line as a slag melting point depressant in a coal spouted bed gasifier.

[0003]

The conventional method for dehydrochlorination in gas is mainly wet cleaning with a scrubber for spraying water or an alkaline solution. Dry cleaning is more advantageous because sensible heat can be effectively used and problems such as wastewater treatment do not occur. In addition, no method has been found by the inventors of the present invention to remove HCl from a reducing gas such as a gasified gas, or to simultaneously perform the removal of HCl and the removal of dust in a dry manner. On the other hand, the amount of combustible waste including chlorine-based plastic is extremely large, and the development of an effective method of using this waste has been desired because of the shortage of landfill for waste and the social needs of resource recycling. The present invention has been made in view of the above points, and an object of the present invention is to gasify combustible waste containing chlorinated plastics and remove HCl and dust in the gasified gas to reduce the utility value. It is to obtain a high clean gasification gas.

[0004]

In order to achieve the above object, a method for treating a plasticized waste gasification gas according to the present invention comprises the steps of jetting combustible waste containing chlorine-based plastic.
One of pivoting gasification furnace waste bed and substantially lateral direction
A small amount of air less than the stoichiometric amount is supplied to reduce and burn to gasify and to extract the molten slag, and then the reducing gasified gas is converted into CaO particles, CaCO ₃ particles, dolomite particles and metal oxide particles. It is configured to be introduced into a moving bed desalination reactor filled with at least one kind of desalinating agent comprising a group, and to simultaneously perform desalination and dust removal in a dry manner. Mn ₂ O ₃ , Co ₃ O ₄ , C
MxOy such as uO is used.

[0005] Further, the method of the present invention comprises the step of disposing combustible waste containing chlorine-based plastic in either a spouted bed or a substantially horizontal direction.
Of air less than the stoichiometric amount of waste in a swirling gasifier
To reduce and burn to gasify and to extract the molten slag, and then to reduce this reducing gasified gas to Ca
After at least one kind of desalinating agent consisting of a group of O particles, CaCO ₃ particles, dolomite particles and metal oxide particles is introduced into a fluidized bed desalting reactor, which is used as a desalinating agent and a fluid medium, and desalted in a dry manner It is characterized in that it is introduced into a dust collector and dedusted.

[0006] The method of the present invention is also directed to a method in which flammable waste containing chlorinated plastic is discharged either in a spouted bed or in a substantially horizontal direction.
Of air less than the stoichiometric amount of waste in a swirling gasifier
Is supplied to the reactor to reduce and combust it to gasify and to extract the molten slag.Then, this reducing gasified gas is introduced into a moving bed desalination reactor filled with metal oxide particles as a desalting agent, and is simultaneously dried. In the meantime, the metal chloride extracted from the moving bed desalination reactor is regenerated into a metal oxide by a heating process while supplying an oxygen-containing gas, thereby obtaining a metal oxide. Circulating to the moving bed desalination reactor.

[0007] Further, the method of the present invention comprises the step of disposing combustible waste containing chlorine-based plastic in either a spouted bed or a substantially horizontal direction.
Of air less than the stoichiometric amount of waste in a swirling gasifier
And reducing combustion to gasify and extract the molten slag, and then introduce this reducing gasification gas into a fluidized bed desalination reactor using metal oxide particles as a desalinating agent and a fluidized medium. After desalination in a dry system, the dust is introduced into a dust collector to remove dust, and the metal chloride extracted from the fluidized bed desalination reactor is regenerated by heating while supplying an oxygen-containing gas. Wherein the metal oxide is circulated to the fluidized bed desalination reactor.

[0008] Further, the method of the present invention comprises the step of disposing combustible waste containing chlorine-based plastic in both a spouted bed and a substantially horizontal direction.
Vaccinated from the stoichiometric amount of waste in some swirling gasifiers
Gas is supplied to reduce and burn to gasify, and at the same time, the molten slag is withdrawn.
aO particles or CaCO ₃ particles are introduced into a moving bed desalination reactor packed as a desalinating agent and simultaneously desalted and dedusted in a dry manner,
On the other hand, CaCl extracted from this moving bed desalination reactor
CaCl ₂ of coated CaO surfaces crushed and surface ₂
, And granulates unreacted CaO and circulates it to the moving bed desalination reactor.

In these methods, a swirling gasifier is used.
In order to lower the melting point of the slag and maintain a stable self-coating function of the furnace wall by the molten slag , it is preferable to supply a desalinating agent to the rotary gasifier. In this case, for example, the amount of the desalinating agent supplied to the swirling gasifier is controlled by the ash in the combustible waste containing chlorine-based plastic. In addition, a part of the used desalting agent extracted from the moving bed desalination reactor is supplied to the rotary gasifier, or the used desalting agent extracted from the fluidized bed desalination reactor and / or the dust collector is used. In some cases, a part of the used desalinating agent is supplied to a rotary gasifier.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of an apparatus for carrying out a method for treating gasified plastic waste gas according to the present invention. Waste containing plastic such as municipal solid waste and industrial waste is crushed in advance and supplied to the swirl-type spouted bed gasifier 10, and gasified by supplying a smaller amount of air than the stoichiometric amount of waste. At this time, the molten slag is extracted and used as a construction material such as a roadbed material and a landfill material. The gasification gas is H ₂ , CO, N ₂ , O ₂ , H ₂ O, HCl, Cl ₂
This gasification gas is introduced into a moving bed desalination reactor (so-called granular moving bed reactor) 12. The moving layer 14 is made of CaO particles, CaCO ₃ particles, dolomite particles, or a metal oxide (for example, Mn ₂ O ₃ , C
o ₃ O _4, desalting agent consisting of particles of MxOy) such as CuO is formed by filling movably. 16 and 18 are air-permeable particle supports, and 20 is a discharger.

HCl in the gasified gas is absorbed by the desalting agent to become metal chlorides (CaCl ₂ when the desalting agent is CaO or CaCO ₃ ), and dust in the gasified gas is removed. . Clean gas from which dust and HCl have been removed is supplied to gas turbine power generation, chemical raw materials, city gas, etc., and CaCl ₂ is used as a raw material for industrial products such as road deicing agents, desiccants, and brine for refrigerators. Note that Ca
The reaction formula of O or CaCO ₃ with HCl is as follows. 2HCl + CaO → CaCl ₂ + H ₂ O 2HCl + CaCO ₃ → CaCl ₂ + H ₂ O + CO ₂

Instead of the swirl type spouted bed gasifier 10 shown in FIG. 1, a substantially horizontal swirl type gasifier 1 as shown in FIG.
It is also possible to use 0a or the like. In order to maintain the self-coating function of the furnace wall by the slag of the rotary gasifier, a certain amount of waste (about 10
~ 30wt%) metal oxides must be contained,
Since the waste is not necessarily a gasification raw material of a stable quality, as shown in FIG. 3, the desalting agent for gas purification is distributed to and supplied to the swirl-type spouted bed gasifier 10 so that the slag melting point is reduced. It is preferable to configure so as to allow the self-coating to be stable while lowering. In this case, the ash in the waste is detected in advance, and this value
It is preferable to control the amount of the desalinating agent supplied to the swirling type spouted bed gasifier 10. Reference numeral 22 denotes an ash analyzer / controller, and reference numeral 24 denotes a feeder. Further, a part of the used desalinating agent extracted from the moving bed desalination reactor 12 may be supplied to the swirl type spouted bed gasifier 10.

FIG. 4 shows another example of an apparatus for implementing the method of the present invention. In this example, the gasified gas is introduced into a fluidized bed desalination reactor 26 using a desalinating agent as a fluidized medium to desalinate, and then introduced into a dust collector 28 such as a bag filter to remove dust. Reference numeral 30 denotes a wind box, 32 denotes a dispersion plate, and 34 denotes a fluidized bed. Further, as shown in FIG. 5, a part of the used desalinating agent extracted from the fluidized bed desalination reactor 26 and / or the dust collector 28 may be supplied to the swirl type spouted bed gasifier 10. is there.
Other configurations and operations are the same as those in FIGS.

FIG. 6 shows another example of an apparatus for implementing the method of the present invention. In this example, CaO particles or CaCO ₃ particles are used as the fluidized medium of the moving bed 14, and CaCl ₂ coated with CaCl ₂ extracted from the moving bed desalination reactor 12 is used.
O is crushed by a surface crusher 36 such as a vibration mill to remove CaCl ₂ on the surface, and then unreacted CaO is granulated by a granulator 38 such as a tumbling granulator and a moving bed desalination reactor. Circulate to 10. In some cases, CaO powder may be supplied to the granulator 38. Other configurations and operations are the same as those in FIGS.

FIG. 7 shows another example of an apparatus for implementing the method of the present invention. In this example, Mn ₂ O ₃ as a desalting agent,
Using MxOy such as Co ₃ O ₄ and CuO, the metal oxide extracted from the moving bed desalination reactor 12 is introduced into the regenerator 40, and 300 to 600 ° C. while supplying the oxygen-containing gas.
(More specifically, 400-600 ° C. for Mn ₂ O ₃ , C
450 to 600 ° C for o ₃ O ₄ and 400 to 6 for CuO
(00 ° C.) to oxidatively decompose and introduce the regenerated desalinating agent into the reoxidizer 42 while supplying oxygen-containing gas.
0 to 600 ° C. (more specifically, 500 to 500 ° C. for Mn ₂ O ₃ )
The regenerated desalinating agent is heated to 600 ° C., 450 to 600 ° C. for Co ₃ O ₄ , and 400 to 600 ° C. for CuO) and circulated to the moving bed desalination reactor 12. The high-temperature gas discharged from the re-oxidizer 42 is introduced into the regenerator 40,
Regeneration gas (N ₂ , O ₂ , H ₂ O, Cl
Part of ₂ ) is circulated to the regenerator 40, and the rest is
Liquefied chlorine is collected by drying, compression cooling, freeze-liquefaction, and liquefied chlorine. Used for refining and metal recovery, and for removing iron from clay and quartz sand. Other configurations and operations are the same as those in FIGS.

The reaction formula of MxOy with HCl (Deaco
n reaction) is as follows. MxOy + 2yHCl → xMCl ₂ + yH ₂ O + (y−x) Cl ₂ (A) MCl ₂ + (y / 2x) O ₂ → (1 / x) MxOy + Cl ₂ (B) Formula (B) is multiplied by x (A) Adding the equation and dividing by 2Y, HCl + ／ O ₂ → → Cl ₂ + ／ H ₂ O When the desalting agent MxOy is Mn ₂ O ₃ , as shown in FIG. 8, Mn ₂ O ₃ + 6HCl → 2MnC
The reaction of l ₂ + 3H ₂ O + Cl ₂ occurs, and the used desalinating agent (MnCl ₂ ) is regenerated in the regenerator by 3MnCl ₂ + 2O ₂ → Mn.
Regenerated desalinating agent (Mn ₃ O) by reaction of ₃ O ₄ +3 Cl _2
4 ), and 4Mn ₃ O ₄ + O ₂ → 6Mn ₂
Oxidized and regenerated by the reaction of O ₃ . When the desalting agent MxOy is Co ₃ O ₄ , as shown in FIG. 9, CoCl ₂ is decomposed and oxidized by an oxygen-containing gas such as air in a regenerator to regenerate Co ₃ O ₄ . If Datsushiozai MxOy is CuO, as shown in FIG. 10, Cu in CuCl ₂ is regenerators
After being converted to Cl, it is oxidized and regenerated to CuO in a re-oxidizer.

FIG. 11 shows still another example of an apparatus for performing the method of the present invention. In this example, after the gasified gas is desalted in the fluidized bed desalination reactor 26, the dust is removed in the dust collector 28. Other configurations and operations are described in FIGS. 4, 5, 7 to 10.
Is the same as

[0018]

As described above, the present invention has the following effects. (1) Jet flammable waste containing chlorine plastic
Stoichiometry of waste in a bed or near-lateral swirling gasifier
By supplying a smaller amount of air, it is possible to dry-dehydrogenate a reducing gasified gas that has been reduced and burned and gasified. In particular, when using a moving bed desalination reactor, dehydrochlorination and dust removal can be performed simultaneously. (2) When supplying a part of the desalinating agent and / or a part of the used desalinating agent to the rotary gasifier, lower the slag melting point.
At the same time, the stable self-coating function of the furnace wall by the molten slag can be maintained. (3) Since dehydrochlorination and dust removal are performed in a dry manner, the sensible heat of the exhaust gas can be effectively used, and the problem of wastewater treatment does not occur.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an example of an apparatus for performing a method for treating a plastic waste gasified gas of the present invention.

FIG. 2 is a system diagram showing another example of an apparatus for performing the method of the present invention.

FIG. 3 is a system diagram showing another example of an apparatus for performing the method of the present invention.

FIG. 4 is a system diagram showing another example of an apparatus for performing the method of the present invention.

FIG. 5 is a system diagram showing another example of an apparatus for performing the method of the present invention.

FIG. 6 is a system diagram showing another example of an apparatus for performing the method of the present invention.

FIG. 7 is a system diagram showing another example of an apparatus for performing the method of the present invention.

FIG. 8 is an explanatory diagram showing regeneration when the desalting agent is Mn ₂ O ₃ .

FIG. 9 is an explanatory diagram showing regeneration when the desalting agent is Co ₃ O ₄ .

FIG. 10 is an explanatory diagram showing regeneration when the desalting agent is CuO.

FIG. 11 is a system diagram showing another example of an apparatus for performing the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 10 swirling spouted bed gasifier 10a swirling gasifier 12 moving bed desalination reactor 14 moving bed 16 air-permeable particle support 18 air-permeable particle support 20 discharger 22 ash analysis / controller 24 Feeder 26 Fluidized bed desalination reactor 28 Dust collector 30 Wind box 32 Dispersion plate 34 Fluidized bed 36 Surface crusher 38 Granulator 40 Regenerator 42 Reoxidizer

Continuation of front page (56) References JP-A-58-36691 (JP, A) JP-A-4-215882 (JP, A) JP-A-59-183817 (JP, A) JP-A-7-71735 (JP) , A) JP-A-56-89821 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01D 53/68 B01D 53/34 B09B 3/00 F23J 15/00

Claims (9)

(57) [Claims] 1. A waste combustible wastes containing chlorine-based plastic in either turning gasification furnace entrained and substantially lateral direction
A smaller amount of air than the stoichiometric amount of waste is supplied to reduce and burn to gasify and to extract molten slag. Then, this reducing gasified gas is converted into CaO particles and CaCO _3.
Plastic waste characterized by being introduced into a moving bed desalination reactor filled with at least one kind of desalting agent consisting of particles, dolomite particles and metal oxide particles and simultaneously desalting and dedusting in a dry manner For treating gasified gas. 2. A waste combustible wastes containing chlorine-based plastic in either turning gasification furnace entrained and substantially lateral direction
A smaller amount of air than the stoichiometric amount of waste is supplied to reduce and burn to gasify and to extract molten slag. Then, this reducing gasified gas is converted into CaO particles and CaCO _3.
Particles, dolomite particles and metal oxide particles are introduced into a fluidized bed desalination reactor as a desalinating agent and a fluidizing medium, wherein at least one of the desalinating agents consisting of a group of particles of dolomite and metal oxides is dried and desalted. A method for treating plastic waste gasification gas, which comprises introducing and removing dust. 3. A waste combustible wastes containing chlorine-based plastic in either turning gasification furnace entrained and substantially lateral direction
A small amount of air less than the stoichiometric amount of waste is supplied to reduce and burn to gasify and to extract molten slag, and then to transfer the reducing gasified gas filled with metal oxide particles as a desalinating agent. Introduced into the bed desalination reactor and simultaneously dry
In the meantime, the metal chloride extracted from the moving bed desalination reactor is regenerated into a metal oxide by a heating process while supplying an oxygen-containing gas, thereby obtaining a metal oxide. A method for treating gasified plastic waste gas, wherein the gas is circulated to the moving bed desalination reactor. 4. A waste combustible wastes containing chlorine-based plastic in either turning gasification furnace entrained and substantially lateral direction
A small amount of air less than the stoichiometric amount of waste is supplied to reduce and burn to gasify and extract molten slag.Then, the reducing gasified gas is converted into metal oxide particles as a desalinating agent and flowing medium. After being introduced into the fluidized-bed desalination reactor and desalted in a dry manner, it was introduced into a dust collector for dedusting treatment, while the metal chloride extracted from the fluidized-bed desalination reactor contained oxygen. A method for treating gasified plastic waste gas, comprising regenerating a metal oxide by a heating treatment while supplying a gas, and circulating the metal oxide to the fluidized bed desalination reactor. 5. waste combustible wastes containing chlorine-based plastic in either turning gasification furnace entrained and substantially lateral direction
Air is supplied in a smaller amount than the stoichiometric amount of the waste to reduce and burn to gasify and to extract the molten slag. Then, this reducing gasified gas is converted into CaO particles or CaCO 2.
_{The three} particles were introduced into a moving bed desalination reactor packed as a desalting agent, and were simultaneously desalted and dedusted in a dry manner, while CaCl ₂ coated with CaCl ₂ extracted from the moving bed desalination reactor was used.
Crushing the surface to remove CaCl ₂ on the surface, granulating unreacted CaO, and circulating the granulated unreacted CaO to the moving bed desalination reactor. 6. A desalinating agent is supplied to a rotary gasifier, and
The lag melting point is lowered, and a stable self-coating function of the furnace wall by the molten slag is maintained.
The method for treating a plastic waste gasified gas according to any one of claims 1 to 5. 7. The ash content in combustible waste containing chlorine-based plastics controls the amount of desalinating agent supplied to the swirling gasifier to lower the slag melting point and to stabilize the furnace wall by molten slag. The method for treating a plastic waste gasified gas according to claim 6, wherein the self-coating function of the gas is maintained. 8. A part of the used desalting agent extracted from the moving bed desalination reactor is supplied to a swirling gasification furnace, and slag melting is performed.
6. The method for treating gasified plastic waste gas according to claim 1 , wherein the temperature is lowered and the function of self-coating the furnace wall with molten slag is maintained. 9. A part of a used desalinating agent extracted from a fluidized bed desalination reactor and / or a dust collector is supplied to a rotary gasifier to lower the melting point of slag and melt slag. The method according to claim 2 or 4, wherein a stable self-coating function of the furnace wall is maintained.