JP2000247636A - Treatment process and equipment for converting halogen in organohalogen compound and organic compound into inorganic matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conversion treatment process for converting a material to be treated which contains an organohalogen compound(s), into nontoxic inorganic compounds at a high efficiency. SOLUTION: This conversion treatment process for subjecting a halogen(s) in an organohalogen compound(s) and a halogen-free organic compound(s) in a residual gas to conversion treatment into nontoxic inorganic matter comprises: gasifying or atomizing a material to be treated which contains an organohalogen compound(s), or an organohalogen compound(s) and an organic compound(s); subjecting the gasified or atomized material to catalytic reaction with particles of calcium oxide, barium oxide or a mixture of them, which particles are heated to 400-700 deg.C, while coutercurrently and continuously moving the particles, to convert a halogen(s) in the organohalogen compound(s) into a calcium and/or barium halide(s); and bringing the residual gas remaining after the catalytic reaction into contact with a platinum or palladium catalyst deposited on a ceramic carrier, at 200-500 deg.C to subject the residual halogen-free organic compound(s) to combustion treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a method for converting an object containing an organic halide into a non-toxic inorganic compound containing no organic compound without generating highly toxic dioxin. To an apparatus for implementing the method.

[0002]

2. Description of the Related Art Volatile organic halides cause the problem of depletion of the ozone layer, non-volatile organic halides cause environmental pollution such as soil and groundwater, and those containing organic halides are incinerated. In some cases, highly intoxicable dioxins may be generated from the incineration facility, these dioxins remain in the human body, and effects from breast milk to infants are estimated to have a significant effect on human health. Giving it is a big social problem. On the other hand, although the use is now banned, the highly toxic PCB
Most of them have been stored because they could not be disposed of.Freon has been discontinued because it is an ozone depleting substance, but there are still many used or stored. I do. In addition, organic compounds containing halogen, although having the above-mentioned problems, have useful properties.For example, fluorocarbons containing fluorine are used in refrigerants, fire extinguishers, cleaning agents, and the like, and those containing chlorine. Triclen,
It is used as a detergent such as methylene chloride and perchrene, and most pharmaceuticals, pesticides, insecticides, etc. contain chlorine. Therefore, these substances are used in a state where they can be controlled, and when used or alternatives are made unnecessary, it is important to convert them into harmless substances. At present, there is no device for implementing the above.

Under these circumstances, techniques for decomposing PCBs and dioxins using microorganisms and techniques for chemically decomposing PCBs and dioxins using a supercritical water reaction have been proposed. Incinerators that can generate
Research and proposals have been made on improved technologies for making incinerators themselves not generate dioxins. However, these proposals have problems such as relatively difficult handling, expensive and complicated equipment. In Japanese Patent Application Laid-Open No. 9-187645 (Japanese Patent Application No. Hei 8-24545), harmful substances such as PCB which is stored for a long period of time and trichlorene and trichloroethane which are stored and used without being processed are treated. As a method for treating an organic chlorine compound, calcium oxide, barium oxide or a mixed oxide thereof is mixed with air or an inert gas in air.
By reacting at 00 to 650 ° C., harmful organic chlorine compounds consisting of converting chlorine in organic chlorine compounds (the most difficult to treat organic chlorine compounds) to calcium chloride or barium chloride are harmless by dechlorination. Although a method for converting the same has been proposed, it is strictly a reaction scale of a glass reactor scale and is far from practical. In addition, organic substances remaining after dechlorination, for example, 50K
Since a mixture of PCB and mineral oil is used as the transformer oil in transformers of v · A or less, in the proposed treatment, it is possible to continuously treat the organic matter in the residual gas after the dechlorination treatment. Can not.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a practical organic halogen which can continuously treat the organic substances in the residual gas in the dechlorination treatment and has no problem of releasing the organic substances into the atmosphere. And a method for converting an object to be treated containing a halide, an organic halide, and an organic compound into a non-toxic inorganic compound without generating highly toxic dioxin. In a study on how to solve the above-mentioned problem, in the treatment method using calcium oxide, barium oxide or a mixed oxide thereof described in the above-mentioned known literature, a compound such as sulfur is contained in the object to be treated. Even if there is, it is understood that sulfur can be removed by the oxide in parallel with the dehalogenation treatment, and combustion treatment using a platinum, palladium or platinum-palladium catalyst is effective for treating organic compounds in the residual gas. I thought it could be used. Therefore, it was studied to design a treatment system that effectively combines the dehalogenation treatment using the oxides and the oxidation treatment using the catalyst system.

[0005]

The gist of the present invention is basically to gasify or atomize an object to be treated containing an organic halide and an organic halide and an organic compound, and to obtain a gas having a temperature of 400 ° C. to 700 ° C. Contact reaction with calcium oxide or barium oxide or a mixture thereof heated to convert halogens of organic halides to halides of calcium and / or barium, and to remove residual gas after the contact reaction from platinum supported on a ceramic carrier. Or converting the halogen of an organic halide and the non-halogenated organic compound in the residual gas into an inorganic substance by burning the residual non-halogenated organic compound by contacting it with a palladium catalyst at 200 to 500 ° C. And, more preferably, the calcium oxide and / or barium oxide particles are continuously coated. In addition to the reaction, the halogen is supplied in such a manner as to cause a contact reaction while being moved countercurrently with the physical material, and the halide, which is a reaction product of the halogen from the generated organic halide and the oxide, is continuously discharged out of the contact reaction zone. A method of converting the halogen of the organic halide and the non-halogenated organic compound in the residual gas into an inorganic substance, and gasifying or atomizing the object to be treated containing the organic halide and the organic halide and the organic compound. A heating furnace for heating and controlling the calcium and / or barium oxide in the reactor to a temperature of 400 ° C. to 700 ° C.
A device for continuously supplying calcium and / or barium oxide particles, a supply section for an organic halide supplied from the gasification or atomization means, and a supply section for an object to be treated containing an organic halide and an organic compound; A reaction section heated by the heating furnace for converting the halogen of the organic halide into a halide of calcium and / or barium by causing a contact reaction while continuously moving object particles in countercurrent with the object to be treated; Calcium and / or
Or a reactor having at least means for continuously discharging barium halide to the outside of the reaction system and means for guiding the residual gas after the catalytic reaction to the combustion treatment step, and residual gas after the catalytic reaction from the reactor. Characterized by having a combustion reactor comprising at least a means for controlling the combustion temperature for burning at a temperature of 200 ° C to 500 ° C and a ceramic carrier holding platinum, palladium or a platinum-palladium catalyst. This is a device for converting halogens of organic halides and organic compounds into inorganic substances.
The present inventor has proposed a dehalogenation treatment in which a calcium, barium oxide or a mixture of these oxides is continuously reacted countercurrently with respect to an object to be treated while contacting the same with platinum, palladium or platinum. -The object has been solved by combining the oxidation treatment with the palladium catalyst as a continuous process.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail. FIG.
1 is an overall view of one specific apparatus for performing the method of the present invention. The object to be treated containing an organic halide is
When the boiling point of the material to be treated is low, it is gasified by a suitable vaporizing means, or when the boiling point is high, is atomized by a spraying means and supplied to the mixer 10 from the supply unit 6 and is pressurized by the compressor 7. The preheater 10 provided as necessary as a mixture in which the concentration of the processing object is adjusted by being mixed with air as a carrier of the processing object whose pressure has been adjusted to 0.1 to 0.5 MPa via the buffer 8. The reactor 1 is supplied to the reactor. The concentration of the mixture needs to be adjusted depending on the chemical composition of the object to be treated, physical properties such as boiling point, etc., but the operation can be generally performed at 4% by volume to 10% by volume.

The reactor 1 has an opening for discharging calcium chloride, barium chloride or a mixture thereof formed in the lower part, and a device for discharging the reaction product while shutting off the outside (in the case of FIG. And an inverted conical part provided with a supply part (two places in the figure) of a mixture of the object to be treated and air, and an oxidation part of calcium and barium on the upper part. And a step of oxidizing the residual gas from the reactor 1 after the contact reaction with a particle supply device for the product or a mixture of these oxides (the device may have the same configuration as the particle discharge device). Is provided. The oxide particles react in the reactor 1 while forming a moving bed with the object and contacting the object in countercurrent.
That is, the reactor 1 constitutes a moving bed type reactor. Further, a suitable temperature-controlled heater is provided in the reactor 1,
For example, a steam heater, an electric heater, and the like are attached.

[0008] Air is supplied to the residual gas containing organic substances from the upper part of the reactor 1 from an air supply unit 11 through a supply control valve, and the residual gas is supplied to a catalytic oxidation (combustion) unit 12 for oxidizing treatment by a catalyst. The supplied organic matter is converted into carbon dioxide gas and taken out of the system by the blower 13. The supply amount of the air is adjusted depending on the concentration of the organic matter in the residual gas so that the optimal oxidation treatment can be performed. Generally, air is supplied in an amount of 1.2 to 1.5 times the theoretical amount of air required for the oxidation of the organic matter.

The catalytic oxidation (combustion) unit 12 has a structure in which a heat-resistant and corrosion-resistant ceramic material carrying platinum, palladium or a platinum-palladium catalyst is filled. Since the catalyst carrier spreads and carries an expensive catalytically active substance such as the noble metal, it plays a role of increasing the mechanical strength of the catalyst and sufficiently exhibiting the functionality (activity and selectivity) of the catalyst. It is important to select from such a viewpoint. Preferred examples of the ceramic material include alumina, silica, zirconia, and cordierite. Alumina is supposed to react with SO ₂ , but in the present invention, calcium oxide and the like are used in the dehalogenation step in the previous step, so that acidic components such as sulfur oxides are removed in the step. Therefore, there is a technical advantage in that the carrier such as alumina can be effectively used, which is combined with a dehalogenation step using calcium oxide or the like. In addition, as the shape of the carrier, a well-known one used as a chemical engineering filler can be adopted, but a honeycomb structure type having a large number of pores through which a gas to be treated is provided is easy to handle. Is advantageous. Further, it is advantageous to provide a heating device equipped with a temperature controller, for example, an electric heater or the like, in the catalytic reactor so that an optimal oxidation treatment can be performed irrespective of fluctuations in organic substances in the residual gas to be treated. It is.

[0010] The continuous supply of calcium oxide and / or barium oxide particles to the reactor 1 is carried out by means of a screw conveyor 3 from a hopper 2 for storing the particles and a screw feeder 3 at the top of the reactor 1 for supplying the particles in a controlled manner. The transfer can be performed to a supply device, for example, a metering supply device. The particles of the oxide have an optimum particle size, in other words, a specific surface area, depending on the physical properties such as the chemical composition and the boiling point of the object to be treated, but the average particle size is in the range of 0.4 to 4.5 mm. It is preferable to use those having a smaller particle size.

[0011]

EXAMPLE 1 An example in which tricrene is used as the organochlorine compound of the object to be treated will be described. Using a screw conveyor 3 from a calcium oxide hopper 2 in a reactor 1, an average particle size of 0.4 to 4.5.
mm of calcium oxide. Set the electric heating furnace 5 to 65
The mixture is heated to 0 ° C., and when a certain temperature is reached, the tricrene is supplied from the supply unit 6. Air is fed from the compressor 7 and the pressure of the air is adjusted to 0.1 MPa using a pressure buffer (controller) 8 to adjust the tricrene and the air using a mixer 9 so that the concentration of tricrene becomes 6%. Then, it was preheated by a preheater (preheater) 10 and introduced into the reactor 1. In the reactor 1, the calcium oxide reacts in a counter-current manner while moving downward in a countercurrent direction with respect to the tricrene, which is an object to be treated. The calcium chloride is sent to the receiving hopper 4 by a rotary valve which is a discharge device for the chloride (calcium chloride). Most of the trichlene from which chlorine is to be removed is converted to water and carbon dioxide, but some organic matter passes through the reaction tower. The residual gas containing the organic matter was previously heated at 400 ° C.
The catalyst was completely oxidized (combusted) by a catalytic reaction with a platinum catalyst supported on a zirconia carrier in a catalytic oxidation (combustion) unit 12 heated to a temperature of 10 min. The amount of air required for catalytic combustion is introduced from the air supply device (11). The pressure of the entire apparatus was adjusted using the adjustment blower 13.

Example 2 In the same manner as in Example 1, the concentration of trichlene was adjusted with air, and the decomposition rate by the dechlorination reaction was measured by changing the temperature of the heating furnace 5 of the reactor 1 in the range of 400 to 650 ° C. did. The result is shown in FIG. From the results in FIG. 2, it can be understood that in the treatment method of the present invention, calcium in tricrene can be converted to calcium chloride by a short contact reaction between calcium oxide and tricrene. The organic matter from which the chlorine has been removed is completely oxidized in a catalytic oxidizer (combustion tower) 12 heated to 500 ° C. That is, according to the method for treating an object containing an organic halide of the present invention, it was found that the performance of the reactor was very good. In addition, in order to perform a dechlorination reaction of 5.5% trichlene-air mixed gas containing lubricating oil and an oxidation treatment of residual organic compounds, it was disposed in a catalytic oxidation (combustion) reactor connected to a reactor 1 shown in the figure. The exhaust gas from the reactor was passed through a zirconia support carrying a palladium catalyst at a temperature of 500 ° C. As a result of measuring the passing gas by gas mass spectrometry, a small amount of methane was detected at a space velocity of 20000 h ^-1 , but no other organic matter was detected.

The treatment method according to the present invention relates to a method of using a fluorine-containing organic halogen compound as a refrigerant, a fire extinguishing agent, a cleaning agent, etc., a transformer or a condenser which has been used for a PCB or a mineral oil which has reached the end of its useful life. And the treatment of methyl bromide used as a fumigant, the treatment of propane bromide used as a cleaning agent, and many other organic halides.

[0014]

As described above, according to the present invention, a dehalogenation treatment in which an oxide of calcium or barium or a mixture of these oxides is continuously and countercurrently moved in a countercurrent manner to cause a contact reaction is performed. By combining the organic matter in the residual gas after the treatment with platinum, palladium or an oxidation treatment with a platinum-palladium catalyst as a continuous step, the object to be treated containing an organic halide can be treated with a high efficiency, a non-toxic inorganic compound. An excellent effect is obtained that the conversion processing can be performed up to.

[Brief description of the drawings]

FIG. 1 is an overall view of one specific apparatus for carrying out the method of the present invention.

FIG. 2 shows the relationship between the temperature of the heating furnace 5 of the reactor 1 in the range of 400 to 650 ° C. and the decomposition rate of the dechlorination reaction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Reactor 2 Hopper for particles such as calcium oxide 3 Screw conveyor 4 Hopper such as calcium chloride 5 Heating furnace 6 Material supply device 7 Compressor 8 Pressure buffer 9 Mixer for material and air to be treated 10 Preheater 11 Air supply device 12
Catalytic oxidation (combustion) unit 13 Blower

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yuji Tsuchiya Morikawa Sangyo Co., Ltd. (150) Morikawa Sangyo Co., Ltd. 150 Morikawa Sangyo Co., Ltd. (Reference) 2E191 BA12 BA13 BA15 BC01 BD13 4D048 AA17 AB01 AB03 BA02X BA08X BA10Y BA15Y BA30X BA31X DA06 4G069 AA03 BA01A BA02A BA05A BA05B BA13A BB02A BB02B BC72A BC72B BC75A BC75B CA04 CA07 CA09 A09 DA05

Claims (3)

[Claims] 1. An organic halide and an object to be treated containing an organic halide and an organic compound are gasified or atomized and contacted with calcium oxide, barium oxide or a mixture thereof heated to a temperature of 400 ° C. to 700 ° C. The reaction converts the halogen of the organic halide to a halide of calcium and / or barium, and the residual gas after the contact reaction is brought into contact with a platinum or palladium catalyst held on a ceramic carrier at 200 ° C. to 500 ° C. to form a residual non-metal. A method of converting a halogen of an organic halide and a non-halogenated organic compound in a residual gas into an inorganic substance by burning the halogenated organic compound. 2. A method for supplying calcium oxide and / or barium oxide particles so as to cause a contact reaction while continuously moving them in a counter-current direction with an object to be treated. 2. The halogen of the organic halide and the non-halogenated organic compound in the residual gas according to claim 1, wherein a halide as a reaction product of (1) is continuously discharged out of the contact reaction zone. How to convert. 3. An apparatus for gasifying or atomizing an organic halide and an object containing an organic halide and an organic compound, and an oxide of calcium and / or barium in a reactor at a temperature of 400 ° C. to 700 ° C. Heating furnace for controlling heating, apparatus for continuously supplying calcium and / or barium oxide particles, and object to be treated containing organic halide and organic halide and organic compound supplied from the gasification or atomization means And the oxide particles are continuously heated in the heating furnace to contact and react with the object while continuously moving the object in a counter-current direction to convert halogen of organic halide into halide of calcium and / or barium. And a means for continuously discharging the produced calcium and / or barium halide to the outside of the reaction system. A reactor having at least means for guiding the residual gas after the catalytic reaction to the combustion treatment step, and the residual gas after the contact reaction from the reactor at 200 ° C to 500 ° C.
A combustion reactor comprising at least a means for controlling the combustion processing temperature for performing combustion processing at a temperature and a ceramic carrier holding a platinum, palladium or platinum-palladium catalyst,
An apparatus for converting a halogen of an organic halide and an organic compound into an inorganic substance.