JPH0722607B2 - Method and apparatus for decomposing organic halogen compound by plasma reaction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an organic compound produced by a plasma reaction method capable of efficiently decomposing an organic halogen compound containing fluorine, chlorine, or bromine in an organic compound such as CFC gas or trichloroethylene. The present invention relates to a method for decomposing a halogen compound.

(Prior Art) Organic halogen compounds containing fluorine, chlorine, and bromine in organic compounds such as CFCs and trichlorethylene are
It is widely used in large quantities in refrigerants, fire extinguishing agents, etc., and is of high importance in industry. However, these compounds are highly volatile, and most of those used in industry are released into the environment such as air, water, and soil, resulting in the destruction of the ozone layer, the generation of carcinogenic substances, and mutagenic substances. It has been pointed out that it has a serious impact on the environment, such as the generation of

(Problems to be Solved by the Invention) In the present situation, when a used organic halogen compound is disposed of as a waste, its reactivity is extremely low, and thus there is no suitable decomposition treatment method.

What has been conventionally reported as a decomposition treatment method is a combustion technique at high temperature. However, in this method, since the organic halogen compound is burned with a large amount of fuel such as hydrocarbon, the energy efficiency is extremely low, and
Since the fuel tank and combustion furnace are large, it is impossible to downsize the entire device. Further, free halogen generated by combustion comes into contact with the high temperature furnace wall, and particularly when the organic fluorine compound is combusted, the corrosion of the furnace is severe.

As a result of intensive studies on a method of easily decomposing an organic halogen compound, the present inventor has found a decomposing method using a prabuma produced by an induction heating method using high frequency waves or microwaves or a direct current heating method. This is based on the fact that a substance is extremely reactive in a plasma state, and a hardly decomposable chemical substance such as an organic halogen compound can be decomposed in a short time. That is, it is considered that almost all molecules are dissociated and decomposed into an atomic state in the high temperature plasma reaching over 10,000 ° C.

A point to be considered in the decomposition method using such a plasma is that in the case of a liquid organic halogen compound, this is efficiently introduced into the plasma flame. That is, even if the liquid organic halogen compound is directly introduced into the plasma flame, the liquid organic halogen compound simply passes through the plasma flame and is not decomposed. Further, when the liquid is directly introduced into the plasma frame, the plasma state becomes unstable, and in an extreme case, the plasma is extinguished.

The present invention has been made in view of the above points, and an object thereof is to provide an organohalogen compound by a plasma reaction method capable of decomposing an organohalogen compound such as Freon and trichlene with high efficiency even at a high concentration. It is to realize a decomposing method and apparatus, and to realize a decomposing apparatus capable of efficiently supplying and decomposing a liquid organic halogen compound in plasma.

(Means for Solving the Problems) In the method for decomposing an organic halogen compound by the plasma reaction method according to the invention of claim 1, a gaseous organic halogen compound and water vapor are introduced into a reaction vessel, and the gas is introduced around the reaction vessel. The feature is that they are turned into induction plasma at the same time by the wound RF coil.

An apparatus for decomposing an organohalogen compound by a plasma reaction method according to the invention of claim 2 is an induction plasma including a cylindrical tube, a gas supply nozzle for supplying gas into the tube, and an RF coil wound around the tube. A torch, a carrier gas source, a carrier gas from this carrier gas source is introduced, a first container in which a liquid organohalogen compound is placed, and a carrier gas from the carrier gas source is introduced, A second container with water in it and a first container
And a carrier gas flow path which introduces the carrier gas containing the organic halogen compound from the container and the carrier gas containing the water from the second container to the gas supply nozzle. .

(Operation) In the inventions of claims 1 and 2, first, a gaseous organic halogen compound and water vapor are introduced into the reaction vessel. And
These are simultaneously turned into inductive plasma by an RF coil wound around the reaction vessel. When the organic halogen compound is in a liquid state, in order to efficiently introduce the organic halogen compound and water into the plasma, in the invention of claim 2, a carrier gas such as argon gas is introduced into the liquid organic halogen compound. , Two kinds of water containing an organic halogen compound and water by introducing the carrier gas into water and bubbling the water while containing an organic halogen compound in the carrier gas by bubbling Are mixed and introduced into a tube in an induction plasma torch which is a reaction vessel.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a decomposition apparatus for implementing the method of the present invention (one embodiment of the apparatus of the present invention). The induction plasma torch 1 is a cylindrical tube formed of an insulating material such as quartz. 2 (in the present invention, it is also a reaction vessel for hydrolyzing an organic halogen compound), and is constituted by a gas supply nozzle 3 and an RF coil 4 wound around a tube 2. A ring-shaped groove 5 is bored in the gas supply nozzle 3, and a ring-shaped plate 6 is provided outside the groove 5.
Are welded. A large number of minute holes 7 are bored in the ring-shaped plate 6, and one end of a hole 8 bored inside the nozzle 3 is connected to the groove 5. The other end of the hole 8 is connected to the pipe 9 at the upper part of the nozzle 3.

The pipe 9 is branched in the middle, one of which is introduced into the first container 10 and the other of which is introduced into the second container 11. First
A liquid organohalogen compound 12 such as Freon 113 to be decomposed is placed in the container 10. First container
One end of a carrier gas supply pipe 13 is inserted in the organic halogen compound in 10. The other end of the carrier gas supply pipe 13 is connected to an argon gas source 15 via a flow controller 14. Water 16 is contained in the second container 11, and a carrier gas supply pipe is contained in the water 16.
One end of 17 is inserted. The other end of the carrier gas supply pipe 17 is connected to the argon gas source 15 via the flow controller 18.
It is connected to the.

A switching valve 19 is provided in the middle of the pipe 9. The switching valve 19 switches the gas from the first container 10 and the second container 11 and the gas from the argon gas source 20 to switch the nozzle 3
It is guided to the hole 8 formed in Argon gas source
The gas flow rate from 20 is controlled by the flow controller 21.

An opening 22 is provided in the lower portion of the cylindrical tube 2 that constitutes the plasma torch 1, and an exhaust tube 23 is connected to this opening 22. The exhaust pipe 23 is connected to a cyclone 24 that traps the powder substance contained in the exhaust gas. The exhaust gas that has passed through the cyclone 24 is guided to a pipe 25, which has an alkaline aqueous solution inside, for example,
It is introduced into a container 27 containing a potassium hydroxide (KOH) aqueous solution 26. A discharge pipe 28 for the internal gas is provided in the upper part of the container 27, and this discharge pipe 28 is connected to the lower part of a container 30 in which an alkaline solid, for example, calcium oxide (CaO) 29 is contained. . At the upper part of the container 30, a gas discharge pipe 31 for passing between the calcium oxide 29 inside is provided.

The operation of the apparatus thus configured will be described below. In the initial state of the apparatus, the switching valve 19 provided in the middle of the pipe 9 is operated so that the argon gas from the argon gas source 20 is supplied into the groove 5 through the hole 8 of the nozzle 3. By supplying the argon gas to the groove 5, the argon gas is jetted into the inside of the cylindrical tube 2 from the numerous minute holes 7 provided in the plate 6. In this state, a high frequency is supplied to the RF coil 4 to ignite the plasma P by an ignition mechanism (not shown).

After that, the switching parver 19 is switched so that the argon gas from the argon gas source 20 is replaced with the argon gas from the first container 10 and the second container 11 so that the gas is supplied into the groove 5 through the hole 8 of the nozzle 3. To In the first container 10, a carrier gas supply pipe 13 connected to an argon gas source 15 is inserted into an organic halogen compound 12 inside, and an end of the pipe 13 opened inside the organic halogen compound 12. Argon gas having an appropriate flow rate is ejected from the section by the flow controller 14. As a result, the organic halogen compound becomes vapor by the bubbling of the argon gas and is contained in the gas, and is discharged from the inside of the first container 10 into the pipe 9. Further, in the second container 11, the carrier gas supply pipe 17 connected to the argon gas source 15 is inserted into the water 16 inside, and the end portion of the pipe 17 opened into the water 16 From
Argon gas having a proper flow rate is ejected by the flow controller 18. As a result, the water becomes vapor by the bubbling of the argon gas, is contained in the gas, and is discharged from the inside of the first container 11 into the pipe 9.

The argon gas containing the vapor of the organic halogen compound and the argon gas containing the water vapor are mixed at the branch portion J in the middle of the tube 9, and the mixed gas is introduced into the groove 5 through the hole 8 of the nozzle 3. . The mixed gas is ejected from the groove 5 into the tube 2 through a large number of minute holes 7 provided in the plate 6, and is introduced into the plasma flame F. At this time, the temperature of the plasma is 10,000 to 15,000 degrees, and the organic halogen compound and water introduced into the plasma flame F are
It decomposes at high temperature with high efficiency and undergoes the following chemical reactions.

When trichlorofluoromethane (CFC-11 ... COl ₃ F) is decomposed in plasma as an organic halogen compound, the following reaction occurs with water.

CCl ₃ F + 2H ₂ O = CO ₂ + 3HCl + HF The exhaust gas containing the decomposed molecules is the opening 22 at the bottom of the pipe 2.
Through the discharge pipe 23 into the cyclone 24. At this time, when the amount of water is less than that of CFC-11, excess carbon is generated, but in this cyclone 24, fine powder such as carbon contained in the exhaust gas is trapped. Cyclone 24
The gas that has passed therethrough is introduced from the pipe 25 into the potassium hydroxide aqueous solution 26 inside the container 27. This aqueous potassium hydroxide solution
By passing the exhaust gas through 26, the exhaust gas containing acids such as HCl and HF is neutralized. The neutralized gas is introduced into the container 30 through the discharge pipe 28 from the bottom of the container 27 and dehydrated by the calcium oxide 29 inside the container 30. The dehydrated gas is a stable compound that hardly affects the environment and is appropriately released into the atmosphere.

FIG. 2 shows another embodiment of the present invention, in which the same parts as those in the embodiment of FIG. 1 are designated by the same reference numerals. In this embodiment, the nozzle 3 of the torch 1 is provided with a hole 50 in the center, in addition to the hole 8 connected to the groove 5. The hole 50 at the center is the first container for bubbling the organic halogen compound.
10 and a pipe 9 serving as a passage for the carrier gas from the second container for bubbling water are connected. A pipe 52 connected to the argon gas source 20 via a flow controller 51 is connected to the hole 8.

In this embodiment, in the initial state of the apparatus, the switching valve 19 provided in the middle of the pipe 9 is operated and the argon gas source 20 is supplied.
Argon gas is supplied to the holes 50 of the nozzle 3. In addition, an argon gas source is provided in the groove 5 through the hole 8.
The argon gas from 20 is supplied by the flow controller 51 at an appropriate flow rate. Therefore, argon gas is ejected into the inside of the tube 2 from the minute holes 7 of the plate 6 and from the two holes 50. When a high frequency is supplied to the RF coil 4 in this state, the plasma P is ignited.

After that, the switching valve 19 is switched so that the argon gas from the argon gas source 20 is replaced and the gas from the first container 10 and the second container 11 is ejected into the pipe 2 through the hole 50 of the nozzle 3. To As a result, similar to the embodiment shown in FIG. 1, the organic halogen compound introduced into the plasma flame F heated to 10,000 to 15,000 degrees vibrates due to high temperature and high energy in plasma. The intermolecular bond is broken by the collision with the electron, and it decomposes with high efficiency.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to these embodiments. For example, in the first embodiment, one groove is provided in the nozzle of the torch, and the argon gas and the carrier gas containing the vapor of the organic halogen compound are switched and supplied to this groove by bubbling. Two grooves are provided, one of which is configured to be supplied by switching between argon gas and a carrier gas containing vapor of an organic halogen compound by bubbling, and the other of which is continuously supplied with argon gas. Is also good.

Further, in the above embodiment, the case where water is used as the solution that reacts with the organic halogen compound 12 has been described as an example.
The present invention is not limited to this, and may be any one as long as it reacts with an organic halogen compound to decompose the organic halogen compound.

Further, a heater and a thermometer are provided inside the container containing the organic halogen compound and water, respectively, and if the organic halogen compound and water are constantly maintained at a temperature of about 30 ° C to 40 ° C, the evaporation is further promoted. can do.

(Effects of the Invention) As described above, according to the invention of claim 1, a gaseous organic halogen compound and water vapor are introduced into a reaction vessel, and by an RF coil wound around the reaction vessel, Since these are simultaneously induced plasma and hydrolyzed, the temperature of the plasma flame is high and the hydrolysis is performed with high efficiency. According to the invention of claim 2, a carrier gas such as argon gas is introduced into a liquid organic halogen compound to cause bubbling, so that the carrier gas contains a gaseous organic halogen compound and at the same time, the carrier gas. By introducing water into the water and bubbling the water into the carrier gas, and mixing the carrier gas containing the gaseous organic halogen compound and the carrier gas containing the water vapor into the reaction vessel. It is introduced into the reaction vessel and the RF coil wound around the reaction vessel simultaneously induces these into inductive plasma to cause hydrolysis. Therefore, the plasma state is stable, and since the plasma has basically the same structure as that of the invention of claim 1, Temperatures between frames is high, hydrolysis with high efficiency is made.

[Brief description of drawings]

FIG. 1 is a diagram showing one embodiment of a disassembling apparatus for realizing the method of the present invention (one embodiment of the apparatus of the present invention), and FIG. 2 is another embodiment of the disassembling apparatus for realizing the method of the present invention. It is a figure which shows (other Example of this invention apparatus). 1 ... Torch, 2 ... Tube (reaction vessel) 3 ... Gas supply nozzle, 4 ... RF coil 5 ... Groove, 6 ... Plate 7 ... Micro hole, 8,50 ... Hole 9,13, 17,25,28,52 …… tube 10 …… first container, 11 …… second container 12 …… organohalogen compound 14,18,21,51 …… flow controller 15 …… argon gas source, 16 …… Water 19 …… Switching valve, 20 …… Argon gas source 22 …… Opening, 23 …… Exhaust pipe 24 …… Cyclone 26 …… Potassium hydroxide aqueous solution 27, 30 …… Container, 29 …… Calcium oxide 31… ... Discharge pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page Patent Law Article 30 Clause 1 Application for labor saving and automation July 1989 (July 1, 1991) Published by Ohmsha Co., Ltd. Published on pages 18 to 19 (72) Inventor Yutaka Konuma 16-3 Onogawa, Tsukuba-shi, Ibaraki Institute of Pollution Resources, Institute of Industrial Technology (72) Inventor Reiji Aizawa 16-3, Onogawa, Tsukuba, Ibaraki Institute of Pollution Resources, Institute of Industrial Technology (72) Inventor, Akira Kushiyama Tsukuba, Ibaraki 16-3 Onogawa, Institute of Pollution Resources, Institute of Industrial Technology (72) Inventor Satoru Kobayashi 16-3, Onogawa, Tsukuba, Ibaraki Prefecture Institute of Pollution Resources, Institute of Industrial Technology (72) Hideo Ouchi 16-3, Onogawa, Tsukuba, Ibaraki (72) Inventor, Takanobu Amano 3-1-2, Musashino, Akishima-shi, Tokyo, Japan Electronics Co., Ltd. (72) Inventor Hisashi Komaki 3-1-2 Musashino, Akishima-shi, Tokyo Nihon Denshi Co., Ltd. (72) Inventor Shoji Hirakawa 3-1-2 Musashino, Akishima-shi, Tokyo Nihon Electronics Co., Ltd. Examiner Yuki Yamaguchi (56) Reference Document JP-A-2-107387 (JP, A)

Claims (2)

[Claims] 1. A method for decomposing an organohalogen compound by a plasma reaction method, which comprises decomposing an organohalogen compound using plasma, wherein a gaseous organohalogen compound and water vapor are introduced into a reaction vessel, and the reaction vessel By the RF coil wound around
A method for decomposing an organic halogen compound by a plasma reaction method, which comprises simultaneously converting these into inductive plasma. 2. An induction plasma torch comprising a cylindrical tube, a gas supply nozzle for supplying gas into the tube, and an RF coil wound around the peripheral surface of the tube, a carrier gas source, and the carrier gas source. A first container in which the carrier gas of (1) is introduced and a liquid organic halogen compound is placed inside, and a second container in which the carrier gas from the carrier gas source is introduced and water is placed inside, A carrier gas containing an organic halogen compound from a container of 1;
A device for decomposing an organohalogen compound by a plasma reaction method, comprising: a carrier gas flow path that mixes with a carrier gas containing water from the container and guides the gas to the gas supply nozzle.