JP2000028500A - Apparatus for collecting hydrogen chloride gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus for efficiently collecting a hydrogen chloride gas from an exhaust gas generated when combustibles containing an organic substance are heated. SOLUTION: A trap 5 is set between a thermal decomposition apparatus for thermally decomposing combustibles containing an organic substance and an absorption bottle 6 storing an absorption liquid 6a for absorbing a hydrogen chloride gas. The trap consists of a trap vessel 5a, an introduction pipe 5b for introducing an exhaust gas to a lower part in the trap vessel 5a, a gas discharge pipe 5c set to an upper part, and a heater 5d for heating the exhaust gas in the trap vessel 5a. The heater 5d is set in the outer periphery of the trap vessel 5a and outer periphery of the introduction pipe 5b in the trap vessel 5a, thereby heating the exhaust gas in the trap vessel 5a to 100-200 deg.C. Also a heater 4 is set to a gas circulation pipe 3 to the trap 5 so that a temperature of the exhaust gas introduced to the trap 5 becomes 150 deg.C or higher, preferably, 300 deg.C or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for collecting hydrogen chloride gas generated during a thermal decomposition treatment in a low-oxygen atmosphere for combustible waste containing organic matter. Things.

[0002]

2. Description of the Related Art When plastics such as vinyl chloride, vinylidene chloride, synthetic resin and rubber are burned by combustible waste containing organic substances, a large amount of harmful hydrogen chloride gas is generated. The emission concentration regulation value of this hydrogen chloride gas emission is 430 ppm (= 700 mg) according to the Air Pollution Control Law.
/ Nm ³ ), and a means for adding a dechlorinating agent such as slaked lime and calcium carbonate to the hydrogen chloride gas contained in the exhaust gas, or a method using a bag filter By doing so, harmful hydrogen chloride gas is prevented from being released into the atmosphere.

In order to measure the concentration of hydrogen chloride in the exhaust gas of the above incinerator, Japanese Industrial Standards (JIS K 0107-
1995), the container is filled with an absorbent such as sodium hydroxide in advance, and the exhaust gas is passed through a ball filter or a glass filter plate attached to the tip of the gas inflow pipe. The solution is introduced into the absorbing solution in the vessel and subjected to bubbling, the hydrogen chloride component in the exhaust gas is collected in the absorbing solution, and then the aqueous solution is taken out of the vessel and analyzed by the analyzer to remove the chloride contained in the solution. In general, a method of measuring and analyzing the amount of hydrogen to determine the concentration of hydrogen chloride in exhaust gas is used.

[0004]

When such combustible waste containing organic matter is completely burned, there is no particular problem because the organic matter hardly remains in the exhaust gas. In the case of incomplete combustion, a large amount of organic matter is contained in the exhaust gas, so that there is a problem that hydrogen chloride gas cannot be collected by the above-described method.

[0005] That is, for example, in the exhaust gas generated by the dry distillation treatment, a substance having a high melting point and a substance having a low melting point are mixed, so that these substances are contained in the absorbing solution or in a pipe before reaching the absorbing solution. There is a problem that solidification or liquefaction causes the organic matter to adhere and remain in the middle of the pipe, or a ball filter or a glass filter plate in the absorption bottle to be clogged, making it impossible to collect hydrogen chloride gas. . Also, clogging of a ball filter, a glass filter plate, or the like may increase the internal pressure of the absorption bottle and cause gas leakage.

Further, since some harmful substances that do not dissolve in the absorbing solution exist in the organic gas in the exhaust gas, the exhaust gas used for the measurement cannot be directly emitted into the atmosphere, and other adsorbents are used. Another drawback is that harmful substances must be adsorbed and then released.

In view of the above, an object of the present invention is to provide an apparatus for efficiently collecting hydrogen chloride gas from exhaust gas generated when a combustible substance containing an organic substance is subjected to a heat treatment such as dry distillation. .

[0008]

According to the present invention, in order to achieve the above object, an absorbing solution for absorbing hydrogen chloride gas is contained in a gas flow pipe of a pyrolysis apparatus for thermally decomposing a combustible substance containing an organic substance. In a hydrogen chloride gas collecting device for collecting hydrogen chloride gas in exhaust gas by connecting an absorption bottle, a trap for capturing organic matter is provided between the thermal decomposition device and the absorption bottle, and the trap is provided. A trap container,
An inlet pipe for introducing exhaust gas from the gas flow pipe to the inside of the trap container, a gas exhaust pipe provided at an upper part of the trap container, and a heater for heating the exhaust gas in the trap container, A collection device is provided.

In practice, the heater is provided on the outer periphery of the trap container, and the temperature of the exhaust gas in the trap container is reduced to 100%.
The heating is performed so that the temperature is not less than 200 ° C. and not more than 200 ° C., or the heater is provided on the outer circumference of the introduction pipe in the trap container.
Heat as follows.

Further, a heater is provided in the gas flow pipe so that the temperature of the exhaust gas introduced into the trap is at least 150 ° C., preferably at least 300 ° C.

According to the apparatus for collecting hydrogen chloride gas,
When a flammable substance containing organic matter is placed in the pyrolysis apparatus and the pyrolysis is performed, the generated exhaust gas passes through the gas flow pipe while being heated to an appropriate temperature by the heater, and is guided into the trap from the introduction pipe. Most of the organic matter contained in the exhaust gas generated upon heating is trapped by the trap and is prevented from reaching the next gas absorption container.

If the temperature in the trap is lower than 100 ° C., moisture may adhere to the inner wall surface, and hydrogen chloride gas may be dissolved and trapped in the water. If the temperature in the trap is higher than 200 ° C., decomposed organic matter may be removed. The temperature inside the trap may be 100 ° C or higher and 20
Keep below 0 ° C.

The exhaust gas that has passed through the trap is guided into the absorbing solution in the absorbing bottle, and the hydrogen chloride gas component is collected by the absorbing solution by bubbling in the absorbing solution and then discharged to the outside from the outlet.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hydrogen chloride gas collecting apparatus according to the present invention will be described below. FIG. 1 is a schematic diagram for explaining a first embodiment of the present invention. In the figure, reference numeral 1 denotes a dry distillation furnace as a closed container for enclosing flammable waste, and 2 denotes a storage of the dry distillation furnace 1. It is an electric furnace to be heated, and the pyrolysis apparatus 1 and the electric furnace 2 constitute a thermal decomposition apparatus.

Reference numeral 3 denotes a gas flow pipe drawn out of the dry distillation furnace 1. Around the gas flow pipe 3, a heater 4 for heating exhaust gas flowing through the gas flow pipe 3 is provided. Note that stainless steel is used as a material for the dry distillation furnace 1 and the gas distribution pipe 3.

Reference numeral 5 denotes a trap for trapping organic matter, which is a sealed container. The trap 5 includes a trap container 5a and an exhaust gas from the gas flow pipe 3 for trapping the exhaust gas.
a, an introduction pipe 5b for introducing the substance to the lower part of
a gas discharge pipe 5c provided in the upper part of
and a heater 5d provided on the outer periphery of the trap container 5a to heat the exhaust gas in the trap container 5a.

Further, an absorption bottle 6 used for collecting hydrogen chloride gas is provided at the gas discharge pipe 5c in this embodiment.
Are connected in series.

The absorption bottle 6 contains sodium hydroxide (0.1N-NaOH) as an absorption solution 6a for absorbing hydrogen chloride gas.
It is composed of an absorption container 6b in which a solution is put, and a discharge port 6c formed on the upper part of the absorption container 6b.

Each of the five absorption bottles 6 is connected in series by connecting the discharge port 6c and the introduction pipe 6d of the adjacent absorption bottle 6.

The reason why five absorption bottles 6 are connected in series is to compensate for the relatively short contact time between gas and liquid in one absorption bottle. Reference numeral 7 denotes a gas adsorption device filled with a gas adsorbent that adsorbs harmful substances that do not dissolve in each absorption liquid 6.

The rubbed portion of each gas absorbing bottle 6 was coated with grease and fixed with a stainless steel joint clip in case an internal pressure rise due to clogging occurred.

In the hydrogen chloride gas trapping device constructed as described above, when combustible waste is put into the dry distillation furnace 1 and subjected to the dry distillation treatment (pyrolysis) by the electric furnace 2, it is generated at that time. The exhaust gas passes through the gas flow pipe 3 while being heated to an appropriate temperature by the heater 4, and is introduced into the trap container 5 a constituting the trap 5 to a lower portion by the introduction pipe 5 b. At this time, the heater 4 is operated so that the temperature of the exhaust gas introduced into the trap 5 becomes 150 ° C. or higher.

Further, the heater 5d provided on the outer periphery of the trap container 5a is operated to heat the exhaust gas in the trap container 5a so that the temperature of the exhaust gas becomes 100 ° C. or more and 200 ° C. or less. Then, most of the organic matter contained in the exhaust gas generated when the combustible waste is heated by the electric furnace 2 is captured by the trap 5 and flows into the next absorption bottle 6 from the gas discharge pipe 5c. .

If the temperature in the trap 5 is 100 ° C. or less, moisture may adhere to the inner wall surface, and hydrogen chloride gas may be dissolved and trapped in the moisture. Conversely, the temperature in the trap 5 may be 200 ° C. In the above, since the decomposed organic matter may be transferred to the next gas absorption container, the temperature in the trap is set to 10
It is necessary to keep the temperature between 0 ° C and 200 ° C.

The exhaust gas that has passed through the trap 5 passes from the gas discharge pipe 5c to the introduction pipe 6d and passes through the absorption liquid 6 in the absorption bottle 6.
a, the hydrogen chloride gas component is collected by bubbling in the absorbing solution 6a, and then discharged to the outside through the discharge port 6c. After the harmful substances are removed by the, it is discharged outside.

Next, using a sample simulating flammable waste containing organic matter, hydrogen chloride gas was collected by the apparatus of the present invention. As samples, papers 61.3 (% by weight),
Plastics including chlorine-containing plastics 21.2
(Wt%), others (fiber, wood, rubber, leather, etc.) 1
What consisted of 7.5 (% by weight) was used.

The heater 4 was set so that the temperature of the exhaust gas was 150 ° C. or higher at which the thermal decomposition of plastics started. More preferably, by setting the temperature of the exhaust gas to be 300 ° C. or higher, dissolution of hydrogen chloride in water condensed in the gas flow pipe 3 is prevented, and liquefaction and solidification of organic substances are prevented, Clogging of the gas distribution pipe 3 and the like can be completely prevented.

As a result, the exhaust gas discharged from the dry distillation furnace 1 can be introduced into the absorption bottle 6 through the trap 5 without clogging due to being heated in the gas flow pipe 3. Further, most of the gas organic matter generated during the thermal decomposition was captured by the trap 5 and did not reach the gas absorption container 7 in the next stage. Therefore, the introduction pipe 6 of the absorption bottle 6
There was no clogging of d due to solidification of the organic matter, and it was confirmed that it flowed smoothly.

After taking out the absorbing solution 6a of each absorbing bottle 6 and removing solid impurities by a filter, the amount of hydrogen chloride collected in the absorbing solution 6a was confirmed by an analyzer. By confirming that almost all of the hydrogen chloride gas in the exhaust gas was collected by 6
It turned out that three or more absorption bottles 6 may be connected and provided. In addition, since most of the organic matter was solidified in the first absorption bottle 6, it is not necessary to use a general filter with a general filter stipulated by Japanese Industrial Standards for the second and subsequent ones. It turned out that no clogging problem occurred.

On the other hand, as a comparative example, the same simulated sample as described above was put into a dry distillation furnace 1, and the electric furnace 2 was driven to heat (dry dry) the sample in a closed state. The tube 3 was heated, and the generated gas was allowed to flow directly into the absorption bottle 6 without using the trap 5.

Water evaporates as the temperature in the dry distillation furnace 1 rises, and when the temperature reaches 150 ° C., gas generation is started. At 300 ° C., gas generation becomes active, and hydrogen chloride gas generated by pyrolysis is generated. Flowed into the absorption bottles 6, and the organic matter adhered to the inner wall surface of each absorption bottle 6 as a brown tar component. Further, as time passes, the outlet 6c and the inlet pipe 6d
Was closed by an organic tar component, the lid of the absorption bottle 6 was detached with an increase in the internal pressure, and the gas flow was stopped, making it impossible to continue the operation.

From the above results, in the case of this embodiment, most of the organic matter contained in the gas generated by the thermal decomposition in the dry distillation furnace 1 is captured by the trap 5, and the next stage of the absorption bottle It turned out that the case reaching 6 hardly occurred.

FIG. 2 is a schematic view for explaining a second embodiment of the present invention, in which a dry distillation furnace 1, an electric furnace 2 and an absorption bottle 6 are used.
Is the same as that of the first embodiment, but in this example, a heater 8 is also provided around the introduction pipe 5b introduced into the trap container 5a. Other configurations are the same as those of the first embodiment.

According to such a configuration, the exhaust gas is heated inside and outside the trap 5 by using the heater 5d shown in the first embodiment and the heater 8 shown in the second embodiment, so that the introduction pipe 5b No organic tar component remained in the inside, and extremely good gas flow performance was obtained.

The absorption bottle 6 may be of any type such as a Kinoshita type gas washing bottle, an Ichise type gas washing bottle, a Muenke type gas washing bottle, etc., provided that there is no filter or filter plate.

The present apparatus is extremely effective when used to collect hydrogen chloride gas from exhaust gas containing a large amount of organic substances generated by unburned or incompletely burned pyrolysis. The decomposition apparatus is not limited to the dry distillation.

[0037]

As described above, according to the apparatus for collecting hydrogen chloride gas of the present invention, the exhaust gas generated when a flammable substance containing an organic substance is placed in a thermal decomposition apparatus and subjected to thermal decomposition treatment. Most of the organic matter contained in the gas is trapped by the trap and is prevented from reaching the next absorption bottle, so that the organic matter does not adhere to the inner wall surface of each absorption bottle and the gas over time. There is no risk of blockage or clogging of the distribution pipe or the introduction pipe, and a good operation state can be maintained. Then, the exhaust gas is guided into the absorption liquid in the absorption bottle while being heated, and the hydrogen chloride gas component can be collected in the absorption liquid by bubbling while sequentially passing through each absorption bottle.

Further, the temperature in the trap is set to 100 ° C. or more and 20
By keeping the temperature at 0 ° C. or lower, the water does not adhere to the inner wall surface of the trap to capture the hydrogen chloride gas, and the decomposed organic matter is prevented from being transferred to the next absorption bottle.

In particular, even if the exhaust gas contains a large amount of organic matter due to unburned or incomplete combustion of combustible substances, the temperature of the gas flow pipe is set to 150 ° C., preferably 300 ° C.
By setting so that liquefaction and solidification of organic matter are prevented, clogging of the gas flow pipe is prevented. Can continue.

Since at least three or more gas absorbing containers are connected in series, almost the entire amount of hydrogen chloride gas in the exhaust gas is collected, so that the exhaust gas can be directly emitted to the atmosphere. An apparatus for efficiently collecting hydrogen chloride gas from exhaust gas can be provided.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a hydrogen chloride gas collecting apparatus according to the present invention.
FIG. 1 is a schematic diagram for explaining an example of an embodiment.

FIG. 2 is an enlarged view of a main part for describing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dry distillation furnace (as a heat processing furnace) 2 ... Electric furnace 3 ... Gas flow pipe 4,5d, 8 ... Heater 5 ... Trap 5a ... Trap container 5b ... Introduction pipe 5c ... Gas discharge pipe 6 ... Absorption bottle 6a ... Absorption Liquid 6b: absorption container 6c: outlet 6d: introduction pipe 7: gas adsorption device

Claims (5)

[Claims] 1. An apparatus for thermally decomposing a combustible substance containing an organic substance, wherein an absorption bottle containing an absorbing solution for absorbing hydrogen chloride gas is connected to a gas flow pipe of the pyrolysis apparatus, whereby hydrogen chloride gas in exhaust gas is connected. A trap for capturing organic matter between the pyrolyzer and the absorption bottle, the trap being a trap container, and a trap container being used for trapping exhaust gas from a gas flow pipe. An apparatus for collecting hydrogen chloride gas, comprising: an inlet pipe for introducing gas to a lower part of the inside of the inside; a gas exhaust pipe provided at an upper part of the trap vessel; and a heater for heating exhaust gas in the trap vessel. 2. The apparatus according to claim 1, wherein the heater is provided on an outer periphery of the trap container.
If the temperature of the exhaust gas in the trap
2. The apparatus for collecting hydrogen chloride gas according to claim 1, wherein the apparatus is heated to a temperature of 0 ° C. or lower. 3. The heater according to claim 1, wherein the heater is provided on the outer periphery of the introduction pipe in the trap container, and the temperature of the exhaust gas in the trap container is 1
2. The apparatus for collecting hydrogen chloride gas according to claim 1, wherein the apparatus is heated so that the temperature is not lower than 00 ° C. and not higher than 200 ° C. 4. The gas flow pipe according to claim 1, wherein a heater is provided in the gas flow pipe, and the temperature of the exhaust gas introduced into the trap is set to 150 ° C. or higher. A device for collecting hydrogen chloride gas according to item 1. 5. The apparatus according to claim 1, wherein a heater is provided in the gas flow pipe so that the temperature of the exhaust gas introduced into the trap is 300 ° C. or higher. A device for collecting hydrogen chloride gas according to item 1.