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High concentration chemical waste gas treatment methods and those?
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Chemical waste gas refers to poisonous and harmful gases discharged from chemical production. There are many kinds of waste gas in the chemical industry, and its components are mixed and disorderly. The exhaust gases produced by different chemical industries vary greatly in composition. In general, we can divide the organic exhaust into two types, low concentration and high concentration. Low concentration organic waste gas treatment methods include UV photocatalytic oxidation, plasma purification, biological method, adsorption method, absorption method, etc. High concentration of waste gas treatment methods are incineration, activated carbon adsorption and desorption catalytic incineration, biological method, condensation method.

1. The incineration method

Incineration is the use of some harmful substances in the exhaust gas can oxidize the characteristics of incineration, so that the incineration into harmless material method. Incineration can be divided into direct, thermal and catalytic incineration.

The waste gas emission concentration greater than 5000mg/m can be used by direct incineration, which USES VOCs waste gas as fuel for incineration and has high treatment efficiency.

For the exhaust gas emission concentration of 1000-5000 mg/m, thermal incineration method can be adopted. The concentration of VOCs in the exhaust gas is relatively low, and the temperature required for thermal incineration is lower than that for direct incineration by virtue of other fuels or combustion gases. The incineration of VOCs waste gas has high efficiency, but the direct emission of incinerated gas will cause secondary pollution. The waste gas treatment by incineration method has a high purification rate, but it has a high capital cost and occupies a large amount of ground, which requires professional personnel to operate. Improper operation will cause secondary pollution.

2. Activated carbon catalytic incineration

The essence of activated carbon adsorption is to use the characteristics of activated carbon adsorption to adsorb the organic solvents in the low concentration of large air volume exhaust gas into the activated carbon and concentrate, after the purification of activated carbon adsorption directly empty the gas, its essence is a process of adsorption and concentration. I didn't get rid of the organic solvent. It's a physical process.

Activated carbon stripping catalytic incineration using catalytic incineration is the nature of the hot air heating in the activated carbon adsorption of organic solvent, make it reach the boiling point of the solvent, the organic solvent stripping from the activated carbon, and the high concentration of exhaust gas burned into the catalytic reactor, after the effects of catalyst for oxidation reaction into harmless water and carbon dioxide into the atmosphere. It is a chemical reaction process, not the burning of open flame, and can completely solve the secondary pollution during desorption.

Activated carbon adsorption desorption catalytic incineration is an effective combination of the above two advantages. That is, the first use of activated carbon adsorption concentration, when the activated carbon adsorption reached full, the use of electric heating catalytic incineration equipment, and the use of hot air part of the heating activated carbon adsorption bed, from the adsorption bed desorption of high concentration of waste gas can be carried out in the catalytic reaction bed oxidation. The high temperature gas after the reaction is transferred by the heat exchanger, part of the gas after the heat transfer is sent to the activated carbon adsorption bed for desorption, and the other part is discharged into the atmosphere. The temperature of the desorbed waste gas increases rapidly after being heated by the heat exchanger. In this way, the catalytic incineration equipment and desorption can reach low power or no power operation.

3. The biological method

The biological purification method USES the decomposition effect of microorganism to purify the organic waste gas. The cost of this method is low. The disadvantage is that the temperature difference is too large or the exhaust gas concentration fluctuates, easy to cause microbial death.

4. The condensation method

The condensation method directly introduces the organic waste gas into the condenser through adsorption, absorption, disassembly and separation, and can recover valuable organic matter. This method is suitable for the working condition of high concentration of organic waste gas, low temperature and small air volume. It is mainly used in the pharmaceutical and chemical industries and rarely used by printing enterprises.
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