The common methods of exhaust gas treatment basically have the following three points:
First, the condensation method has different saturated vapor pressures under different pressures and temperatures according to the exhaust gas treatment pollutants. Some gaseous pollutants can be condensed into a liquid by reducing the temperature and increasing the pressure to achieve the purpose of purification and recovery. . The condensing method has a high operating cost and is suitable for the recovery of high-concentration and high-boiling VOCs. This method is not suitable for low-concentration organic waste gas. The simple condensation method often cannot meet the required separation requirements. Therefore, this method is often used as a purification method for adsorption and combustion. Pretreatment process of concentrated exhaust gas.
Second, the combustion method is also known as thermal oxidation method, thermal combustion method, mainly used for the purification of high-concentration VOCs exhaust gas. For low-to-medium-concentration tail gas that cannot be burned by itself, it usually requires a combustion promoter or heating, which consumes large energy and has a running cost that is more than 10 times higher than that of the catalytic combustion method. It requires high operating technology and is not easy to control and master. This method has not been widely promoted in China. Only a few manufacturers have introduced foreign treatment equipment for high concentration and temperature waste gas treatment in the can and iron industry. However, due to large energy consumption and unstable operation, it is difficult to operate normally. .
Third, the absorption method
Exhaust gas treatment and absorption methods can be divided into chemical absorption and physical absorption. Most organic waste gas should not be chemically absorbed. The absorbent for physical absorption should have higher affinity with the absorbing components, low volatility, and at the same time, it should also have less volatility. After the absorption liquid is saturated, it can be reused after analysis or rectification after exhaust gas treatment. , At the same time can play the role of cooling and cooling, pre-dusting.
4. Catalytic Combustion Method The advantage of this method is that the catalytic combustion is flameless combustion, with good safety, small device size and small floor area; the equipment maintenance and depreciation costs are low. This method is suitable for high temperature, medium and high concentration organic waste gas treatment, and has been widely used at home and abroad, with good results.