How to deal with the exhaust gas of the fume hood

Organic waste gas treatment is to eliminate organic waste gas pollution through various technical measures to reduce fuel consumption, reduce organic solvent consumption or exhaust gas purification. Organic waste gas pollution sources are widely distributed. In order to prevent pollution, exhaust gas purification is a feasible treatment method at present. In addition to reducing fuel consumption and reducing the amount of organic solvents, the generation and emission of organic waste gas can be reduced. Commonly used methods are adsorption, catalytic combustion, thermal combustion and so on. The purification method, according to the specific situation, adopts the method of low cost, low energy consumption, and no secondary pollution, which is unfavorable to the benefit, and completely recovers the components and waste heat. In most cases, the petrochemical industry uses methods such as condensation, absorption, direct combustion, etc., due to the high concentration of exhaust gas. In the paint construction and printing industry, adsorption and catalytic combustion are used due to low exhaust gas concentrations.

1. Condensation method: The organic waste gas directly enters the solution, and the value of the organic matter can be recovered through the condenser of adsorption, absorption and plate separation. This method is suitable for organic waste gas with high concentration and low temperature. Under small flow conditions, it is necessary to The supporting refrigeration equipment is mainly used in pharmaceutical, chemical and printing enterprises.

2. Absorption: The general use of physical absorption, the introduction of absorbing liquid waste gas purification, absorbing liquid heating after saturation, condensed water recovery, gas analysis; this method is suitable for large capacity, low temperature, low concentration, but should be equipped with thermal analysis recovery device, Large equipment, high investment.

Activated carbon adsorption of waste gas generally adopts activated carbon adsorption method. After the adsorption is saturated, the activated carbon is regenerated, the exhaust gas is blown off, and the catalytic combustion is converted into harmless substances. The activated carbon is used continuously after regeneration. After the activated carbon is regenerated for a certain number of times, the adsorption capacity drops significantly, and the activated carbon needs to be regenerated or renewed.

Activated carbon is currently the most commonly used method for treating organic waste gas. It has good adsorption performance for benzene waste gas, but poor adsorption capacity for hydrocarbon waste gas. The main disadvantage is that the operating cost is high and it is not suitable for environments with high humidity, and the use of activated carbon is the most common method in the market. Activated carbon is mainly activated carbon and activated carbon fiber. Activated carbon granules are cheaper but less effective. Compared with activated carbon fiber, the price of activated carbon is higher and the effect is better.

3. Direct combustion method: It uses oil or gas as auxiliary fuel to burn, and the mixed gas is heated, and the high temperature harmful substances are decomposed into harmless substances; the process is simple, the investment is small, and the effect is good.

4. Catalytic combustion method: the exhaust gas is heated and converted into harmless and odorless carbon dioxide and water through catalytic combustion; this method has the advantages of low ignition temperature, energy saving, high purification rate, convenient operation, small footprint, large investment, and suitable for high temperature Or high-concentration organic waste gas.