Due to the complex composition and emission conditions of the process VOCs, in order to achieve efficient and advanced treatment of VOCs-containing exhaust gas, the exhaust gas needs to be pretreated under certain working conditions. The exhaust gas pretreatment mainly affects the VOCs composition, pollutant concentration, temperature, humidity and Adjust the particulate matter.

The "Technical Specification for Industrial Organic Waste Gas Treatment Engineering by Adsorption Method (HJ 2026-2013)" requires that the concentration of organic matter in the organic waste gas entering the treatment device (adsorption, incineration, catalysis, etc.) is less than 25% of its lower explosive limit. When the concentration of organic matter in the exhaust gas is higher than 25% of its lower explosive limit, it should be reduced to 25% of its lower explosive limit before purification. For example, when the adsorption concentration (activated carbon, zeolite runner) + RTO, RCO treatment process is adopted, the concentration of waste gas during the desorption process needs to be controlled.

The exhaust temperature of the vulcanization process is about 60-70°C. If activated carbon adsorption and low-temperature plasma are used for treatment, the temperature needs to be reduced to below 40-50°C. For physical adsorption, the lower the temperature, the better the adsorption. For compounds with low boiling points, the temperature effect is particularly obvious.

For adsorption, catalysis, and incineration devices, the lower the humidity, the higher the purification efficiency. The relative humidity of the exhaust gas has a great influence on the adsorption performance of activated carbon and zeolite molecular sieve. The main methods of exhaust gas dehumidification include: demister and dehumidification by demister (mainly for spray system); condensation and dehumidification; heating and dehumidification (improving the adsorption capacity of adsorbent materials such as activated carbon); adsorption dehumidification (continuous dehumidification device with zeolite rotor) ).

The control of particulate matter is also very important. The content of particulate matter entering the adsorption device should be less than 1mg/m3, and the content of particulate matter entering the incinerator should be less than 10mg/m3. Low-temperature plasma, photooxidation, and biological devices have stricter requirements for particulate matter. For example, paint mist particles are difficult to purify spray waste gas due to their high viscosity and can be removed by dry filtration; the waste gas of rubber products refining process contains high concentration of dust, which needs to be efficiently filtered through a cloth bag before entering the subsequent VOCs treatment equipment. The main methods of particle removal are: mechanical filtration technology (wire mesh filter element, filter felt, filter box, etc.); dry high-efficiency filtration technology, wet filtration technology (Venturi, cyclone tower, etc.), electrostatic filtration technology.