Overall, China’s ecological environment quality continues to improve, showing a steady and positive trend, but the results are not stable, especially in the case of organic waste gas pollution. Owing to the complicated components of of industrial organic waste gas and various production techniques, it difficult to control the pollution. According to the rich experience of BME in the industrial waste gas control, various of treatment technologies need to be combined to control the organic waste gas effectively.
BME’s CND technique creatively solves the energy utilization efficiency problem during the hot gas desorption process. The recovery rate of volatile organic components is more than 95%, and there is no secondary water pollution. This technique is suitable for the control of organic pollutants with higher boiling point to improve economic returns. Besides, it is characterized by the features of low energy consumption, low operation cost, good safety performance and low explosion risk.
The integrated technology of BME is mainly catalytic oxidation and regenerative thermal oxidation combined with zeolite roller adsorption and concentration technology, and can removal different exhaust gases, including benzene, toluene, xylene, ethyl acetate, 2-butanone, butyl acetate, cyclohexanone, etc. The removal rate of VOCs reaches more than 99%.
Regenerative Thermal Oxidizer (RTO)
Working principle: the VOCs are oxidized into CO2 and H2O under high temperature to purify exhaust gas and recover the heat released by the decomposition of waste gas. The three-chamber RTO exhaust gas decomposition efficiency reaches more than 99%, and the heat recovery efficiency reaches more than 95%. The main structure of Regenerative Thermal Oxidizer is composed of combustor, heat storage chamber and switching valve, etc.
The high temperature gas after oxidization flows through specially designed ceramic regenerator and the heat is stored in it to preheat the subsequent VOCs and save the fuel consumption used to heat the exhaust gas. There are two or more ceramic regenerators, and each regenerator goes through the procedures of heat storage, heat release and cleaning successively and works continuously. The regenerator shall be immediately cleaned by introducing an appropriate amount of clean air (to ensure the VOC removal rate reaches more than 98%) after the “heat release”, and only after the cleaning is completed can the regenerator enter the "heat storage" process. Otherwise, the residual VOCs will be discharged into the chimney along with the flue gas to reduce the removal efficiency.
Regenerative Catalytic Oxidizer (RCO)
Working principle: The exhaust gas containing VOCs enters double halt regenerative oxidizer, and the three-way switchover air valve leads the exhaust gas into the heat storage halt for preheating. The polluted exhaust gas is gradually heated by the ceramic regenerator and then enters the catalyst bed. The ceramic regenerator is heated, and the clean gas after combustion and oxidation gradually reduces its temperature, so the outlet temperature is slightly higher than the inlet temperature of the RCO. The three-way switchover air valve switches to change the outlet/inlet temperature of the RCO. If VOCs concentration is high enough and enough heat is released, the regenerative catalytic oxidizer doesn’t need fuel. For example, when the heat recovery rate is above 95%, the outlet temperature of the RCO is only 25℃ higher than the inlet temperature.