A new type of activated carbon (mostly honeycomb carbon or fiber carbon) is used to absorb and concentrate the organic waste gas of low concentration. After the adsorption is nearly saturated, hot air is introduced to heat the activated carbon, so that the organic waste gas is desorbed and enters the catalytic combustion bed for flameless combustion purification treatment. The hot gas is recycled in the system or a secondary heat exchanger is added for heat recovery. In this method, low concentration organic waste gas is concentrated into high concentration organic waste gas through active carbon, and then purified thoroughly by catalytic combustion. This method absorbs the advantages of adsorption method and catalytic combustion method, and overcomes the disadvantages of their separate use. It is a mature and practical method for the treatment of organic waste gas in China at present.

Description of main technical principles

(1) Working principle of activated carbon:

After a period of time, when the activated carbon reaches the saturation state, the adsorption stops, and the organic matter has been concentrated in the activated carbon. Then, the saturated activated carbon is desorbed and regenerated by catalytic combustion and put into use again.

The organic mixed waste gas to be treated is treated by the induced draft fan, and the dust and impurities in the waste gas are removed by the pre-treatment filtration device first, or the micro pore of the activated carbon will be blocked by direct adsorption, thus affecting the adsorption effect and even invalidation. After preliminary filtration, the "relatively pure organic waste gas" will enter the adsorption device for adsorption purification treatment, and the organic matter will be specially treated by the activated carbon The clean gas is discharged into the atmosphere through the chimney. After a period of adsorption, the activated carbon reaches the saturation state. According to the PLC automatic control program, the saturated activated carbon bed and the activated carbon bed to be used after desorption are alternately switched. The CO \ CTO will automatically heat up and send the hot air to the activated carbon bed through the fan to heat up the carbon layer and "steam" the organics out of the activated carbon. The desorbed waste gas belongs to the organic waste gas with high concentration, small air volume and high temperature.

(2) Working principle of electrocatalytic oxidation eco \ CTO: voc-co \ CTO type organic gas catalytic purification device is a purification method that uses catalyst to oxidize and decompose combustible components in harmful gas at a lower temperature. For CnHm and organic dissolving steam, Co \ cto2 and H2O are produced and a lot of heat is released. The reaction equation is:

　　The main structure of the device is composed of three parts: purification device host, induced draft fan and control system. The purification device includes: fire retardant dust remover, heat exchanger, preheater and catalytic combustion chamber.

chart1　VOC-CO\CTOSchematic diagram

The organic waste gas with high concentration, small air volume and high temperature from the desorption of activated carbon enters the special plate heat exchanger after being filtered by the fire retardant dust remover to exchange energy indirectly with the high temperature gas after the catalytic reaction, at this time, the temperature of the waste gas source is increased for the first time; the gas with a certain temperature enters the preheater for the second time; and then it enters the first stage of catalyst At this time, the organic waste gas decomposes at low temperature and releases energy. The waste gas source is heated directly to raise the gas temperature to the optimal temperature of catalytic reaction. The temperature meets the temperature requirements of catalytic reaction through the detection of temperature detection system. The organic gas enters the catalytic combustion chamber and is completely decomposed and releases a lot of heat at the same time. The purified gas is passed through The superheater converts the heat energy into the cold air flow, and the air is discharged by the induced draft fan after cooling.

If the concentration of desorbed waste gas is high enough, the normal use of CO \ CTO requires little electric power or even no electric power heating, so as to achieve real energy saving and environmental protection. At the same time, the whole set of device is safe, reliable and free of any secondary pollution.