Applied Study On Thermal Plasma Technology For Removal Of Organic Waste Gas

Basing on the organic waste gases are harmful to people and cause of trouble, and but the traditional processing methods have many shortcomings and problems, so that it is difficult to meet current environment standards. Plasma technology is considered to be an effective approach to dealing with organic waste gas, of which the study of treating organic waste gases with thermal plasma is less. In this research, using high frequency coupling capacitance plasma technology in experimental study and the DC arc plasma technology in practical engineering case. And they both are thermal plasma technology. With methane and toluene as the research object in the experiment, getting the effect of degrading organic waste gas by thermal plasma, analyzing the degrading products and its variation with time and providing certain theoretical reference for application in industry. In practical engineering, with a resin production workshop exhaust gas treatment in Foshan as an example, using the DC arc plasma technology to obtain the actual treatment effect in the waste gas treating engineering, verify whether the thermal plasma technology can effectively degrade organic waste gas, and calculate and analyze the operation cost. This research designed a set of high frequency capacitive coupling plasma reaction device by combining with plasma generator and plasma power supply. With the high frequency capacitive coupling plasma from reactor as heat source and methane and toluene as the research object, discussing the effect of the input power, the system pressure, gas flow, electrode spacing and catalyst to methane and toluene removal rate. And exploring the concentration changing rule of reaction products CO, CO2, NO and NO2 with the input power and catalyst. The basic principle of response is to produce a large number of high energy electron by thermal plasma discharge and they will produce active particles, such as O3, OH, O and H*, by colliding with O2, H2 O and N2. And active particles and high energy electron will have a oxidation and degradation with organic waste gases to degrade organic waste gas to CO, CO2 and H2 O.The experimental results show that with increasing of input power, the removal rate of methane and toluene rise. The removal rate of methane is higher relatively than toluene, and that has a relationship with the stable structure of toluene ring. For effect of the system pressure and gas flow on the removal rate of methane, with the increase of system pressure and gas flow presented a reduction trend. With the increase of electrode gap, made the electric field intensity between two electrodes, energy density and removal rate abate. When the input power is 40 W, electrode spacing is 3cm, 6cm and 9cm respectively, the removal rate of methane were 82%, 65% and 52%. After placing the catalyst between two electrodes, the removal rate increase more rapidly when input power is low. With the increase of power, the gap will be smaller.After adding catalyst in the reactor, the reaction product concentration of CO2,CO and NO did not to keep a constant value, but it reached the peak in 3 minutes. and then began to fall, the reaction reached basically a steady state after lasting 30 minutes. That is mainly because Al2O3 can absorb processing waste gas at the beginning of the reaction. The increase of organic waste gas concentration increase concentration of the reaction products. As the reaction progress, the exhaust gas absorbed on the Al2O3 was broken down and the reaction tended to be stable. In the quantitative analysis of the reaction product, it was easy to be found that with the increase of input power CO2 concentration increase. With the increase of input power, the concentration of CO began to reduce slowly after mild growth. The reason is that with the increase of the input energy, pert of the CO will be oxidized as to CO2.Taking treatment of organic waste gas in a Foshan resin production workshop as an example, using DC arc plasma technology to deal with organic. The results show that after the exhaust gas was dealt by reactor, the product, such as CO2 and H2 O, is harmless and won't cause pollution to the environment. And the average toluene removal rate reaches 95.7% and the average total hydrocarbon VOCs removal rate reaches 93.1%. Adopting two cases of regenerative plasma reactor with high heat storage function, the regenerator transfer heat with VOCs waste gas and flue gas directly to make full recovery of waste heat of combustion product. And the heat transfer speed is fast and the thermal efficiency is high particularly. And exhaust temperature is below 150? and energy-saving effect is remarkable. After the system put into operation, the operation cost is about 15800 yuan and the daily average is 433 yuan. The operation cost is low.