Removal of gas phase dimethylamine and N,N-dimethylformamide using non-thermal plasma

Abstract

Dimethylamine (DMA) and N,N-dimethylformamide (DMF) are typical N-VOCs exhausted from manufacturing factories. In the present study, the behavior of non-thermal plasma (NTP) was systematically investigated for removal of gas-phase DMA and DMF in a link tooth wheel-cylinder plasma reactor. Experimental results show that DMA is much easier to be decomposed by NTP than DMF. On the other hand, coexisting DMF has no effect on DMA conversion while DMF conversion is significantly promoted by the addition of DMA. It is also found that regardless of initial gas compositions as well as DMA and DMF concentration, COx selectivity increased monotonously with increasing ED. But COx selectivity of 100% cannot be obtained even with ED higher than 70JL−1, indicating the formation of organic intermediates during DMA and DMF decomposition. Based on organic products analysis with GC–MS and molecule optimization results with density functional theory calculation, possible mechanisms on DMA and DMF degradation were proposed. On the other hand, the organic products from DMA and DMF decomposition by NTP were found to have great solubility and high biodegradability. Thus, NTP enhanced absorption/biological method is suggested for complete removal of DMA and DMF.