Abstract：To study the formation mechanism and influencing factors of secondary organic byproducts produced in the process of decomposition of organic waste gas by non-thermal plasma, the organic by-products compositions and concentration from the toluene in the decomposition of nitrogen by non-thermal plasma produced by dielectric barrier discharge (DBD) was detected using real-time online proton transfer reaction time of flight mass spectrometer (PTR-TOF- MS). Further, the formation mechanism of secondary organic byproducts was analyzed and the key factors that affect the generation of secondary organic byproducts were discussed. HCN and CH3CN were the main organic byproducts, and their concentrations of the secondary organic byproducts were related to the mean available energy (J/mol) in the process of decomposition of toluene by non-thermal plasma. Based on the analysis and the test of the mean available energy, the concentration of organic matter had an extreme value under the condition of constant parameters of DBD device, power input, and gas flow rate, and the concentration of organic byproducts would be remarkably increased if the concentration of organic matter exceeded the extreme value. Research showed that the most effective method of reducing organic byproducts under constant parameters of non-thermal plasma device was to control the concentration of organic matter.
