DBD降解氮中甲苯气体产生的二次有机副产物检测

为了研究低温等离子体降解有机废气过程中产生的二次有机副产物的形成机理及其影响因素,以介质阻挡放电(DBD)产生的低温等离子体降解氮中甲苯气体为研究对象,利用质子转移反应飞行时间质谱仪(PTR-TOF-MS)实时在线检测降解尾气中有机副产物的成分及其浓度,分析了二次有机副产物形成的机理,探讨了影响二次有机副产物生成的关键因素.研究发现,氮中甲苯低温等离子体降解尾气中主要的有机副产物为HCN和CH3CN,其浓度与待降解甲苯的平均可资用能有关.由平均可资用能的测试分析可知,在DBD有机物降解装置、电源输入功率、降解气体流量等参数确定的情况下,待降解有机物存在一个浓度极值,大于该浓度极值将使得降解尾气中有机副产物的浓度明显增加.在低温等离子体降解装置参数确定的情况下,控制待降解有机物的浓度是减少有副产物产生的有效手段和方法.

Detection of the secondary organic byproduct produced from toluene in decomposition of nitrogen by DBD

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.