Degradation Of Toluene By Flow Reversal Plasma Reaction System

As a typical VOCs,toluene was chosen to be treated in this study.Heat distribution and the effects of parameters on degradation of toluene were investigated by combining non-thermal plasma with reverse-flow technology.The effects of reverse-flow technology on degradation of toluene was studied on empty reaction tube and non-thermal plasma combined with catalyst.The foundation was layed for the industial application of non-thermal plasma.The effects of discharge parameters of electrical field intensity and frequency,as well as operating parameters of cyclic period,grounding pole number,gas velocity on temperature rise??T?and discharge energy density?SED?were investigated.The results showed that the highest?T and SED could be obtained when cyclic period was 8min,field intensity was13.1kV/cm,frequency was 150Hz,grounding pole number was 7 and gas velocity was 14cm/s,which could reach approximately 187.3?and 284.4J/L,respectively.The temperature of discharge area was the highest,while that of the outlet was the lowest.In the discharge area,?T increased gradually with time.The temperature varied periodically with the cyclic period in the heat storage segment,whose change cycle was consistent with the period of reaction system.The?T?SED increased with electrical field intensity,frequency and grounding pole number increasing,but the?T?SED decreased with gas velocity increasing.The same trend was shown in the?T and SED,which indicated that the higher temperature,the more energy being injected into the reactor.The effects of flow reversal plasma reaction system on the performance of degradation of toluene were also investigated.The effects of diacharge parameters and operating parameters on temperature rise,removal amount,diacharge energy density and energy efficiency were discussed.The results showed that?1?temperature rise,degradation of toluene,removal amount and discharge energy density increased with electrical field intensity,frequency,grounding pole number increasing.Energy efficiency increased firstly and then decreased with electrical field intensity and frequency increasing.Energy efficiency decreased with grounding pole number increasing.?2?Degradation of toluene,removal amount,temperature rise,discharge energy density decreased and energy efficiency slightly increased with cyclic period.?3?Degradation of toluene,temperature rise,discharge energy density declined and removal amount,energy efficiency rised as gas velocity increasing.?4?Degradation of toluene,temperature rise,discharge energy density presented the downward trend and removal amount,energy efficiency presented the upward trend as the inicial concentration of toluene increasing.The influences of electrical field indensity and frequency on degradation of toluene was discussed while using flow reversal plasma reaction system in empty air tube and co-catalysts,mainly on degradation of toluene,removal amount,discharge energy density and energy efficiency,as well as the generation of O₃.Finally,the gasous byproduct was analysed by FT-IR and GC-MS.The results showed that flow reversal plasma was beneficial to degredation of toluene and removal amount.Under the same experimental conditions,flow reversal plasma could improve discharge energy density and be benefit for energy efficiency when the electrical field density was low.The concentration of O₃ decreased significantly by using reverse-flow process,which greatly improved the ability of decomposing O₃.Flow reversal plasma reaction system could not only improve the ability of decomposing O₃,but also contribute to the degradation of toluene and reduce the generation of byproducts.