Microwave Plasma Conversion of Volatile Organic Compounds

Youngsam Ko, Gosu Yang, Daniel P.Y. Chang, Ian M. Kennedy
2003 Journal of the Air and Waste Management Association  
A microwave-induced, steam/Ar/O-2, plasma "torch" was operated at atmospheric pressure to determine the feasibility of destroying volatile organic compounds (VOCs) of concern. The plasma process can be coupled with adsorbent technology by providing steam as the fluid carrier for desorbing the VOCs from an adsorbent. Hence, N-2 can be excluded by using a relatively inexpensive carrier gas, and thermal formation of oxides of nitrogen (NO.) is avoided in the plasma. The objectives of the study
more » ... es of the study were to evaluate the technical feasibility of destroying VOCs from gas streams by using a commercially available microwave plasma torch and to examine whether significant byproducts were produced. Trichloroethene (TCE) and toluene (TOL) were added as eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. representative VOCs of interest to a flow that contained Ar as a carrier gas in addition to O-2 and steam. The O-2 was necessary to ensure that undesirable byproducts were not formed in the process. Microwave power applied at 500-600 W was found to be sufficient to achieve the destruction of the test compounds, down to the detection limits of the gas chromatograph that was used in the analysis. Samples of the postmicrowave gases were collected on sorbent tubes for the analysis of dioxins and other, byproducts. No hazardous byproducts were detected when sufficient O-2 was added to the flow. The destruction efficiency at a fixed microwave power improved with the addition of steam to the flow that passed through the torch. ABSTRACT A microwave-induced, steam/argon/oxygen, plasma "torch" was operated at atmospheric pressure to determine the feasibility of destroying volatile organic compounds (VOCs) of concern. The plasma process can be coupled with adsorbent technology by providing steam as the fluid carrier for desorbing the VOCs from an adsorbent. Hence, nitrogen can be excluded by using a relatively inexpensive carrier gas and thermal NOx formation is avoided in the plasma. The objectives of the study were to evaluate the technical feasibility of destroying VOCs from gas streams by using a commercially available microwave plasma torch and to examine whether significant byproducts were produced. Trichloroethene and toluene were added as representative VOCs of interest to a flow that contained argon as a carrier gas in addition to oxygen and steam. The oxygen was necessary to ensure that undesirable byproducts were not formed in the process. Microwave power applied at 500 W to 600 W was found to be sufficient to achieve the destruction of the test compounds, down to the detection limits of the gas chromatograph that was used in the analysis. Samples of the post microwave gases were collected on sorbent tubes for the analysis of dioxins and other byproducts. No hazardous byproducts were detected when sufficient oxygen was added to the flow. The destruction efficiency at a fixed microwave power improved with the addition of steam to the flow that passed through the torch.
doi:10.1080/10473289.2003.10466191 pmid:12774991 fatcat:yywkcsufpnfjbns4chtmpvvwna