An experimental study on discharge characteristics in a pulsed-dc atmospheric pressure CH3OH/Ar plasma jet.

Recently, C/H/Ar plasma discharges found enormous potential and possibility in carbonaceous compounds conversion and production. In this work, a pulsed-dc CH₃OH/Ar plasma jet generated at atmospheric pressure is investigated by means of optical and electrical diagnosis concerning the variation of its basic parameters, absolute concentration of OH radicals, and plasma temperature with different CH₃OH/Ar volume ratios, in the core region of discharge with needle-to-ring electrode configuration. The voltage–current characteristics are also measured at different CH₃OH/Ar ratios. Laser-induced fluorescence (LIF) results here show that only small amounts of added methanol vapor to argon plasma (about 0.05% CH₃OH/Ar volume ratio) is favorable for the production of OH radicals. The optical emission lines of CH, CN, and C₂ radicals have been detected in the CH₃OH/Ar plasma. And, the plasma temperatures increase with successive amount of added methanol vapor to the growth plasma. Moreover, qualitative discussions are presented regarding the mechanisms for methanol dissociation and effect of the CH₃OH component on the Ar plasma discharge at atmospheric pressure. [ABSTRACT FROM AUTHOR]