Activation of methane in microwave plasmas at high pressure

Methane is converted to C2 products in a microwave plasma under pressure up to 400 torr at maximum plasma power of 100 W. Steam is introduced with met hane into the plasma zone in order to suppress coke formation. Major produc ts are C2 hydrocarbons. Small amounts of benzene are also formed. Very smal l amounts of some unusual highly unsaturated hydrocarbons are also formed. Oxygenated products are CO and CO2. The conversion and yields are related t o experimental variables by an empirical second order linear model. The con version of methane ranges from 10 to 60%. The yield of C2 products ranges f rom 5 to 68%. The major C2 product is acetylene.