Production of Methyl Radicals in Atmospheric Pressure Microreactors for Up-Conversion to High Values Hydrocarbons

Abstract

The on-site up-conversion of methane (CH 4 ) to higher value hydrocarbons is being investigated as a means to minimize the emission of global warming methane during oil production. One proposed method is production of methyl (CH 3 ) radials by a low temperature plasma, followed by reaction with organic metallic complexes in solution. Production of CH 3 radicals using dielectric barrier discharge (DBD) plasma microreactors is being computationally and experimentally investigated. A typical microreactor consists of a 500 μm gap etched on a Si substrate and covered with borosilicate glass as the dielectric. Nanosecond high voltage pulses of up to 10 kV operating at frequencies of 1-10 kHz were used to generate atmospheric pressure plasma in the feed gas consisting of mixtures of Ar and CH 4 . nonPDPSIM , a 2D plasma hydrodynamics model was used to simulate the plasma generation and subsequent plasma chemistry initiated by electron impact dissociation of CH 4 . The spatial and temporal evolution of CH 3 radicals will be discussed as a function of reactor geometry, gas mixture, and solvent location (e.g., along walls or in droplets). Although methyl radicals can be efficiently produced, there is also rapid formation of ethylene (C 2 H 6 ) in the gas phase. The location of CH 3 formation with respect to the solvent is therefore important in maximizing the solvation of the CH 3 radicals for further up-conversion.