Methane conversion in pulsed corona discharge reactors

This work reports the effect of capacitance, cathode material, gas flow rate and specific energy input on methane conversion, energy efficiency and product selectivity in a co-axial cylinder pulsed corona discharge reactor. Ethane and acetylene appear to be formed from dimerization of CH3 radicals and CH radicals, respectively, while ethylene is formed mainly from the dehydrogenation of ethane. At a given power input, low capacitance with high pulse frequency results in higher methane conversion and energy efficiency than operation at high capacitance with low pulse frequency. Platinum coated stainless steel cathodes slightly enhance methane conversion relative to stainless steel cathodes, perhaps due to a weak catalytic effect. As specific energy input increases, energy efficiency for methane conversion goes through a minimum, while the selectivity of acetylene has a maximum value. Comparison of methane conversion for different types of plasma reactors shows that the pulsed corona discharge is a potential alternative method for low temperature methane conversion. (c) 2006 Elsevier B.V. All rights reserved.