| Decomposition of H2S and CH4 in Pulsed Corona Discharge Reactors | ||
| Sanil John1, Gui-Bing Zhao1, Ji-Jun Zhang1, Linna Wang1, Suresh S. Muknahallipatna2, Jerry C. Hamann2, John F. Ackerman1, Morris D. Argyle1 and Ovid A. Plumb3, (1)Department of Chemical & Petroleum Engineering, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, (2)Department of Electrical & Computer Engineering, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, (3)College of Engineering, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071
Decomposition of H2S and CH4 in Pulsed Corona Discharge Reactors Natural gas typically contains 70-90% methane (CH4) and 0-5% hydrogen sulfide (H2S). The conversion of CH4 to hydrogen and more valuable hydrocarbons, like ethylene, is of great importance to the petrochemical industry. Direct decomposition of H2S to yield hydrogen and sulfur is desirable compared to the conventional Claus process, which converts H2S into sulfur and water. CH4 and H2S have been separately decomposed in our experiments in a wire-in-tube pulsed corona discharge reactor. The pulsed corona discharge is a good source for generating chemically active species at room temperature, which initiate chemical reactions leading to CH4 and H2S conversion. A corona discharge was achieved with our present reactor configuration after pure H2S was diluted with argon. The effects of charge voltage, capacitance and frequency on reaction rate and energy efficiency were studied for different concentrations of H2S in argon. At constant power input (100 W), low capacitance (720 pF) operation gave the highest conversion and lowest energy consumption for H2S decomposition. The effect of mixed argon-nitrogen diluents on H2S conversion is being studied. The effect of capacitance, cathode material, gas flow rate and specific energy input on conversion, energy efficiency, and product selectivity on CH4 decomposition was also studied. 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 (1280 pF) with high pulse frequency (1000 Hz) results in higher CH4 conversion and energy efficiency than operation at high capacitance (1920 pF) with low pulse frequency (200 Hz). Platinum coated stainless steel cathodes slightly enhance CH4 conversion relative to stainless steel cathodes, perhaps due to a weak catalytic effect. As specific energy input increases, energy efficiency for CH4 conversion goes through a minimum, while the selectivity of acetylene has a maximum value.
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