Plasma chemical reactions at atmospheric pressure for high efficiency use of hydrocarbon fuels
Plasma chemical reactions at atmospheric pressure for high efficiency use of hydrocarbon fuels
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大气压下的等离子体化学反应可高效利用碳氢化合物燃料
DOI：
10.1016/s0360-5442(96)00129-6
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发表时间：
1997
期刊：
影响因子：
9
通讯作者：
K. Hijikata
中科院分区：
文献类型：
--
作者：
K. Okazaki;S. Hirai;T. Nozaki;K. Ogawa;K. Hijikata
甲烷直接转化为甲醇的最低能耗技术可以利用和再生低质量或低温（100°C）的能源，是高效利用化石燃料的关键技术。为此，一种新的技术，用于直接合成甲醇从甲烷-氧气的混合物已开发使用高度非平衡，方脉冲，无声放电等离子体在大气压和温度。研究了氧气浓度、反应时间和放电参数对转化效率和反应选择性的影响。这种类型的等离子体的反应机制已被阐明，通过使用随时间变化的光发射测量CH自由基在流光电流周期后，一个尖锐的，脉冲电压上升。在单程实验中，甲醇收率和选择性分别达到2.4%和32.6%。通过优化反应条件、将该技术与催化反应相结合以及引入循环反应系统，可以提高这些价值。对脉冲电压陡升后高能粒子的形成过程进行了理论分析。实验数据与理论预测吻合良好。
Direct conversion of methane to methanol with minimum energy consumption could become a key technology for highly efficient utilization of fossil fuel, because low-quality or low-temperature (∼100°C) energy sources can be used and regenerated by converting methanol to hydrogen. For this purpose, a new technique for synthesizing methanol directly from a methane-oxygen mixture has been developed using a highly nonequilibrium, square-pulsed, silent discharge plasma at atmospheric pressure and temperature. Various effects of oxygen concentration, reaction time and discharge parameters on the conversion efficiency and reaction selectivity have been clarified. Reaction mechanisms for this type of plasma have been elucidated by using time-dependent optical emission measurements of CH radicals during the streamer current period just after a sharp, pulsed voltage rise. High values of 2.4 % and 32.6 % for methanol yield and selectivity, respectively, have been successfully obtained in a single-path experiment. These values may be enhanced by optimizing the reacting conditions, combining this technique with catalytic reactions, and introducing a recirculating reaction system. The formation processes for high-energy species just after the sharp, pulsed voltage rise were also analyzed theoretically. Good agreement was found between the experimental data and theoretical predictions.