Partial oxidation of methane using a microscale non-equilibrium plasma reactor
Partial oxidation of methane using a microscale non-equilibrium plasma reactor
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DOI：
10.1016/j.cattod.2004.09.053
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发表时间：
2004-12-14
期刊：
影响因子：
5.3
通讯作者：
Okazaki, K
中科院分区：
文献类型：
--
作者：
Nozaki, T;Hattori, A;Okazaki, K
研制了一种流动型、微尺度、非平衡等离子体反应器，用于无催化剂甲烷的部分氧化。由于微尺度等离子体反应器可去除部分氧化产生的多余热量，从而将反应场维持在接近室温的温度，因此可直接处理各种氧和甲烷混合物，而不会在室温下发生稀释或爆炸。因此，最不活跃的甲烷被高能电子激发，而在极端受限的环境中，活性氧合物的连续破坏同时被最小化。因此，在单个反应器内获得了高度反应性和猝灭性的环境：这些是传统热化学过程中的矛盾条件。液态氧化合物的主要产物是甲醇，在甲烷转化率为30%时，甲醇的选择性达到34%。氧合物如甲醇和甲醛的选择性在很大程度上取决于电子冲击下甲烷解离的破碎模式。当外加电场对应于甲烷的击穿场(80 Td, 1 Td = 10（-17) V cm(2)）时，含氧化合物的最大选择性达到60%。放电电流随外加电场的增大而显著增大，但氧合物的选择性随外加电场的增大而降低。(C) 2004 Elsevier B.V.版权所有
A flow-type, microscale, non-equilibrium plasma reactor was developed for partial oxidation of methane without a catalyst. A wide range of oxygen and methane mixtures was directly processed without dilution or explosion at ambient temperature because the microscale plasma reactor removes excess heat generated by partial oxidation, thereby maintaining a reaction field at temperatures near room temperature. Consequently, the least reactive methane was excited by high-energy electrons, whereas successive destruction of reactive oxygenates was minimized simultaneously within the extremely confined environment. A highly reactive and quenching environment is thereby obtained within a single reactor: these are paradoxical conditions in conventional thermochemical processes. A major product among liquid oxygenates was methanol, whose selectivity reached 34% at 30% of methane conversion. Selectivity of oxygenates such as methanol and formaldehyde depends strongly on the fragmentation pattern of methane dissociation by electron impact. Maximum selectivity of oxygenates, which is estimated from numerical simulation of a filamentary microdischarge, reaches 60% when the applied electric field corresponds to the breakdown field of methane (80 Td, 1 Td = 10(-17) V cm(2)). The discharge current increases markedly with an applied electric field, but the selectivity of oxygenates decreases as the field strength increases. (C) 2004 Elsevier B.V. All rights reserved.