Selective conversion of methane to synthetic fuels using dielectric barrier discharge contacting liquid film
Selective conversion of methane to synthetic fuels using dielectric barrier discharge contacting liquid film
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DOI：
10.1088/0022-3727/44/27/274010
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发表时间：
2011-07
期刊：
影响因子：
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通讯作者：
T. Nozaki;V. Goujard;S. Yuzawa;Shota Moriyama;A. Ağıral;K. Okazaki
中科院分区：
文献类型：
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作者：
T. Nozaki;V. Goujard;S. Yuzawa;Shota Moriyama;A. Ağıral;K. Okazaki
研究了低温等离子体微反应器中甲烷一步部分氧化制甲醇的反应机理。当甲烷在室温（约5 °C）下部分氧化时，会产生大量的过氧化氢（H2 O2）和甲基氢过氧化物（CH 3 OOH）。已知CH 3 OOH是不完全甲烷氧化产物如CH 3OH和HCHO的主要中间体，但迄今为止尚未通过实验证明。H2 O2促进冷凝的等离子体合成液体中的含氧化合物的等离子体后氧化。在液相氧化的早期阶段，H2 O2优先将HCHO氧化成HCOOH，随后，HCOOH被完全氧化成CO2和H2O。取决于含氧化合物和H2 O2的浓度，等离子体溶液的电导率显著增加，这间接地影响等离子体性质。从实用的角度出发，对甲烷空气部分氧化反应进行了研究。活性氮物种（ANS）的产生是在氧存在下促进整体甲烷转化的关键;然而，脆弱的含氧化合物也被ANS分解，因此在氮存在下对有用的含氧化合物的选择性降低。当氧气被完全消耗时，CH 4转化也终止，水煤气变换反应（CO + H2O = CO2 + H2）成为主导。
This paper presents the reaction mechanism of single-step methane partial oxidation to methanol at room temperature using non-thermal plasma microreactor. Macroscopic quantities of hydrogen peroxide (H2O2) and methyl hydroperoxide (CH3OOH) are produced when methane is partially oxidized at room temperature (about 5 °C). CH3OOH is known to be the principle intermediate of incomplete methane oxidation product such as CH3OH and HCHO, but has not been demonstrated experimentally so far. H2O2 promotes post-plasma oxidation of oxygenates in the condensed plasma-synthesized liquid. At an early stage of in-liquid oxidation, H2O2 oxidizes HCHO into HCOOH preferentially; subsequently, HCOOH is fully oxidized to CO2 and H2O. Depending upon the concentration of oxygenates and H2O2, electrical conductivity of the plasma solution dramatically increased, which detrimentally influences plasma properties. Methane partial oxidation with air was also investigated from a practical viewpoint. Generation of active nitrogen species (ANS) is the key to promoting overall methane conversion in the presence of oxygen; however, fragile oxygenates were also decomposed by ANS, thus selectivity for useful oxygenates was degraded in the presence of nitrogen. When oxygen is fully consumed, CH4 conversion is also terminated and water gas shift reaction (CO + H2O = CO2 + H2) becomes predominant.