Efficient Synthesis of Ethanol and Acetic Acid from Methane and Carbon Dioxide with a Continuous, Stepwise Reactor

The synthesis of C(2)-oxygenates such as ethanol and acetic acid accomplished by CH(4) dissociation and subsequent CO(2) insertion onto methyl radicals, named the step-wise reaction technology, has been demonstrated to be both feasible and efficient through initial experiments conducted in microreactor units. This article describes the development of this technology, highlighting the aforementioned stepwise technology using a dual-reactor system, which can ensure that two raw gases enter the reactor uninterruptedly and are not mixed after reaction. The system productivity for acetic acid and ethanol displayed efficiencies greater than 5-10 times that of previous microreactor units. The investigation of mechanism indicates that acetic acid arises from insertion of CO(2) into M-CH(x), while ethanol is formed either by hydrogenation of acetic acid or by hydration of C(2)H(4), which results from homo-coupling of CH(4). The latter route is the preferred of the two. (C) 2009 American Institute of Chemical Engineers AIChE J, 56: 1279-1284, 2010