Single Step Oxidation of Methane to Methanol–Towards Better Understanding

The potential use of methanol as a fuel is well known. Many research scientists are working on single stage production of methanol. Currently it is being produced by a conventional two-step process which is expensive and energy intensive. Conversion of methane to a liquid fuel is a more desirable alternative to compressed natural gas due to ease of storage. The two-step process produces liquid methanol by the steam reforming of methane to synthesis gas followed by the high pressure catalytic conversion of the synthesis gas to methanol.Partial oxidation route offers the advantage of directly converting methane to methanol in a single step reaction. An economically feasible one step process could significantly reduce cost of methanol production cost saving millions of dollars. The methanol thus obtained from methane is in an energy form that is much easier to transport and is more efficient fuel. This would make methane a much more attractive and valuable energy source. Because of increasing demands for energy and environmental protection, the two-step process which includes energy intensive syngas manufacturing is incompatible; here the partial oxidation of methane through the direct synthesis of methanol has been a field of extensive research work for many decades. Nevertheless, yields of organic oxygenates are generally quite low. The methanol yield is generally no more than 5%. This article discusses about thermodynamic feasibility of reaction of direct oxidation of methane. Even thermodynamic analysis shows that at lower temperature signle step process is more favourable over two step reforming process. However, side reactions and poor selectivity possess major challenge. Even after referred first time in 1902, still it poses a major challenge for researchers. This article also describes the work already done and recent advancements in the single-step oxidation of methane to methanol to enhance selectivity of methanol.