SELECTIVE OXIDATION OF METHANE TO METHANOL AT HIGH-PRESSURES

Direct conversion of natural gas to liquid products has been under investigation for most of this century, but no commercial processes are practiced to date. The partial oxidation of methane to methanol would be a particularly attractive option of natural gas upgrading, provided yields in excess of 10% can be achieved. A large number of studies have been published on the subject over the past 70 years, but yields are in general low and more promising results difficult to reproduce. This work focused on the homogenous gas phase partial oxidation of methane to oxygenates in the temperature range 300-500-degrees-C and at pressures of 3-6 MPa and compared the experimental results with model calculations. The most important parameters controlling selectivities and yields were identified as the temperature in the reaction zone and the reactor geometry. The best methanol yield achieved in our study was 1.8 mol %. Innovative reactor design may result in significantly higher methanol yields than have been achieved to date.