Partial oxidation of alkanes to oxygenates in supercritical carbon dioxide

The catalytic partial oxidation of propane in supercritical carbon dioxide has been investigated in a stirred batch reactor. Various metals (oxides) have been used as supported catalysts with respect to their activity and selectivity for the formation of oxygenates. The reactions run with a 1:2.3-2.9:68-108 molar ratio of propane:synthetic air:CO2 at 453-573 K and 80-100 bar. Using a precipitated 2.4 wt.% Co3O4-SiO2 catalyst at 573 K, a total oxygenate (i.e. acetic acid, acetone, acetaldehyde, methanol) selectivity of 59% and a propene selectivity of 21% were obtained at a propane conversion of 12 mol%. The same catalyst has been used to investigate the influence of the supercritical conditions and initial feed composition on the reaction, varying the density of CO2 and the concentration of synthetic air, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.