SINGLE STEP CATALYTIC CONVERSION OF METHANE TO METHANOL AND FORMALDEHYDE

Abstract

Very large reserves of the methane, which often are found in remote regions, could serve as a feedstock for the production of chemicals and as a source of energy in the 21st century. Methane currently is being used in such important applications as the heating of homes and the generation of the hydrogen for ammonia synthesis. Methanol and formaldehyde can be formed from methane, either by conventional method or by new approach, each alternative has its own set of limitations. Economical separation problem is common to all approaches. The world consumption of methanol and formaldehyde is growing continuously. It indicates the importance of these chemicals in the bulk chemical market. The yield and selectivity of formaldehyde are very important. The process economies depend on the conversion of methane and formaldehyde selectivity. In the present work an approach for the development of more effective catalysts for methane (natural gas) partial oxidation to methanol and formaldehyde is outlined and results are discussed. The approach involves identifying suitable metal oxide catalyst components, which activate methane and oxygen to get the desired product. A series of catalysts based on V205 and Mo03 along with oxides of Fe, Cu, Cr and Zn supported by Si02 and A1203 were prepared by wet impregnation method. In general, none of the prepared catalysts gave methanol at atmospheric pressure reaction conditions. V205/Si02, Mo03/S i02 and silica were the only catalysts, which produced formaldehyde. The catalytic activity tests were performed in a fixed-bed continuous flow micro-reactor. The analyses of the reactant and product streams were done using an on-line gas chromatograph. The objective of the present work was to identify suitable catalysts which could convert methane directly into formaldehyde and methanol (in a single-step) at ambient pressure and low temperature conditions.