Conversion of ethane and of propane to higher olefin hydrocarbons. Quarterly report, July 1--September 30, 1991

Purely thermal reactions for the conversion of ethane were carried out in an empty and in a quartz chip filled reactor over a temperature range of 300--800{degrees}C in the absence and presence of oxygen and oxygen plus water. Ethane alone shows no conversion below 600{degrees}C and some conversion to CH{sub 4} and very little C{sub 2}H{sub 4} at 700{degrees} and 800{degrees}C. Ethane and oxygen produce CO{sub 2} as the major product above 400{degrees}C. The additional presence of water does not appreciably change this picture. Converting ethane with oxygen and water over a Ca{sub 3}Ni{sub 1}K{sub 0.1} catalyst at very low space velocity gave increasing conversion with temperature, primarily CO{sub 2} production and a small amount of C{sub 3+} hydrocarbons. The CO{sub 2} production was decreased and slightly more C{sub 3} hydrocarbons were produced when the potassium concentration of the catalyst was increased. Activation energies have been calculated for the various ethane conversion reactions. It appears that the CaNiK oxide catalyst is not suited for oxidative ethane coupling at the conditions thus far investigated. The indications are that much shorter contact times are required to prevent oxidation of intermediates. Blank runs with propane and oxygen in the absence of a catalyst have shown significant reaction at temperatures as low as 400{degrees}C. 12 figs., 3 tabs.