PARTIAL OXIDATION OF ETHANE AND ETHYLENE IN THE PRESENCE AND ABSENCE OF C-13-LABELED METHANE ON REDUCIBLE AND NONREDUCIBLE OXIDE CATALYSTS

Ethane and ethylene were partially oxidized in the presence and absenc e of C-13-labeled methane and catalyst to determine the relative react ivity of ethane and ethylene compared to methane. The relative reactiv ities are in the order of ethylene > ethane >> methane for reactions i n the gas phase (empty reactor) and on catalysts containing reducible oxides of transition metals such as Ca/Ni/K. However, this order chang ed to ethane > ethylene >> methane for a nonreducible catalyst, such a s sodium-promoted Sm2O3. The results also showed that in the presence of methane and catalysts ethane and ethylene, depending on their parti al pressures, compete for active species in the gas phase and active c enters on the catalyst. The effects of pressure, temperature, and cont act time on partial oxidation of ethane and ethylene were investigated in an empty alumina reactor. It was found that the temperatures at wh ich 50% of oxygen converted (at steady state) during partial oxidation of ethane and ethylene were significantly less than the temperature a t which 50% oxygen converted during partial oxidation of methane. The higher reactivity of products compared to the reactant appeared to be a major factor preventing achievement of the yield required for an eco nomical process to convert natural gas to liquid fuels.