REACTION-ENGINEERING STUDIES IN A POLYTROPIC FIXED-BED REACTOR OVER AHIGHLY-ACTIVE AND SELECTIVE CATALYST FOR OXIDATIVE METHANE COUPLING

The oxidative coupling of methane (OCM) was carried out in a polytropi c fixed-bed reactor applying a Zr/La/Sr catalyst developed by the Nest e company. Over this catalyst the OCM reaction follows a complex react ion scheme which includes primary parallel reaction steps to CO, CO2 a nd C2H6 and consecutive reactions of ethane to ethylene or COx. Yield of higher hydrocarbons C2+ Obtained with this catalyst strongly depend ed on reaction conditions, i.e. low partial pressures of methane and o xygen obtained by diluting the feed gas with nitrogen and high reactio n temperatures promoted C2+ selectivity and yield. The maximum yield a mounted to 21.4% (20 Vol-% CH4, 9 Vol-% O-2, 71 Vol-% N-2, T = 860 deg rees C; X(CH4) = 41.8%, SC2+, = 52.5%). This result belongs To the hig hest yields reported in the open literature.(1)).