A novel autothermal reactor concept for thermal coupling of the exothermic oxidative coupling and endothermic steam reforming of methane

A novel reactor concept with autothermal operation is presented for the simultaneous production of ethylene by oxidative coupling (OCM) and synthesis gas by steam reforming of methane (SRM). A detailed reactor model was developed and used to gain insight in the complex behavior of the reactor comprising two seperate reaction chambers which are thermally coupled. The OCM is carried out in packed bed reverse flow membrane reactor tubes submerged into a fluidized bed where the unconverted methane and by-products, from which the valuable C2 (C2H2 and C2H6) components have been separated, are reformed together with some additional steam, thus producing sythesis gas and consuming the reaction heat liberated by the ecothermic OCM. On basis of detailed simulations it has been shown that indeed the exothermic OCM and endothermic SRM can be very efficiently coupled permitting autothermal operation with cyclic steady state C2 yields up to 30% at full methane conversion with a CH4/O2 molar ratio of 2-2.5 and a H2O/CH4 molar ratio of 3 in the SRM fluidized bed reactor.