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 separate 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 C-2 (C2H4 and C2H6) components have been separated, are reformed together with some additional steam, thus producing synthesis gas and consuming the reaction heat liberated by the exothermic 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 C-2 yields up to 30% at full methane conversion with a CH4/O-2 molar ratio of 2-2.5 and a H2O/CH4 molar ratio of 3 in the SRM fluidized bed reactor. (C) 2012 Elsevier B.V. All rights reserved.