Separation of ethylene from the effluent gas of oxidative coupling has been a challenging issue for several years. In a combined process of oxidative coupling and reforming of methane, reactive separation of ethylene via alkylation of benzene to ethylbenzene (EB) is a promising option. Ethylene was successfully converted to the useful chemical intermediate EB using ZSM-5. Yields of EB up to 90% were found at more than 95% conversion and more than 90% selectivity at 360 degrees C. Methane and ethane present in the feed were not converted and can be used for steam reforming in the proposed reaction concept. None of the additional components present in the effluent gas of oxidative coupling (CO, CO2, CH4, C2H6 and H2O) influences activity or selectivity of the alkylation catalyst. Stability of ZSM-5 is also not influenced by the added components, with the exception of water, which even increases stability. (C) 2009 Elsevier Ltd. All rights reserved.