The catalytic oxidative coupling of methane to higher hydrocarbons (OCM) is an alternative route for production of ethylene or liquid fuels and has obtained much attention in the past. In this article the process design of reactor concepts and the gas treatment of the product gas are discussed. In addition to the reaction engineering and thermal separation engineering aspects, the consideration of safety issues is included. In a case study, the OCM process is developed on a mini-plant scale and first, preliminary experimental results are shown. The results of the accompanying safety study based on a HAZOP analysis are discussed for the whole OCM process. The energy savings by implementation of a hybrid separation process based on a membrane separation module and an absorption process for the CO2 removal from the OCM product is presented and validated experimentally on a mini-plant scale.