Oxidative coupling of methane (OCM) is a promising route for the production of ethylene by using natural gas. However, an industrial implementation still remains in its very early stage with the main efforts focused on the search for a sufficiently selective, active, and stable catalyst. During the OCM reaction, CO2 is formed as unwanted by-product and has to be separated in the downstream process. This affects the efficiency of the overall process significantly. For this purpose, an integrated gas treatment process for the CO2 capture in a mini plant scale has been built.