A process for the adsorption of at least carbon dioxide, water and oxides of nitrogen and preferably acetylene from a feed gas, comprises contacting the feed gas with an adsorbent mixture of a zeolite and an alumina. The process may be operated as a swing adsorption process comprising contacting the gas with the adsorbent at a first temperature and pressure to adsorb at least carbon dioxide, water and oxides of nitrogen therefrom and periodically regenerating the adsorbent by reducing the pressure and or increasing the temperature to which the adsorbent is exposed.