Abstract: The present invention concerns the application of adsorption gas separation technologies to anaesthesia equipment and falls within the technical domains of adsorption separation units and medical devices. The invention concerns a device and processes for recovering xenon from gas mixtures released from anaesthesia gas machines (1) using xenon as anaesthetic. The purged xenon is collected using a system which includes a shift valve (6), and then separated and purified (38-40). The recycled xenon is then pressurised (31) and reintroduced in the anaesthesia circuit (48) using a shift valve (12). The separation and purification process combines different adsorption separation/purification technologies. The device is external to the anaesthesia gas machine and is compatible with any standard anaesthesia circuit able of perform xenon anaesthesia.