Gas recovery method

A process for purifying a fluid, the process comprising the steps of:

• 1.1 Providing an insulated adsorption vessel (1) comprising an adsorptive media;
• 1.2 Providing a first fluid F1;
• 1.3 Cooling the insulated adsorption vessel (1) and/or cooling the first fluid, F1, to an operating temperature T1 in the range of from −40° C. to −130° C.;
• 1.4 Contacting the fluid F1 with the insulated adsorption vessel (1) to remove one or more impurities G1;
• 1.5 Collecting the resulting purified fluid F2;
• and
• 1.6 Regenerating the insulated adsorption vessel (1) by vacuum whilst maintaining the temperature of the vessel at a temperature in the range T1 to T1+50° C. (i.e. in the range +10° C. to −130° C.).