Abstract: A process for continuously separating the constituents of a mixture characterized in that it consists in introducing the gaseous mixture in an enclosure containing a selective adsorption agent or adsorbent, and subjecting the said mixture to a cyclical series of hot and cold steps induced by sudden variations of temperature between a temperature T.sub.c called the "hot temperature" and a temperature T.sub.F called the "cold temperature" in order to create in the cold steps three distinct zones moving in the flow-direction at different speeds:a zone of low-speed propagation comprising a sorption front in which the concentration of gas having the most adsorbable constituents decreases;a zone called the "thermal wave" induced at times determined by the sudden cooling of the load mixture;a desorption zone where the mixture is enriched in the most adsorbable constituents.