Abstract: An apparatus for separating or purifying gaseous material having more or less adsorbable components includes a high pressure inlet chamber, a high pressure outlet chamber and a low pressure chamber. Adsorbent means retain an adsorbent capable of selectively adsorbing the more adsorbable component at a predetermined pressure level. There are also means for establishing a high pressure flow path for the gaseous material from the high pressure inlet chamber through the adsorbent means to the high pressure outlet chamber. The more adsorbable component is adsorbable by the adsorbent in the high pressure flow path. Further means establish a low pressure desorption flow path from the adsorbent means to the low pressure chamber. The two means for establishing flow paths are operable simultaneously to continuously separate or purify the gaseous material. A process for separating or purifying gaseous material is also disclosed.