Abstract: A non-cryogenic system for gas separation includes an absorbent system for removing condensable hydrocarbons from a feed gas. The feed gas is then directed into a gas-separation membrane. The absorbent system includes a liquid absorbent having an affinity for hydrocarbons. The liquid absorbent can be, for example, compressor oil or mineral oil. A chiller and a carbon bed may optionally be positioned between the absorbent system and the membrane. The absorbent is periodically regenerated by reducing the pressure or increasing the temperature of the liquid.

Abstract: An air dehydration membrane module is provided with a sweep gas which is taken from the waste gas of a pressure swing adsorption (PSA) unit. No additional compressor is required, other than the compressor forming part of the PSA unit. In another embodiment, the sweep gas includes the combination of dried product gas, taken from the dehydration membrane module, and a supplemental gas, which may be ambient air, or permeate gas from an air separation membrane, or waste gas from a PSA unit. An air ejector combines the streams, without the use of an additional compression step, and the combined gas is used as a sweep stream for the dehydration module. The invention also includes the method of selecting an optimum point at which the sweep gas is injected into the module.