Process and apparatus for pressure swing adsorption

TLDR: In this paper, a partial countercurrent pressure reduction prior to the conventional countercurrent release is used to release void volume gas from the main adsorber bed to an auxiliary bed, which can simultaneously release gas at its outlet end.

Abstract: The bed utilisation and the product yield, especially in pressure swing adsorption processes designed for high pressure applications, are improved in that the cocurrent pressure reduction is ended at a relatively high intermediate pressure level. Additional void volume gas is liberated from each main adsorber bed by partial countercurrent pressure reduction prior to the conventional countercurrent release. This additional gas is passed to an auxiliary bed, which can simultaneously release gas at its outlet end, as a result of which the auxiliary bed is depressurised by the intermediate pressure level in the cocurrent flow. The gas released in this manner is passed to the outlet end of one or more auxiliary beds and/or one or more main beds for pressure equalisation and/or flushing purposes. The auxiliary bed belongs to an adsorber bed auxiliary group, which includes fewer and smaller beds than the main bed system. The auxiliary beds are not subjected to a higher pressure than the intermediate pressure level.