Pressure swing adsorption heat recovery

Claim 1

In a pressure swing adsorption process for the separation of a more readily adsorbable component of a feed gas mixture containing said component and a less readily adsorbable component in an adsorption system including at least one adsorbent bed containing adsorbent material capable of selectively adsorbing said more readily adsorbable component, said process comprising a processing sequence carried out in each bed on a cyclic basis and including (1) introducing a feed gas mixture to the feed end of the bed at an upper adsorption pressure, and withdrawing the less readily adsorbable component from the opposite end of the bed; (2) decreasing the pressure of the bed to a lower desorption pressure, with release of more readily adsorbable component from the feed end of the bed; and (3) repressurizing the bed to said upper adsorption pressure, with the feed gas mixture being compressed to said upper adsorption pressure in a feed gas compressor prior to passage to the bed during step (1) thereof and being heated by the resulting heat of compression, with said heat of compression under cool ambient temperature conditions not being sufficient to achieve a desired adsorbent bed temperature, the improvement comprising (a) capturing waste heat generated in the adsorption system, or portions thereof, and (b) utilizing the captured waste heat to preheat the feed gas mixture passing to said feed gas compressor, the feed gas mixture passing to the bed at the upper adsorption pressure having been preheated by said captured waste heat and further said heat of compression, whereby the energy efficiency of the process is enhanced and such waste heat recovery enables the feed gas mixture to attain a higher temperature than would be attained upon compression of the feed gas mixture alone at under cool ambient temperature conditions, thereby enhancing the performance of the process.