| abstract |
A pressure swing adsorption (PSA) dryer for separating water and carbon dioxide from a gas stream includes two compound adsorbent columns [32, 42]. Each column comprises a primary adsorption material for adsorbing water and a secondary adsorbent that adsorbs carbon dioxide. The secondary adsorbent comprises a solid amine. The secondary adsorbent may be, for example, a highly porous polystyrene matrix with amine groups bonded to the porous resin structure. Preferably, a mixture of the primary and secondary adsorbent materials forms an intermediate layer [38, 48] sandwiched between a top layer [34, 44] and bottom layer [36, 46] of pure water adsorbent material in each of the columns [32, 42]. |