MODIFIED DISPLACEMENT CHROMATOGRAPHY CYCLES FOR GAS SYSTEMS

Three displacement chromatography processes were experimentally studie d for gas mixtures. Process A is standard displacement chromatography applied to gases. Process B involves the column being initially satura ted with the most weakly adsorbed species in the feed instead of using a carrier gas. Process C uses the most strongly adsorbed component in the feed as the desorbent. Processes B and C are novel. The gas syste m studied consists of a 50%/50% methane/ethane feed mixture in Process es A and B and a 50%/30%/20% methane/ethane/propane feed mixture in Pr ocess C. Propane is used as the desorbent in all three processes. Hydr ogen or helium is used as the presaturant in Process A. The adsorbent used was zeolite 5A. Processes A, B, and C were all found to produce b ands of pure components when the appropriate feed time was used. The a mount of ethane input into the column was crucial to obtain good separ ations. A local equilibrium theory was developed and predictions from the theory were compared with experimental results.