TAPERED PRESSURE SWING ADSORPTION COLUMNS FOR SIMULTANEOUS AIR PURIFICATION AND SOLVENT VAPOR RECOVERY

The performance of a tapered pressure swing adsorption (PSA) column is investigated on the basis of rigorous nonisothermal numerical modelin g, for simultaneous nitrogen purification and butane vapor recovery. T he results indicate that the tapered column improves the process perfo rmance when feeding from the wider end of the column and purging from the narrower end. An optimum taper angle (5 degrees) is also found for the constant length and volume system investigated with an order of m agnitude increase in the light product purity. The favorable effects a re manifested through complex temperature variations and corresponding local concentration wave velocity variations associated with heating and cooling effects that are caused by adsorption and desorption of th e butane vapor. The favorable effects of a tapered PSA column also imp rove as the heat effects become more pronounced.