DUAL REFLUX PRESSURE SWING ADSORPTION CYCLE FOR GAS SEPARATION AND PURIFICATION

摘要

A new dual reflux (DR) PSA cycle that combines the essential features of a conventional (stripping reflux) PSA cycle with those of a relatively new enriching reflux PSA cycle, is analyzed to show its potential for separating gas mixtures with a minimal expenditure of energy. Based on isothermal equilibrium theory applied to a binary linear isotherm system, the ultimate separation is carried out where the binary feed is separated into two pure components with 100% recovery of each. This idealized analysis reveals that such an ultimate separation is indeed possible over a wide range of conditions and most surprisingly with pressure ratios as low as 1.1 to 1.5! In reality, it may be entirely feasible to separate binary gas mixtures into two relatively pure components at very high recoveries using only two DR PSA columns operating in tandem with a very small pressure ratio.