Transport of binary gas mixtures in microporous membranes: transient-state separation factors

Abstract Transient-state separation factors and amounts permeated have been calculated as functions of time and over a range of temperatures for transport of some binary gas mixtures through high-area microporous carbon and Vycor porous glass membranes. The calculations of these factors are based upon previously measured transient-state time-lags and steady-state permeabilities for transport of single components of the mixtures with sorption in, or just outside, the Henry's law region. An alternative, early-time, expression for the separation factor, involving error functions, has been developed. p]For many of the mixtures examined, good fractionations were found for the initial portion of the transient-state flow. A fractionation technique is envisaged in which pulses of much enriched component are collected and combined by switching the mixture successively to each of a series of membranes. Some factors affecting the efficiency of such a technique are indicated