Membranes for purification of chlorine in the chlor-alkali industry:: A viable option

Polydimethylsiloxane, surface-modified glass, unmodified glass, and hollow-fiber were evaluated as membrane materials for chlorine beneficiation. The purification of industrial grade chlorine and the recovery of chlorine from a tail gas in a chlor-alkali process were considered. Polydimethylsiloxane (at low temperature) appeared to be a suitable material for both cases. The cost of separation was is an element of 0.04/kg Cl-2 recovered for Case 1 and is an element of 0.07/kg Cl-2 for Case 2. The selectivity of the surface-modified glass is lower and complex, expensive configurations were required. Glass hollow fibers achieved the purity specifications but low permeabilities necessitate large modules.