Selective Membrane Separations for Ammonia

Membranes made of crosslinked block copolymers of styrene and sulfonated styrene are over one hundred times more permeable to ammonia than to nitrogen and hydrogen. This selectivity, measured with mixed gases, is the same as that expected from the fluxes of pure gases, i.e., the actual selectivity is within experimental error the same as the ideal selectivity. The membranes may find application in separating the outlet stream of the Haber process reactor.