Separation of 1,3-propanediol from aqueous solutions using pervaporation through an X-type zeolite membrane

1,3-Propanediol was separated from aqueous solutions by pervaporation throu gh an X-type zeolite membrane on a gamma -Al2O3 support. Binary, ternary, a nd quaternary mixtures and a cell-free fermentation broth were used. At 308 K. the total fluxes for the quaternary solution and the fermentation broth were 2.1 and 1.2 kg/(m(2) h), respectively. Prevaporation fluxes of all co mponents increased with temperature, but the water flux increased at the fa stest rate. From 308 to 328 K, the 1,3-propanediol/glycerol selectivity for the quaternary model solution increased from 59 to 67; it increased from 6 1 to 110 for the broth. The 1,3-propanediol/glucose selectivity increased f rom 1900 to 2200. The 1,3-propanediol/glycerol selectivity was mainly contr olled by preferential adsorption, and the 1,3-propanediol/glucose selectivi ty it as mainly controlled by differences in diffusion rates. The membrane was stable during the pervaporation of the quaternary mixture for at least one week. In contrast, after 60 h, the broth started to foul the membrane, and the 1,3-propanediol permeate concentration decreased. The membrane was regenerated by calcination at 653 K for 4 h.