ZSM-11 membranes: Characterization and pervaporation performance

✍ Scribed by Shiguang Li; Vu A. Tuan; Richard D. Noble; John L. Falconer

• Publisher: American Institute of Chemical Engineers
• Year: 2002
• Tongue: English
• Weight: 1020 KB
• Volume: 48
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690480211

✦ Synopsis

Abstract

High‐quality boron and aluminium‐substituted ZSM‐11 membranes were prepared on porous tubular supports to separate alcohols from water by pervaporation. The C~1~–C~3~ alcohols were preferentially separated from aqueous solutions through the B‐ZSM‐11 membrane, and the maximum flux was 1.7 kg/m^2^·h for a 5 wt.% methanol/water mixture. The alcohol fluxes decreased as the carbon number increased. The methanol/water separation selectivity decreased with pervaporation temperature, but other alcohol/water selectivities increased. All selectivities increased with decreasing alcohol feed concentration. In a range of 1 to 50 wt. % alcohol, the separation selectivities at 333 K for the C~1~–C~3~ linear alcohols were higher than vapor/liquid equilibrium selectivities. The highest selectivities observed for methanol/water, ethanol/water, 1‐propanol/water, and 2‐propanol/water were 28, 97, 34, and 26, respectively, at 1 wt. % alcohol feed concentrations. The separation selectivities were based on both preferential adsorption of alcohols and differences in diffusion rates.