Butanol Separation from Humid CO2-Containing Multicomponent Vapor Mixtures by Zeolitic Imidazolate Frameworks

Abstract

Butanol is a promising renewable fuel and feedstock. A major challenge in fermentative butanol production is to find a cost-effective butanol separation process from dilute aqueous solutions, usually an acetone-butanol-ethanol (ABE) mixture. Nanoporous zeolitic imidazolate frameworks (ZIFs) have shown potential for alcohol separation from dilute solutions. However, little is known about butanol separation from multicomponent mixtures using ZIFs, including the effects of the humid acid gas (CO2) used to sparge the fermenter and generate the vapor product stream. We present a study of butanol separation by ZIF-8, ZIF-90, ZIF-71 and hybrid ZIF-8–90 and ZIF-8–71 adsorbents with binary butanol/water and multicomponent ABE feeds. To obtain reliable structure–property relations for ZIF adsorbents in realistic conditions, we combine multicomponent vapor breakthrough with structural, textural, and stability characterization techniques in humid CO2 environments. In the absence of CO2, more hydrophobic materials suc...