Adsorption of Bio-based Butanol and Butyric Acid Solution by Using ZSM-5

Abstract: Butanol can be produced by ABE (acetone, butanol, ethanol) fermentation. The main problem with ABE fermentation by Clostridium microbial stain is butanol toxicity to the culture. For increasing the ABE fermentation products must be removed during fermentation.
In the present work, high silica zeolite (ZSM-5) was used to study the adsorption of butanol from model aqueous solution and model ABE solutions. In addition, ZSM-5 was used to examine the recovery of butyric acid from model aqueous solution and model acetic-butyric acid solutions.
The adsorption experiments showed that high silica ZSM-5 with a hydrophobic nature has a strong affinity for butanol and butyric acid in aqueous solutions. ZSM-5 hydrophobicity increased with the increase of the Si/Al ratio.
The result of the work showed higher adsorption affinity for butanol than acetone and ethanol, and also higher affinity for butyric acid than acetic acid in butyric-acetic acid aqueous mixture.