Production of anhydrous biobutanol using a biosorbent developed from oat hulls

Bio-butanol is an important source of renewable biofuels. It contains significant amount of water in the production process through fermentation. The current technologies to remove water from butanol are energy intensive and costly. In this work, oat hulls, representative of cellulosic material abundantly generated as agricultural by-product, was used to dehydrate butanol in a packed column in order to produce biofuel product. The results demonstrate that the oat hull based biosorbent is able to effectively remove water from butanol. The biosorbent was characterized by Brunauer, Emmett and Teller (BET) surface area, thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM). The adsorption performance and breakthrough curve of the single component (butanol or water) adsorption on the biosorbent were investigated separately. Besides, the separation factors of water over butanol on the biosorbent were determined according to the equilibrium data in the butanol-water binary system. The effects of feed concentration and temperature on adsorption capacity were investigated. The water adsorption equilibrium data in the single water system and the butanol-water binary system were fitted to the Dubinin-Polanyi model. The approximate sorption site energy distribution was calculated to analyze the adsorption equilibrium data on the biosorbent. The results indicate the oat hulls based biosorbent has the capability for butanol dehydration.