Adsorption Properties of Bioethanol on Commercial Zeolites and Their Effect on Fermentation

作者：Maeda Shota^*; Kuroki Kuniko; Ohe Kaoru; Oshima Tatsuya; Baba Yoshinari

来源：Kagaku Kogaku Ronbunshu, 2011, 37(3): 223-228.

DOI：10.1252/kakoronbunshu.37.223

• Bioethanol
• Zeolite
• Adsorption
• Pore Structure
• Yeast

Bioethanol for fuel is a renewable alternative to petroleum, but because it is generally separated and concentrated by distillation, much energy is necessary to produce ethanol with a low water content due to the azeotropic point between ethanol and water. To develop an environmentally friendly method for purification of bioethanol, we examined its adsorption on hydrophobic zeolites. The adsorption properties of ethanol at 303 K and the effect of zeolites on the proliferation and fermentation of yeast at 301 K were investigated. The specific surface areas of zeolites were found to be 300-800 m(2) g(-1) by the N(2) gas adsorption method. The N(2) adsorption/desorption isotherms on zeolites were of type I (micro pore), III (atreto) and IV (meso pore). The adsorption rate of ethanol on zeolites in powder form reached equilibrium within 0.5 min, and the adsorption isotherm of ethanol on zeolites from aqueous solution was of the Freundlich type. It was found from the adsorption results that adsorption capacities of ethanol on zeolites were influenced by hydrophobicity, micropore size and percentage of micropore volume of zeolites. The highest adsorption capacity for 5 vol% ethanol was 90 mg g(-1) using the commercial zeolite HISIV-3000, which indicates that the molecular diameter of ethanol fit the micropore size of the zeolite. An increase of proliferation and fermentation ability was observed with pellet zeolites because yeast adhered to the pellet zeolites.

• 出版日期2011