Metal oxide promoted ceria-zirconia (Ce/Zr = 6/4) catalysts was applied to deoxygenation (DO) of oleic acid in batch mode at 300℃ under 1 bar of 20% H2/N2 condition. Metal oxide promoted ceria-zirconia catalysts were prepared by a co-precipitation method. As a result, Ni-Ce0.6Zr0.4O2 catalyst exhibited much higher oleic acid conversion, selectivity to C9 ~ C17 compounds (diesel fuel range), and oxygen removal efficiency than the others. This is due to the presence of free NiO species, synergy effect of nickel and Ce0.6Zr0.4O2, highest BET surface area, and the strong metal to support interaction (SMSI).
For the practical feasibility of lactic acid (LA) fermentation process, a continuous operation using mixed culture and the use of cheap and non-food raw materials are essential. In this study, a continuous LA fermentation of food waste was attempted using indigenous mixed culture. During the operation, temperature was gradually increased from 35℃ to 55℃, with showing the highest performance at 50℃. At 35-45℃, other organic acids such as acetic acid and butyric acid were also observed. At 50℃ and HRT 1.0 d, both LA production yield and its productivity were maximized to 1.8 mol LA/mol hexoseadded and 1.4 g LA/L/hr, respectively. A pyrosequencing result showed that Lactobacillus amylolyticus was the predominant species performing LA fermentation of food waste. The combined process of nanofiltration and water-splitting electrodialysis could recover highly purified LA from the fermentation broth by removing 95% of mineral ions and 77% of ammonium and glucose.
Ce(1-x)Zr(x)O2 catalysts were investigated for bio-diesel production from oleic acid using catalytic deoxygenation. In this study, deoxygenation reaction has been carried out at 300 oC under 1 bar of 20% H2/N2 pressure in batch mode. Ce(1-x)Zr(x)O2 catalysts were prepared by co-precipitation method. Ce0.6Zr0.4O2 catalyst showed the highest oleic acid conversion and C9~C17 selectivity. It has been found that the deoxygenation reaction depends strongly on the reduction property and depends partly on the crystallite size of Ce(1-x)Zr(x)O2. Thus, Ce0.6Zr0.4O2 can be selected as the most promising catalyst for deoxygenation reaction.