Catalytic deoxygenation of hexadecyl palmitate as a model compound of Euglena oil in H2 and N2 atmospheres

Abstract

Hexadecyl palmitate (C15 H31 COOC16H33, used as a model compound for Euglena oil) was deoxygenated to hydrocarbons over various solid catalysts in autoclave reactors. In a H2 atmosphere, 1 wt.% of Pd/Mg(Al)O catalyst, derived from a hydrotalcite precursor, yielded a C15H31COOQ16H33 conversion close to 100%, and a C10-C16 (aviation fuel range) hydrocarbon yield of 90.2% for the deoxygenation of C15H31COOC16H33 at 300 °C for 2 h. In a N2 atmosphere, 1 wt.% of Pd/Mg(Al)O catalyst yielded a C10-C16 hydrocarbon yield of 63.5%, which was much higher than those obtained with Mg(Al)O (15.1%), H-ZSM-5 (8.3%), and 1 wt.% Pd/C (26.2%) for the deoxygenation of C15 H31 COOC161 H33 at 300 °C for 2 h. The Pd metal site and the solid base site in Mg(Al)O had a synergetic effect on the deoxygenation of C15H31COOC16H33 in N2 atmosphere over the Pd/Mg(Al)O catalyst. By prolonging the reaction time to 5 h for reaction at 300 °C in N2 atmosphere, the yield of C10-C16, hydrocarbons increased to 80.4% with a C15 H31COOC16H33 conversion of 99.1% over the 1 wt.% Pd/Mg(Al)O catalyst.