Effect of Biomass Feedstocks on the Production of Hydrogenated Biodiesel

Abstract

Hydrogenated biodiesel is one of the most promising renewable fuels. It has many advantages over conventional biodiesel, including higher cetane number, higher heating valu e, lower viscosity, and lower corrosiveness due to its absen ce of oxygen. From previous work, Pd/TiO2 gave high conversion and selectivity in hydrogenated biodiesel. In this work, the effect of biomass feedstocks (i.e. beef fat, chicken fat, pork fat, and jatropha oil) on the production of hydrogenated biodiesel over Pd/TiO2 has been studied. Biomass feedstocks were analyzed by ICP-OES (inductively coupled plasma optical emission spectrometry) to identify the cont ent of impurities (i.e. P, K, Ca, Na, and Mg). The deoxygenation cata lyst, Pd/TiO2, was prepared by incipient wetness impregnation (IWI) and tested in a continuous flow packed-bed reactor at 500 psig, 325 °C, H2/feed molar ratio of 30, and LHSV of 4 h -1 for its catalytic activity and selectivity in hydrodeoxygenation. All feedstocks g ave high selectivity in diesel specification range hydrocarb ons and the main hydrocarbons were n-pentadecane (n-C15) and n-heptadecane (n- C17), resulting from the decarbonylation/decarboxyl ation reaction. Intermediates such as oleic acid, stearic acid, pal mitic acid, and esters were also detected in minor amount. The conversion of triglycerides in jatropha oil is higher than those of chicken fat, pork fat, and beef fat, respectively. The higher concentration of meta l impurities in feedstock, the lower conversion of feedstock.