Catalytic chemistry of preparation of hydrocarbon fuels from vegetable oils and fats

Abstract

The problem of preparing engine fuels from renewable feedstocks via the catalytic processing of inedible vegetable oils and fats is considered. Different types of inedible feedstocks are described, including algae, inedible plants, wood processing products, and waste fats and oils. Catalytic processes are considered for preparing the second generation biodiesel through the hydrodeoxygenation and deoxygenation of triglycerides and fatty acids, and of their derivatives. Brief information on catalysts for the deoxygenation of fatty acids is given. Special attention is given to analyzing the mechanism and kinetics of the deoxygenation reaction. Based on conducted kinetic and quantum-chemical investigations and using the literature data, a deoxygenation mechanism is proposed by the authors that explains the observed dependences of decarboxylation and decarbonylation contributions on the reaction conditions (the stearic acid, water, and catalyst concentrations, the hydrogen and CO pressures, and the temperature). Examples of the application of hydrocarbon biodiesel in transport are presented.