Deoxygenation of Fatty Acids in Supercritical Hexane over Bimetallic Catalyst for Biodiesel Production

Abstract

Deoxygenation process is considered to be a promising way to produce the second generation of biodiesel. The main drawbacks of this process are high temperature, high reaction time and the necessity in hydrogen presence aimed at the formation of saturated diesel-range hydrocarbons. In order to solve the deoxygenation problems, the supercritical fluids can be used as a solvent. The reaction performance in the medium of supercritical fluids allows sufficiently reducing the reaction duration as well as avoiding the use of molecular hydrogen. In the current work, stearic acid deoxygenation in the medium of supercritical hexane in the presence of Ni-Co bimetallic catalyst supported on hypercrosslinked polystyrene by hydrothermal method was studied. The influence of metal loading was estimated. The Ni-Co/HPS catalyst containing 10 wt. % Ni and 10 wt. % Co was found to be an effective catalyst for the deoxygenation process allowing reaching the C16-C18 hydrocarbons yield up to 95 % at 100 % substrate conversion.