Palm fatty acid distillate derived biofuels via deoxygenation: Properties, catalysts and processes

Research on the production of renewable biofuels as a replacement for non-renewable diesel has been gaining interest due to the relatively low-toxicity and low carbon dioxide emission of biofuels. In this regard, the production of biofuels via catalytic deoxygenation reactions of palm fatty acid distillate has been reviewed in this contribution. Decarboxylation and decarbonylation reactions that can be conducted under low hydrogen pressure condition or inert atmosphere are preferable due to their cost-effectiveness when compared to hydrodeoxygenation reaction that consumes a huge amount of highly pressurized hydrogen. Utilization of non-noble metals in catalysts as a replacement of noble metals that are expensive and less abundant, together with the formation of coke in side reaction are the issues that yet to be solved. Among the non-noble metals, Ni shows comparable performance with noble metals and is the most promising catalyst option. Discussion on the catalyst, support, promoter and operating condition are also presented to understand their roles in affecting the quality and the quantity of biofuels. Description: The major contents in the review are summarized in the graphical abstract. • Palm fatty acid distillate (PFAD) as the feedstock for biofuels production. • Decarboxylation and decarbonylation of PFAD under low hydrogen or inert atmosphere. • Replacement of noble metal catalysts with non-noble metal catalysts. • Mitigation of coke formation via side reaction. • Process study to achieve optimum catalyst performance.