Catalysis

Decarbonylation

Hydrodeoxygenation

Engineering

Vegetable oil refining

Diesel engine

Diesel fuel

Biodiesel

Waste management

Organic chemistry

Noble metal

Deoxygenation

Biofuel

Automotive engineering

Chemistry

Selectivity

Pulp and paper industry

Decarboxylation

Molecular Catalysis

Green diesel is a second-generation biofuel developed in response to the increasing demand for liquid fuel and the predicted decrease in the availability of fossil fuels, especially diesel as the main liquid fuel used in transportation vehicles. Green diesel can be produced via deoxygenation from various feedstocks, such as vegetable oils, animal fats, fatty acids, and waste cooking oils. Normally, the deoxygenation reaction in green diesel production occurs in a multiphase system. There are three main pathways in the liquid phase of the reaction: decarboxylation, decarbonylation, and hydrodeoxygenation, from which liquid alkane hydrocarbons can be derived, and these are known as green diesel. This review paper discusses several deoxygenation pathways in a multiphase-reaction process to produce green diesel. Nickel metal is a non-noble metal catalyst which has been confirmed from many studies for use in deoxygenation with good performance. The performance of the nickel catalyst depends on different factors including the type of catalyst support and promoter, reaction temperature, reaction pressure, and reaction time. Finally, recent progress and future trends in green diesel production are discussed.

Review of green diesel production from fatty acid deoxygenation over Ni-based catalysts