Algae can be used to produce ' green diesel ' (also known as renewable diesel, hydrotreating vegetable oil  or hydrogen-derived renewable diesel)  through a hydrotreating refinery process that breaks molecules down into shorter hydrocarbon chains used in diesel engines.   It has the same chemical properties as petroleum-based diesel  meaning that it does not require new engines, pipelines or infrastructure to distribute and use. It has yet to be produced at a cost that is competitive with petroleum .  While hydrotreating is currently the most common pathway to produce fuel-like hydrocarbons via decarboxylation/decarbonylation, there is an alternative process offering a number of important advantages over hydrotreating. In this regard, the work of Crocker et al.  and Lercher et al.  is particularly noteworthy. For oil refining, research is underway for catalytic conversion of renewable fuels by decarboxylation .  As the oxygen is present in crude oil at rather low levels, of the order of %, deoxygenation in petroleum refining is not of much concern, and no catalysts are specifically formulated for oxygenates hydrotreating. Hence, one of the critical technical challenges to make the hydrodeoxygenation of algae oil process economically feasible is related to the research and development of effective catalysts.