Fuel production from renewable and carbon-neutral biomass has attracted much attention due to concerns for the depletion of petroleum reserves and global warming by greenhouse gases. Microalgae offer several advantages over conventional biomass as they have faster growth rate

do not require agricultural land for growth

and consume less water than terrestrial biomass. However

crude bio-oil from noncatalytic liquefaction of microalgae has a high content of oxygen

limiting its direct applications for transportation fuel. The high oxygen content suffers from some drawbacks such as lower energy density

poor oxidation stability and high corrosivity

so it should be deoxygenation upgraded as a high grade fuel. In this review

the effect of reaction atmosphere and nature of catalyst on the reaction pathways of the deoxygenation of fatty acids model compounds is discussed firstly. Then

related researches are reviewed based on crude oil of microalgal. Finally

problems in current bio-oil catalytic deoxygenation technologies

improvement advices and future prospect are also presented.