The expeditious increase in population has led to prioritizing the use of
biological sources as biofuels. The biofuels have been converted into different fuels by
the virtue of green and sustainable approach. Other than the conventional sources of
raw materials, specialized energy crops, some varieties of algae, seaweed and
microalgae have been reported to be potential sources of biofuels. In recent years,
various methods of conversion of organic matter into biofuels have been reported. High
energy investment along with the added cost of solvent or catalyst is included in the
thermochemical methods. Meanwhile, the biochemical route suffers from the
drawbacks of lengthy cycle period and comparatively reduced efficiency in the bulk
breakdown of the recalcitrant biomass. Hydrothermal routes have been employed to
improve the overall efficiency of the biochemical process. The integration of
thermochemical and biochemical routes also may lead to inhibition of microorganisms
by the catalysts or mediated solvents. This review paper focuses on the recent catalytic
methods for the conversion of biomass into biofuels namely biodiesel along with the
pros and cons of the methods.
Keywords: Biochemical process, Biofuels, Conventional sources, Catalytic methods, Hydrothermal routes.
