Abstract:
In the modern world, as the population rises and fossil fuel supplies decline, energy
demands continue to rise. Moreover, the use of fossil fuels harms the ecology, contributing to
pollution and global warming. In order to overcome these difficulties, several approaches are
revealed, such as the utilization of biomass as a renewable source of energy. Studies revealed that
biomass can be converted into bioenergy via several thermal conversion processes, like pyrolysis,
gasification, and torrefaction. Pyrolysis is the most convenient process to obtain three different types
of biofuels (biochar as a solid, bio-oil as a liquid, and syngas as a gas). The biofuels produced in this
process are normally lower in quality and cannot be used directly as fuel because they contain many
undesirable components. Catalytic pyrolysis is one of the best processes to upgrade the quality of
biofuels. Several varieties of catalysts are used in the catalytic pyrolysis process (ex situ and in situ).
Due to stable operating conditions, both catalytic and non-catalytic pyrolysis procedures produce
biochar that has a consistent output. Meanwhile, the effects of catalysts in the catalytic pyrolysis
process considerably enhance the quality and quantity of bio-oils and syngas. By removing the
unwanted oxygenated and nitrogenous components, the bio-oils produced through the catalytic
pyrolysis method have a higher calorific value, reduced viscosity, and improved stability. Many
researchers have looked at ways to increase the rate of pyrolysis, whereas a few have focused on
maximizing the effects of the factors in order to improve the efficiency of catalytic pyrolysis. This
review addresses the impact of catalysts on the catalytic pyrolysis of biomass to enhance the quality
of the bio-oils in great detail. Machine learning and techno-economic analysis were investigated, as
well as the future potential of the catalytic pyrolysis method for the generation of bio-oil.
