An Overview of the Recent Advances in the Application of Metal Oxide Nanocatalysts for Biofuel Production

Abstract

Fossil fuels are still primary resources of energy supply; however, they are undoubtedly responsible for most of the environmental pollutions. Over the last decades, renewable sources as clean alternative energies have received an increasing deal of attention due to the limitation of fossil fuel resources for reliable fulfillment of future energy demands and to address the environmental crises. Renewable energies predominately include solar, wind, biomass, hydrogen, and geothermal sources. Among these, biofuels derived from biomass are considered as the most promising candidate owing to a number of reasons such as direct conversion of biomass to liquid biofuels. Gases and liquid biofuels can be produced from biomass feedstock by three main approaches: thermochemical, biochemical, and microbiological technologies. Gasification, pyrolysis, liquefaction, hydrolysis, transesterification, and anaerobic digestion are main routes for biomass to biofuel conversion. In all biofuel production processes, developing the highest quality products with an optimized process (in terms of cost, energy consumption, etc.) is desirable which necessitates the exploitation of modern sciences such as nanotechnology. Among various aspects of nanotechnology, over the last several years, utilization of highly active nanocatalysts for biofuel production has been growing quickly. Recent research studies have mainly focused on developing efficient nanocatalysts for improving conversion, accessing milder operating conditions, and lowering the process cost of biofuel production to collectively try to industrialize these green fuels. This chapter summarizes an overview of various biofuel production processes and, moreover, strives to comprehensively discuss metal oxide nanocatalysts used for biofuel production.