Algae: Nature’s Renewable Resource for Fuels and Chemicals

Abstract

Microalgae-based renewable energy, industrial chemicals, and food have received great attention during the last decade. This review article highlights the versatility of algal biomass as a feedstock for producing various commodities and high-value products, including aromatic hydrocarbons and lipids within biorefinery systems. Lipid content and the composition of algal biomass cultivated in various media, specifically in wastewater streams generated at agricultural and industrial production facilities, are reviewed. Technical and chemical aspects of algal biomass conversion via thermochemical techniques including pyrolysis, hydrothermal liquefaction, and hydrothermal carbonization are discussed. The properties of the final products are reviewed based on the conversion process employed. Studies published within the last 5 years are reviewed. The importance of further research on inexpensive and more effective catalysts and the development of downstream processes to upgrade crude products obtained from thermal conversion processes is emphasized. This review concludes with an in-depth discussion of the opportunities and challenges involved in algal biomass-based bioproduct manufacturing and commercialization.