Role of Microalgae in Sustainable Energy and Environment

Abstract

Abstract The fast-growing global population is pressing the requirement of energy leading to the extensive use of fossil fuels globally which tends to their exhaustion, alongside the environmental pollution. The need of a third-generation fuel which is viably sustainable has increased and for that microalgae are standing out among various other competitors. Microalgae may be prokaryotic, like cyanobacteria or eukaryotic, like green algae. They are highly efficient in converting solar energy into biomass and can be cultivated in a wide range of conditions. Microalgae are the sources of biofuels, bioactive medicinal products, and food supplements. They have an outstanding photosynthetic efficiency and biomass productivity with high contents of fatty acids, polysaccharides, and proteins. Biofuels derived from microalgae have immense potential for carbon dioxide (CO2) sequestration, whereby 1 kg of algal biomass may fix 1.8 kg of CO2. Microalgae are termed as ‘living biorefinery’ because they can produce a wide range of green chemicals like biopesticides and biofertilizers. Keeping in mind the severe impacts of chemical fertilizers, sustainable agricultural system is opting for biofertilizers and biopesticides. Biopesticides help prevents the attack of pathogenic fungus and soil borne diseases without causing any harm to plants and environment. The remarkable features of biofertilizers include enhanced crop productivity per area; reduced amount of energy consumption and contamination of soil and water; and increased soil fertility. Biofuels derived from microalgae are of various kinds including Biochar (solid); bioethanol, biodiesel, and vegetable oil (liquid); bio hydrogen and bio syngas (gaseous). Some of the pros of bioethanol obtained from microalgae are high octane number, minimal production of greenhouse gases, and the exclusive biofuel which can directly be used in automotive industry. This paper will provide an insight on the viability and feasibility of microalgal biomass in the production of biofuels and other bioactive compounds with the constraints and challenges faced in commercializing these products. This review shall elaborate on the potential of microalgae as a sustainable solution for future energy crises and environmental deterioration.