Algae as a Sustainable and Renewable Bioresource for Bio-Fuel Production

Abstract Micro and macroalgae are the most commonly available bioresources that have received significant importance worldwide as potential feedstock for producing sustainable biofuels. Algae are aquatic organisms lacking complex cell structures. They are in photoautotrophic forms converting solar energy into chemical energy through photosynthesis. They are found in diverse environments, and do not compete with food or fuel-based crop materials for their cultivation. Besides proteins, vitamins, pigments, minerals, antioxidants, etc., most algal biomass are also rich in polysaccharides (sugars) and lipids (triglycerides), the raw materials for producing bioethanol and biodiesel, respectively. Algae are considered as clean renewable energy source as they do not cause pollution to the ecosystem. Biofuels, currently produced through algal biomass are bioethanol, biomethanol, biobutanol, biodiesel, biomethane, biohydrogen, and bio-oil. The perceived benefits provide the supporting rationale for much of the researchers’ attention directed towards microalgal research. On the other hand, despite many research findings being published every year on biofuel generation from algae, the advancement of technology to compete with fossil fuel with respect to cost economics still remains a major challenge. In the commercial scenario, currently many companies are venturing to produce biodiesel from algae, yet it is limited by the biomass supply. The key challenges in the production of biofuel from algae lies with an efficient harvesting methodology and the cost of pretreatment for conversion into biofuel, which is higher than the algal cultivation cost. However, much advancements in chemistry/biochemistry addresses some of these key challenges and paves way for the use of algal biomass as a potential feedstock for biofuel generation. Recently, many microalgal biomasses are effectively used to generate bioelectricity through microbial fuel cell technology. Green synthesis of ionic liquids and its use in conversion of algal biomass to biofuel is one of the emerging recent techniques in the world. This chapter examines various aspects of algal production that will ultimately determine the future energy sustainability, economic viability, and environmental impacts.