Chapter 1 - Clean energy production by microorganisms: A sustainable approach

Abstract

In the current century, the present energy demand is expected to be increased approximately by threefold, which is expected not to be fulfilled by fossil fuels, especially considering that the fossil fuel reservoir is getting depleted day by day. In this current scenario, biofuel and bioenergy produced by different microbes would play a key role in sustaining the energy demand in the coming era. The clean production of biofuel includes the production of biodiesel, bioethanol, bio-butanol as well as bio-hydrogen, whereas microbial fuel cells (MFCs) can produce bioelectricity, which is considered the cleanest bioenergy. Among these, biodiesel and bioethanol are the most dominating biofuels being produced in the present era. As per a report published in 2018, the United States is a leading producer of both bioethanol and biodiesel (60.79 billion liters per year and 7903.25 million liters per day). According to the USDA, corn is used as the primary feedstock for bioethanol production, whereas soybean is used as the primary feedstock for biodiesel production. Brazil stands as the second-highest biofuel producer, producing 30.755 billion liters of ethanol in 2018 and about 5745 million liters of biodiesel per year. Sugarcane and sugarcane bagasse are chiefly used for bioethanol production and soybean for biodiesel production in Brazil. Contradictorily, Germany produced 3.2 million tonnes of biodiesel in 2018, using rapeseed and cooking oil as the primary feedstock. Like bio-hydrogen and bio-butanol, other biofuels have complexities such as low productivity, high production cost, producer organism, and substrate rigidity that limit them within the lab scale. Biodiesel and bioethanol production has different improved aspects of fulfilling the worldwide demand. The electricity generation from MFC was also found insufficient to fulfill large-scale demand. In this current chapter, different aspects of biofuel and bioenergy production will be studied elaborately, and different ongoing research studies will be addressed to improve the existing process.