161 © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 R. K. Jyothi, P. K. Parhi (eds.), Clean Coal Technologies, https://doi.org/10.1007/978-3-030-68502-7_7 Chapter 7 Bio-Desulfurization of Coal Using Biotechnological Approach, Making Coal a Less Harmful Fuel Hafz Ahmad Ishfaq, Ayantika Banerjee, and Sanaullah Qamar 7.1 Introduction Coal is known as the most abundant form of fossils fuel on earth. There is a persis- tent increase in the global demand of energy. To meet global energy demands com- mercialization and utilization of lower quality fossils fuels (Rajendran et al. 2020) is mandatory. Although coal is the most abundant, but most of the discovered coal is not of good quality. Clean coal is one of the most viable solutions to our energy requirement (Acharya et al. 2004). International Energy Agency sites to see the maximum increase in the amount of coal demand among all the primary energy resources. The demand has showed an increase of 38% in the decade of 2005 to 2015 will increase by a fold to 73% by 2030 as indicated in Fig. 7.1 (Patzek and Croft 2010). There is a rampant need to develop clean coal technologies which can help us to attenuate the environmental aspect of coal as well as to improve the effciency of the Hafz Ahmad Ishfaq, Ayantika Banerjee and Sanaullah Qamar contributed equally with all other contributors. H. A. Ishfaq (*) · S. Qamar Fuel Cell Research Center, Korea Institute of Energy Research (KIER), Daejeon, South Korea Department of Advanced Energy and System Engineering, University of Science and Technology (UST), Daejeon, South Korea e-mail: sqamar.che5@scme.nust.edu.pk A. Banerjee Decontamination and Decommissioning Division, Korea Atomic Energy Research Institute (KAERI), Daejeon, South Korea Quantum Energy Chemical Engineering, University of Science and Technology (UST), Daejeon, South Korea e-mail: banerjee93@kaeri.re.kr