294 Int. J. Exergy, Vol. 30, No. 3, 2019 Copyright © 2019 Inderscience Enterprises Ltd. Exergy and energy analysis of a biogas-fuelled micro-tubular flame fuel cell Milad Nasrzad, Samad Jafarmadar* and Parisa Mojaver Department of Mechanical Engineering, Faculty of Engineering, Urmia University, Urmia, Iran Email: m.nasrzad94@gmail.com Email: s.jafarmadar@urmia.ac.ir Email: p.mojaver@urmia.ac.ir *Corresponding author Abstract: In the present study, a combination of 60% CH4 and 40% CO2 was used as the fuel. The performance of the fuel cell was studied at three different equilibrium ratios of fuel to air entering the burner. The effects of current density and equivalence ratio were investigated on the fuel cell voltage, voltage drops, output power, methane molar flow rate, and efficiency. The results indicated that a maximum power of 0.724 W, 0.955 W, and 1.201 W was achieved for a single fuel cell at the equivalence ratios of 1.2, 1.3, and 1.4, respectively. Exergy efficiency was increased from 21.93% to 46.68% by reducing the current density from 1800 A/m 2 to 100 A/m 2 at the equivalence ratio of 1.4. The maximum efficiency and the minimum inlet methane molar flow rate were observed at the equivalence ratio of 1.4. Keywords: energy; exergy; biogas; partial oxidation; micro-tubular flame fuel cell; equivalence ratio. Reference to this paper should be made as follows: Nasrzad, M., Jafarmadar, S. and Mojaver, P. (2019) ‘Exergy and energy analysis of a biogas-fuelled micro-tubular flame fuel cell’, Int. J. Exergy, Vol. 30, No. 3, pp.294–306. Biographical notes: Milad Nasrzad is an MSC student in Urmia University. Samad Jafarmadar received his PhD in Internal Combustion Engine from the Tabriz University, Iran, in 2006. He has more than 16 years of teaching, research, and administrative experiences. Currently, he is working as a Full Professor in the Department of Engineering, Urmia University. His broad areas of research include internal combustion engines modelling and exergy analysis in combustion process and experimental and numerical simulation in heat exchangers. He has published more than 260 research papers in international and national journals/conferences. Parisa Mojaver received his BS and MSC in Mechanical Engineering from the Urmia University, Urmia, Iran. Currently, he is a Senior PhD student at Urmia University and is currently working on exergy analysis in Power Plant.