Evaluation of a pilot-scale sewage biogas powered 2.8 kWe Solid Oxide Fuel Cell: Assessment of heat-to-power ratio and influence of oxygen content

• Published in: Journal of power sources Vol. 300; pp. 325 - 335
• Main Authors: de Arespacochaga, N., Valderrama, C., Peregrina, C., Mesa, C., Bouchy, L., Cortina, J.L.
• Format: Journal Article Publication
• Language: English
• Published: Elsevier B.V 30.12.2015
• Subjects: Biogas; Biogas treatment; Biogàs; Cogeneració de calor i d'electricitat; Cogeneration of electric power and heat; Energies; Energies renovables; Energy valorisation; Gas reforming; Heat-to-power ratio; Innovacions tecnològiques; Piles de combustible d'òxid sòlid; Recursos energètics renovables; Renewable energy sources; Solid Oxide Fuel Cell; Solid oxide fuel cells; Àrees temàtiques de la UPC; Biogas; Solid Oxide Fuel Cell; Gas reforming; Energy valorisation; Biogas treatment; Heat-to-power ratio
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.09.086

Biogas from anaerobic digestion of organic matter is a promising renewable energy source and fuel cells appear as a breakthrough technology to improve the performance of the biogas-to-energy valorisation chain. The vast majority of studies addressing biogas energy recovery through Solid Oxide Fuel Cells published in recent years correspond to simulations and lab-scale performance with synthetic biogas. This paper assesses the pilot performance of a 2.8 kWe SOFC unit powered with cleaned sewage biogas for around 700 h in a Wastewater Treatment Plant. The biogas thorough treatment consisting of a biological desulphurisation with a biotrickling filter followed by a deep cleaning step based on adsorption is successful for removing sulphur compounds, siloxanes and hydrocarbons. The influence of the heat-to-power ratio on fuel cell performance is investigated operating the system at O/C ratio of 2, reforming temperature of 550 °C, stack temperature of 800 °C and at a constant voltage of 43 V. At optimized conditions for electrical production satisfying heat demand in the WWTP, system electrical and thermal efficiencies account for 34% and 28%. Cogeneration efficiency remains constant at around 59–62% for all the heat-to-power ratios tested. Furthermore, the impact of the oxygen content in the biogas is also studied. •A biogas powered SOFC is operated for 700 h at pilot-scale in a WWTP.•The selected biogas treatment configuration is suitable for fuel cell applications.•The influence of the heat-to-power ratio on the fuel cell performance is investigated.•System electrical and thermal efficiencies account for 34% and 28%.•Stack electrical efficiencies larger than 50% are obtained.