SOFC operating with ammonia: Stack test and system analysis G. Cinti a,* , G. Discepoli a , E. Sisani a , U. Desideri b a Department of Engineering, Universit a degli Studi di Perugia, Via G. Duranti 93, 06125 Perugia, Italy b Department of Energy, Systems, Territory and Constructions Engineering, Universit a di Pisa, Largo L. Lazzarino, 56122 Pisa, Italy article info Article history: Received 14 February 2016 Received in revised form 23 May 2016 Accepted 3 June 2016 Available online xxx Keywords: Ammonia Fuel SOFC Energy vector Sustainable energy storage abstract Ammonia has been studied as a potential energy vector and suitable fuel for Solid Oxide Fuel Cells (SOFCs). The use of ammonia could guarantee high electrical efficiency, with a carbon free and high energy density fuel. This study analyzes the potential of a power generation system based on a SOFC fueled by NH 3 . Experimental tests on a SOFC short stack were developed using both pure and diluted ammonia. The tests demonstrated the operation of the concept and highlighted possible advantages in terms of thermal equi- librium. Decomposition of ammonia introduces an endothermic reaction that permits heat absorbance in the anode and a better control of stack temperature. Based on tests results, a thermodynamic model of a complete system was designed and studied. The results demonstrate that the ammonia fueled SOFC is more efficient than an equivalent hydrogen fueled one, due to the cooling effect of internal reactions that reduces ancillaries energy consumptions related to cathode air flow. © 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Ammonia is the most produced chemical worldwide and its production is based on a well-known and efficient technology. Moreover, ammonia is widely distributed, due to its utilization as fertilizer in agriculture and a logistic network is already present. Those aspects, along with a high energy density and a carbon free status, make ammonia a potential green and sustainable energy vector, especially if renewable energy is used to produce the basic chemicals (hydrogen and nitrogen) necessary for its synthesis [1]. Ammonia has a higher density than other energy vectors, since it can be stored as a liquid phase at low pressure (20 bar) and it can be easily and efficiently transported [1,2]. During its combustion, ammonia reacts with oxygen producing only nitrogen and water, without CO 2 emissions. Additional advantages can be obtained if hydrogen and nitrogen are produced using carbon free energy sources following the so called path to Green Ammonia [3]. Currently, almost the entire worldwide ammonia stock is made using hydrogen produced by natural gas reforming, which does not make ammonia a carbon free fuel [4], even though, in this plants, carbon dioxide is usually recovered and commercial- ized as a pure technical gas for other purposes (gaseous soft drinks and production of other chemicals), and it is not directly emitted in the atmosphere. Abbreviations: SOFC, Solid Oxide Fuel Cell; X, Molar Concentration; OCV, Open Circuit Voltage; ASC, Anode Supported Cell; AB, After Burner; HE, Heat Exchanger. * Corresponding author. Department of Engineering, Universit a degli Studi di Perugia, Via G. Duranti 93, 06125 Perugia, Italy. Tel./fax: þ39 075 5853991. E-mail address: giovanni.cinti@unipg.it (G. Cinti). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2016) 1 e8 http://dx.doi.org/10.1016/j.ijhydene.2016.06.070 0360-3199/© 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Cinti G, et al., SOFC operating with ammonia: Stack test and system analysis, International Journal of Hydrogen Energy (2016), http://dx.doi.org/10.1016/j.ijhydene.2016.06.070