An effective semi-empiric model for MCFC kinetics: Theoretical development and experimental parameters identification

Bosio, B.,Di Giulio, N.,Nam, S.W.,Moreno, A. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.23

The aim of this work is to develop a semi-empirical model of the kinetics of MCFCs for laboratory and industrial simulation. The rigorous theoretical approach takes into account the polarisation due to chemical as well as physical phenomena, but the number of parameters to be identified in the kinetic formulation has been reduced to the minimum in order to obtain an effective and accurate but, nevertheless, simplified instrument. Validation has been performed thanks to experimental tests carried out at the Fuel Cell Centre laboratories of the Korea Institute of Science and Technology (KIST) using 100 cm<SUP>2</SUP> single cell facilities. I-V curves, EIS and gas analyses have furthermore been carried out to support the investigation. A method for the parameter identification has been proposed on the basis of temperature, partial pressures and current density effects on performance. Both experimental and theoretical results will be discussed in detail, presenting the resulting simulation tool as an effective instrument for the design, optimisation of operating conditions, diagnosis and control of MCFC devices.

Extension of an effective MCFC kinetic model to a wider range of operating conditions

Audasso, E.,Bosio, B.,Nam, S. Pergamon Press ; Elsevier Science Ltd 2016 International journal of hydrogen energy Vol.41 No.12

<P>The aim of this work is to improve the semi-empirical MCFC kinetics model previously developed by the authors for laboratory and industrial simulation to make it applicable to a wider range of feeding compositions. New parameters are taken into account and identified to describe O-2 and cathode induced flux effects, which were neglected in the previous formulation. The newly obtained equation is integrated as kinetic core in the SIMFC (SIMulation of Fuel Cells) code, an MCFC 3D model set up by the UNIGE PERT group, to test its reliability. Validation is performed using experimental data collected through experimental tests carried out at the Fuel Cell Research Centre laboratories of the Korea Institute of Science and Technology (KIST) using 100 cm(2) single cell facilities. The results will be discussed in detail giving examples of the simulated performance varying operating conditions and evaluating the different polarisation contributions. Through the final formulation the average percentage error obtained for all the simulated cases respect to experimental results is maintained around 1% despite the very wide operating range. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.</P>

Experimental analysis of SO₂ effects on Molten Carbonate Fuel Cells

Di Giulio, N.,Bosio, B.,Han, J.,McPhail, S.J. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.23

The aim of this work is to investigate how SO<SUB>2</SUB> can affect MCFC performance and to discover the possible mechanisms involved in cathode sulphur poisoning, specifically considering the possible use of MCFCs in CCS (Carbon Capture and Storage) application. The different contributions of cathodic, anodic and electrolyte reactions have been considered to get a complete picture of the evolution of performance degradation. Experimental tests have been performed at the Fuel Cell Centre laboratories of Korea Institute of Science and Technology (KIST) thanks to 100 cm<SUP>2</SUP> single cell facilities and comparing results using both an optimized gas for laboratory conditions and a gas composition that simulates MCFCs when running in a Natural Gas Combined Cycle (NGCC) power plant. Polarisation curves, endurance tests, impedance measurements and gas analyses have been carried out to support the investigation.

A combined theoretical and experimental study on the oxidation of fulvic acid by the sulfate radical anion

Gara, Pedro M. David,Bosio, Gabriela N.,Gonzalez, Monica C.,Russo, Nino,Michelini, Maria del Carmen,Diez, Reinaldo Pis,Martire, Daniel O. Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.7

The kinetics of the reaction of sulfate radicals with the IHSS Waskish peat fulvic acid in water was investigated in the temperature range from 289.2 to 305.2 K. The proposed mechanism considers the reversible binding of the sulfate radicals by the fulvic acid. The kinetic analysis of the data allows the determination of the thermodynamic parameters ${\Delta}G^{\circ}$ = -10.2 kcal $mol^{-1}$, ${\Delta}H^{\circ}$ = -16 kcal $mol^{-1}$ and ${\Delta}S^{\circ}$ = -20.3 cal $K^{-1}mol^{-1}$ for the reversible association at 298.2 K. Theoretical (DFT) calculations performed with the Buffle model of the fulvic acids support the formation of H-bonded adducts between the inorganic radicals and the humic substances. The experimental enthalpy change compares well with the theoretical values found for some of the investigated adducts.

Preliminary model and validation of molten carbonate fuel cell kinetics under sulphur poisoning

Audasso, E.,Nam, S.,Arato, E.,Bosio, B. Elsevier Sequoia 2017 Journal of Power Sources Vol. No.

<P><B>Abstract</B></P> <P>MCFC represents an effective technology to deal with CO<SUB>2</SUB> capture and relative applications. If used for these purposes, due to the working conditions and the possible feeding, MCFC must cope with a different number of poisoning gases such as sulphur compounds. In literature, different works deal with the development of kinetic models to describe MCFC performance to help both industrial applications and laboratory simulations. However, in literature attempts to realize a proper model able to consider the effects of poisoning compounds are scarce.</P> <P>The first aim of the present work is to provide a semi-empirical kinetic formulation capable to take into account the effects that sulphur compounds (in particular SO<SUB>2</SUB>) have on the MCFC performance. The second aim is to provide a practical example of how to effectively include the poisoning effects in kinetic models to simulate fuel cells performances. To test the reliability of the proposed approach, the obtained formulation is implemented in the kinetic core of the SIMFC (SIMulation of Fuel Cells) code, an MCFC 3D model realized by the Process Engineering Research Team (PERT) of the University of Genova.</P> <P>Validation is performed through data collected at the Korea Institute of Science and Technology in Seoul.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Experimental investigation of the effect of Sulphur fed at the cathode side of MCFC. </LI> <LI> Set up of an MCFC kinetic formulation which takes account of the presence of SO<SUB>2</SUB>. </LI> <LI> Performance simulation and validation of MCFC single cells poisoned with SO<SUB>2</SUB>. </LI> </UL> </P>

Experimental influence of operating variables on the performances of MCFCs under SO₂ poisoning

Di Giulio, N.,Audasso, E.,Bosio, B.,Han, J.,McPhail, S.J. Elsevier 2015 International journal of hydrogen energy Vol.40 No.19

<P><B>Abstract</B></P> <P>Molten Carbonate Fuel Cells have reached the status of commercialization and are now ready for the challenge of market penetration. Nevertheless, new innovative applications such as the use of non-conventional fuels and their possible implementation in a Carbon Capture and Storage system, have given new importance to research activities. In particular, the gas feedings used in these applications contain impurities that can damage MCFCs and, of these, sulphur compounds seem to be the most harmful, even at low concentrations.</P> <P>The aim of this work is to test the effect of SO<SUB>2</SUB> on the role of the operating variables governing the electrochemical kinetics of MCFCs, investigate the relationships and advance additional data necessary for the reading of the complex interaction phenomena taking place in these conditions. The current work is therefore not intended to probe into the fundamental electrochemical mechanisms, but more to validate the window of viable operating conditions that can be expected in real applications. In particular, an experimental campaign was performed, feeding 2 ppm of SO<SUB>2</SUB> to the cathode of MCFC single-cells at different operating temperature and gas partial pressures (H<SUB>2</SUB>, CO<SUB>2</SUB>, O<SUB>2</SUB>), taking into account possible chemical, electrochemical and physical poisoning mechanisms.</P> <P>The experimental tests were performed at the Fuel Cell Research Centre laboratories of KIST (South Korea) and a preliminary theoretical analysis was also proposed to suggest operating strategies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Low temperatures favour the SO<SUB>2</SUB> poisoning effect, especially under 640 °C. </LI> <LI> Optimal range for hydrogen composition is between 40% and 60%. </LI> <LI> The Oxygen concentration does not influence SO<SUB>2</SUB> poisoning for CO<SUB>2</SUB>/O<SUB>2</SUB> < 0.9. </LI> <LI> CO<SUB>2</SUB> compositions under 6% strongly amplify the impact of SO<SUB>2</SUB> poisoning. </LI> </UL> </P>