Performance of a PEMFC system integrated with a biogas chemical looping reforming processor: A theoretical analysis and comparison with other fuel processors (steam reforming, partial oxidation and auto-thermal reforming)

Abstract In this work, the performance of a PEMFC (proton exchange membrane fuel cell) system integrated with a biogas chemical looping reforming processor is analyzed. The global efficiency is investigated by means of a thermodynamic study and the application of a generalized steady-state electrochemical model. The theoretical analysis is carried out for the commercial fuel cell BCS 500W stack. From literature, chemical looping reforming (CLR) is described as an attractive process only if the system operates at high pressure. However, the present research shows that advantages of the CLR process can be obtained at atmospheric pressure if this technology is integrated with a PEMFC system. The performance of a complete fuel cell system employing a fuel processor based on CLR technology is compared with those achieved when conventional fuel processors (steam reforming (SR), partial oxidation (PO) and auto-thermal reforming (ATR)) are used. In the first part of this paper, the Gibbs energy minimization method is applied to the unit comprising the fuel- and air-reactors in CLR or to the reformer (SR, PO, ATR). The goal is to investigate the characteristics of these different types of reforming process to generate hydrogen from clean model biogas and identify the optimized operating conditions for each process. Then, in the second part of this research, material and energy balances are solved for the complete fuel cell system processing biogas, taking into account the optimized conditions found in the first part. The overall efficiency of the PEMFC stack integrated with the fuel processor is found to be dependent on the required power demand. At low loads, efficiency is around 45%, whereas, at higher power demands, efficiencies around 25% are calculated for all the fuel processors. Simulation results show that, to generate the same molar flow-rate of H 2 to operate the PEMFC stack at a given current, the global process involving SR reactor is by far much more energy demanding than the other technologies. In this case, biogas is burnt in a catalytic combustor to supply the energy required, and there is a concern with respect to CO 2 emissions. The use of fuel processors based on CLR, PO or ATR results in an auto-thermal global process. If CLR based fuel processor is employed, CO 2 can be easily recovered, since air is not mixed with the reformate. In addition, the highest values of voltage and power are achieved when the PEMFC stack is fed on the stream coming from SR and CLR fuel processors. When a H 2 mixture is produced by reforming biogas through PO and ATR technologies, the relative anode overpotential of a single cell is about 55 mV, whereas, with the use of CLR and SR processes, this value is reduced to ∼37 and 24 mV, respectively. In this way, CLR can be seen as an advantageous reforming technology, since it allows that the global process can be operated under auto-thermal conditions and, at the same time, it allows the PEMFC stack to achieve values of voltage and power closer to those obtained when SR fuel processors are used. Thus, efforts on the development of fuel processors based on CLR technology operating at atmospheric pressure can be considered by future researchers. In the case of biogas, the CO 2 captured can produce additional economical benefits in a ‘carbon market’.

[1]  Luciane Neves Canha,et al.  An electrochemical-based fuel-cell model suitable for electrical engineering automation approach , 2004, IEEE Transactions on Industrial Electronics.

[2]  William F. Northrop,et al.  Thermally integrated fuel processor design for fuel cell applications , 2012 .

[3]  Zuomin Dong,et al.  Optimization of a PEM fuel cell system based on empirical data and a generalized electrochemical semi-empirical model , 2006 .

[4]  Dennis Y.C. Leung,et al.  A review of biomass-derived fuel processors for fuel cell systems , 2009 .

[5]  Takuma Mori,et al.  Autothermal reforming of biogas over a monolithic catalyst , 2010 .

[6]  Sangobtip Pongstabodee,et al.  Preferential oxidation of carbon monoxide in simulated reformatted gas over PtAu/CexZnyO2 catalysts , 2010 .

[7]  Guangwen Xu,et al.  Producing H2‐rich gas from simulated biogas and applying the gas to a 50w PEFC stack , 2004 .

[8]  H. Hofbauer,et al.  Catalytic steam reforming of model biogas , 2008 .

[9]  Hermann Hofbauer,et al.  Syngas and a separate nitrogen/argon stream via chemical looping reforming – A 140 kW pilot plant study , 2010 .

[10]  Johan E. Hustad,et al.  Experimental and thermodynamic studies of the catalytic partial oxidation of model biogas using a plasma-assisted gliding arc reactor , 2011 .

[11]  G. Manzolini,et al.  CO2 capture from combined cycles integrated with Molten Carbonate Fuel Cells , 2010 .

[12]  J. Fierro,et al.  Biogas reforming over bimetallic PdNi catalysts supported on phosphorus-modified alumina , 2011 .

[13]  Takafumi Yoshida,et al.  Optimising H2 production from model biogas via combined steam reforming and CO shift reactions , 2005 .

[14]  Juan Adánez,et al.  Hydrogen production by chemical-looping reforming in a circulating fluidized bed reactor using Ni-based oxygen carriers , 2009 .

[15]  Juan Adánez,et al.  Optimization of hydrogen production by Chemical-Looping auto-thermal Reforming working with Ni-based , 2011 .

[16]  Zuomin Dong,et al.  Optimal fuel cell system design considering functional performance and production costs , 1998 .

[17]  Rajesh K. Ahluwalia,et al.  A natural-gas fuel processor for a residential fuel cell system. , 2009 .

[18]  J. V. Zee,et al.  Effect of Reformate Components on PEMFC Performance Dilution and Reverse Water Gas Shift Reaction , 2004 .

[19]  M. Johansson,et al.  The use of NiO as an Oxygen Carrier in Chemical-Looping Combustion , 2006 .

[20]  Miroslaw L. Wyszynski,et al.  Biogas upgrade to syn-gas (H 2CO) via dry and oxidative reforming , 2011 .

[21]  I. L. Muller,et al.  Operation of solid oxide fuel cells on glycerol fuel: A thermodynamic analysis using the Gibbs free energy minimization approach , 2010 .

[22]  Takuma Mori,et al.  Durability of a Ni based monolithic catalyst in the autothermal reforming of biogas , 2009 .

[23]  Iduvirges Lourdes Muller,et al.  Thermodynamic analysis of ethanol steam reforming using Gibbs energy minimization method: A detailed study of the conditions of carbon deposition , 2009 .

[24]  Theophilos Ioannides,et al.  Efficiency of a solid polymer fuel cell operating on ethanol , 2000 .

[25]  Jens R. Rostrup-Nielsen,et al.  Technologies for large-scale gas conversion , 2001 .

[26]  D. Duprez,et al.  Cooperative effect between copper and gold on ceria for CO-PROX reaction , 2012 .

[27]  James Larminie,et al.  Fuel Cell Systems Explained , 2000 .

[28]  Viktor Hacker,et al.  Hydrogen for fuel cells from ethanol by steam-reforming, partial-oxidation and combined auto-thermal reforming: A thermodynamic analysis , 2008 .

[29]  R. Besser.  Thermal integration of a cylindrically symmetric methanol fuel processor for portable fuel cell power , 2011 .

[30]  W. Pies,et al.  I. Barin, O. Knacke, O. Kubaschewski: Thermochemical Properties of Inorganic Substances — Supplement. Springer‐Verlag, Berlin‐Heidelberg‐New York; Verlag Stahleisen, Düsseldorf 1977. 861 Seiten, Preis: DM 170,– , 1978 .

[31]  Q. Jing,et al.  Combined catalytic partial oxidation and CO2 reforming of methane over ZrO2-modified Ni/SiO2 catalysts using fluidized-bed reactor , 2006 .

[32]  J. C. Amphlett,et al.  A model predicting transient responses of proton exchange membrane fuel cells , 1996 .

[33]  F. Büchi,et al.  In-situ resistance measurements of Nafion® 117 membranes in polymer electrolyte fuel cells , 1996 .

[34]  J. C. Amphlett,et al.  Performance modeling of the Ballard Mark IV solid polymer electrolyte fuel cell. II: Empirical model development , 1995 .

[35]  M. Soria,et al.  Thermodynamic and experimental study of combined dry and steam reforming of methane on Ru/ ZrO2-La2O3 catalyst at low temperature , 2011 .

[36]  Brant A. Peppley,et al.  Integrated fuel processors for fuel cell application : A review , 2007 .

[37]  J. C. Amphlett.  Performance Modeling of the Ballard Mark IV Solid Polymer Electrolyte Fuel Cell , 1995 .

[38]  P. Baggio,et al.  A thermodynamic analysis of natural gas reforming processes for fuel cell application , 2007 .

[39]  Arnaud Delebarre,et al.  Biogas combustion in a chemical looping fluidized bed reactor , 2009 .

[40]  A. J. Assis,et al.  Thermodynamic assessment of hydrogen production and cobalt oxidation susceptibility under ethanol re , 2011 .

[41]  S. Kolaczkowski,et al.  Evaluation of thermodynamically favourable operating conditions for production of hydrogen in three different reforming technologies , 2002 .

[42]  Javier A. Francesconi,et al.  Effects of PEMFC operating parameters on the performance of an integrated ethanol processor , 2010 .

[43]  Brant A. Peppley,et al.  Henry's Law and the solubilities of reactant gases in the modelling of PEM fuel cells , 2006 .

[44]  Pierre R. Roberge,et al.  Development and application of a generalised steady-state electrochemical model for a PEM fuel cell , 2000 .

[45]  Junichi Takahashi,et al.  Biogas as a reproducible energy source: Its steam reforming for electricity generation and for farm machine fuel , 2006 .

[46]  Thomas Aicher,et al.  A portable fuel processor for hydrogen production from ethanol in a 250 Wel fuel cell system , 2009 .

[47]  Alessandra Perna,et al.  Hydrogen from ethanol: Theoretical optimization of a PEMFC system integrated with a steam reforming processor , 2007 .

[48]  Daniel V. Applegate,et al.  Hydrogen from natural gas: part I—autothermal reforming in an integrated fuel processor , 2005 .

[49]  A. Lyngfelt,et al.  Synthesis gas generation by chemical-looping reforming in a continuously operating laboratory reactor , 2006 .

[50]  Manos Mavrikakis,et al.  Preferential CO oxidation in hydrogen: reactivity of core-shell nanoparticles. , 2010, Journal of the American Chemical Society.

[51]  Hyun Chul Lee,et al.  A compact and highly efficient natural gas fuel processor for 1-kW residential polymer electrolyte membrane fuel cells , 2007 .

[52]  I. Barin,et al.  Thermochemical properties of inorganic substances , 1973 .

[53]  Tadashi Yoshida,et al.  Process development of hydrogenous gas production for PEFC from biogas , 2004 .

[54]  Paloma Ferreira-Aparicio,et al.  Development of biogas reforming Ni-La-Al catalysts for fuel cells , 2007 .

[55]  Anders Lyngfelt,et al.  NiO supported on Mg–ZrO2 as oxygen carrier for chemical-looping combustion and chemical-looping reforming , 2009 .