Flow, Turbulence and Combustion

, Volume 89, Issue 2, pp 215–230 | Cite as

Numerical Investigation on the Hydrogen-Assisted Start-Up of Methane-Fueled, Catalytic Microreactors

Article

Abstract

The hydrogen-assisted start-up of methane-fueled, catalytic microreactors has been investigated numerically in a plane-channel configuration. Transient 2-D simulations have been performed in a platinum-coated microchannel made of either ceramic or metallic walls. Axial heat conduction in the solid wall and surface radiation heat transfer were accounted for. Simulations were performed by varying the inlet pressure, the solid wall thermal conductivity and heat capacity, and comparisons were made between fuel mixtures comprising 100% CH4 and 90% CH4–10% H2 by volume. A significant reduction in the ignition (t ig) and steady-state (t st) times was evident for microreactors fed with hydrogen-containing mixtures in comparison to pure methane-fueled ones, for all pressures and reactor materials investigated, with hydrogen having a direct thermal rather than chemical impact on catalytic microreactor ignition. The positive impact of H2 addition was attenuated as the pressure (and the associated CH4 catalytic reactivity) increased. Reactors with low wall thermal conductivity (cordierite material) benefited more from hydrogen addition in the fuel stream and exhibited shorter ignition times compared to higher thermal conductivity ones (FeCr alloy) due to the creation of spatially localized hot spots that promoted catalytic ignition. At the same time, the cordierite material required shorter times to reach steady state. Microreactor emissions were impacted positively by the addition of hydrogen in the fuel stream, with a significant reduction in the cumulative methane emissions and no hydrogen breakthrough. Finally, gas-phase chemistry was found to elongate the steady-state times for both ceramic and metallic materials.

Keywords

Catalytic microreactors Transient simulation Hetero-/homogeneous combustion Hydrogen-assisted combustion 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Fernandez-Pello, A.C.: Micropower generation using combustion: issues and approaches. Proc. Comb. Instit. 29, 883–899 (2002)CrossRefGoogle Scholar
  2. 2.
    Gomez, A., Berry, J.J., Roychoudhury, S., Coriton, B., Huth, J.: From jet fuel to electric power using a mesoscale, efficient Stirling cycle. Proc. Combust. Inst. 31, 3251–3259 (2007)CrossRefGoogle Scholar
  3. 3.
    Karim, A.M., Federici, J.A., Vlachos, D.G.: Portable power production from methanol in an integrated thermoelectric/microreactor system. J. Power Sources 179, 113–120 (2008)CrossRefGoogle Scholar
  4. 4.
    Ahn, J.M., Eastwood, C., Sitzki, L., Ronney, P.D.: Gas-phase and catalytic combustion in heat-recirculating burners. Proc. Combust. Inst. 30, 2463–2472 (2005)CrossRefGoogle Scholar
  5. 5.
    Kaisare, N.S., Deshmukh, S.R., Vlachos, D.G.: Stability and performance of catalytic microreactors: simulations of propane catalytic combustion on Pt. Chem. Eng. Sci. 63, 1098–1116 (2008)CrossRefGoogle Scholar
  6. 6.
    Maruta, K., Takeda, K., Ahn, J., Borer, K., Sitzki, L., Ronney, P.D., Deutschmann, O.: Extinction limits of catalytic combustion in microchannels. Proc. Combust. Inst. 29, 957–963 (2002)CrossRefGoogle Scholar
  7. 7.
    Karagiannidis, S., Mantzaras, J., Jackson, G., Boulouchos, K.: Hetero-/homogeneous combustion and stability maps in methane-fueled catalytic microreactors. Proc. Combust. Inst. 31, 3309–3317 (2007)CrossRefGoogle Scholar
  8. 8.
    Pizza, G., Mantzaras, J., Frouzakis, C.E., Tomboulides, A.G., Boulouchos, K.: Suppression of combustion instabilities of premixed hydrogen/air flames in microchannels using heterogeneous reactions. Proc. Combust. Inst. 32, 3051–3058 (2009)CrossRefGoogle Scholar
  9. 9.
    Kaisare, N.S., Stefanidis, G.D., Vlachos, D.G.: Comparison of ignition strategies for catalytic microburners. Proc. Combust. Inst. 32, 3027–3034 (2009)CrossRefGoogle Scholar
  10. 10.
    Tischer, S., Correa, C., Deutschmann, O.: Transient three-dimensional simulation of a catalytic combustion monolith using detailed models for heterogeneous and homogeneous reactions and transport phenomena. Catal. Today 69, 57–62 (2001)CrossRefGoogle Scholar
  11. 11.
    Schneider, A., Mantzaras, J., Eriksson, S.: Ignition and extinction in catalytic partial oxidation of methane–oxygen mixtures with large H2O and CO2 dilution. Combust. Sci. Technol. 180, 89–126 (2008)CrossRefGoogle Scholar
  12. 12.
    Karagiannidis, S., Mantzaras, J.: Numerical investigation on the start-up of methane-fueled catalytic microreactors. Combust. Flame 157, 1400–1413 (2010)CrossRefGoogle Scholar
  13. 13.
    Schneider, B., Karagiannidis, S., Bruderer, M., Dyntar, D., Zwyssig, C., Guangchun, Q., Diener, M., Boulouchos, K., Abhari, R.S., Guzzella, L., Kolar, J.W.: Ultra-high-energy-density converter for portable power. Power-MEMS 2005, November 28–30, Tokyo, Japan (2005)Google Scholar
  14. 14.
    Isomura, K., Murayama, M., Teramoto, S., Hikichi, K., Endo, Y., Togo, S., Tanaka, S.: Experimental verification of the feasibility of a 100 W class micro-scale gas turbine at an impeller diameter of 10 mm. J. Micromechanics Microengineering 16, 254–261 (2006)CrossRefGoogle Scholar
  15. 15.
    Peirs, J., Waumans, T., Vleugels, P., Al-Bender, F.T.S., Verstraete, T., Stevens, S., D’hulst, R., Verstraete, D., Fiorini, P., Van der Braembussche, R., Driesen, J., Puers, R., Hendrick, P., Baelmans, M., Reynaerts, D.: Micropower generation with microgasturbines: a challenge. J. Mech. Eng. Sci. 221, 489–500 (2007)Google Scholar
  16. 16.
    Dogwiler, U., Benz, P., Mantzaras, J.: Two-dimensional modelling for catalytically stabilized combustion of a lean methane–air mixture with elementary homogeneous and heterogeneous chemical reactions. Combust. Flame 116, 243–258 (1999)CrossRefGoogle Scholar
  17. 17.
    Siegel, R., Howell, J.R.: Thermal Radiation Heat Transfer, p. 271. Hemisphere, New York (1981)Google Scholar
  18. 18.
    Deutschmann, O., Maier, L.I., Riedel, U., Stroemman, A.H., Dibble, R.W.: Hydrogen assisted catalytic combustion of methane on platinum. Catal. Today 59, 141–150 (2000)CrossRefGoogle Scholar
  19. 19.
    Warnatz, J., Dibble, R.W., Maas, U.: Combustion, Physical and Chemical Fundamentals, Modeling and Simulation. Springer, New York (1996)Google Scholar
  20. 20.
    Reinke, M., Mantzaras, J., Schaeren, R., Bombach, R., Inauen, A., Schenker, S.: High-pressure catalytic combustion of methane over platinum: in situ experiments and detailed numerical predictions. Combust. Flame 136, 217–240 (2004)CrossRefGoogle Scholar
  21. 21.
    Reinke, M., Mantzaras, J., Bombach, R., Schenker, S., Inauen, A.: Gas phase chemistry in catalytic combustion of methane/air mixtures over platinum at pressures of 1 bar to 16 bar. Combust. Flame 141, 448–468 (2005)CrossRefGoogle Scholar
  22. 22.
    Kee, R.J., Dixon-Lewis, G., Warnatz, J., Coltrin, M.E., Miller, J.A.: A Fortran computer code package for the evaluation of gas-phase multicomponent transport properties. In: Sandia National Laboratories, Report No. SAND86-8246 (1996)Google Scholar
  23. 23.
    Coltrin, M.E., Kee, R.J., Rupley, F.M.: Surface Chemkin: a Fortran package for analyzing heterogeneous chemical kinetics at the solid surface–gas phase interface. In: Sandia National Laboratories, Report No. SAND90-8003 (1996)Google Scholar
  24. 24.
    Kee, R.J., Rupley, F.M., Miller, J.A.: Chemkin II: a Fortran chemical kinetics package for the analysis of gas-phase chemical kinetics. In: Sandia National Laboratories, Report No. SAND89-8009 (1996)Google Scholar
  25. 25.
    Lutz, A.E., Kee, R.J., Miller, J.A.: SENKIN: a Fortran program for predicting homogeneous gas phase chemical kinetics with sensitivity analysis. In: Sandia National Laboratories, Report No. SAND87-8248 (1996)Google Scholar
  26. 26.
    Karagiannidis, S., Marketos, K., Mantzaras, J., Schaeren, R., Boulouchos, K.: Experimental and numerical investigation of a propane-fueled, catalytic mesoscale combustor. Catal. Today 155, 108–115 (2010)CrossRefGoogle Scholar
  27. 27.
    Mantzaras, J.: Catalytic combustion of syngas. Combust. Sci. Technol. 180, 1137–1168 (2008)CrossRefGoogle Scholar
  28. 28.
    Ghermay, Y., Mantzaras, J., Bombach, R.: Experimental and numerical investigation of hetero-/homogeneous combustion of CO/H2/O2/N2 mixtures over platinum at pressures up to 5 bar. Proc. Combust. Inst. 33, 1827–1835 (2011)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Combustion ResearchPaul Scherrer Institute (PSI)VilligenSwitzerland

Personalised recommendations