Please use this identifier to cite or link to this item:
Numerical study of Hydrogen Production by Ammonia Decomposition
|關鍵字:||重組器;NH3 decomposition;氨氣熱裂解反應;填充床法;氨氣轉換率;packed-bed reactor;partially filled reactor;decomposition efficiency;volumetric feed rate||出版社:||機械工程學系所||引用:|| 衣寶廉 編著，黄朝榮、林修正 校訂，燃料電池-原理與應用，2004。  曲新生，氫能源應用與燃料電池發展現況，2005。  R.Z. Sorensen, L.J.E. Nielsen, S. Jensen, O. Hansen, T. Johannessen, U. Quaada, C.H. Christensen, Catalytic ammonia decomposition: miniaturized production of COx–free hydrogen for fuel cells, Catalysis Communications 6 (2005) 229–232.  T. Saika, M. Nakamura, T. Nohara, S. Ishimatsu, Study of hydrogen supply system with ammonia fuel, J. JSEM 49 (2006) 78–83.  J.C. Ganley, E.G. Seebauer, R.I. Masel, Porous anodic alumina microreactors for production of hydrogen from ammonia, J. AIChE 50 (2004) 829–834.  J.C. Ganley, E.G. Seebauer, R.I. Masel, Development of a microreactor for the production of hydrogen from ammonia, J. Power Sources 137 (2004) 53–61.  A. Brown, K. Jupp, Comparison of Ni/Al2O3 and Pt/Al2O3 catalysts for ammonia decomposition using a flux response technique, Chemical Engineering 24 (2004) 1–6.  S.F. Yin, B.Q. Xu, X.P. Zhou, C.T. Au, A mini–review on ammonia decomposition catalysts for on–site generation of hydrogen for fuel cell applications, Applied Catalysis A: General 277 (2004) 1–9.  R.Z. Sorensen, A. Klerke, U. Quaade, S. Jensen, O. Hansen, C.H. Christensen, Promoted Ru on high–surface area graphite for efficient miniaturized production of hydrogen from ammonia, Cat. Lett. 112 (2006) 1–2.  W. Zheng, J. Zhang, H. Xu, W. Li, NH3 decomposition kinetics on supported Ru clusters: morphology and particle size effect, Cat. Lett. 119 (2007) 311–318.  M.T. Lee, R. Greif, C.P. Grigoropoulos, H.G. Park, F.K. Hsu, Transport in packed–bed and wall–coated steam–methanol reformers, J. Power Sources 166 (2007) 194–201.  S.R. Deshmukh, A.B. Mhadeshwar, D.G. Vlachos, Microreactor modeling for hydrogen production from ammonia decomposition on ruthenium, Ind. Eng. Chem. Res. 43 (2004) 2986–2999.  S.R. Deshmukh, D.G. Vlachos, CFD simulations of coupled, countercurrent combustor/reformer microdevices for hydrogen production, Ind. Eng. Chem. Res. 44 (2005) 4982–4992.  M.R. Rahimpour, A. Asgari, Modeling and simulation of ammonia removal from purge gases of ammonia plants using a catalytic Pd–Ag membrane reactor, Hazardous Materials 153 (2008) 557–565.  M.E.E. Abashar, Y.S. Al–Sughair, I.S. Al–Mutaz, Investigation of low temperature decomposition of ammonia using spatially patterned catalytic membrane reactors, Applied Catalysis A: General 236 (2002) 35–53.  A.S. Chellappa, C.M. Fischer, W.J. Thomson, Ammonia decomposition kinetics over Ni–Pt/Al2O3 for PEM fuel cell applications, Applied Catalysis A: General 227 (2002) 231–240.  G.G. Park, S.D. Yima, Y.G. Yoon, C.S. Kim, D.J. Seo, K. Eguchi, Hydrogen production with integrated microchannel fuel processor using methanol for portable fuel cell systems, Catalysis Today 110 (2005) 108–113.  A. Bejan, Convection heat transfer, Wiley Publication, New York (1984).  H.C. Brinkman, A calculation of the viscous force expected by a flowing fluid on a dense swarm of particles, Applied Science Reserch A1 (1947) 27–34.  J.S. Suh, M.T. Lee, R. Greif, C.P. Grigoropoulos, A study of steam methanol reforming in a microreactor, J. Power Sources 173 (2007) 458–466.  W.L. McCabe, J.C. Smith, P. Harriot, Unit operations of chemical engineering, New York: McCraw–Hill 7 (1993).  A.F. Mills, Mass Transfer, Prentice Hall, Upper Saddle River, N.J. (2001).  H.G. Park, J.A. Malen, W.T. Piggott, III, J.D. Morse, R. Greif, C.P. Grigoropoulos, R. Upadhye, M.A. Havstad, Methanol steam reformer on a silicon wafer, J. MEMS 15 (2006) 976–985.||摘要:||
The goal of this study aims to explore more understanding regarding the hydrogen production from NH3 decomposition for fuel cell applications. A numerical model based on the commercial computational fluid dynamics package Fluent is developed to solve the governing equations simultaneously. The numerical model is verified using the available experimental data reported in the literature using packed Ni-Pt/Al2O3 particles as the catalyst in a cylindrical reactor.
Based on the good agreement between the numerical and experimental data, the established numerical model is extended to investigate the NH3 decomposition efficiency using partially filled catalyst layer inside the reactor. It is intended to examine the flow effect on the NH3 decomposition. Under the same catalyst loading and NH3 feed rate, it is found that the packed bed reactor has better performance as compared with those with partially filled catalyst layers under the isothermal reaction. The reason may be attributed to that the decomposition is essentially temperature governed and flow plays insignificant role during the isothermal chemical reaction.
Since heat flux is usually applied at the reactor wall in practical operation of reactor, the present study also investigate the NH3 decomposition efficiency with heat flux applied at the reactor wall. Under such thermal condition, it is found that the reactor with partially filled catalyst layer has better performance as compared with the packed bed reactor. This is because of large temperature gradient generated by the fast flow outside the catalyst layer.
For both isothermal and applied heat flux operated reactors, the present study also shows that NH3 volumetric feed rate is an important factor that determining the decomposition efficiency in addition to the type of catalyst.
Keywords: NH3 decomposition, packed-bed reactor, partially filled reactor, decomposition efficiency, and volumetric feed rate.
|Appears in Collections:||機械工程學系所|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.