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Ammonia Decomposition Coupled with Methane Combustion in Catalytic Microreactors for Hydrogen Production

Received: 3 January 2017     Accepted: 14 January 2017     Published: 6 February 2017
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Abstract

The ammonia decomposition over ruthenium thermally coupled with the catalytic combustion of methane-air mixtures over platinum in catalytic microreactors for hydrogen production was studied numerically, using a two-dimensional computational fluid dynamics model that included detailed chemistry and transport. The effect of flow configuration on the operation characteristics was studied in catalytic microreactors consisting of alternating combustion and decomposition channels separated by a thermally conducting wall. Different performance measures were evaluated to assess the operability of the reactor. It was shown that the high temperatures generated through catalytic combustion result in high conversion in short contact times and thus to compact reactors. Complete conversion of ammonia can be obtained at the micro-scale in both flow configurations. A proper balance of the flow rates of the decomposition and combustion streams is crucial in achieving this. For a given flow rate of combustible mixture, material stability determines the lower power limit, caused by high temperatures generated at low decomposition stream flow rates. In contrast, the maximum power generated is determined by extinction at large decomposition stream flow rates. The two flow configurations were contrasted based on multiple performance criteria, such as reactor temperature, conversion, power exchanged, and hydrogen yield by constructing operating regime. They were found to be practically equivalent for highly conductive materials. Using properly balanced flow rates, the co-current flow configuration expands the operating regime to low and moderate thermal conductivity materials as compared to the counter-current flow configuration that exhibits a slightly superior performance but in a rather narrow operating regime of highly conductive materials and high ammonia flow rates.

Published in Chemical and Biomolecular Engineering (Volume 2, Issue 1)
DOI 10.11648/j.cbe.20170201.14
Page(s) 19-26
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2017. Published by Science Publishing Group

Keywords

Catalytic Microreactor, Ammonia Decomposition, Hydrogen Production, Reactor Design, Process Optimization, Catalytic Combustion

References
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Cite This Article
  • APA Style

    Junjie Chen, Longfei Yan. (2017). Ammonia Decomposition Coupled with Methane Combustion in Catalytic Microreactors for Hydrogen Production. Chemical and Biomolecular Engineering, 2(1), 19-26. https://doi.org/10.11648/j.cbe.20170201.14

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    ACS Style

    Junjie Chen; Longfei Yan. Ammonia Decomposition Coupled with Methane Combustion in Catalytic Microreactors for Hydrogen Production. Chem. Biomol. Eng. 2017, 2(1), 19-26. doi: 10.11648/j.cbe.20170201.14

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    AMA Style

    Junjie Chen, Longfei Yan. Ammonia Decomposition Coupled with Methane Combustion in Catalytic Microreactors for Hydrogen Production. Chem Biomol Eng. 2017;2(1):19-26. doi: 10.11648/j.cbe.20170201.14

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  • @article{10.11648/j.cbe.20170201.14,
      author = {Junjie Chen and Longfei Yan},
      title = {Ammonia Decomposition Coupled with Methane Combustion in Catalytic Microreactors for Hydrogen Production},
      journal = {Chemical and Biomolecular Engineering},
      volume = {2},
      number = {1},
      pages = {19-26},
      doi = {10.11648/j.cbe.20170201.14},
      url = {https://doi.org/10.11648/j.cbe.20170201.14},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.cbe.20170201.14},
      abstract = {The ammonia decomposition over ruthenium thermally coupled with the catalytic combustion of methane-air mixtures over platinum in catalytic microreactors for hydrogen production was studied numerically, using a two-dimensional computational fluid dynamics model that included detailed chemistry and transport. The effect of flow configuration on the operation characteristics was studied in catalytic microreactors consisting of alternating combustion and decomposition channels separated by a thermally conducting wall. Different performance measures were evaluated to assess the operability of the reactor. It was shown that the high temperatures generated through catalytic combustion result in high conversion in short contact times and thus to compact reactors. Complete conversion of ammonia can be obtained at the micro-scale in both flow configurations. A proper balance of the flow rates of the decomposition and combustion streams is crucial in achieving this. For a given flow rate of combustible mixture, material stability determines the lower power limit, caused by high temperatures generated at low decomposition stream flow rates. In contrast, the maximum power generated is determined by extinction at large decomposition stream flow rates. The two flow configurations were contrasted based on multiple performance criteria, such as reactor temperature, conversion, power exchanged, and hydrogen yield by constructing operating regime. They were found to be practically equivalent for highly conductive materials. Using properly balanced flow rates, the co-current flow configuration expands the operating regime to low and moderate thermal conductivity materials as compared to the counter-current flow configuration that exhibits a slightly superior performance but in a rather narrow operating regime of highly conductive materials and high ammonia flow rates.},
     year = {2017}
    }
    

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  • TY  - JOUR
    T1  - Ammonia Decomposition Coupled with Methane Combustion in Catalytic Microreactors for Hydrogen Production
    AU  - Junjie Chen
    AU  - Longfei Yan
    Y1  - 2017/02/06
    PY  - 2017
    N1  - https://doi.org/10.11648/j.cbe.20170201.14
    DO  - 10.11648/j.cbe.20170201.14
    T2  - Chemical and Biomolecular Engineering
    JF  - Chemical and Biomolecular Engineering
    JO  - Chemical and Biomolecular Engineering
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    EP  - 26
    PB  - Science Publishing Group
    SN  - 2578-8884
    UR  - https://doi.org/10.11648/j.cbe.20170201.14
    AB  - The ammonia decomposition over ruthenium thermally coupled with the catalytic combustion of methane-air mixtures over platinum in catalytic microreactors for hydrogen production was studied numerically, using a two-dimensional computational fluid dynamics model that included detailed chemistry and transport. The effect of flow configuration on the operation characteristics was studied in catalytic microreactors consisting of alternating combustion and decomposition channels separated by a thermally conducting wall. Different performance measures were evaluated to assess the operability of the reactor. It was shown that the high temperatures generated through catalytic combustion result in high conversion in short contact times and thus to compact reactors. Complete conversion of ammonia can be obtained at the micro-scale in both flow configurations. A proper balance of the flow rates of the decomposition and combustion streams is crucial in achieving this. For a given flow rate of combustible mixture, material stability determines the lower power limit, caused by high temperatures generated at low decomposition stream flow rates. In contrast, the maximum power generated is determined by extinction at large decomposition stream flow rates. The two flow configurations were contrasted based on multiple performance criteria, such as reactor temperature, conversion, power exchanged, and hydrogen yield by constructing operating regime. They were found to be practically equivalent for highly conductive materials. Using properly balanced flow rates, the co-current flow configuration expands the operating regime to low and moderate thermal conductivity materials as compared to the counter-current flow configuration that exhibits a slightly superior performance but in a rather narrow operating regime of highly conductive materials and high ammonia flow rates.
    VL  - 2
    IS  - 1
    ER  - 

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Author Information
  • Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, China

  • Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, China

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