Exergy recuperation of mid and low quality heat by chemical reactions

Takao Nakagaki, Takayuki Ozeki, Yuuta Watanabe

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    Conventional thermal power generation, as typified by gas turbines, has steadily increased power generation efficiency by elevating temperature of heat, but there is a limit to the maximum availability of electric energy. Exergy rate is a unified index indicating the quality of energy in deferent forms. We have no way in thermal conversion to extract all of the availability, while almost hydrocarbon fuels have exergy rate around 95%. 25% of exergy is inevitably lost through the combustion process from chemical to heat at maximum temperature of 2000°C. Hydrogen's low exergy rate provides "exergy recuperation" in which degrading 12% from 95% to 83% can take low quality heat up to availability of 83% as a kind of chemical heat pump. Chemically Recuperated Gas Turbine (CRGT) is a specific example, and dimethyl ether (DME) is one of the most suitable fuels because steam reforming occurs around 300°C. Electrochemical partial oxidation (EPOx) is another way to convert mid-quality heat into electric energy as much as difference between change in Gibbs free energy and change in enthalpy. This paper reports concept and industrially-feasible applications of this unconventional and non-cascadic use of heat.

    Original languageEnglish
    Title of host publicationASME 2011 5th International Conference on Energy Sustainability, ES 2011
    Pages2017-2023
    Number of pages7
    EditionPARTS A, B, AND C
    DOIs
    Publication statusPublished - 2011
    EventASME 2011 5th International Conference on Energy Sustainability, ES 2011 - Washington, DC
    Duration: 2011 Aug 72011 Aug 10

    Other

    OtherASME 2011 5th International Conference on Energy Sustainability, ES 2011
    CityWashington, DC
    Period11/8/711/8/10

    Fingerprint

    Exergy
    Chemical reactions
    Availability
    Power generation
    Gas turbines
    Hot Temperature
    Steam reforming
    Gibbs free energy
    Enthalpy
    Ethers
    Hydrocarbons
    Pumps
    Oxidation
    Hydrogen
    Temperature

    ASJC Scopus subject areas

    • Energy Engineering and Power Technology
    • Renewable Energy, Sustainability and the Environment

    Cite this

    Nakagaki, T., Ozeki, T., & Watanabe, Y. (2011). Exergy recuperation of mid and low quality heat by chemical reactions. In ASME 2011 5th International Conference on Energy Sustainability, ES 2011 (PARTS A, B, AND C ed., pp. 2017-2023) https://doi.org/10.1115/ES2011-54702

    Exergy recuperation of mid and low quality heat by chemical reactions. / Nakagaki, Takao; Ozeki, Takayuki; Watanabe, Yuuta.

    ASME 2011 5th International Conference on Energy Sustainability, ES 2011. PARTS A, B, AND C. ed. 2011. p. 2017-2023.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Nakagaki, T, Ozeki, T & Watanabe, Y 2011, Exergy recuperation of mid and low quality heat by chemical reactions. in ASME 2011 5th International Conference on Energy Sustainability, ES 2011. PARTS A, B, AND C edn, pp. 2017-2023, ASME 2011 5th International Conference on Energy Sustainability, ES 2011, Washington, DC, 11/8/7. https://doi.org/10.1115/ES2011-54702
    Nakagaki T, Ozeki T, Watanabe Y. Exergy recuperation of mid and low quality heat by chemical reactions. In ASME 2011 5th International Conference on Energy Sustainability, ES 2011. PARTS A, B, AND C ed. 2011. p. 2017-2023 https://doi.org/10.1115/ES2011-54702
    Nakagaki, Takao ; Ozeki, Takayuki ; Watanabe, Yuuta. / Exergy recuperation of mid and low quality heat by chemical reactions. ASME 2011 5th International Conference on Energy Sustainability, ES 2011. PARTS A, B, AND C. ed. 2011. pp. 2017-2023
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