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Biological self-heating of compost piles with air flow

Conference Paper


Abstract


  • We formulate and investigate a one-dimensional model for self-heating

    in compost piles. The self-heating occurs through a combination of

    biological and chemical mechanisms. Biological heat generation is known

    to be present in most industrial processes handling large volumes of

    bulk organic materials. The heat release rate due to biological

    activity is modelled by a function which at sufficiently low temperatures

    is a monotonic increasing function of temperature. At higher temperatures

    it is a monotonic decreasing function of temperature. This functionality

    represents the fact that micro-organisms die or become domant at

    higher temperature. The heat release due to oxidation reaction

    is modelled by Arrhenius kinetics. The model consists of mass

    balance equations for oxygen and energy. Steady-state temperature

    diagrams are determined as a function of the size of the compost pile

    and the flow rate of air through the pile. We show that there is a range

    of flow rates for which elevated temperatures, including the possibility

    of spontaneous ignition, occur within the pile.

Authors


  •   Luangwilai, Thiansiri (external author)
  •   Sidhu, Harvinder S. (external author)
  •   Nelson, Mark I.
  •   Chen, Xiao Dong (external author)

Publication Date


  • 2009

Citation


  • Luangwilai, T., Sidhu, H. S., Nelson, M. I. & Chen, X. (2009). Biological self-heating of compost piles with air flow. Proceedings of the 37th Australasian Chemical Engineering Conference, CHEMECA 2009 (pp. 1-10). Perth, Western Australia: Engineers Australia.

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Abstract


  • We formulate and investigate a one-dimensional model for self-heating

    in compost piles. The self-heating occurs through a combination of

    biological and chemical mechanisms. Biological heat generation is known

    to be present in most industrial processes handling large volumes of

    bulk organic materials. The heat release rate due to biological

    activity is modelled by a function which at sufficiently low temperatures

    is a monotonic increasing function of temperature. At higher temperatures

    it is a monotonic decreasing function of temperature. This functionality

    represents the fact that micro-organisms die or become domant at

    higher temperature. The heat release due to oxidation reaction

    is modelled by Arrhenius kinetics. The model consists of mass

    balance equations for oxygen and energy. Steady-state temperature

    diagrams are determined as a function of the size of the compost pile

    and the flow rate of air through the pile. We show that there is a range

    of flow rates for which elevated temperatures, including the possibility

    of spontaneous ignition, occur within the pile.

Authors


  •   Luangwilai, Thiansiri (external author)
  •   Sidhu, Harvinder S. (external author)
  •   Nelson, Mark I.
  •   Chen, Xiao Dong (external author)

Publication Date


  • 2009

Citation


  • Luangwilai, T., Sidhu, H. S., Nelson, M. I. & Chen, X. (2009). Biological self-heating of compost piles with air flow. Proceedings of the 37th Australasian Chemical Engineering Conference, CHEMECA 2009 (pp. 1-10). Perth, Western Australia: Engineers Australia.

Start Page


  • 1

End Page


  • 10