A diffuse-interface formulation for melting and vaporization of plastics

ORAL

Abstract

Thermo-chemical recycling of plastics, which uses heat and oxidizer-reduced atmospheres to convert waste into syngas, is an emerging technology for recycling multi-polymer materials.

Plastics undergo molecular breakdown during melting and vaporization. Capturing this complex phenomenon in simulations necessitates accurate interface-resolved simulations to account for phase changes and gas phase transport with compressibility effects. Additionally, a surrogate representation of the thermophysical properties for each phase is required. Diffuse Interface (DI) method formulations are a viable alternative for scenarios involving mass transfer, as DI allows solving mass balance equations in each phase, thus satisfying mass conservation at a discrete level.

This work aims to derive a diffuse interface formulation for multiple solids and multi-component systems under non-dilute conditions for liquid and vapor phases. The formulation further includes melting and vaporization terms to account for phase change. The model's capabilities are demonstrated using multi-layer films commonly found in food packaging, consisting of low-linear polyethylene and polypropylene.

*We thank Stanford University's Center for Turbulence Research for supporting part of this work during their 2024 summer program.

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Publication: (Planned) A diffuse-interface formulation for melting and vaporization of plastics

Presenters

  • Danny Long

    • Norwegian University of Science and Technology

Authors

  • Danny Long

    • Norwegian University of Science and Technology

  • Aritra Mukherjee

    • Norwegian University of Science and Technology

  • Salar Zamani Salimi

    • Norwegian University of Science and Technology
    • Norwegian University of Science and Technology, Norway

  • Lucy J Brown

    • Center for Turbulence Research, Stanford University
    • Center for Turbulence Research

  • Henry Collis

    • Stanford University

  • Shahab Mirjalili

    • Stanford University
    • Department of Mechanical Engineering, Stanford University

  • Suhas Jain

    • Woodruff School of Mechanical Engineering, Georgia Institute of Technology, USA. Center for Turbulence Research, Stanford Universty, USA
    • Georgia Institute of Technology, Flow Physics and Computational Sciences Lab
    • Woodruff School of Mechanical Engineering, Georgia Tech
    • Flow Physics and Computational Science Lab, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA
    • Woodruff School of Mechanical Engineering, Georgia Institute of Technology; Center for Turbulence Research, Stanford University
    • George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA

  • Luca Brandt

    • Politecnico di Turino
    • Politecnico di Torino, Italy

  • Corinna Netzer

    • Norwegian University of Science and Technology