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Contribution to the elaboration of a process simulator for the physicochemical transformation of bio-based materials : application to the reactive extrusion of biopolymers ; Contribution à l'élaboration d'un outil de simulation de procédés de transformation physico-chimique de matières premières issues des agro ressources : application aux procédés de transformation de biopolymères par extrusion réactive

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  • معلومة اضافية
    • Contributors:
      Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM); CentraleSupélec; Ecole Centrale Paris; Arsène Isambert
    • بيانات النشر:
      HAL CCSD
    • الموضوع:
      2010
    • Collection:
      École Centrale Paris: HAL-ECP
    • نبذة مختصرة :
      The development of biorefineries requires integrating and optimizing plants and handling a large number of material flows and unit operations. The development of a process simulator dedicated to this field would thus be of great interest. This is what we intended to initiate by relying on the example of the oxidation of biopolymers by reactive extrusion. Reactive extrusion is characterized by a strong coupling between flow, heat transfer and reaction kinetics. This coupling depends on the desired reactions. We here intended to elaborate aflexible model, being easily integrated into a static process simulator, and enabling to reach agood compromise between the predictive character of the model and the amount of experiments required to adjust model parameters. Therefore, we adopted a hybrid modelling approach combining a flow description based on ideal reactors and continuum mechanics laws. Flow is modeled as a cascade of continuous stirred tank reactors (CSTR) with possible backflow. Flow rates between CSTRs are calculated using physical laws taking into account the operating conditions and geometric parameters of the equipment. Each CSTR is characterized by a filling ratio, which depends on the operating conditions. The calculation of steady-state filling ratio, pressure and flow rates between the CSTRs is achieved by performing a material balance in each CSTR. Material temperature in each CSTR is calculated through a thermal balance. The chemical modification of the material is described using three reactions: the oxidative depolymerization, the formation of functional groups(carbonyl and carboxyl) and the thermomechanical degradation of the biopolymer induced by heating and shearing. The number-averaged and weight-averaged molecular weight of the biopolymer and the oxidant content in each CSTR are computed simultaneously by applying the moment operation to population balance equations. Viscosity is linked to the mean molecular weight. An iterative algorithm enables to couple material balance, thermal balance ...
    • Relation:
      NNT: 2010ECAP0020; tel-01171596; https://theses.hal.science/tel-01171596; https://theses.hal.science/tel-01171596/document; https://theses.hal.science/tel-01171596/file/Memoire.pdf
    • الدخول الالكتروني :
      https://theses.hal.science/tel-01171596
      https://theses.hal.science/tel-01171596/document
      https://theses.hal.science/tel-01171596/file/Memoire.pdf
    • Rights:
      info:eu-repo/semantics/OpenAccess
    • الرقم المعرف:
      edsbas.328471A4