ECOCONCEPTION DE FILIERES DE PRODUCTION DE MICROALGUES ET CYANOBACTÉRIES

par Ryma Laifa

Projet de thèse en Génie des Procédés et de l'Environnement

Sous la direction de Pascal Guiraud et de Ligia Tiruta-Barna.

Thèses en préparation à Toulouse, INSA , dans le cadre de École doctorale Mécanique, énergétique, génie civil et procédés , en partenariat avec TBI - Toulouse Biotechnology Institute, Bio & Chemical Engineering (laboratoire) et de TIM - Transfert, Interface, Mélange (equipe de recherche) depuis le 14-06-2018 .


  • Résumé

    Le travail de thèse combinera des aspects expérimentaux et de simulation destinés à évaluer in fine les performances techniques et environnementales de la filière de production. Les expériences contribueront à définir un système de récolte performant par flottation et à le modéliser. Des expériences sur le photobioréacteur de culture seront menées en collaboration avec Alg&You sur leur site expérimental. L'analyse des résultats expérimentaux alimentera des modèles à différentes échelles, hydrodynamique locale (CFD), production de biomasse, récolte par flottation, filière de production de spiruline fraiche. Ces modèles d'opérations unitaires seront couplés avec des modèles de calculs d'impacts environnementaux par la méthode d'analyse de cycle de vie. Le calcul des performances techniques et environnementales permettra une optimisation du procédé dans une approche d'Ecoconception de la filière de production de spiruline.

  • Titre traduit

    ECODESIGN OF PRODUCTION SYSTEMS FOR MICROALGAE AND CYANOBACTERIAE


  • Résumé

    Microalgae and cyanobacteria cultures are promising production processes for a wide range of bio-sourced products of interest, such as organic compounds for pharmaceuticals and cosmetics, human and livestock nutrition, and maybe in the future for biofuels. Microalgae production processes need water, nutriments, light for cell growth, and energy for temperature control, mixing and harvesting. Light available varies with the plant geographical position and along the year as well as the ambient temperature does. As a consequence, the number of parameters that have to be accounted for the design and for the optimal process running is great and the design has to be specifically done for each production plant. Whatever the application domain, the prediction of the technical, economic and environmental performances of the whole production process remains a challenge for the design due to the lack of suitable models for each successive involved unit operations. For the same reasons, optimizing the parameters with the idea to reach the best performances keeps far from fulfilled. The objective of the presented work is the development of the benchmark simulator for microalgae production and harvesting operations which accounts for their design and operating parameters, with the final aim of evaluating the technical performances of the whole production process and its environmental performances knowing the geographical plant position. As an example, the presented developments and results concern the production of fresh spirulina for the market of human food. Spirulina is the largest produced microalgae in the world, a great number of spirulina production sites of different scales are already existing, and other are planned to be built. The analysis of experimental and literature results feed theoretical models at different scales: local hydrodynamics (CFD), biomass production, harvesting by flotation, value chain for fraiche spirulina production. The developed models for unit processes are coupled with models for environmental impact calculation through Life Cycle Assessment method. The evaluation of technical and environmental performances allow the process optimization by an ecodesign approach of the production process.