Actualités | Symbiose

> Le projet Symbiose est à la recherche de compétences

17-12-09 par Symbiose

Dans le cadre de son activité recherche en modélisation pour le projet, l'équipe Comore de l'INRIA de Sophia-Antipolis est à la recherche :

- d'étudiants en Master automatique ou mathématiques appliquées pour un sujet en lien avec la modélisation et le contrôle du procédé Symbiose (possibilité de poursuivre en thèse).

- d'un Post-doctorant, ayant un doctorat en contrôle optimal ou en optimisation, si possible appliqué à des systèmes biologiques (durée: 18 mois).
Contact et renseignements : olivier.bernard@sophia.inria.fr

> ACV dynamique de la production de biogaz à partir de microalgues

14-10-09 par Symbiose

Dans le cadre de l'évènement "Life cycle conference" à Boston du 29 septembre au 2 octobre 2009, furent présenté les premiers résultats d'un travail portant sur une approche dynamique de l'ACV et appliquée à la méthanisation des microalgues. Ce travail s'inscrit dans la thèse de Pierre Collet (INRA-LBE, SupAgro) et qui participe de l'approche ACV dans le cadre du projet Symbiose (contact collet(at)supagro.inra.fr)

Dynamic Life Cycle Assessment of biogas production from micro-algae
Collet Pierre, Montpellier SupAgro
Arnaud Hélias, Montpellier SupAgro
Laurent Lardon, INRA
Jean-Philippe Steyer, Montpellier SupAgro
télécharger la présentation

Fossil fuel depletion and climate change have lead many research groups and private companies to focus on use of biomass to produce renewable energy and fuel. Because of their high production yield, micro-algae have been pointed as an interesting alternative. A relevant mean to upgrade the energy value of micro-algae with optimal performances is the anaerobic digestion of the algae. It enables achievement of environmental benefits and production of energy from renewable resources. However such processes only exist at lab-scale. In order to assess and optimize its performances and environmental impacts, one has to stimulate its behaviour through dynamical models. In broad outline the two major compartments of the system (micro-algae culture and anaerobic digestion process) are linked by internal flows (micro-algae, digestates…) and receive external flows (light, cosubstrates…). As a consequence, overall behaviour is determined by the interaction of several time-dependent processes. For example, the temporal availability of winery effluents induces a better anaerobic digestion due to the high C/N ratio of this kind of cosubstrate, and consequently a bigger production of biogas. So, due to the close loop operating, the needs of chemical fertilizers are lower, and the emissions caused by their production too. This shows the necessity to realize a dynamic Life Cycle Assessment. In our context, a pertinent Life Cycle Inventory can not be achieved without taking into account the dynamic of several processes; some economic flows are determined according to the temporal evolution of processes. Consequently, we integrate dynamic system modeling of micro-algae growth and anaerobic digestion of biomass in the LCA in order to obtain dynamic flows. This approach allows us to obtain dynamic data for the Life Cycle Inventory. This is a preliminary step to more accurate impact assessment.

> Méthanisation des microalgues (Algal Biomass Summit - 09, San Diego)

07-10-09 par Symbiose

Dans le cadre du sommet sur la biomasse algale à San Diego du 6 au 9 Octobre 2009 organisé par l'Organisation de la Biomasse Algale a été présenté un poster qui illustre les enjeux et les défis associés à la méthanisation des microalgues. (contact bruno.sialve(at)naskeo.com)

Anaerobic Digestion of photosynthetic biomass toward sustainable production of bioenergy.

Sialve Bruno^a, Bernet Nicolas^b, Olivier Bernard^c , Monique Ras^b, Laurent Lardon^b and Steyer Jean-Philippe^b

^a Naskeo Environnement, Avenue des Etangs, Narbonne F-11100, France

^bINRA, UR050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France

^cINRIA-COMORE, 2004 Avenue des lucioles, BP93, Sophia-Antipolis F-06902, France

Abstract :

Cultivation of microalgae as energetic biomass or as for CO₂ fixation is subject to intense academic and industrial research. Whatever the energetic valorization strategies, massive cultures require high amounts of fertilizers and the management of residual biomass nitrogen and phosphorus rich. Anaerobic digestion is a process that can solve these issues. Indeed, it makes possible the production of energy from organic waste together the recovery of essentials nutrients such as ammonium and phosphate. However, microalgae conversion into methane is limited by three main bottlenecks: potential resistance of cell walls, high protein content (potential risk of toxic ammonia release) and presence of sodium for marine species. Several strategies are available to efficiently increase the conversion yield. Co-digestion with various types of substrates, physicochemical pretreatments of biomass and control of gross composition can be successfully applied. The ability of algal biomass to consume CO₂ from flux gases or biogas, reinforce the interest of closely associating microalgal cultures and anaerobic digestion.

The Symbiose research project has recently been launched with the ambition to develop an integrated system designed to produce methane using a source of industrial CO₂, a source of organic waste and solar energy. Research of ecosystems with a tolerance to the process conditions and the understanding of their ecology, two steps anaerobic digestion for improved conversion yields, modelisation and ecodesign of the integrated process are the principal fields of research addressed. Symbiose relies on recent advances in both control of microalgae cultivation and anaerobic digestion processes and it integrates ecology of pond ecosystems and ecodesign. Expected results from this program will be of key interest for most of the projects dealing with mass cultivation of microalgae.