LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

GROUP 4, SESSION B: CROP PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
93. Salinalgue project: designing a sustainable production system of
biofuel and by-products from microalgae
Mélissa Cornélus 1,* , Pierre Collet 1 , Stéphane LePochat 3 , Roberto Bellino 3 , Jean-Philippe Steyer 1 , Arnaud
Hélias 1,2
1 INRA, UR50, Laboratoire de Biotechnologie et de l’Environnement, Avenue des Etangs, 11100 Narbonne,
France, 2 Montpellier SupAgro, 2 Place Viala, 34060 Montpellier Cedex 1, France, 3 EVEA, 56 Bd de la
Fraternité, 44100 Nantes, France, Corresponding author. E-mail: melissa.cornelus@supagro.inra.fr
Future developments for the microalgae sector are looking promising with high production yields and no
direct competition with arable lands (Chisti, 2007). However, there remain some major bottlenecks related to
the process chain where energy and water issues challenge the industrialisation of microalgae-based processes
(Lardon et al., 2009).
In addressing these challenges, Life Cycle Assessment (LCA) has become an essential eco-design tool in the
R&D step of algorefinery projects. As a consortium of 13 institutional and private partners, the Salinalgue
project deals with the current environmental challenges underlined in several LCA studies on algal systems.
This system features a culture set in an old farming salty land in the aim of reconversion with an extremophile
native species. This ensures there will be no contamination and no competition against arable lands.
Moreover thanks to the proximity with an industrial area, microalgae may be supplied with industrial CO2
from exhaust gas. LCA aims at paving the way towards building more sustainable systems. Figure 1 gives an
overview of the process chain: from the culture of biomass, its transformation by downstream processes to
the use of oilcake and its conversion into energy and digestates which can later be recycled as inputs of the
system. Below are the 4 key points addressed by the LCA study on the Salinalgue project:
(1) As there are no industrial facilities yet (even at pilot-scale) (Brentner et al., 2011), most of data is scaled
up according to partners' knowledge and literature review. LCA helps to foresee the environmental impacts
of emerging technologies. Several process technologies are considered at each step: such as green extraction
by new technologies.
(2) Taking up the biorefinery concept, LCA helps partners by pointing out the hotspots, comparing options
and informing eco-choices. This approach is reiterated at each stage of the system. For example, several CO2
supply chains for the algae culture have been compared.
(3) The whole life cycle is analysed: from the production of algal nutrition to the recycling of nutrients contained
in the oilcake (with the liquid fraction being recirculated towards cultivation ponds) (Collet et al.,
2011). Thereby, LCA provides a holistic point of view. This is useful in such a collaborative project where
each partner is mostly focused on its respective operation stage.
(4) Salinalgue is a multi-output system. In such a complex system, it is critical to deal with all the byproducts
in the LCA study, which raises some methodological issues such as allocation or substitution.
Salinalgue is a two-stage project, where an industrial scaling-up of the system will follow the experimental
R&D stage. A step by step approach where the most preferable technology is selected will provide a roadmap
towards the most sustainable process chain to yield biofuel and bioproducts from microalgae.
References
Brentner, L. B., Eckelman, M. J. et Zimmerman, J. B., 2011. Combinatorial Life Cycle Assessment to Inform
Process Design of Industrial Production of Algal Biodiesel. Environ. Sci. Technol. 45 (16) pp.7060-
67.
Chisti, Y., 2007. Biodiesel from microalgae. Biotechnology Advances 25 (3) pp.294-306.
Collet, P., Hélias, A., Lardon, L., Ras, M., Goy, R.-A. et Steyer, J.-P., 2011. Life-cycle assessment of microalgae
culture coupled to biogas production. Bioresource Technology 102 (1) pp.207-14.
Lardon, L., Hélias, A., Sialve, B., Steyer, J.-P. et Bernard, O., 2009. Life-Cycle Assessment of Biodiesel
Production from Microalgae. Environ. Sci. Technol. 43 (17) pp.6475-81.
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