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

GROUP 6, SESSION B: METHODS, TOOLS, DATABASES 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
159. Ecodesign of plant-based building materials using LCA: crop
production and primary transformation of hemp
Andrianandraina 1,* , Hayo van der Werf 2,3 , Anne Ventura 4 , Rachida Idir 5
1 Université Nantes-Angers-Le Mans (LUNAM), Agence de l’Environnement et de la Maîtrise de l’Energie
(ADEME), Institut Français Sciences et Technologies Transport Aménagement Réseaux (IFSTTAR), Département
Matériaux, F-44341 Bouguenais, France, 2 INRA, UMR1069 Sol, Agro and hydroSystem, F-35000
Rennes, France, 3 Agrocampus Ouest, F-35000 Rennes, France, 4 Université Nantes-Angers-Le Mans (LU-
NAM), Institut Français Sciences et Technologies Transport Aménagement Réseaux (IFSTTAR), Département
Matériaux, F-44341 Bouguenais, France, 5 Laboratoire Eco-Matériaux, CETE Ile de France, Paris,
France, Corresponding author. E-mail: andy.andrianandraina@ifsttar.fr
France has ambitious environmental goals regarding climate change and energy use, in particular since the
so-called Grenelle de l’Environnement laws were passed. The building and housing sector is a major contributor
to these impacts. New building materials, in particular thermal insulators, using plants like hemp as a
raw material as presented by Korjenic et al. (2011) and Kymalainen and Sjoberg (2008), have appeared in
the building materials market in recent years. These new products are often qualified as "green" low-impact
materials because of their renewable origin.
A full life cycle assessment (LCA) of the material will be made for the following stages: crop production,
industrial transformations, use and end-of-life. The environmental assessment of these materials using LCA
is however complex, due to their multi functionality in buildings, and the lack of data on major life cycle
stages, such as their behaviour in the use phase.
One of the main scientific challenges of this work is to develop and implement an LCA approach combined
with a sensitivity analysis, in order to quantify the contribution and variability of technological, environmental
and methodological factors to life cycle impacts (Fig. 1). This information will then be used to ecodesign
scenarios for the production, use, and end-of-life stages of plant-based building materials. The aim is
to highlight the environmental hotspots of the life cycle of these materials and to reinforce the robustness of
results of the LCA results by testing several scenarios.
The present article is focused on the production step of hemp fibres and shives: the agricultural system and
primary transformation. Several scenarios are compared. Various sources of variability are taken into account:
(i) technological variables such as the hemp cultivar, the various crop production modes (tillage intensity,
harvest of seed and fibre or fibre only), primary industrial processes; (ii) environmental variables such
as the soil type and the climate, (iii) as well as LCA methodological variables such as models (emission factors
vs. dynamic simulation models) used to estimate direct emissions (e.g. nitrate) during crop production
and allocation methods (based on mass, economic value or plant physiological mechanisms).
The repercussions of the variability of these input parameters are examined at the output i.e. the life cycle
impact assessment. Using these results, eco-design scenarios for hemp fibres and shives production including
crop production and primary transformation are proposed using processes which present interesting environmental
potentials, and future improvements for each process are proposed.
Acknowledgments: The authors acknowledge the financial support of the French Agency for Environment
and Energy Management (ADEME) and the Pays de la Loire region.
References
Korjenic, A., Petranek, V., Zach, J., Hroudova, J., 2011. Development and performance evaluation of natural
thermal-insulation materials composed of renewable resources. Energy and Buildings 43:2518-2523.
Kymalainen, H.R., Sjoberg, A.M., 2008. Flax and hemp fibres as raw materials for thermal insulations.
Building and Environment 43:1261-1269.
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