SV Sustainability
Our approach
By manufacturing a more environmentally friendly, biodegradable and less harmful insulation material using synthetic biology, our team was already aware of the environmental challenges caused by our current lifestyles. In particular, Alice, a member of the protein team, is part of the Zero Emission Group (ZEG) initiative1, which brings together students who want to find solutions to reduce CO2 emissions. It was at her instigation that we considered carrying out a Life Cycle Assessment (LCA) and contacted the EPFL SV Sustainability office2. Responsible for measuring and quantifying the impacts of the section's activities (CO2 calculator), promoting more responsible practices (green lab initiatives), and providing support for students' led projects aimed at reducing the carbon footprint of research (Plast it Back3), they are at the heart of the scientific, administrative and student apparatus of the Life Sciences faculty of EPFL. We spoke to Margot Wendling, analyst, and Juliane Miane, project officer.
Lifetime unknown, equation difficult to calculate
For the logic of LCA to be respected, it was essential that the lifetime of the material was taken into account. Between an aerogel that lasts 10 or 30 years, the impact varies immensely. Indeed, with an insulator lasting 10 years versus an alternative lasting 30 years, it was absolutely necessary to count three times the production, use and end of life of the former, to allow a comparison of the two solutions. It is automatically done in an LCA.
Juliane and Margot suggest that we find what is called a proxy, a close-enough well known material for which data are extensively compiled. For example, we could base our lifespan estimate on the lifespan of straw insulation, which is also cellulose-based. However, in our case, this proxy is not ideal. First, due to the organised sed structure of our material, based on purer cellulose, the aerogel lifetime should be longer, as it should take longer to be degraded. Secondly, aerogel manufacturing requires much more energy than the production process of straw insulation which requires adjustment calculations accordingly.
An ecological source: using agricultural waste!
The raw material being considered, cellulose, had a very interesting advantage over what is usually used from the outset, it was then necessary to ensure that the raw material supply chain was as sustainable and light as possible.
Thus, using agricultural waste as suggested by Michka could be all the more interesting, as it would allow a circular production system, beneficial for the environment. The main problem with this solution would be that it would result in less pure cellulose (as it is extracted from agricultural waste). This could lead to the production of a less perfect and therefore less efficient cellulose aerogel.
End of life impact
To quantify the release of CO2 and methane by the product at the end of its life would again require finding similar materials, in databases, and studying different end-of-life scenarios? (incineration, composting, reuse as an energy source, etc.).
In order to valorise cellulose aerogel during its end-of-life, it could perhaps be used as an energy source for organisms using cellulose and producing compounds of interest… that could be engineered by future iGEM teams for example !
Conclusion : an LCA, an overly ambitious project
Our desire to carry out an LCA rather than a greenhouse gas analysis was good, as it allowed us to assess the material or practice from a more environmentally interesting point of view (taking into account air quality, water quality, resource depletion, etc.). However, However, at this stage of the project, given the numerous unknowns concerning the steps for upscaling the manufacturing process of the product to achieve a rigorous LCA, was too ambitious. The two main obstacles being time and available data!
References
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Zero Emission Group
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EPFL Life Science Sustainability Office
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Plast it Back EPFL page