Environmental Sustainability Assessment of Advanced Agricultural Waste echnologies and Agricultural Territories

Abstract

The sustainability of emerging biotechnologies seeking to close the loop with circular economy alternatives is questionable. Biomass resources are finite and management of these resources has to improve dramatically if we are to ensure a sustainable future for coming generations. All things bio, such as bioproducts, bioenergy, biochemicals have a tendency to be perceived as environmentally superior to their fossil counterparts. However, research has shown this is not always the case and that the answer to the question, “is bio sustainable?” is always it depends. During the course of this PhD project the sustainability of various biorefinery setups, which are a result of emerging biotechnological developments, and their products have been assessed with the life cycle assessment (LCA) methodology in specific regional contexts. The aim of this project is to increase our understanding of the variables and patterns that should be included in the assessment in order to succeed in the identification of sustainable bio-options. For this purpose, 3 perspectives of focus were introduced with regards to building appropriate assessments. The territorial perspective, which includes considerations that must be made about the background system in LCA includes variables such as land, feedstock provisioning, and the energy grid supplying the biotechnologies. In this context, mass flow analysis of the regions of interest can be coupled with LCA i.e. material flows going in and out of the region, and dynamic inventories can be produced to account for changes in time i.e. changing background energy grid mix. The assessment of various systems throughout this project showed that the added information from a dynamic energy mix is a necessary component of future LCAs that either use biomass resources, or have energy intensive processing. On the other hand, the mass flow analysis is useful in drawing attention to potential pressures from the feedstock provisioning side, though a more definitive analysis of land use change is necessary to avoid potential negative impacts from feedstock sourcing. This is a global issue and thus should be assessed taking the consequences at a global scale. The foreground and early design perspective introduced in this project centers around process design, a.k.a. the foreground system. This refers to biotechnologies in early development phases, such as laboratory scale, which could benefit from a hot spot assessment that may point out process design improvement areas for more environmentally friendly technologies at industrial scale. Results showed that LCA is capable of pointing out design hot spots in biotechnologies at an early stage of development by the use of a quick carbon foot printing. The project exemplifies how to utilize process design software that is routinely used by the chemical/biotech industries, together with LCA to produce multi-angle assessments. The combination has the potential to become a powerful tool that would benefit from the level of standardization already available to LCA practitioners. Combining for example, techno-economic assessments (TEA) and LCA can lead to process design, which may be optimized from both an environmental and economic side. Furthermore, this project applied multi-criteria decision analysis methods in order to derive clear decision support from compound assessment such as combined TEA-LCA. The methods of MCDA tested during this project proved effective and were in agreement. However, further research is needed in order to decrease the subjectivity of weighting profiles and valuation of externalities. The last perspective analyzed in this project is the products perspective. Novel products lack the level of coverage that conventional products have in LCA databases. Moreover, The functionality of novel products is, at times, poorly understood or contains value that is outside of the scope of the LCA methodology as it is today. Several improvement areas were identified in regards to increasing our understanding of novel products and the methodological needs that are needed for a more complete assessment of these products. Most importantly, a framework was developed to include the impacts of plastic products in a more thorough way, which includes the contribution of microplastics to particulate matter formation. However, there is an urgent need for increasing our understanding of the microplastics cycle including, but not limited to: degradation rates of plastic in the natural environment, better understanding of degradation rates of conventional plastic in landfill and of littered plastic, increased understanding of the fate of macro and microplastic and finally, increased understanding of damage from this source of pollution to human health and ecosystem health. Additionally, the value of biodegradable materials should be carefully considered and might need to be redefined, as it is probable that the value of biodegradable materials extends beyond the scope of the LCA methodology into ecological perspectives poorly covered by LCA e.g. biodiversity, ecosystems services. The three perspectives explored and findings produced during this project will facilitate the assessment of various biotechnologies in their regionally specific context. Depending on the goal and scope of future LCAs, the methodological elements identified here might be needed in their entirety or in a partial manner. Cross-disciplinary interactions will be key to ensure that the LCA methodology continues to develop and realizes its full potential, so that in the future when asked if bio is sustainable we can finally answer with a definitive statement.