Contribution of the European Chemical Industry to the Planetary Boundaries

Abstract

As environmental degradation and resource depletion accelerate worldwide risking the stability of the planet and undermining its capacity to maintain its current state (the only geologic epoch able to favour human development), mechanisms for the analysis and enhancement of the sustainability level of human activities are becoming increasingly relevant. Acknowledging the challenge posed by the need for a shift towards a greener future of the European chemical industry, this study assessed the degree of disturbance chemical plants operating with current practices exert on the main environmental processes regulating the Earth’s functions through the PB-LCIA framework. This methodology allows to combine Life Cycle Assessment (LCA) with the Planetary Boundaries (PBs). The former is a tool capable of identifying the impacts associated with the different stages of the life-cycle of a system based on its exchanges with the environment (called Life Cycle Inventories or LCIs). Meanwhile, the latter is a framework developed by Rockström et al. (2009) which quantifies the resilience of the principal environmental processes in order to avoid human action to exceed the ecologic carrying capacity of the planet (i.e., the maximum rate of pollution and resource harvesting environments are capable to sustainably support). This framework has been, and still is, gaining interest not only from the scientific community but also from businesses, policymakers, and investors (Lucas et al., 2020). As proved in this work, it allows to portray the severity of the environmental damage caused by the assessed activities and size improvement actions, as well as providing a complete priority assessment (Ryberg et al., 2018). A production-based study of the sustainability level of the chemical industry was developed taking a cradle-to-gate approach, where not only impacts derived from the strict in-plant production but also those related to the obtention of feedstocks, energy, and the treatment of wastes, are included. Firstly, the boundaries of the study were defined in regard to which PBs were to be quantified, which chemicals were relevant for the study, and which was the level of detail desired. All PBs for which a threshold contribution (a pressure level above which the Earth process is at risk) has been defined to date were selected to be included in the research. Besides, the chemical industry was characterized into a representative range of chemicals and processes, resulting in a model ix which considered if the products of a process were used as feedstocks in another, to understand relationships happening within the cradle-to-gate system. Secondary, LCI data was collected from LCA database ecoinvent v3.5, and an attributional LCA was conducted following the standards defined by ISO 14044. Afterwards, the contributions on the PBs attributed to the sector were computed through the PB-LCIA framework. A data quality analysis was included to assess the adaptation of the collected data to the goals of the study and to compute the uncertainty carried by the results. Since the PBs are defined at a global scale, their downscale to the sector under study was performed through two different allocation criteria. The results highlighted the relevancy of transparency in the allocation method selected in PB-LCIA assessments. It was found that the industry is transgressing at least 4 out of the 9 PBs by alarming numbers, including those related to climate change (total imbalance caused at top of atmosphere and CO2 concentration), ocean acidification, and aerosol loading. Ammonia, PP, HDPE, styrene, benzene, and propylene oxide were found to be the top contributors to the global unsustainability of the sector. However, an additional, significant number of impacts stemmed from sectors beyond the boundaries of the industry, such as the energy sector. In light of the obtained results and besides specific actions targeted at critical processes described along the report, four principal improvement pathways were proposed and modelled: (i) the powering of the processes by a more sustainable electricity mix, the deployment of carbon dioxide capture and storage technologies, including (ii) bioenergy with carbon capture and storage and (iii) direct air capture and storage, and (iv) the production of hydrogen through water electrolysis instead of steam reforming powered by wind energy combined by the powering of the chlor-alkali electrolysis with the sustainable mix presented in scenario (i). Even if all proposed routes for improvement yielded positive results and palliated the impact of the industry on the PBs, their modelling put in evidence no “silver bullet” exists which would allow to improve the performance of the industry alone, since every action causes burden-shifting (i.e., solving a problem on an environmental category poses a burden on another). Therefore, a combination of measures and technological alternatives is needed to drive the industry towards a sustainable future