The biobased chemical industry is characterised by strong growth. Innovative products and materials such as biopolymers have been developed, and current European demand for biopolymers exceeds the domestic supply. Agroforestry residues can serve as main sources of the basic building blocks for chemicals and materials. This work assesses sustainably available agroforestry residues to feed a high added-value materials and product bioeconomy. To evaluate bioeconomic potential, a structured three-step approach is applied. Cultivation practices, sustainability issues, legislative restrictions, technical limitations and competitive applications are considered. All data regarding bioeconomic potential are processed on a regional level and mapped by ArcGIS. Our results identify wheat straw as the most promising source in the agricultural sector, followed by maize stover, barley straw and rape straw, which all contain a total concentration of lignocellulose of more than 80% of dry matter. In the forestry sector, residue bark from two coniferous species, spruce and pine, is the most promising source, with approximately 70% lignocellulose. Additionally, coniferous bark contains considerable amounts of tannin, which has attracted increasing interest for industrial utilisation. A sensitivity analysis concerning removal rates, residue-to-crop ratios, changes in farming technologies and competing applications is applied at the end of the study to consolidate our results.

Supply risk assessments are an integral part of raw material criticality assessments frequently used at the country or company level to identify raw materials of concern. However, the indicators used in supply risk assessments to estimate the likelihood of supply disruptions vary substantially. Here, we summarize and evaluate the use of supply risk indicators and their normalization to supply risk scores in 88 methods published until 2020. In total, we find 618 individual applications of supply risk criteria with 98 unique criteria belonging to one of ten indicator categories. The most often used categories of supply risk indicators are concentration, scarcity, and political instability. The most frequently used criteria are the country concentration of production, depletion time of reserves, and geopolitical risk. Indicator measurements and normalizations vary substantially between different methods for the same criterion. Our results can be used for future raw material criticality assessments to screen for suitable supply risk indicators and generally accepted indicator normalizations. We also find a further need for stronger empirical evidence of widely used indicators.

The Circular Economy is gaining traction in the European Union and all over the world as a transition away from the extractive and exploitative linear economy. In Hawaiʻi, the cultural value of aloha ʻāina is a philosophy describing a set of values grounded in a relationship of kinship between people and the environment. Aloha ʻĀina structured centuries of sustainability and it has evolved over generations to frame community responses to crucial issues today, such as climate change, oligopolistic markets, and contemporary land management. This paper sits at the intersection of cross-disciplinary collaboration, sustainability, and sustainable development. Participative moderate observations and intentional cross-cultural exchanges of knowledge over five years between scholars and experts in the major fields of indigenous Hawaiian knowledge and industrial ecology inspired the concepts explored in this paper, which address the question of how aloha ʻāina and the Circular Economy can engage with each other in the collective effort to combat climate change, guide sustainable development efforts, and transition societies toward sustainability. Extensive literature reviews and insight gained through site visits to sustainability projects inform the discussion of best practices from opposite parts of the globe—Hawaiʻi and Germany—to put into conversation two worldviews and present resulting implications and lessons learned. Essential findings describe the benefits of knowledge exchange between members of global practitioner networks. By shifting expert and participant roles according to which projects are being observed, cross-cultural characteristics can be explored at a deeper level, which allow participants to employ best practices to their respective theories. The Circular Economy’s engagement with indigenous knowledge systems is an opportunity to ally and produce solutions to the challenges associated with changing the linear economy while addressing both environmental and social justice issues.

Nickel-based superalloys contain various elements which are added in order to make the alloys more resistant to thermal and mechanical stress and to the adverse operating environments in jet engines. In particular, higher combustion temperatures in the gas turbine are important, since they result in higher fuel efficiency and thus in lower CO₂ emissions. In this paper, a semi-quantitative assessment scheme is used to evaluate the relative supply risks associated with elements contained in various Ni-based superalloys: aluminium, titanium, chromium, iron, cobalt, niobium, molybdenum, ruthenium, tantalum, tungsten, and rhenium. Twelve indicators on the elemental level and four aggregation methods are applied in order to obtain the supply risk at the alloy level. The supply risks for the elements rhenium, molybdenum and cobalt are found to be the highest. For three of the aggregation schemes, the spread in supply risk values for the different alloy types (as characterized by chemical composition and the endurance temperature) is generally narrow. The fourth, namely the cost-share’ aggregation scheme, gives rise to a broader distribution of supply risk values. This is mainly due to the introduction of rhenium as a component starting with second-generation single crystal alloys. The resulting higher supply risk appears, however, to be acceptable for jet engine applications due to the higher temperatures these alloys can endure.

The bioeconomy can be integral to transforming the current economic system into one with reduced environmental and social impacts of material consumption. This work describes a bio-based multi-layer panel that is based on residual coniferous bark. To ensure that the presented bio-based panel positively contributes to environmental protection while remaining competitive with conventional products and meeting high social standards, the development of the panel is accompanied by a life cycle sustainability assessment. This study performs a comparative LCA and LCC of the developed panel to conventional benchmark panels, as well as a qualitative social life cycle assessment. While the panel performs only economically marginally weaker than the benchmarks, the results are more heterogeneous for the environmental dimension with benefits of the bio-based panel in categories such as climate change, acidification, and ozone formation and detriments in categories including eutrophication. The S-LCA analysis shows that all of the involved companies apply social principles in direct proximity; however, social responsibility along the supply chain could be further promoted. All results need to be viewed with the caveat that the manufacturing processes for the new panel have been implemented, to date, on a pilot scale and further improvements need to be achieved in terms of upscaling and optimisation cycles.