A Data-Driven Analysis on Sustainable Energy Security

This study provides a data-driven analysis that illustrates a clear renewable energy depiction in sustainable energy security and unveils the regional issues due to the literature solely occupies energy security concept in the descriptions view, and renewable energy differences related to regions are rarely discussed. A hybrid method is proposed to valid those indicators and shows the trend of future studies. This study enriches the challenges and opportunities by contributing to understand the fundamental knowledge of renewable energy in sustainable energy security frontier, conveyance directions for future study and investigation, and assessment on global renewable energy position and regional disparities. There are valid 19 indicators, in which energy demand, energy policy, renewable resources, smart grid, and uncertainty representing the future trends. World regional comparison includes 115 countries/territories and categorized into five geographical regions. The result shows that those indicators have addressed different issues in the world regional comparison.

Irreversible and Self-Healing Electrically Conductive Hydrogels Made of Bio-Based Polymers

Electrically conductive materials that are fabricated based on natural polymers have seen significant interest in numerous applications, especially when advanced properties such as self-healing are introduced. In this article review, the hydrogels that are based on natural polymers containing electrically conductive medium were covered, while both irreversible and reversible cross-links are presented. Among the conductive media, a special focus was put on conductive polymers, such as polyaniline, polypyrrole, polyacetylene, and polythiophenes, which can be potentially synthesized from renewable resources. Preparation methods of the conductive irreversible hydrogels that are based on these conductive polymers were reported observing their electrical conductivity values by Siemens per centimeter (S/cm). Additionally, the self-healing systems that were already applied or applicable in electrically conductive hydrogels that are based on natural polymers were presented and classified based on non-covalent or covalent cross-links. The real-time healing, mechanical stability, and electrically conductive values were highlighted.

Sustainable Reactive Polyurethane Hot Melt Adhesives Based on Vegetable Polyols for Footwear Industry

The aim of this work is to develop sustainable reactive polyurethane hot melt adhesives (HMPUR) for footwear applications based on biobased polyols as renewable resources, where ma-croglycol mixtures of polyadipate of 1,4-butanediol, polypropylene and different biobased polyols were employed and further reacted with 4-4′-diphenylmethane diisocyanate. The different reactive polyurethane hot melt adhesives obtained were characterized with different experimental techniques, such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), softening temperature and melting viscosity. Finally, their adhesion properties were measured from T-peel tests on leather/HMPUR adhesives/SBR rubber joints in order to establish the viability of the used biobased polyols and the amount of these polyols that could be added to reactive polyurethane hot melt adhesives satisfactorily to meet the quality requirements of footwear joints. All biobased polyols and percentages added to the polyurethane adhesive formulations successfully met the quality requirements of footwear, being comparable to traditional adhesives currently used in footwear joints in terms of final strength. Therefore, these new sustainable polyurethane adhesives can be considered as suitable and sustainable alternatives to the adhesives commonly used in footwear joints.

Has the European Union entered a bioeconomy transition? Combining an output-based approach with a shift-share analysis

The bioeconomy is a collective of activities charged with the production of biologically renewable resources or ‘biomass’ (e.g. agriculture, forestry), its diverse application (e.g. food, textiles, construction, chemicals) and subsequent reuse (e.g. compositing, waste management). Since the European Union (EU) launched its bioeconomy strategy in 2012, further bioeconomy policy initiatives have proliferated at regional, national and pan-European levels. Moreover, the EU Green Deal announced in 2019 targets a transition towards a low-carbon sustainable model of growth, food and energy security, biodiversity and natural resource management, where it is envisaged that the bioeconomy will play a key role. Despite a paucity of available data, the surge in policy interest has triggered the need for evidence-based monitoring of bioeconomy sectors and the efficient tailoring of policy support. Thus, on a Member State (MS) basis for the period 2008–2017, we (1) adopt an ‘output-based’ approach to construct a panel data of performance indicators and (2) characterise the sources of growth and transitional stage of the bioeconomy. Results reveal that the bioeconomy has maintained its relative importance within the total EU27 economy. At the EU level, agriculture and the food industry have played a key role in driving a transition in the primary and industrial bioeconomy sectors due to their significant labour productivity-enhancing impact. Four Northern MS exhibit a bioeconomy transition by modernising their bioeconomy activities and operating structural changes. Other Northern and Western EU MS are still in the early stages of a transition, whilst in Eastern and Central Europe, such a transition remains elusive.

Deep Eutectic Solvents For Efficient Processing of Renewable Resources Into Sustainable Biofuels and High Value-Added Carbon-Based Fine Chemicals: Recent Developments, Challenges, and Future Perspectives

Green chemistry techniques for the exploitation of renewable resources have emerged as beneficial techniques for producing sustainable biofuels and high value-added carbon-based fine chemicals with the potential to decrease the impact of anthropogenic activities on the environment. Despite various green chemistry technologies for processing renewable resources into different valuable products, there are still several major issues concerning the pretreatment processes and techniques, such as high cost and high-energy consumption. Thankfully, deep eutectic solvents (DESs), a potentially attractive “green solvent” biodegradable substitute to environmentally harmful organic solvents, have been progressively exploited for renewable resources processing. Therefore, the central focus of this review is to present recent developments and challenges of DESs as processing green solvents for renewable resources. We believe this comprehensive review will provide new insights towards developing state-of-the-art sustainable and new green technologies for the efficient processing of renewable resources for sustainable biofuels and value-added carbon-based fine chemicals.

Life Cycle Assessment of Circular Bio-Based Construction

The construction sector is a large consumer of non-renewable resources and it is responsible of 44% of global energy related CO2 emissions. Circular economy is an emerging strategy that has potential to make significant improvements in the construction industry, by taking efficient and sustainable actions against climate change. The principles of circular economy are to minimise the waste of resources, by maximizing materials' performances, whilst in use, and recycle and regenerate them at the end of their service life. Natural materials can potentially be suitable in this strategy, due to the use of renewable resources, carbon sequestration potential, and high suitability for reuse and recycling. The development of bio-based wall panel is a first step into the integration of a circular economy approach in the construction sector. In this study, vapour responsive bio-based panel prototypes with low thermal transmittance (U<0.20 W/m2K) are being designed, taking into consideration the burdens and benefits of natural materials over their entire life cycle. The challenge is to assess the environmental impact of the panels during their design and production, maximise performance and life span, when in use, and regenerate and recycle panel components at the end of the service life. In this paper, a life cycle assessment of a prototype bio-based panel designed with circular economy principles is investigated. The environmental impact of the panel is analysed to investigate limitation in assessing emissions and use of resources in a circular prospective. The objective of the research is to integrate environmental impact analysis during the early stage of panel design. This will put the basis for the development of a sustainable and circular building industry and for identifying area of improvements for the development of sustainable circular panels with expected hygrothermal benefits conferred using bio-based materials.

Productivity and Management of Renewable Resources: Why More Efficient Fishing Fleets Should Fish Less

This article analyses the effect of productivity improvements on optimal fisheries management. It is shown that when harvest costs are independent of resource stock and the stock is below its steady state level, then for any given stock it is optimal to reduce harvest levels in response to a productivity increase unless optimal harvest rate is already zero. If harvest costs are stock dependent this result is modified; for stock dependent harvest costs there exists an interval of stock sizes below the steady state where it is optimal to reduce the harvest rate for any given stock size whereas if the harvest rate is close to an economically optimal steady state it is optimal to increase the harvest rate.