Found 36 results
Open Access
Review
14 May 2025Current Status of Biological Production Using C2 Feedstocks
C2 feedstocks have emerged as promising carbon sources for the biological production of various value-added chemicals. Compared to the traditional C6/C5 sugars-contained/constituted feedstocks, C2 feedstocks have diverse and abundant sources, including non-food biomass, industrial by-products, and C1 gases. This diversification not only eliminates competition with human food demands but also aligns with environmental sustainability goals. Moreover, the metabolic route for C2 compounds to enter central carbon metabolism is more direct, which minimizes the carbon loss and enhances the efficiency of bio-based production processes. This review extensively analyzes three prominent C2 chemicals: ethylene glycol, ethanol, and acetate. After introducing the sources of those compounds, it details the metabolic pathways through which they are converted into acetyl-CoA in vivo. Several chemicals produced from these C2 feedstocks in fermentation are also exemplified. Furthermore, different perspectives are proposed to promote the efficient utilization of C2 feedstocks.
Open Access
Article
29 April 2025Application of recovered Carbon Black (rCB) by Waste Tire Pyrolysis as an Alternative Filler in Elastomer Products
The increasing global accumulation of End-of-Life (EoL) tires and the growing demand for fossil industrial Carbon Black (CB) call for sustainable alternative solutions. In this context, tire pyrolysis and the resulting recycled raw material recovered Carbon Black (rCB), are considered potential alternatives. In the study, various rCBs were incorporated into new elastomer compounds using a laboratory internal mixer and their properties were investigated. The compounds were selected based on examples of applications such as bicycle inner tubes and hydraulic membranes. By comparing the in-rubber properties of rCB-based compounds with CB reference compounds, an initial assessment of the potential use of rCB for the chosen products was derived. Compared to industrial carbon black, the use of rCB leads to a reduction in performance. Although increasing the filler content partially compensated for the mineral content in rCB and led to a slight improvement, it could not fully offset the performance loss.
Open Access
Article
28 April 2025Production and Characterization of Recovered Carbon Black (rCB) by Waste Tire Pyrolysis as a Potential Carbon Black (CB) Substitute
Recovered Carbon Black (rCB) from scrap tire pyrolysis offers a potential alternative to fossil-based virgin Carbon Black (CB) in the context of a circular economy. This study investigated the influence of pyrolysis process parameters on rCB yield and quality at laboratory and semi-industrial scales. The resulting rCBs were characterized and found to have surface and structural properties comparable to N500 and N600 series CBs, but with higher mineral and volatile contents. The quality of rCB is influenced by the feedstock composition, particularly the ratio of organic to inorganic components as well as key process parameters such as heating rate, pyrolysis temperature and residence time. Higher heating rates accelerate degradation and shift product distribution toward increased oil yield and reduced rCB formation, while higher pyrolysis temperatures lead to lower volatile content in rCB. Additionally, reactor and process design affect heat distribution, transfer efficiency, and mixing behavior, further shaping rCB properties. However, further testing is required to evaluate the actual in-rubber properties of rCBs. Therefore, additional tests are planned, incorporating rCB into butyl and nitrile rubber-based elastomer compounds, which will be addressed in a follow-up study. In addition, data from the current experiments will support a comprehensive Life Cycle Assessment (LCA) to evaluate the environmental impacts of tire pyrolysis and rCB production compared to other recycling methods, with details to follow in a future publication.
Open Access
Article
15 April 2025Technical and Eco-Efficiency Implications of the Use of Basalt Fibre in Hybrid Composites
The use of hybrid composites can be environmentally friendlier than the traditional materials since renewable resources, both natural and synthetic fibres can be incorporated into the composites, resulting in lighter weight, enhanced resource efficiency, durability, and biodegradability, which could potentially make them sustainable materials for structural applications. Basalt fibre being treated with hydrochloric acid exhibits superior adhesion with the epoxy matrix, improving overall strength and stiffness. Thus, the aim of this paper is to determine the eco-efficiency of two types of hybrid composites: glass/basalt and carbon/basalt fibre-reinforced under flexural loading. The flexural strengths of these composites were obtained through a Finite Element Analysis (FEA) model using Ansys workbench. These simulation-based flexural strengths form the basis for the quadratic regression model to establish a relationship between the different flexural strengths and fibre volume fractions combinations. Given the required flexural strength between 900 and 1300 MPa, the optimal candidates/layups were identified with the aid of the model. An environmental study following a life cycle assessment (LCA) and eco-efficiency framework of unidirectional glass/basalt and carbon/basalt fibre-reinforced hybrid composites with varying fibre volume fractions is presented in this paper to select the eco-efficient composites. In the case of glass/basalt fibre-reinforced hybrid composites, the designs with the highest eco-efficiency for 900 and 1200 MPa are [BG3]S with more glass fibre and [G7B] with more glass fibre, respectively, due to having lower costs and environmental impacts. For carbon/basalt fibre-reinforced composites, the stacking sequence [B8] was deemed to be the most eco-efficient. Finally, epoxy has the highest economic and environmental cost. Therefore, composite designs with high glass fibre content are considered eco-efficient since they have a lower epoxy content.
Open Access
Review
26 February 2025Recent Progress on Utilising Visible Light to Better Catalyst Stability for the Dry Reforming of Methane
Dry reforming of methane (DRM) is a promising strategy to closing the carbon loop. DRM valorises CO2 and CH4 by producing synthesis gas (H2 and CO), the precursor to various synthetic fuels. Key limitations of the DRM are the high-temperature requirements (600–1000 °C) and competing side reactions, many of which produce carbon that can deactivate the catalyst. Designing a stable, low-cost and active catalyst remains one of the greatest DRM challenges. One potential strategy to curtail the limitations that hinder DRM is to utilise visible light to access the localised surface plasmon resonance (LSPR) of metal catalysts. The current review discusses the recent developments in designing catalysts for LSPR-assisted thermocatalytic DRM. The thermodynamic and kinetic principles that underpin DRM are first introduced, followed by an overview of thermocatalyst design strategies. The mechanism behind LSPR is discussed, with recent developments and strategies for introducing LSPR to the DRM examined. The review offers a thorough overview of catalyst design for light-assisted DRM and may be used as a guide to developing stable and light-receptive catalysts for the reaction.
Open Access
Article
17 February 2025Comparative Study of Elastomer Nanocomposites Respectively Containing SWCNTs and MWCNTs
Carbon nanotubes (CNTs) are essential for providing polymers with mechanical reinforcement and multifunctional properties. This study investigated two groups of nitrile butadiene rubber (NBR) nanocomposites containing single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), respectively. SWCNTs were purified to remove appro-ximately 20 wt.% of impurities, and both CNTs were modified with polyethylene glycol tert-octylphenyl ether (Triton X-100) before emulsion compounding and 2-roll milling with NBR. MWCNTs were found to disperse in the elastomer matrix relatively uniformly, while SWCNTs formed aggregates. Consequently, NBR/MWCNT nanocomposites exhibited superior mechanical properties, e.g. a tensile strength of 10.8 MPa at 4.02 vol.% MWCNTs, compared to 5.6 MPa for NBR/SWCNT nanocomposites. Additionally, NBR/MWCNT nanocomposites exhibited more remarkable electrical conductivity and swelling resistance to toluene. The diameter of elastomer macromolecules (0.2–0.5 nm) is close to that of SWCNTs (1–2 nm), and their single graphene wall with a hollow structure makes SWCNTs almost as flexible as elastomer macromolecules. This similarity suggests that SWCNTs should be treated as a special type of polymer. SWCNTs cannot disperse as uniformly as MWCNTs in the elastomer matrix, likely due to their smaller size and lower sensitivity to mechanical shearing during the emulsion compounding and 2-roll milling process.
Open Access
Review
20 January 2025Adsorption and High-Value Transformation of Volatile Fatty Acids from Microbial Fermentation Products: A Review
To mitigate the aforementioned global environmental issues, the concept of carbon capture and storage is crucial in addressing the necessity for carbon peaking and carbon neutrality. The buildup of volatile fatty acids during anaerobic fermentation is a primary factor contributing to the suboptimal performance or outright failure of anaerobic digestion systems. In response to the pressing demand for volatile organic acid recovery and high-value conversion, we primarily outlined the sources, recovery techniques, adsorption materials, and methods for high-value conversion of volatile fatty acids. The methods of adsorbing volatile acetic acid were presented, encompassing adsorption materials, mechanisms, and interfacial modifications of the adsorbent. Furthermore, drawing from recent research advancements, we have synthesized the high-value conversion techniques for volatile fatty acids and evaluated the research challenges and future prospects in this domain.
Open Access
Article
21 November 2024The Impact of Renewable Energy Consumption, Economic Growth, Globalization, and Financial Development on Carbon Dioxide Emissions: Evidence from Selected G7 Economies
The aggregate upsurge in carbon dioxide emissions (CO2) witnessed through environmental degradation and global climate change is a call for great concern. This, therefore, calls for the enactment, utilization and implementation of provisions and policies geared towards curbing this global economic bad without impeding global economic growth rates. This study ascertains the extent to which renewable energy consumption (REC), economic growth (GDP), population growth (POP), globalization (GLO), and financial development (FD) affect carbon dioxide emissions (CO2) in selected G7 economies (France, Germany, Canada, Italy, and the United Kingdom) from 1990–2020. The Dynamic Fixed Effect Autoregressive Distributive Lag (DFE-ARDL) and the Pooled Mean Group ARDL (PMG-ARDL) methods were employed for analysis. The empirical findings for DFE-ARDL showed that REC, GDP, and POP have an adverse association with CO2 in the long-term. However, in the short-term, REC and FD improve the environment, while GDP and POP drive CO2. It is observed that the result for REC in the short and long-run is consistent. The PMG-ARDL results revealed that REC and GLO negatively affect CO2 in the long-run, and in the short-run, GDP spurs CO2, while FD reduces it. The result summary of both methods employed demonstrates that REC, GLO, and FD benefit the environment. At the same time, GDP and POP harm the environment in the short-run but reduce CO2 in the long-run. Conclusively, the research recommends increasing the utilization of renewable energy and policies that enable economic growth and CO2 to move in the opposite direction.
Open Access
Article
18 November 2024Developing a Climate Litigation Framework: China’s Contribution to International Environmental Law
Although “climate litigation” is not an indigenous term in China, localizing it is essential to support the development of an independent environmental legal knowledge system in China. Rooted in China’s judicial tradition, which emphasizes substantive rationality, traditional legal theories have primarily focused on environmental law. However, the contemporary practices in the rule of law have created an unclear trajectory for climate litigation. Research in this area has long been trapped in a paradigm that relies on lawsuits for ecological environmental damage compensation and environmental public interest litigation, leading to a significant disconnect between theoretical framworks and practical application. With the advancement of the "dual carbon" strategic goals—carbon peaking and carbon neutrality—it has become imperative to redefine the concept of climate litigation within the Chinese context. We need to establish a theoretical framework that aligns with the “dual carbon” objectives while providing theoretical and institutional support for climate litigation, ultimately contributing to the international discourse on climate justice. Additionally, Hong Kong’s proactive climate governance and robust ESG (Environmental, Social, and Governance) practices provide valuable insights for developing comprehensive climate litigation mechanisms. Based on this analysis, we propose concrete plans for building a climate litigation system in China, establishing a preventive relief system and a multi-source legal framework at the substantive level and developing climate judicial mechanisms for mitigation and adaptation at the procedural level.
Open Access
Review
01 November 2024Waste Resin Derived Carbon Materials for Sodium-Ion Batteries
As the environmental issues caused by waste resin become increasingly severe, there is an urgent need to develop ways to handle it in a high-value and harmless manner. Turning waste resin into functional carbon materials is a realizable and promising scheme, which could be a trigger to carry forward emerging sustainable battery technologies and applications. However, there are few review articles about the basics and research progress of the waste resin derived carbon materials for sodium-ion batteries. This review article provides a brief overview mainly about resin recycling and the potential usage of the resultant carbon materials for sodium-ion batteries. Specifically, we show the potential improvements in existing research, focusing on utilization of the waste as well as the significance of new routes for resin recycling. This work offers insights for the design of sustainable carbon materials for battery systems.
