Compressed CO₂ energy storage (CCES) system has received widespread attention due to its superior performance. This paper proposes a novel CCES concept based on gas-liquid phase change and cold-electricity cogeneration. Thermodynamic and exergoeconomic analyses are performed under simulation conditions, followed by an investigation of the impacts of various decision parameters on the proposed system. Next, a multi-objective optimization is conducted with the total energy efficiency and total product unit cost as the objective functions. Finally, brief comparisons are made between the proposed system and existing systems. The results indicate that the total energy efficiency of the proposed system reaches 79.21% under the given simulation conditions, outperforming the electrical efficiency of 61.27%. Additionally, the total product unit cost of the system is 25.61 $/GJ. A key component, T1, plays an important role due to its large exergy destruction rate (1.0591 MW) and total investment cost rate (154.85 $/h). Despite this, the exergoeconomic factors of T1 is only 41.08%, indicating that investing in T1 to improve the efficiency is practicable. The analysis shows that a lower CO₂ condensation temperature benefits the proposed system performance. While improving the isentropic efficiencies of the compressors and turbines enhances total energy efficiency, excessive isentropic efficiencies can lead to a significant increase in total product unit cost. Through multi-objective optimization, an optimal favorable operating condition is identified, yielding a compromise result with a total energy efficiency of 111.91% and a total product unit cost of 28.35 $/GJ. The proposed CCES system efficiently delivers both power and cooling energy, demonstrating clear superiorities over previous systems.

The extensive utilization of fossil fuels has led to a significant increase in carbon dioxide (CO₂) emissions, contributing to global warming and environmental pollution, which pose major threats to human survival. To mitigate these effects, many researchers are actively employing state-of-the-art technologies to convert CO₂ into valuable chemicals and fuels, thereby supporting sustainable development. However, few studies have employed bibliometric methods to systematically analyze research trends in CO₂ reduction reaction (CO₂RR), resulting in limited macroscopic insights into this field. This study aims to conduct a scientometric analysis of academic literature on electrocatalytic, photocatalytic, and thermocatalytic CO₂RR from 2015 to 2023. Utilizing bibliometric analysis tools Citespace, Bibliometrix, and Vosviewer for data visualization, it establishes a knowledge framework for catalytic CO₂RR. The results show that China, the United States, and India are the top three countries with the highest number of published papers in this field, with China and the United States having the highest levels of collaboration. The journal Applied Catalysis B-Environmental published the most articles and received the highest citation count, with 3.4% of the articles in this field appearing in the journal and a total of 62526 citations. Keyword analysis revealed that terms like “CO₂RR,” “CO₂,” “conversion,” and “reduction” are the most frequently occurring, indicating key areas of focus. Additionally, “selectivity” and “heterojunction” emerged as prominent research hotspots. The discussion section highlights the current challenges in the field and proposes potential strategies to address these obstacles, providing valuable insights for research in the field of catalytic CO₂RR.

This paper presents a techno-economic assessment (TEA) combined with an environmental life cycle assessment (LCA) of various hydrogen delivery options within Europe, aiming to identify the most sustainable and cost-effective methods for transporting renewable hydrogen. Five hydrogen carriers—compressed hydrogen, liquid hydrogen, ammonia, methanol, and a liquid organic hydrogen carrier—are compared, assuming that hydrogen is produced via renewable electrolysis in Portugal and transported to the Netherlands by either ship or pipeline. The findings align with much of the existing literature, indicating that the most economically and environmentally sustainable options for long-distance hydrogen delivery are shipping liquid hydrogen and transporting compressed hydrogen via pipeline. Chemical carriers tend to involve higher costs and environmental impacts, largely due to the additional energy and materials (e.g., extra solar panels) required in hydrogen conversion steps (i.e., packing and unpacking). While the findings offer valuable insights for policymakers, further research is needed to address the limitations of multi-criteria assessments for emerging hydrogen technologies, particularly the uncertainties associated with the early development stages of processes along the hydrogen value chain. Future research should also focus on extending the scope of sustainability assessments and enhancing model reliability, especially for underrepresented environmental and social impact categories.

A study published in Biochar reports a sustainable strategy for improving zinc-iodine batteries by turning biomass-derived materials into a functional coating for battery separators. The research team developed a nitrogen and phosphorus co-doped porous carbon, made from chitin and phytic acid, that helps address several major barriers facing zinc-iodine battery technology, including poor iodine utilization, polyiodide “shuttling,” slow reaction kinetics, and zinc dendrite growth.

New report from the Partnership for International Vaccine Initiatives Finds Countries with Seasonal Influenza Programs Achieved 2.5× Higher COVID-19 Vaccination Coverage