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Increasing needs for taller wind turbines with bigger capacities, intended for places with high wind velocities or at higher altitudes, have led to new technologies in the wind energy industry. A recently introduced structural system for onshore wind turbine towers is the hybrid steel tower. Comprehension of the environmental response of this hybrid steel structural system is warranted. Even though life cycle assessments (LCAs) for conventional wind turbine tubular towers exist, the environmental performance of this new hybrid structure has not been reported. The present paper examines the LCA of 185 m tall hybrid towers. Considerations made for the LCA procedure are meticulously described, including particular attention at the erection and transportation stage. The highest environmental impacts arise during the manufacturing stage followed by the erection stage. The tower is the component with the largest carbon emissions and energy requirements. The obtained LCA footprints of hybrid towers are also compared to the literature data on conventional towers, resulting in similar environmental impacts.

The emission of CO2 and energy requirement in the production of Ordinary Portland Cement (OPC) causes the continuous depletion of ozone layer and global warming. The introduction of geopolymer concrete (GPC) technology in the construction industry leads to sustainable development and cleaner environment by reducing environmental pollution. In this article, constituents of GPC and their influence on properties of GPC has been reviewed critically. Fresh and hardened properties of GPC as well as the factors influencing these properties are discussed in detail. Flow charts have been proposed to show which factors have higher/lower impact on the fresh and hardened properties of GPC. A comprehensive review on the mix design of GPC, nanomaterial-based GPC, 3D printing using GPC, reinforced GPC and Global warming potential (GWP) assessment was conducted. Finally, the practical applications of GPC in the construction industry are provided.

PURPOSE: Biological sequestration can increase the carbon stocks of non-atmospheric reservoirs (e.g. land and land-based products). Since this contained carbon is sequestered from, and retained outside, the atmosphere for a period of time, the concentration of CO₂ in the atmosphere is temporarily reduced and some radiative forcing is avoided. Carbon removal from the atmosphere and storage in the biosphere or anthroposphere, therefore, has the potential to mitigate climate change, even if the carbon storage and associated benefits might be temporary. Life cycle assessment (LCA) and carbon footprinting (CF) are increasingly popular tools for the environmental assessment of products, that take into account their entire life cycle. There have been significant efforts to develop robust methods to account for the benefits, if any, of sequestration and temporary storage and release of biogenic carbon. However, there is still no overall consensus on the most appropriate ways of considering and quantifying it. METHOD: This paper reviews and discusses six available methods for accounting for the potential climate impacts of carbon sequestration and temporary storage or release of biogenic carbon in LCA and CF. Several viewpoints and approaches are presented in a structured manner to help decision-makers in their selection of an option from competing approaches for dealing with timing issues, including delayed emissions of fossil carbon. RESULTS: Key issues identified are that the benefits of temporary carbon removals depend on the time horizon adopted when assessing climate change impacts and are therefore not purely science-based but include value judgments. We therefore did not recommend a preferred option out of the six alternatives presented here. CONCLUSIONS: Further work is needed to combine aspects of scientific and socio-economic understanding with value judgements and ethical considerations.

Halogenated cycloalkanes (cyc-C n X s , n  = 4, 5 & 6 and X = H, F & Cl) benefit the environment and the economy. These chemicals have various industrial and agricultural applications due to their low Global Warming Potential (GWP) and negligible ozone depletion Potential (ODP). This study uses ab initio methods, MP2, and density functional theory (B3LYP, M06-2X, and ωB97x-D) to investigate the atmospheric impacts. Utilizing these methodologies, we have calculated radiative efficiencies (REs), Global Warming Potential (GWP), Global Temperature change Potential (GTP), integrated Global Temperature change Potential (iGTP), ozone depletion Potential (ODP), photo ozone creation Potential (POCP), and acidification Potential (AP) of cyc-C n X s ( n  = 4, 5 & 6 and X = H, F & Cl) compounds. For atmospheric reactivity analysis (NCI, MEP, and FMO), we employed the ωB97x-D/def2-TZVP level of theory. FMO analysis demonstrated that cyclo-α-C 6 H 6 Cl 6 and cyclo-γ-C 6 H 6 Cl 6 have a reduced energy gap and higher reactivity than other chemicals. Ab initio and DFT calculations conclude that several fluorine atom-containing molecules always have a significant radiative efficiency value. We have evaluated the cyc-C n X s ( n  = 4, 5 & 6 and X = H, F & Cl) dielectric strength (DS). We have found none of them could be used as an insulating material to replace SF 6 .

Although pulse-modulated plasma has overcome various problems encountered during the development of the high aspect ratio contact hole etching process, there is still a lack of understanding in terms of precisely how the pulse-modulated plasma solves the issues. In this research, to gain insight into previously observed phenomena, SiO2 etching characteristics were investigated under various pulsed plasma conditions and analyzed through plasma diagnostics. Specifically, the disappearance of micro-trenching from the use of pulse-modulated plasma is analyzed via self-bias, and the phenomenon that as power off-time increases, the sidewall angle increases is interpreted via radical species density and self-bias. Further, the change from etching to deposition with decreased peak power during processing is understood via self-bias and electron density. It is expected that this research will provide an informative window for the optimization of SiO2 etching and for basic processing databases including plasma diagnosis for advanced plasma processing simulators.

The growing challenges of climate change, the depletion of fossil fuel reserves, and the urgent need for carbon-neutral energy solutions have intensified the focus on renewable energy. In this perspective, the generation of green hydrogen from renewable sources like biogas/landfill gas (LFG) offers an intriguing option, providing the dual benefits of a sustainable hydrogen supply and enhanced waste management through energy innovation and valorization. Thus, this review explores the production of green hydrogen from biogas/LFG through four conventional reforming processes, specifically dry methane reforming (DMR), steam methane reforming (SMR), partial oxidation reforming (POX), and autothermal reforming (ATR), focusing on their mechanisms, operating parameters, and the role of catalysts in hydrogen production. This review further delves into both the environmental aspects, specifically GWP (CO2 eq·kg−1 H2) emissions, and the economic aspects of these processes, examining their efficiency and impact. Additionally, this review also explores hydrogen purification in biogas/LFG reforming and its integration into the CO2 capture, utilization, and storage roadmap for net-negative emissions. Lastly, this review highlights future research directions, focusing on improving SMR and DMR biogas/LFG reforming technologies through simulation and modeling to enhance hydrogen production efficiency, thereby advancing understanding and informing future research and policy initiatives for sustainable energy solutions.

Due to the global warming and resulting problems, attention has been paid to greenhouse gases released into the atmosphere since the 1980s and 1990s. For this reason, the Montreal Protocol and the Kyoto Protocol have tightened regulations on the use of gaseous refrigerants in both HVAC systems and industrial refrigeration. Gradually, new generations of gaseous refrigerants, that theoretically have much less negative environmental impact than their predecessors, are introduced into the market. The key parameter describing environmental impact is the GWP index, which is most often defined on a time horizon of 100 years. The long-term use of new generations of gaseous refrigerants in HVAC systems reduces CO2 emissions into the atmosphere; however, given that new generation gases often have a short lifetime, it seems that the adopted assessment may not be applicable. The aim of the article was to show how emissions of CO2 equivalent to the atmosphere differs in the short and long time horizon. The article presents the results of calculations of equivalent CO2 emissions to the atmosphere caused by the operation of compressor cooling devices used in HVAC systems, where cooling is done with the use of water or a water-glycol solution. The analysis was carried out for 28 commonly used devices on the world market. The analyzed devices work with refrigerants: R513A, R454B, R290, R1234ze, R32, R134a, R410A. The equivalent emissions values for GWP 100 and GWP 20 were analyzed in relation to the unit power of the devices depends on refrigerant mass and number of fans. The study showed that in the case of new generation refrigerants with a very short lifetime, the use of GWP 100 indicators is misleading and does not fully reflect the effects of environmental impact, especially in the area of refrigeration equipment application. The article shows that the unit value of the cooling load related to the number of fans or the unit would be helpful in assessing the environmental impact of a cooling device.

In recent years, the world has witnessed one of the most severe raw material crises ever recorded, with serious repercussions for maintaining its agri-food supply chain. This crisis risks dramatically impacting the poorest areas of the planet and poses profound reflections on global food security. In this complex geopolitical context, the recovery and recycling of renewable resources have become an obligatory path and, today, more than ever, essential in the fertiliser industry. To achieve these objectives, TIMAC AGRO Italia S.p.A. has undertaken a research activity to review the formulation of fertilisers by diversifying the raw materials used and introducing recycled raw materials. This article carried out a life cycle assessment (LCA) on four fertilisers to identify and quantify whether the changes influenced the environmental impacts, highlighting how applying the circular economy within industrial processes can reduce the pressure on natural resources. The results demonstrate that the global warming potential (GWP) impacts of the different reformulated fertilisers show a considerable variation of 4.4–9.2% due to the various raw materials used, the nitrogen content, and related emissions deriving from environmental dispersion. This study shows the importance of the LCA methodology to analyse and quantify the impact categories generated on the life cycle of fertiliser production and to identify the optimal by-products and end-of-waste for the fertiliser industry to find a synergy between environmental and agronomic performance. It also highlights the relevance of the transition to circular production and consumption systems to reduce environmental pressures and their effects on communities and ecosystems without compromising yields. Finally, the positive results encourage accelerating the circular transition and finding alternatives to virgin-mined raw materials.

The construction industry faces various sustainability challenges, and modern methods of construction (MMC) have been promoted as an effective alternative to mitigate environmental impact and improve productivity. However, to gain a thorough understanding of the benefits, there is a need for more objective data. To address this, the present study employs a simplified life-cycle assessment (LCA) methodology to evaluate a set of environmental and efficiency metrics in a case study. The study aims to demonstrate the benefits of using an MMC known as the “VAP system” by comparing it with its conventional counterpart built with reinforced masonry. Adopting the MMC resulted in significant reductions in embodied carbon (EC) and embodied energy (EE) related to materials, as well as a reduction in global warming potential (GWP), cumulative energy demand (CED), and construction waste. Additionally, it shortened delivery times and increased labor productivity. Furthermore, when both local and European parameters were considered in the evaluation, the percentage of materials circularity (PMC) was higher. The study concludes that the adoption of the MMC leads to higher sustainability by reducing carbon emissions, minimizing construction waste, and conserving resources. This research has significant implications for promoting the adoption of MMC globally, leading to more sustainable and efficient construction practices.

As the construction industry continues to evolve, energy consumption of buildings, particularly CO2 emissions, has become a critical focus for sustainable development. The need for effective design decisions regarding the selection of materials throughout the project life cycle is apparent, yet the link between specifications and CO2 emissions has not been set yet. This study presents a comprehensive life cycle assessment (LCA) of CO2 emissions across various Construction Specifications Institute (CSI) categories, aiming to identify the carbon footprint of different building systems and materials. The methodology focuses on using 3D building model case studies to evaluate the design decisions versus their impact on global warming potential (GWP). The results of this study emphasize that within CSI categories, concrete divisions consistently emerge as the predominant contributors to GWP, exceeding 75% in several instances. Following closely, metals contribute approximately 50% in multiple projects. The study also explores sustainable design options across CSI divisions to provide insights into building components contributing most to a building’s overall carbon footprint. This deeper understanding of sustainable design principles regarding CSI divisions and their impact on carbon footprint reduction will help sustainable designers and construction managers to implement carbon-conscious material choices and design strategies early in the planning phase.