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Research has focused on the threat of global warming-induced climate change to modern human civilization. Carbon dioxide (CO2) is a primary greenhouse gas that causes global warming. Current efforts have focused on using CO2 as a raw source for producing value-added chemicals. Among the different CO2 conversion processes, the Sabatier process, also known as "CO2 methanation," is an effective approach, particularly if H2 is generated by renewable energy sources. In this process, methane (CH4) and water (H2O) are produced from CO2 and H2 using different transition-metal-based catalysts. Although numerous studies have been conducted to assess the significance of CO2 methanation, quantitative analysis of the publication trends in this research field is still lacking. This review presents the global research landscape of CO2 methanation over the last 20 years (2000–2022). The Web of Science (WoS) database was used to extract 1657 publications, and the VOSviewer software was used for bibliometric investigations. Bibliometric analysis revealed that 77.53% of the papers were published within the past 5 years (2018–2022). The International journal of hydrogen energy is leading journal publishing research articles about CO2 methanation followed by Applied Catalysis B. This study conducted a statistical analysis on the influence of leading countries, institutions, journals, authors, and top keywords in the field of CO2 methanation. Additionally, future research directions and findings of the most cited publications are discussed. Because the CO2 methanation reaction requires a highly stable and active catalyst, a brief introduction and major challenges of these catalysts are also reviewed. We hope that bibliometric findings will help scholars to understand this field of research more effectively and comprehensively. [ABSTRACT FROM AUTHOR]

Abstract The main goal in this paper is to supply a national load by multiple renewable power connections to utility grid at different geographic locations. The national load demand of the country of Jordan is supplied in this case study by finding the optimal configurations and locations (near cities). Cities of higher potential for wind and/or photovoltaic (PV) energy location are selected for connecting to renewable power. The annual system cost of energy (ASCE) for this optimized renewable energy system is shown to be 32.57% less than the conventional grid energy price. Further, the Carbon Dioxide (CO 2) emissions are reduced by 80.13%. These are excellent indications for the feasibility and environmental benefits of retrofitting conventional grid with renewable power in developing countries. Multi-figure of merits (MFOM) based on a Nondominated Sorting Genetic Algorithms (NSGA) optimization cases are investigated which include annual emission indicator (AEI), ASCE, levelized cost of energy (LCOE) and renewable penetration (RP). Results are either two dimensions (2D) or three dimensions (3D) Pareto frontier, where various competitive non-dominant solutions exist. A sweet spot selection (triple-S) procedure is proposed to help select the best point in the two (figure of merits) FOMs Pareto frontier to have both environmental and feasible solutions. Highlights • The contributions of this paper are multi-point connection to a national grid, holistic definition and modeling of the engineering and financial problems, optimal design tool solutions to the multi-point connection problem definition and model, suggesting this as a case study of the concept of "local solutions for a global problem." Such a holistic approach is recommended especially in the developing countries. • The importance of moving toward sustainable energy stems from global climate change and the need to provide access to affordable energy to all of humanity. The ultimate goal is to satisfy a country's national load demand by establishing multiple utility grid connections to various geographic locations of high wind or solar energy resources. This is done by building a new optimization design tool which investigates economic feasibility and environmental impacts. Then, Single figure of merit and multi-figure of merits optimizations have been investigated. • A mathematical modeling is developed for each component, and the optimal configuration is determined for each city. The annual system cost of energy (ASCE) is optimized to be 32.57% less than grid energy price, and the CO 2 emissions (AEI) are reduced by 80.13%. These are excellent indications for the economic feasibility and the environmental benefits of the designed system. The levelized cost of energy (LCOE), total net present cost, renewable penetration (RP) and AEI are 0.058212 $/kWh, $8.713857 billion, 59.49817% and 4.576 Megatonne/year respectively. • A new equation to calculate the salvage cost has been developed in this paper. Moreover, a new procedure in a multi-optimization problem was developed in this paper, which is the Sweet Spot Selection (triple-S) procedure. It is developed to help select the sweet point in the two FOMs Pareto frontier to have both environmental and economic feasible solutions. • Multi-figure of merits (MFOM) optimization cases based on a non-sorting genetic algorithm are investigated such as: AEI vs. ASCE, AEI vs. LCOE, AEI vs. RP and (RP, LCOE, AEI). The MFOM optimization results are either 2D or 3D Pareto frontier, where exists various competitive non-dominant solutions. The sweet spot selection (triple-S) procedure is proposed to help select the sweet spot in the two figure of merits Pareto frontier in order to have both environmental and feasible solutions. [ABSTRACT FROM AUTHOR]

This study predicts the probabilities of achieving the carbon dioxide (CO 2 ) emission targets set by the Paris Agreement and the Intended Nationally Determined Contribution (INDC) of the top ten CO 2 emitters (TTCE). The TTCE are China, USA, India, Russia, Japan, Germany, South Korea, Iran, Saudi Arabia and Indonesia based on their emission trends over 1991–2015 period. The methods of trend extrapolation and back propagation (BP) neural networks are used in this paper to overcome the weakness of multiple linear regression (MLR) and the assumptions of the environmental Kuznets curve (EKC). The results show that the model performs well and has high predictive accuracy. The volume of the CO 2 emissions by the TTCE in 2030 is predicted to increase by 26.5–36.5%, compared with 2005. According to different trends of economic growth, energy consumption, and changes in share of renewable energy, the results show that China, India and Russia will achieve their INDC targets in some scenarios, whereas there will be a shortfall in achieving targets by USA, Japan, Germany, and South Korea. In particular, the carbon reduction situations of Saudi Arabia, Iran and Indonesia are quite severe. Moreover, the results show that there is no common trend that can be used as a suitable benchmark for every country for the implementation of carbon reductions targets of the Paris Agreement and their INDC goals. Finally, there are signs of improvement of the equality of carbon emissions based on the analysis of the Gini coefficient. [ABSTRACT FROM AUTHOR]

This paper reviews climate change impacts on the production, physiology, yield, and product quality of vegetables affected by shifting CO 2 and O 3 concentrations, precipitation and temperature conditions, as well as subjected to extreme weather events. The emphasis is on the temperate cool climate of Western Europe. Physiological processes such as respiration and photosynthesis can acclimate to increasing atmospheric CO 2 and temperatures. The effect of increased CO 2 on vegetables is mostly beneficial for production, but may alter internal product quality, or result in photosynthetic down-regulation. Heat stress reduces fruit set of fruiting vegetables, and speeds up development of determinate vegetables, shortening their time for photoassimilation. In both cases, yield losses result with an impaired product quality, thereby increasing production waste. A longer growing season, arising from warmer temperatures, allows a greater number of plantings to be cultivated, contributing to greater annual yields. However, some vegetables need a period of cold accumulation to produce a harvest. Despite the increasing potential for winter cultivation in the future, perennials like asparagus might increasingly suffer from a lack of winter chilling. In cauliflower, higher temperatures will likely cause insufficient vernalization delaying head induction. This review may contribute in improving the adaptation strategies of vegetable production to climate change for a sustainable horticulture due to an effective risk management by meeting the problems of possible waste increase; breeding of new heat, drought and pest tolerant cultivars; secure water resources; increase the use of renewable energy sources; stimulating new ideas in innovative technologies; development of new approaches to secure stable yields and improve the product quality of vegetables for a cleaner production. © Elsevier. All rights. [ABSTRACT FROM AUTHOR]

Reducing local and global emissions is one of the drivers behind the promotion of renewable energy technologies (RETs). Some RET projects (e.g. solar, marine power, and some biomass and wind) usually require supplemental income from carbon credits in order to make them economically viable. This paper presents the mathematical development of nodal marginal CO 2 emission metrics for hydrothermal systems. These metrics are obtained from optimal power flow and hydrothermal dispatch models considering hydro uncertainty. The proposed model allows a more accurate assessment of the emission reduction effect of RET projects and the provision of efficient carbon signals to the system. Modeling of hydro reservoirs and intertemporal constraints also allows incorporating the emission mitigation potential of water storage. The concepts of marginal CO 2 emissions for hydrothermal systems are first exemplified using a small test system, and then simulations on a real hydrothermal system illustrate how these metrics can inform investment and operational decisions. Theoretical and simulation results show that transmission and hydro storage constraints neglect may provide wrong signals for RET investors, missing the incentives to install in areas where the potential for emissions reduction is higher (where renewable energy displaces a larger amount of coal or diesel). Policy makers can use the proposed model to assess the cost-effectiveness of emission reduction policies. [ABSTRACT FROM AUTHOR]

It is not the first time in human history, nor will it be the last for that matter, that a collective problem calls for a collective response. Climate change fueled by greenhouse emissions affects humankind alike. Despite the disagreement among policymakers and scientists on the severity of the issue, the truth is that the problem remains. A broad look at different technologies being used today in different fields has led to the idea of bringing them together in an attempt to offer a viable solution to reducing anthropogenic CO2. The following paper describes how the nanotechnologies, available or soon to be available, would make CO2 capture, cache, and conversion (coined the three Cs) a valid way for achieving a more sustainable energy society. Authors also set out to highlight with this work how knowledge transfer is instrumental in the development of technology and how methodical assessment of crossovers can expedite research when time plays against us. [ABSTRACT FROM AUTHOR]

With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology--a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The goal of this study is to review the fundamental structures and chemistries of wood and wood-derived materials, which are essential for a wide range of existing and new enabling technologies. The scope of the review covers multiscale materials and assemblies of cellulose, hemicellulose, and lignin as well as other biomaterials derived from wood, in regard to their major emerging applications. Structure--properties-- application relationships will be investigated in detail. Understanding the fundamental properties of these structures is crucial for designing and manufacturing products for emerging applications. Today, a more holistic understanding of the interplay between the structure, chemistiy, and performance of wood and wood-derived materials is advancing historical applications of these materials. This new level of understanding also enables a myriad of new and exciting applications, which motivate this review. There are excellent reviews already on the classical topic of woody materials, and some recent reviews also cover new understanding of these materials as well as potential applications. This review will focus on the uniqueness of woody materials for three critical applications: green electronics, biological devices, and energy storage and bioenergy. [ABSTRACT FROM AUTHOR]

The scientific evidence of climate change as a result of greenhouse gas emissions which causes ozone layer depletion is becoming increasingly obvious and clear. Findings revealed that energy from the fossil fuel is the major source of greenhouse emission which destroys the environment and makes it unhealthy for living beings. In Nigeria, conventional energy (oil and gas) with gas flaring has the highest percentage of 52% and liquid fuel of 32% of carbon dioxide (CO2) respectively. This sector contributes revenue of over 70% to Nigeria s economy and generates an average total 21.8% of greenhouse gas emission. In Nigeria, there is a much more potential for share renewables with 15.4% of total energy production and 8.6 % of energy consumption. In reality with global environmental concern, Nigeria s carbon dioxide emissions have increased with energy production and consumption. The Integrated Renewable Energy Master Plan of 2008 projects a 26.7% renewable energy contribution to the Nigeria s energy use and this is expected to reduce CO2 and greenhouse gas emissions at 38% by2025. Nigeria has not been playing significant role by reducing emissions of greenhouse gases. This paper highlights Nigeria s climate change situation and penetration requirements for various renewable energy deployments as mitigating instrument for climate change towards healthy and productive environment. [ABSTRACT FROM AUTHOR]