Search

Composite materials have been widely used because of their superior properties compared to those of the original material. Separation of the constituent materials is not easy in the recycling process, and such an effort lowers economic viability. As such, this study employed a pyrolysis as a valorizing method for the composite material. Disposable paper cup waste (DPCW) was chosen as the model compound for paper-plastic composites. To offer green/sustainable features, CO2 was employed as a raw and reactive material in the pyrolysis process. It was proved that DPCW primarily composed of cellulose (outer layer) and polyethylene (inner layer). In the single-stage and multistage pyrolysis of DPCW, the CO2 reactivity in the homogeneous reaction of CO2 and DPCW-derived volatiles was not rapid. To accelerate the reaction kinetics governing the reactivity of CO2, the catalytic pyrolysis of DPCW over Ni/SiO2 was performed. The formation of syngas increases significantly, suggesting that CO2 reactivity was catalytically enhanced. The generation of syngas (enhanced by CO2) was inversely related to the DPCW oil generation, indicating that more carbon was assigned from the oil to the gaseous pyrogenic products. The study results would offer a strategic means to valorize paper-plastic composites and CO2 into energy through pyrolysis. [ABSTRACT FROM AUTHOR]

The case studies are introduced in this study, highlighting freight transportation via road and road rail between satellite cities in Pakistan's Punjab and Sindh provinces. The case study analysis contributes to developing environmentally friendly and cost-effective transportation solutions and reducing nitrous oxide (N2O) and carbon dioxide (CO2) emissions associated with road and intermodal freight transit. We developed a mixed-integer linear programming (MILP) model to formulate the bi-objective problem, including real-life constraints, emissions at starting nodes, ending notes, and between the arc. In the mathematical model, the cost and emissions functions are developed to minimize the primary and secondary objective functions in the road and intermodal transportation. Furthermore, five distinct sets (locations, starting stations, ending stations, transport orders, and transport service) with parameters relating to container movement between the starting and ending nodes are a necessary part of the MILP formulation. The multiobjective optimization problem is solved by metaheuristic techniques such as the multiobjective genetic algorithm as the goal of applying a metaheuristic algorithm is to find the search space to search the near to optimized solutions. The Pareto front solutions are provided for balancing the costs and emissions of transporting supplies from Punjab to Sindh using the MATLAB solver toolbox. We gathered data from one of Pakistan's most well-known logistics service providers in the paper industry. According to the findings, intermodal transportation is 72% more cost-effective than road transportation. Additionally, by substituting intermodal transportation for road transportation, N2O, and CO2 emissions can be reduced by 74% and 57%, respectively. [ABSTRACT FROM AUTHOR]

In the global ecosystem, wetlands are vital carbon sinks, playing a crucial role in absorbing greenhouse gases such as carbon dioxide and mitigating global warming. Accurate estimation of wetland carbon content is essential for research on wetland carbon sinks. However, the carbon cycle of wetlands is complex, and the carbon sinking of wetlands is affected by climate, topography, water level conditions, vegetation types, soil types, and other factors. This has caused significant challenges in the estimation of wetland carbon sinks. In current studies, most research has focused on the impact of individual factors on wetland carbon sinks, often ignoring the interaction between various factors, which further leads to uncertainty in wetland carbon measurements. This paper aims to elucidate the process of the wetland carbon cycle, summarize the factors affecting wetland carbon sinks, and explore the interplay between various factors and their influence on wetland carbon sinks, aiming to provide theoretical support for the study of wetland carbon sinks. Additionally, this paper reviews the advantages and disadvantages of current wetland carbon measurement methods, proposes research directions for combining machine learning methods, identifies existing difficulties in current wetland carbon measurement, and offers suggestions to serve as a reference for future wetland carbon sink estimation and wetland management.Highlights: The potential and significance of wetland carbon sinks are explained. The advantages and disadvantages of current wetland carbon measurement techniques are summarized. The prospective method for integrating machine learning into integrated wetland carbon measurement is proposed. [ABSTRACT FROM AUTHOR]

A paper-based electrochemical dual-function biosensor capable of determining pH and TCO2 was synthesized for the first time using an iridium oxide pH electrode and an all-solid-state ion electrode (ASIE). In the study, to obtain highly reliable results, the biosensor was equipped with a real-time pH correction function before TCO2 measurements. Compared to traditional liquid-filling carbon dioxide detection sensors, the utilization of ferrocene endows our novel sensor with abundant positive sites, and thus greatly improves its performance. Conversely, the introduction of MXene with conductivity close to that of metals reduces electrode resistance, which is beneficial for accelerating the electrochemical reaction of the sensor and reducing LOD. After optimization, the detection range of TCO2 is 0.095 nM–0.66 M, with a detection limit of as low as 0.023 nM. In addition, the sensor was used in real serum sample-spiked recovery experiments and comparison experiments with existing clinical blood gas analyzers, which confirmed the effectiveness of its clinical application. This study provides a method for the rational design of paper-based electrochemical biosensors and a new approach for the clinical detection of blood carbon dioxide. [ABSTRACT FROM AUTHOR]

Reducing the use of fossil fuels is critical to human society. In recent years, electrocatalytic carbon dioxide (CO2) reduction has attracted widespread attention. A suitable CO2 reduction catalyst is essential to convert CO2 into more valuable chemical products with high selectivity and efficiency. In this paper, a highly selective ZnAlCe-Ternary metal hydroxides (ZnAlCe-THs) nanocomposite electrocatalyst material was designed and prepared, and its performance as an electrocatalyst for catalytic reduction of CO2 to carbon monoxide (CO) was explored. The layered structure of ZnAlCe-THs nanocomposites facilitates electron transfer as well as CO2 and proton transfer, providing a high specific surface area for the electroactive sites of the electrocatalytic reduction reaction. At the same time, the ZnAlCe-THs catalyst generates CO at an overpotential of − 0.5 V. At − 1.2 V versus the reversible hydrogen electrode (vs. RHE), the bias current density is about 10.46 mA cm−2 with high selectivity of 89.3% Faraday efficiency. Its excellent electrochemical properties make it a good catalyst for the selective reduction of CO2 to CO. In this paper, ZnAlCe-Ternary mental hydroxides (ZnAlCe-THs) with a layered hydrotalclike structure were prepared by hydrothermal and co-precipitation methods. It showed excellent catalytic performance in the electrocatalytic reduction of carbon dioxide to carbon monoxide with a Faraday efficiency of 89.3% at − 1.2 V vs. RHE and a current density of 10.46 mA cm−2 for higher selectivity for CO. In addition, the ZnAlCe-THs catalyst is stable and it can operate for 5 h without particularly significant deactivation. [ABSTRACT FROM AUTHOR]

The urgent need to address global carbon emissions and promote sustainable energy solutions has led to a growing interest in carbon dioxide (CO2) conversion technologies. Among these, the transformation of CO2 into methanol (MeOH) has gained prominence as an effective mitigation strategy. This review paper provides a comprehensive exploration of recent advances and applications in the direct utilization of CO2 for the synthesis of MeOH, encompassing various aspects from catalysts to market analysis, environmental impact, and future prospects. We begin by introducing the current state of CO2 mitigation strategies, highlighting the significance of carbon recycling through MeOH production. The paper delves into the chemistry and technology behind the conversion of CO2 into MeOH, encompassing key themes such as feedstock selection, material and energy supply, and the various conversion processes, including chemical, electrochemical, photochemical, and photoelectrochemical pathways. An in-depth analysis of heterogeneous and homogeneous catalysts for MeOH synthesis is provided, shedding light on the advantages and drawbacks of each. Furthermore, we explore diverse routes for CO2 hydrogenation into MeOH, emphasizing the technological advances and production processes associated with this sustainable transformation. As MeOH holds a pivotal role in a wide range of chemical applications and emerges as a promising transportation fuel, the paper explores its various chemical uses, transportation, storage, and distribution, as well as the evolving MeOH market. The environmental and energy implications of CO2 conversion to MeOH are discussed, including a thermodynamic analysis of the process and cost and energy evaluations for large-scale catalytic hydrogenation. [ABSTRACT FROM AUTHOR]

Near miscibility widely exists in carbon dioxide (CO2) injection development projects. However, there is no existing approach to quantify the effect of near miscibility on oil recovery. In this paper, slim tube experiments were conducted to study near miscible region. The oil displacement efficiency curve is divided into immiscibility, near miscibility and miscibility. And three linear function is obtained, respectively. Then, the space between production well and CO2 injection well is discrete to characterize the effect of near miscibility on oil recovery. Then, a new approach is proposed to calculate oil recovery of CO2 displacement in tight oil reservoirs. This approach can calculate oil recovery considering near miscibility. It is found that minimum miscibility pressure (MMP) without considering near miscibility is 4 MPa lower than considering near miscibility. The near miscible pressure range is from 0.77 times to 1 time MMP considering near miscibility. Oil displacement efficiency difference reaches to be the maximum when the pressure is the minimum miscibility pressure without considering near miscibility. The maximum of the oil displacement efficiency difference is 3.4%. The optimal formation pressure considering near miscibility is 5 MPa larger than that without considering near miscibility. The oil recovery considering near miscibility is from 0.9 to 1.3% lower than that not considering near miscibility. It reaches to be the maximum when the pressure is the optimal formation pressure level without considering near miscibility. The maximum of the oil recovery difference is 1.3%. [ABSTRACT FROM AUTHOR]

Utilizing carbon dioxide in chemical processes is one of the suggested remedies for reducing its atmospheric concentration. In this paper, the simulation of the propylene carbonate production process using 1,2-propanediol and carbon dioxide has been performed. The impact of temperature was examined between 75 and 400°C. It has been found that as temperature rises, reaction conversion increases. Additionally, the impact of recycling ratio was examined in the range of 0.1–0.5, which demonstrates that a rise in the recycle ratio results in a fall in conversion. Furthermore; it was observed that the pressure initially increases the solubility of carbon dioxide in 1,2-propanediol and improves the conversion of the reaction, but when enough carbon dioxide is supplied in the reaction, increasing the pressure does not affect the corresponding reaction. The effect of all studied parameters depends on the residence time of the reactants in the reactor. Investigating the interaction of parameters and optimizing the process has shown several optimal point of the process such as temperature of 295 °C, a recycle ratio 0.1, feed ratio 0.8 and a residence time of 12.61 h, with the related conversion being 59.6%. [ABSTRACT FROM AUTHOR]

This paper investigates whether carbon dioxide (CO2) intensity of gross domestic product (GDP) matters for environmental deregulations in Southern European countries over the period of 1990–2018 while controlling economic growth, globalization, and energy consumption. The present study uses the second generation panel based techniques, namely cross-sectional dependency test, cross-sectional unit-root test, Westerlund cointegration test, augmented mean group and common correlated effects mean group estimators, and Dumitrescu–Hurlin causality test to measure the effect of CO2 intensity of GDP, economic growth, globalization, and energy consumption on environmental degradation. The empirical finding of the present study reveals that the CO2 intensity of GDP is an important factor in determining environmental degradation in South European countries, as the outcomes show that a 1% boost in CO2 intensity of GDP is causing a 1.7728% increase in CO2 emissions. Moreover, a 1% increase in economic growth caused a 0.2568% boost in CO2 emissions. The result is crucial for policy decision-making and can perhaps be applied to take decisive policy actions to mitigate environmental issues. [ABSTRACT FROM AUTHOR]

Accurate estimation of CO2-brine Interfacial Tension (IFT) is of great importance since it is required to model the residual/capillary trapping of CO2 in geological formations. In this paper, a novel correlation is proposed based on the classical orthogonal polynomials to estimate the CO2-brine IFT of monovalent salts with common anion. To do so, CO2-brine IFT samples composed of samples from the literature and experimentally measured values using an in-house high-pressure high-temperature IFT measurement device were collected within a wide range of temperatures, pressures, and salinities. The utilized brines included NaCl and KCl salts. Then, a predictive model was developed based on the Group Method of Data Handling approach as a function of temperature, pressure, and ionic strength. The proposed method was compared with four methods from the literature in terms of average absolute percentage error (AAPE), coefficient of determination R 2 , histograms of error, and percent error plots. Results showed the superiority of the proposed method over other methods with an AAPE of 9.85 and R 2 of 0.719. Also, it was shown that the proposed method did not produce too large errors, contrary to other methods. Therefore, the proposed method can be used reliably as a tool for CO2-brine IFT estimation in CO2 storage projects. [ABSTRACT FROM AUTHOR]

One of the possible sources of carbon dioxide emission into the atmosphere can be river ecosystems. The paper presents the results of measuring CO2 fluxes from the surface of several rivers and lakes in Tomsk Region. In the experimental period, average carbon dioxide fluxes were 143.7 ± 21.7 (August 13–14, 2023), 53.3 ± 21.2 (August 19), and 80.4 ± 59.9 mgC m−2 h−1 for the Ob River; 66.1 ± 17.3 mgC m−2 h−1 for the Ket River; 33.3 ± 17.3 mgC m−2 h−1 for the swamp Karasevoye Lake, 50.2 ± 23.0 mgC m−2 h−1 for the Suiga River, and 81.9 ± 11.5 mgC m−2 h−1 for the Iksa River. The flux magnitudes significantly depended not only on the object of the study, but also on hydrometeorological conditions. [ABSTRACT FROM AUTHOR]

Catalytic synthesis of urea is a bright substitutable to Haber–Bosch progression and industrial urea synthesis. Electrochemical C–N coupling of carbon dioxide and nitrogen oxides under environmental conditions is a newly developed method, which also provides a novel opinion for solving nitrate contamination. Conjugated organic frameworks (COFs) have been used as prospective electrocatalysts for nitrogen reduction reactions and carbon dioxide reduction reactions (CO2RR) as a result of their regulate structure and multihole properties, resulting in efficient electron transfer. This paper reports the efficient synthesis of urea from carbon dioxide and nitrate over MoM1S-Pc-M2PPs COF (M as a transition metal) electrocatalyst. According to the calculation of DFT, it was found that it was difficult for carbon dioxide and nitrogen oxide to coadsorb on MoM1S-Pc to synthesize urea, so we chose to synthesize CO on the metal porphyrin (M2PPs) structural unit, and then overflow on the bimetallic phthalocyanine and nitrogen oxide to synthesize urea. The possibility of nitrate adsorption on different catalysts was verified by calculation. We screened the stability, nitrate adsorption strength, and catalytic activity of MoM1S-Pc candidates, and the results showed that the most promising candidate catalyst was MoFeS-Pc. At the same time, the CO2RR M2PPs substrate was also screened, and the VPPs structure was selected as the best. In the study of coupling between different nitrogen-containing intermediates and *CO, the C–N coupling mechanism shows that *NOH and *CO are two possible C–N coupling nitrogen intermediates, which are shown to be thermodynamically spontaneous and have an inferior activation barrier. This study not only provisions novel perceptions into urea synthesis by coupling nitrogen oxides with carbon dioxide under environmental conditions, but also paves the way for boosting the sustainable production of carbon and nitrogen-coupled products. [ABSTRACT FROM AUTHOR]

This paper evaluated ZnO, SiO2 and zeolite 13X for removing CO2 from normal heptane (nC7) as synthetic gas condensates in batch mode. Based on the results of CO2 adsorption isotherms, zeolite 13X had the highest CO2 uptake in 1400–3700 ppm at atmospheric pressure. Due to the higher specific surface area of granular zeolite 13X, its CO2 uptake was more than that of zeolite 13X powder. Also, the CO2 adsorption equilibrium time was less than 30 min for zeolite 13X powder. The selectivity of zeolite 13X powder (i.e., H2S/CO2) was 2.36–4.08 for 2001–3930 ppm H2S with 1668 ppm CO2. Besides, the CO2 breakthrough time for zeolite 13X powder was 50–4 min for WHSV (weight hourly space velocity) = 5–20 h−1 at 30 bar in continuous mode. Additionally, for the increased CO2 concentration from 1000 to 3000 ppm, the CO2 breakthrough time decreased from 30 to 11 min with WHSV = 10 h−1. The CO2 breakthrough time diminished by 2.5-fold as the pressure was reduced from 30 bar to atmosphere for the initial CO2 concentration of 1000 ppm in nC7 and WHSV = 10 h−1. Subsequently, the regeneration of zeolite 13X by stagnant hot air was investigated for the CO2 concentration range of 1000–3000 ppm, air-adsorbent contact time range of 30–180 min and temperature range of 100–300 °C using Box–Behnken design. Its regeneration efficiency was more than 95% for the CO2 concentration below 1000 ppm. [ABSTRACT FROM AUTHOR]

ZnZrOx has been used in large quantities for the preparation of light olefins from CO2, but the relationship between structure and performance remains unclear at present. In this paper, ZnZrOx were prepared by co-precipitation method, and a series of oxides with different sizes were prepared by varying the calcination temperatures. Subsequently, these oxides were combined with SAPO-34 to create a composite bifunctional catalyst for the synthesis of light olefins by CO2 hydrogenation, in which the impact of nanocrystal size effect was examined. The catalytic performance significantly increased as the nanocrystal size reduced from 18 to 12 nm. However, when the nanocrystal size was further decreased to 8 nm, the catalytic performance decline. Characterizations revealed a gradual increase in the number of oxygen vacancies with decreasing nanocrystal size. However, the oxide with the smallest nanocrystal size, prepared by varied calcination temperatures, did not yield the optimal catalytic performance due to sintering occurring during the reaction process. The results show that the assumption that smaller nanocrystal sizes inherently equate to improved catalytic performance is not universally valid, and stability must be considered when the nanocrystal size is decreased. The bifunctional catalysts used in this paper for the prepared light olefins from CO2 in yield as high as 13.8%, which is higher than most previous reports. [ABSTRACT FROM AUTHOR]

In order to study the cruise safety of aircraft under high altitude and low pressure, the combustion characteristics of protective cover and insulation layer of waxy aviation cable FXL under normal pressure and low pressure are studied in this paper. The minimum ignition time (TTI), the maximum radiation temperature, the flue gas density and the mass loss rate of the protective cover and insulation layer of the waxy FXL aviation cable under 96 kPa and 61 kPa were studied. It is found that the minimum radiation temperature and TTI of the cable at 61 kPa are slightly higher than those at 96 kPa, but the activation energy is basically not affected by the air pressure. The smoke density and smoke composition under 96 kPa and 61 kPa were further studied, and it was found that the smoke density of the cable under 61 kPa sheath and insulation layer was lower than that under 96 kPa. The oxygen, carbon dioxide and carbon monoxide components in the flue gas were studied. It was found that the O2 concentration of 96 kPa and 61 kPa cable protective sleeve and insulation layer decreased steadily at first and then increased. The change trend of CO2 concentration was opposite, and the CO concentration showed a double-peak phenomenon. In addition, the mass loss rate (MLR) at different O2 concentrations increases linearly with the increase in O2 concentration. This work helps to understand the difference of combustion characteristics between 96 and 61 kPa, and provides a reference for improving civil aviation safety performance. [ABSTRACT FROM AUTHOR]

Mars has nearly ideal conditions for CO2 dissociation by glow discharge plasmas. The directly generation of O2 and CO on Mars was considered to be feasible and practical for in situ resource utilization of Martian atmosphere to get respirable O2 and fuel. In this paper, we conduct several experiments under simulated Martian conditions to investigate the process and how the key parameters effect the generation of O2 and CO in CO2 glow discharge reactions. The yields of new products (i.e., O2 and CO) under various gas discharge work parameters (i.e., discharge power, frequency, voltage, gap between the discharge plane electrodes and gas pressure) were systematically investigated. The reaction mechanism and reaction path of CO2 glow discharge has been discussed. In our study the max yield of O2 by CO2 discharge dissociation was got about 21.8 g/h at 168 W which is very close to that of NASA MOXIE (Mars Oxygen In-Situ Resource Utilization Experiment) at the same power. Our results showed the great potentiality of glow discharge for the practicable technology of O2 and CO generation for in-situ resource utilization on Mars. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new extension of the Vasicek model to the multivariate case and analyze its characteristics, including its probability density function, marginal trends, and correlation functions. We also conduct statistical estimation on the model, including likelihood parameter estimation and estimation of the marginal trend and correlation functions. To validate the effectiveness of our proposed model, we use simulation studies and examine the goodness of fit. Additionally, we apply our model to a bivariate case involving the analysis of CO 2 and N 2 O concentrations. We describe the data, fit the bivariate Vasicek stochastic diffusion model, and compare it with the univariate case. Finally, we summarize our findings and discuss the potential applications of our proposed model. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate-co-terephthalate) (PBAT) foam is regarded as one of the ideal alternatives to petroleum-based polymer foams in view of its advantages of lightweight, high elasticity, biodegradability and biocompatibility, while the problem of shrinkage after foaming has seriously limited its application in industry. In this paper, the no-shrinkage chain-extend PBAT-glycerin monostearate (GMS) foams with ultra-high volume expansion ratio (VER) were prepared by scCO2-assisted molten foaming method. The chain extension reaction between PBAT and chain extender (CE) were investigated by torque curves, gel fraction and FTIR measurements. Comparing with torqued PBAT, the storage modulus of CE-PBAT2 specimen increased 3 orders of magnitude and their crystallization temperature rose from 72.5 to 87.2 ℃. Furthermore, the addition of GMS was beneficial to enhance the dimensional stability of CE-PBAT foams. When 2 phr CE and 2.5 phr GMS were incorporated into PBAT, CEPBAT-GMS2.5 foam attained ultra-high VER of 25.38 times, resilience ratio of 87% with no-shrinkage, which revealed admirable compression and resilience properties. In conclusion, this study provided a feasible new method for improving the VER and dimensional stability of PBAT foams. [ABSTRACT FROM AUTHOR]

Purpose: This paper reports a life cycle impact assessment (LCIA) to calculate the environmental footprint of a dental appointment using N2O, comparing single-use equipment with reusable equipment. Nitrous oxide (N2O) is used successfully in dentistry to provide sedation and pain relief to anxious patients, most commonly in children. However, N2O is a powerful climate pollutant 298 times more damaging than carbon dioxide over a 100-year estimate. Methods: The functional unit chosen for this LCIA was 30 min delivery of N2O to oxygen in a 50:50 ratio at 6 L per minute flow rate as inhalation sedation to one patient. Two types of equipment were compared to deliver the anaesthetic gas: reusable and disposable items. Results: The use of disposable equipment for N2O sedation produces a significantly larger environmental impact across nearly all of the environmental impact scores, but the overall global warming potential is comparable for both types of equipment due to the vast environmental pollution from N2O itself. Conclusion: N2O sedation is a reliable treatment adjunct but contributes to climate change. Single-use equipment has a further deleterious effect on the environment, though this is small compared to the overall impact of N2O. Dental priorities should be to deliver safe and effective care to patients that protects staff, minimises waste and mitigates impact on the environment alongside promoting research into alternatives. [ABSTRACT FROM AUTHOR]

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]

In this study, we conduct a comprehensive history matching study for the FluidFlower benchmark model. This benchmark was prepared and organized by the University of Bergen, the University of Stuttgart, and Massachusetts Institute of Technology, for promoting understanding of the complex physics of geological carbon storage (GCS) through in-house experiments and numerical simulations. This paper synthesizes the experiences of history matching the benchmark data encountered by the Delft-DARTS and CSIRO participants. History matching is first performed based on a low-dimensional-zonated structured model using a simple Poisson-like solver. The permeability of six facies and two faults is inferred in this stage to match the digitized concentration data. The history matching is then further enhanced to richer spatial and physical models to capture the spatial variation of permeability and buoyancy effects, using an unstructured grid. Efficient adjoint methods are used to evaluate the gradient used in the optimization of data misfits or equivalent Bayesian log-likelihoods. With efficient optimization methods available for both maximum a posteriori model inference and Randomized Maximum Likelihood methods for model uncertainty, we perform history matching using both binary and continuous concentration observations. The results show that the tracer plumes in the enriched model match the experimental plumes more accurately compared with the results from the parsimonious-zonated model. The history matching results based on the concentration observations provide more similar plume shapes compared with the case based on the binary observations. The permeability difference between the model before and after history matching reveals that the tracer plume zone and the high permeable zone are the regions of high sensitivity in terms of data misfit between the model response and observations. Surprisingly, CO 2 concentration plume forecasts based on these history-matched models were not especially sensitive to the improvements observed in the enhanced model. [ABSTRACT FROM AUTHOR]

Successful deployment of geological carbon storage (GCS) requires an extensive use of reservoir simulators for screening, ranking and optimization of storage sites. However, the time scales of GCS are such that no sufficient long-term data is available yet to validate the simulators against. As a consequence, there is currently no solid basis for assessing the quality with which the dynamics of large-scale GCS operations can be forecasted. To meet this knowledge gap, we have conducted a major GCS validation benchmark study. To achieve reasonable time scales, a laboratory-size geological storage formation was constructed (the "FluidFlower"), forming the basis for both the experimental and computational work. A validation experiment consisting of repeated GCS operations was conducted in the FluidFlower, providing what we define as the true physical dynamics for this system. Nine different research groups from around the world provided forecasts, both individually and collaboratively, based on a detailed physical and petrophysical characterization of the FluidFlower sands. The major contribution of this paper is a report and discussion of the results of the validation benchmark study, complemented by a description of the benchmarking process and the participating computational models. The forecasts from the participating groups are compared to each other and to the experimental data by means of various indicative qualitative and quantitative measures. By this, we provide a detailed assessment of the capabilities of reservoir simulators and their users to capture both the injection and post-injection dynamics of the GCS operations. [ABSTRACT FROM AUTHOR]

The CO2 enhanced oil recovery(EOR) technology is widely utilized in the development of shale oil reservoirs. However, reservoir plugging issues often occur during the CO2 injection process, leading to reduced onsite development efficiency. Currently, the mechanism behind reservoir plugging is still unclear. Therefore, this research selects Jimsar crude oil from Xinjiang to conduct CO2 displacement experiments on shale cores and analysis of crude oil components. A comparative analysis is conducted with previous studies to explore the plugging mechanism. The research results demonstrate that core plugging occurs when the displacement pressure exceeds 25 MPa, resulting in a significant decrease in core permeability. Under a displacement pressure of 40 MPa, the additional resistance accounts for as much as 72% of the total resistance, with high asphalt content and the extractive effect of CO2 on crude oil components being important factors leading to core plugging. Therefore, in the field development process, the CO2 enhanced oil recovery technology should be applied in a rational and tailored manner according to the properties of the field's crude oil. [ABSTRACT FROM AUTHOR]

Agriculture is the leading sector that is responsible for global climate change through its significant contribution to greenhouse gas (GHG) emissions. Intriguingly, sub-Saharan Africa (SSA) is experiencing higher temperatures and lesser rainfall due to climate change enhanced by anthropogenic GHG emissions. Agriculture and energy use in the SSA predominantly influence the anthropogenic GHG leading to global warming. Therefore, reducing agricultural GHG emissions (such as carbon dioxide, nitrous oxide, and methane) plays a significant role in climate change adaptation. This paper reviews the potential implication of agriculture and energy use on climate change and its implications on environmental sustainability in SSA. Herewith, we explored various GHGs emitted through agriculture-energy use, their effects on climate change, as well as several climate change adaptation mechanisms, and gaps in existing knowledge that necessitate more research, were also explored. We found that agriculture had negative implications on climate change impacts in the SSA countries and that a more focused strategy that is both economically and technically feasible in terms of preferences for land use, effective energy use, and food supply would aid in GHG emission reduction and environmental sustainability. Adapting to the projected changes in the short term while investing in long-term mitigation strategies might be the only way toward a sustainable environment in this region. [ABSTRACT FROM AUTHOR]

This paper investigates the impacts of new digital technology on carbon emissions in China. To better capture the feature of new digital technology, we distinctively measure it using the invention patent stock of new generation information technology industry. The empirical results show that the development of new digital technology significantly reduces carbon dioxide (CO2) intensity. The results are still robust after addressing the endogeneity issues using instrumental variable regressions. The carbon reduction mechanisms of new digital technology include reducing energy intensity, optimizing energy structure, and advancing treatment technology. We further confirm the spatial spillover and nonlinear effects of new digital technology on CO2 intensity and the moderating effect of urban digitalization in carbon reduction. The study suggests that the potential of new digital technology in reducing carbon emissions should be highly attentioned by governments. [ABSTRACT FROM AUTHOR]

The growing need for carbon dioxide (CO2) removal in various industrial sectors has led researchers to focus on the positive features of mixed matrix membranes (MMMs). Covalent triazine frameworks (CT-1) and polysulfone (PSF) were both used in the creation of MMMs. Due to the high porosity, significant area of surface, uniform dimension of pores, and thermal and chemical resistance, CT-1 was selected. The newly developed CT-1/PSF MMMs were prepared with different CT-1 loadings (0, 0.1, 0.3, 0.8, 1.1, and 1.5 wt %) in dope solution. The performance of membranes was evaluated using FTIR, FESEM, TGA, mechanical properties, and gas separation tests. In pure gas tests, the CO2 permeance and ideal CO2/N2 and CO2/CH4 selectivity increased when CT-1 loading was increased from 0 to 0.8 wt %. MMMs confirmed 109.12 and 91.42% increases in CO2/N2 and CO2/CH4 selectivities compared to pure PSF, respectively. However, a further increase in CT-1 loading beyond 0.8 wt % led to a drop in ideal selectivity. CO2 permeance and selectivity were reduced with pressure (2, 3, 4, and 5 bar). Additionally, investigated the effect of the feed stream (3/97 vol % of CO2/CH4) on CO2 separation. This paper describes a new technique for improving the ability of mixed matrix membranes through CT-1 fillers. [ABSTRACT FROM AUTHOR]

Porous polymer beads with grafted poly(tertiary amine) were prepared by grafting triethylenetetramine to porous crosslinked poly(methyl acrylate) beads via ester amidation reaction, followed by Eschweiler–Clarke methylation reaction using formaldehyde and formic acid to converting the primary and secondary amine groups to tertiary amines in the beads. The tertiary amine groups in the beads were protonated with hydrochloric acid, hydrobromic acid or hydriodic acid, and the protonated tertiary amine group-containing beads showed high catalytic activity and high selectivity for the formation of propylene carbonate through cycloaddition of propylene oxide with CO2, while free tertiary amine group-containing beads exhibited almost no catalytic activity. The recyclability of the catalyst was studied, and slight loss of the activity was observed after five runs. [ABSTRACT FROM AUTHOR]

The exchange of trace gases between the atmosphere and the ocean plays a key role in the Earth's climate. Fluxes at the air-sea interface are affected mainly by wind blowing over the ocean and seawater temperature and salinity changes. This study aimed to quantify the use of CO 2 partial pressure (pCO 2 ) measurements at different depths (1, 5, and 10 m) in ocean surface layers to determine CO 2 fluxes (FCO 2 ) and to investigate the impacts of wind-sheltered and wind-exposed regions on the carbon budget. Vertical profiles of temperature, salinity, and pCO 2 were considered during a daily cycle. pCO 2 profiles exhibited relatively high values during sunny hours, associated with relatively high sea temperatures. However, the largest FCO 2 corresponded with higher wind speeds. Estimated fluxes between measurements at 1 and 10 m depths decreased by 71% in the sheltered region and 44% in the exposed region. According to the SOCAT dataset, at a depth of 5 m, the Atlantic basin emits approximately 0.29 Tg month - 1 of CO 2 to the atmosphere; nevertheless, our estimates suggest that FCO 2 at the surface is 12.02 Tg month - 1 , which is 97.6% greater than that at 5 m depth. Therefore, future studies should consider sampling depth to adequately estimate the FCO 2 . [ABSTRACT FROM AUTHOR]

In the context of ever-growing demand for food and associated concerns regarding the environmental impacts of high-input agricultural systems, there is growing interest in mixed farm enterprises to deliver greater sustainability compared with mono-enterprise production systems. However, assessments of such systems are complex and require high-resolution data to determine the true value and interconnectivity across enterprises. Given the scarcity of information on mixed crop–livestock systems and the difficulties of its analysis, we perform life cycle assessment using temporally high-resolution data (2019–2022) from a long-term experiment in South America to evaluate the 'cradle-to-farmgate exit' greenhouse gas emissions intensities of four rotational crop–livestock systems. Systems evaluated were continuous cropping: 2 years of continuous cropping; short rotation: 2-year continuous cropping plus 2-year pasture; long rotation: 2-year continuous cropping followed by 4-year pasture; and forage rotation: continuous pasture. Emissions intensities for beef throughput were reported as kilograms of carbon dioxide equivalents (CO2-eq) per kilogram of liveweight gain (LWG) using the Intergovernmental Panel for Climate Change's Sixth Assessment Report (AR6 2021) CO2 characterisation factors. Point estimate results were found to be 11.3, 11.8, 11.8 and 16.4 kg CO2-eq/kg/LWG for continuous cropping, short rotation, long rotation and forage rotation, respectively. Emission averages arising from crops, which were separated from animal-based emissions using economic allocation, were 1.23, 0.53 and 0.52 kg CO2-eq/kg for soybean, wheat and oat, respectively. The inclusion of soil organic carbon stock changes had notable effects on reducing each system's emissions: by 22.4%, 19.2%, 25.3% and 42.1% under continuous cropping, short rotation, long rotation and forage rotation, respectively, when soil organic carbon was included. Given there are few life cycle assessment studies available on such mixed-enterprise 'semi-circular' systems, particularly with novel primary data, this study adds critical knowledge to agri-food-related sustainability literature by addressing environmental issues in complex production systems compared to extant and broad coverage of mono-enterprise systems. [ABSTRACT FROM AUTHOR]

A sample of a catalytic system based on nickel and a carbon-containing material, microcellulose, was obtained using a hydrothermal synthesis method. A catalytic study of the synthesized system in the process of selective hydrogenation of carbon monoxide and carbon dioxide was carried out with calculation of the apparent activation energy. The sample was demonstrated to be highly active in the selective hydrogenation reactions of carbon oxides. A 100% conversion of carbon monoxide and carbon dioxide and selectivity for methane of 90 and 80%, respectively, were obtained. [ABSTRACT FROM AUTHOR]

Methanogenic hydrocarbon degradation can be carried out by archaea that couple alkane oxidation directly to methanogenesis, or by syntrophic associations of bacteria with methanogenic archaea. However, metagenomic analyses of methanogenic environments have revealed other archaea with potential for alkane degradation but apparent inability to form methane, suggesting the existence of other modes of syntrophic hydrocarbon degradation. Here, we provide experimental evidence supporting the existence of a third mode of methanogenic degradation of hydrocarbons, mediated by syntrophic cooperation between archaeal partners. We collected sediment samples from a hot spring sediment in Tengchong, China, and enriched Hadarchaeota under methanogenic conditions at 60 °C, using hexadecane as substrate. We named the enriched archaeon Candidatus Melinoarchaeum fermentans DL9YTT1. We used 13C-substrate incubations, metagenomic, metatranscriptomic and metabolomic analyses to show that Ca. Melinoarchaeum uses alkyl-coenzyme M reductases (ACRs) to activate hexadecane via alkyl-CoM formation. Ca. Melinoarchaeum likely degrades alkanes to carbon dioxide, hydrogen and acetate, which can be used as substrates by hydrogenotrophic and acetoclastic methanogens such as Methanothermobacter and Methanothrix. Methanogenic hydrocarbon degradation can be carried out by archaea either by coupling alkane oxidation directly to methanogenesis, or in syntrophic associations with bacteria. Here, the authors provide experimental evidence supporting that methanogenic degradation of hydrocarbons can also be mediated by syntrophic cooperation between archaeal partners. [ABSTRACT FROM AUTHOR]

Although several studies examine the convergence of per capita carbon dioxide (CO2) at the country level, research at the regional level is scarce except in countries like China and the USA. This study bridges this research gap by considering India's regional-level CO2 emissions convergence. In particular, this study proposes to undercover the convergence patterns of carbon emissions towards designing effective carbon reduction policies in the future at the regional level in India. Addressing this research is vital since this question is closely allied with fairness in the distribution of per capita emissions. In order to achieve the stated objective, this study first computes per capita CO2 emissions. Then, it uses the convergence notion to analyse the CO2 emissions in the case of 16 Indian states from 2003–04 to 2018–19. By employing Phillips and Sul's clustering procedure, this study supports the presence of overall divergence when all 16 Indian states are considered as a group. This suggests that all states together are not forming a single steady state rather, they are forming multiple steady (or club convergence) due to heterogeneity in per capita CO2 emissions. Moreover, 16 states cluster into three clubs which have distinct transition paths. From the policy perspective, it is important for the government of India to target reducing per capita CO2 emissions by focusing on clusters of states in a phase-wise manner. [ABSTRACT FROM AUTHOR]

Effective management of surface emissions from abandoned gob methane (AGM) is crucial for mitigating greenhouse gas emissions and ensuring public safety. An important geochemical characteristic of near-surface AGM migration is the potential presence of abnormal component concentrations in near-surface soil gas over abandoned coal gobs. To investigate this phenomenon, a surface geochemical survey was conducted based on four survey lines in the Dongyi and Dongsan abandoned gob groups in the Xinghua Coal Mine, Jixi Basin, in China. The gas chromatography technique was used to analyze the concentrations of methane, carbon dioxide, ethane, propane, and butane in the collected 43 soil gas samples. The results revealed a significant anomaly of soil gas concentrations, particularly methane and carbon dioxide anomalies, in the near-surface soil over abandoned gobs. The background concentration for methane was determined to be 7.49 ppm, with an anomalous threshold set at 10 ppm based on a statistical analysis and an iterative method. This threshold could be confirmed by examining the coupling and decoupling relationship between methane, carbon dioxide, and C2–3 as well. A spatial correlation between regions exhibiting anomalous methane and carbon dioxide concentrations and the positions of gob areas, abandoned surface wells, and faults was observed. Abandoned and sealed coalbed methane surface wells and faults near gas-rich gob areas have the potential to act as conduits for AGM leakage to the surface. Furthermore, concentrations of methane, carbon dioxide, and C2–3 in soil gas over abandoned coal gobs were significantly higher compared to areas unaffected by mining activities. This suggests that elevated concentrations of methane, carbon dioxide, and C2–3 in soil gas may originate from underground AGM. [ABSTRACT FROM AUTHOR]

The direct co-conversion of methane and carbon dioxide into valuable chemicals has been a longstanding scientific pursuit for carbon neutrality and combating climate change. Herein, we present a photo-driven chemical process that reforms these two major greenhouse gases together to generate green methanol and CO, two high-valued industrial chemicals. Isotopic labeling and control experiments indicate an oxygen-atom-graft occurs, wherein CO2 transfers one O into the C–H bond of CH4 via photo-activated interfacial catalysis with AuPd nanoparticles supported on GaN. The photoexcited AuPd/GaN interface effectively orchestrates the CH4 oxidation and the CO2 reduction producing 13.66 mmol g−1 of CH3OH yield over 10 h. This design provides a solid scientific basis for the photo-driven oxygen-atom-grafting process to be further extended to visible light region. The direct co-conversion of CH4 and CO2 into valuable chemicals has been a longstanding scientific pursuit. Here, the authors present a photo-driven process that reforms these greenhouse gases together to generate CH3OH and CO over AuPd/GaN. [ABSTRACT FROM AUTHOR]

Existing studies indicate that future global carbon dioxide (CO2) removal (CDR) efforts could largely be concentrated in Asia. However, there is limited understanding of how individual Asian countries and regions will respond to varying and uncertain scales of future CDR concerning their energy-land-water system. We address this gap by modeling various levels of CDR-reliant pathways under climate change ambitions in Asia. We find that high CDR reliance leads to residual fossil fuel and industry emissions of about 8 Gigatonnes CO2yr−1 (GtCO2yr−1) by 2050, compared to less than 1 GtCO2yr−1 under moderate-to-low CDR reliance. Moreover, expectations of multi-gigatonne CDR could delay the achievement of domestic net zero CO2 emissions for several Asian countries and regions, and lead to higher land allocation and fertilizer demand for bioenergy crop cultivation. Here, we show that Asian countries and regions should prioritize emission reduction strategies while capitalizing on the advantages of carbon removal when it is most viable. Global future carbon removal efforts could largely be concentrated in Asia. Here, this study shows that multi-gigatonnes expectation of carbon removal could have adverse impact on the energy-land-water system of countries and regions within the continent. [ABSTRACT FROM AUTHOR]

Photoionization can initiate structural reorganization of molecular matter and drive formation of new chemical bonds. Here, we used time-resolved extreme ultraviolet (EUV) pump – EUV probe Coulomb explosion imaging of carbon dioxide dimer ion C O 2 2 + dynamics, that combined with ab initio molecular dynamics simulations, revealed unexpected asymmetric structural rearrangement. We show that ionization by the pump pulse induces rearrangement from the slipped-parallel (C2h) geometry of the neutral C O 2 dimer towards a T-shaped (C2v) structure on the ~100 fs timescale, although the most stable slipped-parallel (C2h) structure of the ionic dimer. Moreover, we find that excited states of the ionized C O 2 dimer can exhibit formation of a CO 3 moiety in the C 2 O 4 + complex that can persist even after a suitably time-delayed second photoionization in a metastable C 2 O 4 2 + dication. Our results suggest that charge asymmetry plays an important role in the ionization-induced dynamics in such dimers that are present in C O 2 rich environments. In a time-resolved Coulomb explosion imaging study using ultrafast extreme ultraviolet pulses, combined with theoretical simulations, authors reveal unexpected asymmetric rearrangement of carbon dioxide dimer ion, including a CO3 moiety formation. [ABSTRACT FROM AUTHOR]

Highlights: Ordered intermetallic pallium-zinc (PdZn) electrocatalyst comprising a high density of PdZn pairs is synthesized for achieving co-adsorption and co-activation carbon dioxide and nitrate. Both operando measurements and theoretical calculations reveal that the PdZn pairs provide a dual-site geometric structure conducive to the key C–N coupling with a low kinetical barrier. The intermetallic PdZn displays excellent performance for the co-reduction of nitrate (NO3–) and carbon dioxide (CO2) toward urea, with a maximum FEurea of 62.78% at a small potential of – 0.4 V versus RHE. Electrochemical co-reduction of nitrate (NO3–) and carbon dioxide (CO2) has been widely regarded as a promising route to produce urea under ambient conditions, however the yield rate of urea has remained limited. Here, we report an atomically ordered intermetallic pallium-zinc (PdZn) electrocatalyst comprising a high density of PdZn pairs for boosting urea electrosynthesis. It is found that Pd and Zn are responsible for the adsorption and activation of NO3– and CO2, respectively, and thus the co-adsorption and co-activation NO3– and CO2 are achieved in ordered PdZn pairs. More importantly, the ordered and well-defined PdZn pairs provide a dual-site geometric structure conducive to the key C–N coupling with a low kinetical barrier, as demonstrated on both operando measurements and theoretical calculations. Consequently, the PdZn electrocatalyst displays excellent performance for the co-reduction to generate urea with a maximum urea Faradaic efficiency of 62.78% and a urea yield rate of 1274.42 μg mg–1 h–1, and the latter is 1.5-fold larger than disordered pairs in PdZn alloys. This work paves new pathways to boost urea electrosynthesis via constructing ordered dual-metal pairs. [ABSTRACT FROM AUTHOR]

A corrosion inhibitor composite was developed for carbon dioxide corrosion and it was adapted to the requirements of dosage, protective capacity, temperature characteristics, and compatibility with other reagents. The development process and the main requirements, observance of which was monitored, are described stage-by-stage. The outcome of the conducted research was two grades of a carbon dioxide corrosion inhibitor based on an imidazoline derivative. The difference between the developed composites lies in the solvent type and, correspondingly, in the temperature characteristics (flash and dew points). The influence of the amount of the active base on the effectiveness of the composite was evaluated and the optimum content of the components in the corrosion inhibitor was found. The importance of flash and dew points for corrosion inhibitors is underscored and a way of controlling these composite indicators is proposed. [ABSTRACT FROM AUTHOR]

The study was motivated by increased carbon emissions and high inequality in many of the countries in sub-Saharan Africa (SSA). In this study, we examine whether income inequality in SSA countries increases CO2 emissions, and also investigate empirically whether financial inclusion and institutional quality moderate this connection from the period 2000–2018. For the purpose of examining these links, two proxies for financial inclusion (FI) and an index of institutional quality (IQX) are used. Advanced econometric techniques such as cross-sectional augmented autoregressive distributed lags (CS-ARDL) and augmented mean group (AMG) techniques were used to account for robust, cross-sectional dependence and heterogeneity. The CD-ARDL results demonstrate that the inequalities in the short and long runs are essentially positive, indicating that environmental pollution would rise progressively as the wealth difference widened in the 32 selected SSA nations. The square of income disparity has a negative impact on CO2 emissions, albeit the magnitude varies in the short and long run. Income disparity continues to have a positive impact on CO2 emissions after interacting with financial inclusion in both the short and long run. The results of the interaction term (INEQ*IQX) show that institutional quality has a considerable negative effect on CO2, implying that institutional quality has a major impact on the inequality-CO2 nexus. The robustness of the models is tested using AMG, and the results are congruent with the CS-ARDL estimated results. Hence, based on our findings, we recommend several measures to reduce CO2 emissions in SSA countries. [ABSTRACT FROM AUTHOR]

To reduce the usage of classical lubricants in deep drawing, a new tribological system based on volatile lubricants was developed. Therefore, a volatile medium is injected under high pressure into the interstice between drawing tool and sheet metal. Depending on temperature and pressure, the temporary lubricant may exist in its gaseous or liquid phase. In this study, a novel high fluid pressure tribometer was designed to investigate the friction and wear of dry steel contacts under comparable conditions like in dry deep drawing. Therefore, a new ball-on-disc tribometer was designed and integrated into a high-pressure vessel. To specifically investigate the effects of different environments (technical air, liquid and gaseous carbon dioxide, nitrogen, argon) at atmospheric and high pressure (0.1 MPa, 6 MPa) on tribology, the specimens and all components were operating unlubricated. During the experiments, the friction was measured continuously. Results show that the highest friction occurs in air and the lowest in carbon dioxide environment. Subsequent to the experiments, the wear of the specimens was assessed along with changes in surface chemistry related to tribochemical reactions. Therefore, the tribology of the dry sliding contacts is correlated to changes of the surface chemistry. Also differences as well as similarities regarding the different fluid environments are shown. As the results show, the differences between the media used are most pronounced at elevated pressure. Concluding, this work gives clear indications on the suitability of volatile lubricants in dry friction or rather gas lubrication, especially for dry deep drawing. [ABSTRACT FROM AUTHOR]

CO2 reduction and fixation are one of the most interesting topics in the fields of environmental electrochemistry and electrocatalysis. Many studies on CO2 electroreduction using various metal electrodes have been reported. However, this reaction requires a high overpotential in general, which lowers the energy conversion efficiency and prevents its practical applications to reduce CO2 emission to the atmosphere. The use of a membrane electrode assembly (MEA) is expected to be a breakthrough for the CO2 electroreduction. Particularly, methanation (converting CO2 into CH4) with MEAs incorporating Cu-based catalysts attracts special attention as a tool for carbon cycling, thanks to high faradaic efficiencies and relatively high energy conversion efficiencies. Different from Cu, Pt has long been recognized as an inactive catalyst for CO2 reduction. Contrary to the common consensus, MEAs incorporating a Pt-based electrocatalyst were found very recently to be as active as Cu-based catalysts toward methanation under specific reaction conditions. The high activity of Pt arises from a reaction mechanism different from that for Cu; most likely the Langmuir–Hinshelwood mechanism for Pt and the Eley–Rideal mechanism for Cu. This mini-review discusses CO2 electrochemical methanation using MEAs as a potential method for carbon capture. The CO2 reduction to CH4 using a H2-CO2 fuel cell is also presented. [ABSTRACT FROM AUTHOR]

According to the Intergovernmental Panel on Climate Change (IPCC) of the United Nations (UN), rise in atmospheric concentration of carbon dioxide (CO 2 ) due to anthropogenic factors is considered as the primary driver for global climate change. With almost every major corporation around the world working towards their "net-zero goals", it is becoming increasingly important to have more technologies that can help reduce carbon footprint. Achieving sequestration of CO 2 in the subsurface through Carbon Capture Utilization and Storage (CCUS) technologies like CO 2 -Enhanced Oil Recovery, CO 2 -Enhanced Geothermal Systems, CO 2 -Enhanced Coal Bed Methane, etc. is well accepted. We introduce yet another attractive CCUS opportunity through well rehabilitation. Aqua Freed® and Aqua Gard® are well-known well rehabilitation and preventive well maintenance technologies that utilize (inject underground) liquid CO 2 for the purpose. The goal of this study was to quantify the storage capacity of Aqua Freed® and Aqua Gard®, and establish their CCUS credentials. Depending on the well being serviced, these technologies can inject up to 40 US tons of CO 2 per well. Based on field data collection and statistical modeling, we estimated that 82–96% (median 90%) of the injected CO 2 remains in the subsurface post injection. Overall, our results and analysis of the US market suggest that using CO 2 for well rehabilitation and maintenance has a storage potential of several megatonnes of CO 2 annually in the US alone. [ABSTRACT FROM AUTHOR]

Because of the low reactivity of cyclic nitrides, liquid-phase synthesis of carbon nitride introduces challenges despite its favorable potential for energy-efficient preparation and superior applications. In this study, we demonstrate a strong interaction between citric acid and melamine through experimental observation and theoretical simulation, which effectively activates melamine-condensation activity and produces carbon-rich carbon nitride nanosheets (CCN NSs) during hydrothermal reaction. Under a large specific surface area and increased light absorption, these CCN NSs demonstrate significantly enhanced photocatalytic activity in CO2 reduction, increasing the CO production rate by approximately tenfold compared with hexagonal melamine (h-Me). Moreover, the product selectivity of CCN NSs reaches up to 93.5% to generate CO from CO2. Furthermore, the annealed CCN NSs exhibit a CO conversion rate of up to 95.30 μmol/(g h), which indicates an 18-fold increase compared with traditional carbon nitride. During the CCN NS synthesis, nitrogen-doped carbon quantum dots (NDC QDs) are simultaneously produced and remain suspended in the supernatant after centrifugation. These QDs disperse well in water and exhibit excellent luminescent properties (QY = 67.2%), allowing their application in the design of selective and sensitive sensors to detect pollutants such as pesticide 2,4-dichlorophenol with a detection limit of as low as 0.04 µmol/L. Notably, the simultaneous synthesis of CCN NSs and NDC QDs provides a cost-effective and highly efficient process, yielding products with superior capabilities for catalytic conversion of CO2 and pollutant detection, respectively. [ABSTRACT FROM AUTHOR]

Several developing countries in Asia are relying on agricultural practices in which climate change is a challenging concern. The trends change in atmospheric parameters and vegetation indices are questioned and vague. Consequently, the trend variations of the environmental characteristics were introduced in the first decade of 21 century to better understand the trend changes and envisage the relationship between the atmospheric parameters and the vegetation cover. The Moderate Resolution Imaging Spectroradiometer and the Atmospheric Infrared Sounder provide several atmospheric parameters, e.g., Air Temperature, Aerosol Optical Depth (AOD), and Carbon Dioxide (CO2). In addition, NDVI was estimated and aimed at the role of the interactions among the atmospheric parameters based on statistical analysis. The results showed that AOD and NDVI were air temperature dependent; meanwhile, AOD, NDVI, and air temperature were exchanging and influencing one another. Furthermore, the average minimum air temperature of the region increased during this period and carbon dioxide was a time-dependant parameter that was rising at a steep slope, which may lead to environmental crises. The trend analysis outlines what policies, programs, and procedures should be used to balance the ecosystem and mitigate the climatic negative effects. The Current research strengthens on the social awareness and the international cooperation to reduce socio-economic and political harm and loss in the face of climate change. [ABSTRACT FROM AUTHOR]

Improving transport efficiency and optimizing freight structure are the core of achieving sustainable transport development. However, few studies have conducted an in-depth analysis of freight structure optimization and transport efficiency at the provincial level in China. Hence, a new economy and carbon dioxide (CO2) emissions evaluation model based on the slack-based measurement data envelopment analysis (SBM-DEA) with undesirable outputs was proposed to analyze the transport efficiency and optimize freight structure in five provinces of China from 2005 to 2019. And optimization potential of the freight and passenger transport sector was uncovered in the provinces. The results showed that: (1) the regional difference in transport efficiency was significant, which indicated room for improvement in these provinces. (2) Freight structure was estimated and optimized by the slack variables of the evaluation model. The slack variables of railway, road, and waterway freight transport were large among these provinces. (3) The optimization potential of the freight transport sector was greater than that of the passenger transport in the regions. It indicated optimizing freight structure should be prioritized over passenger transport. Finally, some implications were put forward for sustainable transport development in China. The results provide significant insight into freight structure optimization as well as novel perspectives into the formulation of carbon mitigation strategies. [ABSTRACT FROM AUTHOR]

In the present study, trends and variations in carbon dioxide (CO2), temperature and water vapour are analysed using 9 years (2003–2011) of mid-tropospheric (300–500 hPa) Atmospheric Infrared Sounder (AIRS) data. The focus of analysis remains on both a global as well as regional (India) scale along with improved understanding of their inter relationship. It was observed that the mid-tropospheric carbon dioxide increased from ~ 373 to ~ 393 ppm and ~ 373 to ~ 392 ppm, respectively, over the globe and the Indian region during 9 years. However, no substantial trends (increasing or decreasing) were observed in the temperature and water vapour observations for the same period of time. De-trended data of CO2, temperature and water vapour were further analysed to understand the inter relationship between these parameters and the influence of two greenhouse gases (CO2 and water vapour) on temperature. Analysis suggests a very high correlation (~ 0.90) between temperature and water vapour, however, no significant correlation was observed between temperature and carbon dioxide data, indicating that change in water vapour may have stronger influence on temperature compared to the change in CO2, this feature can play a more significant role as a greenhouse gas than CO2. [ABSTRACT FROM AUTHOR]

To minimize greenhouse gas emissions, efficient carbon dioxide capture and utilization need to be addressed. In this study, to determine the structure–activity interplay, three different promising catalytic systems for the CO2 hydrogenation process were synthesized using mesoporous silica SBA-15 as a support material: copper-based catalyst with zinc, indium-based catalyst with palladium and iron-based catalyst with potassium. The role of metal–metal oxide interaction has been showed. The use of Cu/Zn catalytic system and SBA-15 allowed to obtain very small crystallite size of tenorite and zinc oxide, good dispersion of active phases with strong basic sites. In order to find the most effective catalyst providing the maximal methanol yield and selectivity, these catalytic systems were compared under the same reaction conditions (250 °C, 20 bar, H2 to CO2 molar ratio 4 to 1) using fixed-bed tubular micro-activity reactor. Results showed that the highest methanol yield can be obtained with Cu/Zn/SBA-15 catalyst as might be expected according to obtained characterization. [ABSTRACT FROM AUTHOR]

The need for public engagement is increasingly evident as discussions intensify around emerging methods for carbon dioxide removal and controversial proposals around solar geoengineering. Based on 44 focus groups in 22 countries across the Global North and Global South (N = 323 participants), this article traces public preferences for a variety of bottom-up and top-down engagement practices ranging from information recipient to broad decision authority. Here, we show that engagement practices need to be responsive to local political cultures and socio-technical environments, while attending to the global dimensions and interconnectedness of the issues at stake. Establishing public engagement as a cornerstone of inclusive and sustainable governance of climate-intervention technologies requires (i) recognizing the diversity of forms and intensities of engaging, (ii) considering national contexts and modes of engagement, (iii) tailoring to technological idiosyncrasies, (iv) adopting power-sensitive practices, (v) accounting for publics' prior experience, (vi) establishing trust and procedural legitimacy and (vii) engaging with tensions and value disagreements. Meaningful public engagement is key to sustainable governance of carbon removal and solar radiation modification. A study across 22 countries emphasizes tailored approaches sensitive to local contexts, technological nuances, power dynamics and trust. [ABSTRACT FROM AUTHOR]

The objective of this study is to perform an analysis to determine the most suitable type of wind turbine that can be installed at a specific location for electricity generation, using annual measurements of wind characteristics and meteorological parameters. Wind potential analysis has shown that the analyzed location is suitable for the development of a wind farm. The analysis was carried out for six different types of wind turbines, with a power ranging from 1.5 to 3.0 MW and a hub height set at 80 m. Wind power potential was assessed using the Weibull analysis. The values of the scale coefficient c were determined, and a large monthly variation was observed, with values ranging from 1.92 to 8.36 m/s and an annual value of 4.95 m/s. Monthly values for the shape coefficient k varied between 0.86 and 1.53, with an annual value of 1.07. Additionally, the capacity factor of the turbines was determined, ranging from 17.75 to 22.22%. The Vestas turbine, with a nominal power of 2 MW and a capacity factor of 22.22%, proved to be the most efficient wind turbine for the specific conditions of the location. The quantity of greenhouse gas emissions that will be reduced if this type of turbine is implemented was also calculated, considering the average CO2 emission intensity factor (kg CO2/kWh) of the national electricity system. [ABSTRACT FROM AUTHOR]

Breakthroughs in efficient use of biogas fuel depend on successful separation of carbon dioxide/methane streams and identification of appropriate separation materials. In this work, machine learning models are trained to predict biogas separation properties of metal-organic frameworks (MOFs). Training data are obtained using grand canonical Monte Carlo simulations of experimental MOFs which have been carefully curated to ensure data quality and structural viability. The models show excellent performance in predicting gas uptake and classifying MOFs according to the trade-off between gas uptake and selectivity, with R2 values consistently above 0.9 for the validation set. We make prospective predictions on an independent external set of hypothetical MOFs, and examine these predictions in comparison to the results of grand canonical Monte Carlo calculations. The best-performing trained models correctly filter out over 90% of low-performing unseen MOFs, illustrating their applicability to other MOF datasets. Breakthroughs in the efficient use of biogas fuel depend on the successful separation of carbon dioxide/methane streams and identification of appropriate separation materials. Here, machine learning models are trained to predict biogas separation properties of metal-organic frameworks. [ABSTRACT FROM AUTHOR]