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A scalable papermaking process was employed herein to manufacture cellulosic papers from native and phosphorylated cellulose microfibers (referred to as CMF and PCMF, respectively) impregnated with polyethyleneimine (PEI) for Direct Air Capture (DAC) applications. These papers were analyzed in terms of their physico-chemical properties using several techniques. The impact of PEI content on desorbing the co-adsorbed H 2 O and CO 2 from the air, as well as on the anisotropic microporous network, was explicitly analyzed. The results indicated that phosphorylation promotes the uptake of both CO 2 and H 2 O in the corresponding neat and PEI-loaded papers, reaching a superior CO 2 adsorption capacity of ∼0.7–0.9 mmol.g−1 for PCMF papers versus 0.07–0.3 mmol.g−1 for CMF papers. Furthermore, the CMF and PCMF papers exhibited H 2 O adsorption capacities in the range of 1.5–1.8 mmol.g−1 and 2.2–3.8 mmol.g−1, respectively. This work further highlights the combined role of phosphorylation and favorable PEI impregnation in tuning the cellulose CO 2 adsorption properties under humid conditions, facilitating the rapid release of the adsorbed CO 2 under mid conditions. [Display omitted] • Manufacturing of scalable solid cellulosic papers with amine functionalities and enhanced carbon capture. • Microstructural and chemical characterization of amine functionalized paper with various amine ratios. • Valorization of Alfa biomass in Carbon capture applications. • The combined role of phosphorylation and PEI impregnation in tuning the H 2 O and CO 2 co-adsorption properties. [ABSTRACT FROM AUTHOR]

The global energy system is in transition. It is attempting to reach net‐zero greenhouse gas emissions by 2050. The systemic changes mean that the role of bioenergy will change. The potential of bioenergy to make a flexible contribution to the energy system is key for the achievement of global emission reduction ambitions and the functioning of the low‐carbon energy system and economy. As the volume of sustainably available biomass resources is limited, defining the contributions from bioenergy to a low‐carbon energy system and finding balances – and ideally synergies – between the different possible energy and climate system services that biomass can provide will be very important. The recognized system services include, among others, the flexible operation of bioenergy plants to integrate variable renewable energy sources and to provide negative carbon dioxide (CO2) emissions. Interest in flexible operation of bioenergy value chains, bioenergy with carbon capture and utilization as well as synergies with renewable hydrogen‐based value chains has increased recently. The objective of this paper is to present a holistic definition of flexible bioenergy as a system service based on the work conducted in International Energy Agency (IEA) Bioenergy Technology Collaboration Programme's Task 44 Flexible Bioenergy and System Integration, and to provide some practical examples. The paper also presents the different bioenergy system services and considers their definitions and interactions, as this is important in energy system design. The definition of flexible bioenergy shows that the flexibility provision from bioenergy goes far beyond the traditional definition of providing short‐term flexibility in the power sector. Indicators to demonstrate the value of services as well as further quantitative assessment of synergies and trade‐offs are needed to valorize the different services from bioenergy and create viable business cases. [ABSTRACT FROM AUTHOR]

This paper explores green hydrogen-based carbon dioxide (CO 2) hydrogenation for the production of oxygenates, presenting it as a pivotal strategy for mitigating carbon emissions and advancing sustainable energy solutions. The conversion of CO 2 into oxygenates through hydrogenation emerges as a promising avenue, particularly in the context of transportation applications where the storage of hydrogen poses challenges. The substitution of fossil diesel and gasoline fuels with green hydrogen-derived dimethyl ether, or methanol/ethanol, is advantageous from a life cycle analysis (LCA) CO 2 emission perspective even without the capture of the CO 2. However, the greatest sustainability appeal is contingent on the crucial aspect of capturing CO 2 when utilizing these fuels, which is an aspect currently absent in the literature. This narrative review comprehensively explores catalytic processes, mechanisms, sustainability perspectives, and the current state of research in this evolving area. It encompasses both the production of oxygenates through CO 2 hydrogenation and the subsequent utilization of these oxygenates in fuel cells or combustion systems, emphasizing the integration of CO 2 capture technologies. The paper contributes to the discourse surrounding the environmental and technological dimensions of energy storage ecosystems, providing a holistic view of their potential to foster sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Strategies for changing the conductivity of Li 2 CO 3 is introduced into the fabrication of Li-CO 2 battery. Benefitting from the favorable hierarchical architecture constructed (CPM-MnO 2), facile charge transfer occurs between catalytic surface and Li 2 CO 3 by –OH⋯O hydrogen bonds improves the metallicity of Li 2 CO 3 , facilitating the formation/decomposition of Li 2 CO 3 and bestowing an ultra-long-term stability of 1087 cycles (4348 h). Taking into account its simplicity, scalable character and outstanding performance, this hierarchical composite electrode paves an effective trajectory for the future development of highly efficient cathodes for durable metal-CO 2 batteries. [Display omitted] • Excellent hierarchical structure of MXene and MnO 2 on carbon paper was fabricated. • Enriched charge transfer occurred on MXene and the MnO 2 by OH⋯O hydrogen bonding. • The prepared batteries showed an ultra-long cycle lifetime and low overpotential. • The optimized electronic structure can improve the metallicity of Li 2 CO 3. • The accelerated decomposition of discharge products promoted CRR and CER kinetics. Lithium-CO 2 batteries are recognized as an essential strategy for efficient carbon sequestration and energy storage to achieve carbon neutrality. Their cycle-ability and polarization voltage, however, are hindered by high decomposition voltage (≈4.3–4.5 V) of insulating Li 2 CO 3. Herein, we report a significant advance toward the rational design of self-supporting and ultra-long cycle lifetime cathode for Li-CO 2 batteries, dependence on a favorable hierarchical architecture and rich charge transfer constructed by homogeneously distributed MnO 2 nanoplates rooted in the MXene surface supported by carbon paper. Detailedly, it exhibits impressive ultra-long-term stability of 1087 cycles (4348 h) with a low polarization gap (≈ 0.47 V) at a high current of 200 μA cm−2, which is outperformed by all the liquid electrolyte-based Li-CO2 batteries reported previously. Electronic structure analysis reveals that facile charge transfer occurs between catalytic surface and Li 2 CO 3 , springing from the –OH functional group (in MXene) to MnO 2 by –OH⋯O hydrogen bonds, which acts as charge transfer channels, improving the metallicity of Li 2 CO 3 and facilitating its decomposition and extending battery cyclability. This work paves an effective trajectory for the future development of highly efficient cathodes for durable metal-CO 2 batteries. [ABSTRACT FROM AUTHOR]

The adverse effects of climate change calls for the rapid transformation of manufacturing processes to decrease the emissions of carbon dioxide. In particular, a lower carbon footprint can be achieved by capturing carbon dioxide at the site of emission. Here we review the use of industrial effluents, waste and residues to capture carbon dioxide. Waste include steelmaking slag, municipal solid waste incinerator ashes, combustion fly ash, black liquor, paper mill waste, mining waste, cement waste, construction and demolition waste, waste from the organic industry, and flue gas desulfurization gypsum waste. Capture capacities range from 2 to 800 kg of carbon dioxide per ton of waste, depending on processes, waste type and conditions. Cement waste and flue gas desulfurization gypsum waste show the highest capture capacity per ton of waste. [ABSTRACT FROM AUTHOR]

Singapore has committed to achieving net zero emissions by 2050, which requires the pursuit of multiple decarbonization pathways. CO 2 utilization methods such as fuel production may provide a fast interim solution for carbon abatement. This paper evaluates the feasibility of green hydrogen-based synthetic fuel (synfuel) production as a method for utilizing captured CO 2 . We consider several scenarios: a baseline scenario with no changes, local production of synfuel with hydrogen imports, and overseas production of synfuel with CO 2 exports. This paper aims to determine a CO 2 price for synfuel production, evaluate the economic viability of local versus overseas production, and investigate the effect of different cost parameters on economic viability. Using the current literature, we estimate the associated production and transport costs under each scenario. We introduce a CO 2 utilization price (CUP) that estimates the price of utilizing captured CO 2 to produce synfuel, and an adjusted CO 2 utilization price (CCUP) that takes into account the avoided emissions from crude oil-based fuel production. We find that overseas production is more economically viable compared to local production, with the best case CCUP bounds giving a range of 142–148 $/t CO 2 in 2050 if CO 2 transport and fuel shipping costs are low. This is primarily due to the high cost of hydrogen feedstock, especially the transport cost, which can offset the combined costs of CO 2 transport and fuel shipping. In general, we find that any increase in the hydrogen feedstock cost can significantly affect the CCUP for local production. Sensitivity analysis reveals that hydrogen transport cost has a significant impact on the viability of local production and if this cost is reduced significantly, local production can be cheaper than overseas production. The same is true if the economies of scale for local production is significantly better than overseas production. A significantly lower carbon capture cost can also the reduce the CCUP significantly. [ABSTRACT FROM AUTHOR]

At the core of carbon monoxide dehydrogenase (CODH) active site two metal ions together with hydrogen bonding scheme from amino acids orchestrate the interconversion between CO2 and CO. We have designed a molecular catalyst implementing a bimetallic iron complex with an embarked second coordination sphere with multi‐point hydrogen‐bonding interactions. We found that, when immobilized on carbon paper electrode, the dinuclear catalyst enhances up to four fold the heterogeneous CO2 reduction to CO in water with an improved selectivity and stability compared to the mononuclear analogue. Interestingly, quasi‐identical catalytic performances are obtained when one of the two iron centers was replaced by a redox inactive Zn metal, questioning the cooperative action of the two metals. Snapshots of X‐ray structures indicate that the two metalloporphyrin units tethered by a urea group is a good compromise between rigidity and flexibility to accommodate CO2 capture, activation, and reduction. [ABSTRACT FROM AUTHOR]

At the core of carbon monoxide dehydrogenase (CODH) active site two metal ions together with hydrogen bonding scheme from amino acids orchestrate the interconversion between CO2 and CO. We have designed a molecular catalyst implementing a bimetallic iron complex with an embarked second coordination sphere with multi‐point hydrogen‐bonding interactions. We found that, when immobilized on carbon paper electrode, the dinuclear catalyst enhances up to four fold the heterogeneous CO2 reduction to CO in water with an improved selectivity and stability compared to the mononuclear analogue. Interestingly, quasi‐identical catalytic performances are obtained when one of the two iron centers was replaced by a redox inactive Zn metal, questioning the cooperative action of the two metals. Snapshots of X‐ray structures indicate that the two metalloporphyrin units tethered by a urea group is a good compromise between rigidity and flexibility to accommodate CO2 capture, activation, and reduction. [ABSTRACT FROM AUTHOR]

Carbon dioxide capture, utilization, and storage (CCUS) is one of the essential approaches to achieving permanent CO2 emission reduction. A new idea of absorbing and mineralizing CO2 with industrial wastewater and converting activated calcium into micron CaCO3 powder is proposed in this paper, which synchronizes water softening and CO2 fixation. Therefore, this paper investigated the characteristics of circulating water quality in the iron and steel industry and the transformation behaviors of CO2 capture by activated calcium to CaCO3 powder in the mild aqueous environment under different process parameters. The phase composition, morphology, and particle size distribution (PSD) of CaCO3 powder were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and (laser particle size analyzer) LPSA, respectively. In addition, a green integrated cycle system for industrial water capture of mineralized CO2 was preliminarily constructed, which provides a reference method for carbon reduction and economic utilization of carbon sources in an industrial system. [ABSTRACT FROM AUTHOR]

This paper reviews and evaluates work on the structural complexity of the potential carbon dioxide storage sites in the North Sea, including the nature of the reservoir structures, the reservoir rocks, the presence of inter-layers, faults, and fractures, and how these factors influence carbon dioxide capacity. In particular, the review emphasises the significance of studying caprocks in detail, not just the reservoir rock's carbon dioxide storage capacity. This work also particularly considers reservoir simulation work on North Sea sites and illustrates the importance of using fully coupled flow–geomechanical–geochemical modelling to ensure that complex feedback and synergistic effects are not missed. It includes comparisons with other sites where relevant. It also discusses recent challenges and controversies that have arisen from simulations of sequestration in North Sea reservoirs and the need for comprehensive field data to resolve these issues. [ABSTRACT FROM AUTHOR]

In order to reverse the trend of increasing carbon dioxide (CO 2) emissions, the development of efficient and economical CO 2 trapping agents is an urgent necessity for the sustainable development of industry. In this paper, hierarchical porous hydroxyl aluminum oxide (AlOOH) hollow microspheres with controllable structure and morphology were prepared by conventional hydrothermal synthesis using malonic acid as a structure guiding agent. Then, potassium carbonate (K 2 CO 3) based adsorbents were prepared using AlOOH hollow microspheres as supports, and their CO 2 trapping performance was assessed by simulating industrial flue gas flow in a fixed bed. The results show that the loading of K 2 CO 3 , the pore structure, and the surface basic site of the adsorbent have a significant influence on the trapping performance of CO 2. Among the prepared K 2 CO 3 /AlOOH adsorbents, 30 wt% K 2 CO 3 /AlOOH adsorbent has the best CO 2 capture ability, which is about 2.15 times higher than that of K 2 CO 3 /C–Al 2 O 3 adsorbent prepared from commercial alumina (C–Al 2 O 3). There may be two explanations for this. Firstly, it may be due to the nanostructured shell and hierarchical porous structure of the adsorbent, which reduces the intra-particle diffusion resistance of CO 2 , and secondly, it may be due to the suitable surface basic sites of the adsorbent. In addition, the adsorbent was regenerated at 120 °C after trapping CO 2 , and then CO 2 was captured in a cycle. It was found that the CO 2 capture capability of the adsorbent did not decrease significantly after 10 cycles. In this work, an excellent technique for preparing porous honeycomb adsorbents with suitable surface basic sites has been devised, which provides a creative strategy for capturing and utilizing CO 2. [Display omitted] [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) emissions are a serious hazard to human life and the ecosystem. This is the reason that many measures have been put in place by the International Energy Agency (IEA) to reduce the anthropogenic-derived CO2 concentration in the atmosphere. Today, the potential of renewable energy sources has led to an increased interest in investment in carbon capture and storage technologies worldwide. The aim of this paper is to investigate state-of-the-art carbon capture and storage (CCS) technologies and their derivations for the identification of effective methods during the implementation of evidence-based energy policies. To this extent, this study reviews the current methods in three concepts: post-combustion; pre-combustion; and oxy-fuel combustion processes. The objective of this study is to explore the knowledge gap in recent carbon capture methods and provide a comparison between the most influential methods with high potential to aid in carbon capture. The study presents the importance of using all available technologies during the post-combustion process. To accomplish this, an ontological approach was adopted to analyze the feasibility of the CCS technologies available on the market. The study findings demonstrate that priority should be given to the applicability of certain methods for both industrial and domestic applications. On the contrary, the study also suggests that using the post-combustion method has the greatest potential, whereas other studies recommend the efficiency of the oxy-fuel process. Furthermore, the study findings also highlight the importance of using life cycle assessment (LCA) methods for the implementation of carbon capture technologies in buildings. This study contributes to the energy policy design related to carbon capture technologies in buildings. [ABSTRACT FROM AUTHOR]

This paper consists of a deep analysis and data comparison of the main strategies undertaken for achieving truly reversible capture of carbon dioxide involving optimized gas uptakes while affording weakest retention strength. So far, most strategies failed because the estimated amount of CO2 produced by equivalent energy was higher than that captured. A more viable and sustainable approach in the present context of a persistent fossil fuel-dependent economy should be based on a judicious compromise between effective CO2 capture with lowest energy for adsorbent regeneration. The most relevant example is that of so-called promising technologies based on amino adsorbents which unavoidably require thermal regeneration. In contrast, OH-functionalized adsorbents barely reach satisfactory CO2 uptakes but act as breathing surfaces affording easy gas release even under ambient conditions or in CO2-free atmospheres. Between these two opposite approaches, there should exist smart approaches to tailor CO2 retention strength even at the expense of the gas uptake. Among these, incorporation of zero-valent metal and/or OH-enriched amines or amine-enriched polyol species are probably the most promising. The main findings provided by the literature are herein deeply and systematically analysed for highlighting the main criteria that allow for designing ideal CO2 adsorbent properties. [ABSTRACT FROM AUTHOR]

The global warming and climate change caused by the continuing rise in carbon dioxide (CO2) emissions have attracted the attention of the public, scientists, and governments in recent years. An effective approach to limit the impact of such emissions is the implementation of advanced carbon capture and storage systems. This paper provides an overview of technologies and recent advances in carbon capture and utilization. The main methods include postcombustion, precombustion, and oxyfuel-combustion, adsorption, and membrane capture. In addition, various problems associated with the storage, transportation, and utilization of CO2 are discussed. [ABSTRACT FROM AUTHOR]

Carbon Capture and Storage (CCS) involves transportation of liquefied CO 2 from capture sites to permanent storage locations, which is usually achieved by pipeline transportation or maritime shipping. Over long distances, maritime shipping at pressures around 16 bara has proved to be a more effective solution than transportation through pipelines. These conditions, although safe, offer a significant pressure margin with respect to the triple point of CO2 for more cost-effective ship design with larger transportation capacity. However, the reliability of this technology has not been fully demonstrated regarding depressurization operations commonly performed to minimize hazards associated to emergencies. For CO2, this operation entails risks such as dry ice formation. This paper focuses on two purposes. First, it reports detailed and extensive experimental tests of CO2 depressurization of a tanks at low pressure (< 20 bara). An extensive review of public domain literature showed that this data is scarce [20] This work focuses on contributing to close that gap. Finally, this work will present detailed simulations of the experiments using commercial flowsheeters to assess the reliability of standards models that are commonly used for engineering studies and design. All the experimental work was carried out using a bench scale tank of 2 m3 with ample instrumentation according to an experimental design. The results of the runs were modelled using the EO-Blowdown utility implemented in UniSim Design®. The results showed that modelling of CO2 systems with the EO-Blowdown utility is reliable and can reproduce accurately most key process variables, although it has some limitations such inability to model solid phases and metastable liquids [Display omitted] [ABSTRACT FROM AUTHOR]

CO 2 sequestration is an effective technology for reducing greenhouse gas effect. To ensure the safety, assessment of well applicability should be conducted before CO 2 sequestration. However, current studies mainly focus on identifying which barrier has the highest risk of leakage rather than selecting a target well for injection in specific geological formation. To further investigate, this paper proposes well applicability assessment method combining reservoir and wellbore properties together for CO 2 sequestration. A novel assessment system combing Fuzzy comprehensive evaluation and Analytic hierarchy process has been established. Twenty-nine indexes subjected to seven categories (i.e., formation, well, cement sheath, cementing quality, casing, tubing, and wellhead properties) are taken into consideration. The weighting factors of these seven categories are 0.0673, 0.0552, 0.096, 0.1537, 0.2283, 0.2637 and 0.1369, respectively. Tubing and casing properties have the greatest influence on safety injection. Furthermore, the proposed system has been applied to S gas reservoir, China. Results show that Wells #P1 and #P2 are suitable for injection. Since more comprehensive indicators are considered comparing with previous studies, the results are more accuracy and objective. The findings of this paper could help efficiently and effectively evaluating well applicability for CO 2 sequestration and reducing the risk of CO 2 leakage. [ABSTRACT FROM AUTHOR]

Recent scientific assessments of climate change have shifted towards evaluating solutions for removing atmospheric carbon dioxide (CDR). This paper reports a participation experiment in which we involved an interdisciplinary group of researchers in mapping issues relating to two CDR approaches: afforestation and bioenergy with carbon capture and storage (BECCS). We describe the responses of individual researchers when presented with visualisations aggregated from posts about afforestation and BECCS on the platform Twitter. We then compare the researchers' responses with a qualitative analysis of a subset of the Twitter data. The analysis highlights challenges the researchers experienced in identifying issues and relating these visualisations to their own research on afforestation and BECCS. We discuss the prospects for bringing experimental approaches to mapping issues, publics and participation into closer relation with science and technology assessments. The paper concludes with reflections on the value of qualitative traditions of STS research for digital controversy analysis. [ABSTRACT FROM AUTHOR]

The roles digital media-technologies play in raising public issues relating to emerging technologies and their potential for engaging publics with science and policy assessments is a lively field of inquiry in Science and Technology Studies (STS). This paper presents an analysis of controversies over proposals for the large-scale removal of atmospheric carbon dioxide (CDR). The study combines a digital method (web-querying) with document analysis to map debates about two CDR approaches: bioenergy with carbon capture and storage (BECCS) and afforestation. In the first step, we locate actors using the web to engage with BECCS and afforestation and map their alignments in relation to competing framings of CDR. In a second step, we examine the devices deployed by UK-based actors to evidence and contest the feasibility of BECCS and afforestation. Our analysis shows that policy distinctions between "natural" and "engineered" CDR are used flexibly in practice and do not map neatly onto actor engagement with BECCS and afforestation. We highlight the predominance of cross-cutting techno-economic expertise and argue that framings of CDR as a solution to governing climate change may contribute to public disengagement from climate policy processes. The paper reflects on methods for studying controversies, publics, and issues emerging around processes of technoscientific assessment. [ABSTRACT FROM AUTHOR]

CO 2 sequestration has proven to be an attractive way to combat global warming. However, due to the corrosive nature of CO 2 , chemical reactions between CO 2 and the host rock can happen after the injection. This study reviews the current state of knowledge about chemical reactions and their effects on the mineralogy, structure, mechanical, deformation, and transport properties of different types of rocks from research papers published in 2004–2024. In addition to drawing a comprehensive picture of the research that has been done on the subject and the gaps that need to be filled, this review combined the data from the papers to introduce the relationships between exposure conditions (CO 2 pressure, exposure duration, and temperature) and mineralogy, strength, and elastic properties, and permeability of multiple types of rocks. Results showed that some minerals like quartz are not affected by CO 2 while others like carbonates can easily be dissolved. Datapoints from various papers showed a negative effect of CO 2 pressure and exposure duration, and a positive effect of temperature on the strength properties of rocks. An increase in permeability was another consequence of CO 2 treatment in most cases. This study is one of the first works to gather data from multiple sources in developing relationships between CO 2 treatment conditions and the strength properties of rocks. Results will potentially improve understanding and prediction of the effect of CO 2 on the properties and behavior of rocks. [Display omitted] • Quartz, unlike carbonates, is not impacted by CO 2. • Dissolution/precipitation of minerals leads to increase/decrease in pore volume. • The compressive strength mostly decreases with an increase in CO 2 pressure. • Bulk and elastic moduli of rocks decrease after CO 2 treatment. • CO 2 increases the permeability of most rocks. [ABSTRACT FROM AUTHOR]

Carbon dioxide is an indispensable carbon resource in the life activities, however, the excessive emission of carbon dioxide enhances the greenhouse effect which leads to more extreme weather globally. In this paper, a fictional hunting action with a code name of “carbon capture” is anthropomorphically described, in which the CO2 capture technology is vividly introduced. The advantages and disadvantages of individual techniques are summarized, based on which the future prospects of research direction is presented. [ABSTRACT FROM AUTHOR]

In previous decades, shale gas production has been given special attention as a clean source of energy. Technological advancements in multi-well especially horizontal drilling and hydraulic fracturing, have raised more research on how to produce shale gas commercially while studying its challenges. CH4 gas production by using CO2 injection is a combination of several parameters, including both fracking and geologic parameters. This paper investigated the influence of aligned and staggered multiwell placement patterns to enhance CH4 gas recovery and CO2 sequestration. A three-dimensional reservoir model was built and simulated, and the influence of reservoir and fracking parameters was analyzed. The results revealed that the staggered well pattern is the best pattern for CH4 gas recovery during continuous injection, with a 37% increase of recovery with late CO2 breakthrough, compared with the aligned well pattern, which had 31% increase recovery, associated with early CO2 breakthrough. In terms of CO2 gas storage, the aligned well pattern had a significant amount of CO2 storage during continuous injection and huff and puff injection by storing 4% more carbon dioxide during continuous injection and 7% more during huff and puff injection than that in the staggered well pattern. Different injection timings of 1, 2, and 3 years, and injection cycles of one, three, and five cycles were analyzed during huff and puff injection. The results showed that five cycles of injection had the highest methane gas recovery, 23% and 21%, in aligned and staggered well patterns, respectively. Furthermore, the influence of injection start time also was analyzed, and results showed that injection after 10 years of production produced higher methane gas recovery and CO2 storage in both aligned and staggered well patterns, followed by injection after 5 years of production, after 3 years of production, and during the first year of production. Sensitivity analysis revealed that horizontal matrix permeability, vertical matrix permeability, initial reservoir pressure, reservoir temperature, injection pressure, injection rate, fracture porosity, and fracture spacing played a vital role in both methane gas recovery and carbon dioxide gas storage in both well patterns. In addition, results showed that methane recovered during continuous injection is higher than during huff and puff injection in both aligned and staggered well patterns. Results obtained from this paper can help to improve shale gas production in multiwell placements, and save time and cost. This paper should motivate more research into the mitigation of global warming through CO2 geosequestration. [ABSTRACT FROM AUTHOR]

The paper reviewed the current perspectives on the development of carbon dioxide (CO2) sequestration through its process conversion into calcite. The process occurs in either geological or biological systems. However, geological sequestration is an expensive process, which is slow in comparison to bio-sequestration. Recently, the bio-sequestration of atmospheric CO2 into the soil using microorganisms such as algae has been investigated. However, the algae cannot be used in the bio-concrete due to their nature as phototrophic organisms. In contrast, bacteria are the most potent organisms in bio-concrete technology. The use of bacterial species in the bio-aerated concrete bricks (B-ACB) and its potential to bio-sequestrate CO2 represents a future strategy to reduce high CO2 pollution. Bacterial cells can capture CO2 by accelerating the carbonation processes, which convert CO2 into calcium carbonate (CaCO3) via carbon anhydrase and urease enzymes. The present paper aimed to highlight and discuss the applicability of bacteria in the B-ACB for capturing and storing CO2. It is evident from the literature that the new trends to use bio-concrete might contribute to the reduction of CO2 by accelerating the carbonation process and strengthening the B-ACB. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization, and storage (CCUS) technology is considered an effective way to reduce greenhouse gases, such as carbon dioxide (CO2), which is significant for achieving carbon neutrality. Based on Derwent patent data, this paper explored the technology topics in CCUS patents by using the latent Dirichlet allocation (LDA) topic model to analyze technology's hot topics and content evolution. Furthermore, the logistic model was used to fit the patent volume of the key CCUS technologies and predict the maturity and development trends of the key CCUS technologies to provide a reference for the future development of CCUS technology. We found that CCUS technology patents are gradually transforming to the application level, with increases in emerging fields, such as computer science. The main R&D institutes in the United States, Europe, Japan, Korea, and other countries are enterprises, while in China they are universities and research institutes. Hydride production, biological carbon sequestration, dynamic monitoring, geological utilization, geological storage, and CO2 mineralization are the six key technologies of CCUS. In addition, technologies such as hydride production, biological carbon sequestration, and dynamic monitoring have good development prospects, such as CCUS being coupled with hydrogen production to regenerate synthetic methane and CCUS being coupled with biomass to build a dynamic monitoring and safety system. [ABSTRACT FROM AUTHOR]

In the face of mounting global climatic pressures, negative emission technologies (NETs) for carbon dioxide removal (CDR) are increasingly proposed as necessary for meeting climate targets. While initial work has identified the potential of terrestrial NETs, a diverse set of marine/ocean-based NETs are gaining new and particular attention. Emerging studies on the feasibility of marine NETs are urgently needed, especially to explore the logics that public groups use to judge different approaches, and to ensure that design and governance of these technologies align with public values and priorities. This study explores factors of interest in understanding public views on four marine NETs, both perceptions of climate severity and urgency, and beliefs about marine environments. It uses a quantitative survey to explore how a representative sample of people in British Columbia, Canada and Washington state, United States evaluate four marine NETs: coastal restoration; ocean alkalinity enhancement; ocean fertilization; and offshore direct air carbon capture and storage. We find that perceived severity and urgency of climate change predicts greater comfort with all NETs studied, and views of marine environments as adaptable, fragile and manageable vary in predicting both greater and lesser comfort. Drawing upon these insights, the paper offers reflections on the conditional thinking linked with emerging views of marine NETs, concluding with methodological suggestions for future research on public perceptions as concerns the deployment of ocean-based CDR near and long term. Incorporating these insights into policy for ocean-based CDR will be important to ensuring responsible governance of these technologies. Key policy insights Incorporating research on public perceptions will be important to the design of marine NETs and accompanying policies. Public groups in both British Columbia and Washington expressed high levels of comfort with coastal restoration, some comfort with offshore direct air carbon capture and storage, and some discomfort with ocean alkalinity enhancement and ocean fertilization. Perceived severity and urgency of climate change predicted greater comfort with all approaches; this evidence aligns with a small but growing body of scholarship indicating openness to environmental intervention amongst public groups concerned with climate impacts. Beliefs about marine environments, namely whether they are 'adaptable', 'manageable' or 'fragile', also predicted comfort, suggesting that CDR in ocean contexts requires further examination regarding public perceptions. [ABSTRACT FROM AUTHOR]

This paper introduces GCAM-CDR 1.0, an integrated assessment model for climate policy based on the open-source Global Change Analysis Model (GCAM). GCAM-CDR extends GCAM v5.4 by enabling users to model additional carbon dioxide removal (CDR) technologies and additional policies and controls related to CDR. New CDR technologies include terrestrial enhanced weathering with basalt, ocean liming, and additional versions of direct air capture. New CDR policies and controls include integration of bioenergy with carbon capture and storage (BECCS) into the CDR market, interregional trade in CDR, exogenous control over the rate of growth of CDR, the ability to set independent targets for emissions abatement and CDR, and a variety of mechanisms for setting demand for CDR at the regional and/or global level. These extensions enhance users' ability to study the potential roles of CDR in climate policy. [ABSTRACT FROM AUTHOR]

In recent years, there has been a notable surge in focus on the mitigation of carbon emissions, mostly motivated by the urgent concern about global warming and its adverse impacts on the Earth's climate. Power-to-gas (PtG) systems have emerged as a promising technological solution in the pursuit of mitigating carbon emissions. This paper presents a mathematical modeling framework that aims to accurately represent the power-to-gas system integrated with wind power plants while taking into account the technological constraints of the system in practical scenarios. To analyze the proposed system under the stresses, worst situations caused by existing uncertain parameters, especially wind power, is modeled using a risk modeling technique called downside risk constraints (DRC). The DRC endeavors to mitigate the likelihood of situations resulting in significant stresses by incorporating an expected downside risk into the proposed framework. This paper will provide a number of conservative tactics to be employed in the decision-making process under the realizations of uncertainties. These tactics, including strategic operational control strategies, provide a structured approach for decision-making under uncertain conditions. By incorporating downside risk constraints, the framework enables conservative decision-making that prioritizes mitigating potential losses and minimizing the operational risk within scheduling horizon of proposed PtG facility. The findings demonstrate that the implementation of PtG technology has the potential to yield a substantial reduction in external energy consumption, namely by 39.1 %. Additionally, it has been seen that PtG may effectively mitigate carbon emissions, resulting in a decrease of 38.9 %. The utilization of PtG technology and gas storage will result in a substantial reduction in wind curtailment, ultimately leading to a near elimination of curtailment. Further study is conducted on the model in order to explore the benefits of carbon and methane storage, as supported by the results obtained. [ABSTRACT FROM AUTHOR]

Using geopolymer concrete (GC) is a technically feasible decarbonization strategy in the cement and concrete industry shown by numerous papers. A key factor determining its commercial application is whether its cost is competitive. However, related study is scarce. In this paper, we present the analysis of GC's CO 2 avoidance cost, the cost incurred to reduce one metric ton of CO 2 emissions. The results show that among the 486 GC mixtures analyzed, only seven yield negative CO 2 avoidance costs, while 379 are even more expensive than capturing CO 2 from cement plants, which is another technically feasible decarbonization strategy and has been evaluated to have a CO 2 avoidance cost of 55 USD/tCO 2 in Chinese demonstration project. Only a few GC mixtures with lower CO 2 avoidance costs will be considered by the industry, and they are associated with low activator dosage and high compressive strength. To quantify this relationship, we introduce the activator index (Ai), which refers to the activator dosage (kg·m−3) required to achieve 1 MPa of compressive strength. The result shows that Ai values below certain thresholds correspond to lower CO 2 avoidance costs and significant emission reductions of GC. This Ai -based criterion helps identify the optimal GC mixture that effectively reduces CO 2 emissions at the lowest possible cost, thereby promoting its commercial application. [Display omitted] • Only 7 of 486 geopolymer concrete (GC) mixtures have negative CO 2 avoidance costs. • CO 2 avoidance costs of most GC in literature exceed CO 2 capture. • The lower activator dosage per MPa strength, the lower CO 2 avoidance cost of GC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Membrane contactor performance with alkali absorbent was studied. • Removing of CO 2 and H 2 S from gaseous stream with NaOH solution was studied. • In-liquid diffusion and gas/membrane contact time are key factor influence on performance. • Utilization of membrane contactor allows to reduce H 2 S content down to 7 ppm. • Conditions for selective H 2 S removing in presence of CO 2 was found, allowing to attain H 2 S/CO 2 selectivity >1500. The paper reports a comprehensive review of the performance of nanoporous gas-liquid polypropylene membrane contactor with NaOH absorbents for removal of H 2 S and CO 2 components from the gas streams. The experiments at different operation conditions, including variation of acid gas content in a feed stream, alkali concentration in absorbent, gas and liquid absorbent volume flow rates, absolute and gas-liquid differential pressures are discussed as a function of the absorbent saturation levels. In-liquid diffusion of components and gas/membrane contact times were determined as main governing factors limiting contactor efficiency. Mass transfer rates of acid gas removal on the membrane contactor over 3 × 10−3 mol/(m2 × s) for CO 2 and 7.5 × 10−3 mol/(m2 × s) for H 2 S were attained. Ultimate processed gas quality with H 2 S content below 5 ppm and CO 2 content below 0.01% was achieved at the contactor performance over 7 m3/(m2 × h) and initial acidic gas content of 2%, while achieving a membrane packing density in the contactor over 3000 m2/m3. The paper also provides an experimentally-proven theoretical model for calculating removal efficiency and residual acid gas partial pressures depending on the membrane parameters and operation conditions. It is shown, the mass transfer coefficient and removal efficiency differ significantly for H 2 S and CO 2 due to the difference in dissolution mechanism involving kinetically limited deprotonation reaction of solvated water in case of CO 2(aq) while engaging direct deprotonation of H 2 S. This allows to attain residual partial pressure of H 2 S in retentate stream equal to the equilibrium pressure above the absorbent solution, while CO 2 residual pressure exceeds an equilibrium value few orders of magnitude. The effect has been successfully utilized for the selective removal of H 2 S from both CO 2 and H 2 S-containing mixtures with H 2 S/CO 2 selectivity exceeding 1500. [ABSTRACT FROM AUTHOR]

Following China and the United States, India is the third highest CO2 emitter in the world. With its fast rising population and an industry primarily reliant on coal and oil, the country's emissions will continue to rise unless appropriate measures are taken. In India generally the carbon sequestration is done by storing CO2 in sedimentary basins where it gets capped by the impermeable cap rocks. The study aims to unfold the other techniques of carbon sequestration in subsurface formations, except for narrating the different types of carbon capture and sequestration techniques along with its storage in different types of environments. For instance, abiotic and biotic environments for CO2 sequestration. It further talks about carbon injections of oceanic, geological, and terrestrial types, to name just a few. Types of carbon emission sources are discussed too. In this paper three different approaches are described for carbon mitigation, namely CarbFix, CO2 Plume technology and Carbon Trading. A prefeasibility study was done in order to implement the three techniques in Dholera geothermal region in Gujarat, India. In literature review, it can be seen how the three techniques can help in permanent mitigation of captured carbon through carbonate mineralization, power generation and industrial applications. For any project government and public participation is important. In this regard the study gives a brief understanding about the steps to be taken by government and the public to promote such projects for carbon mitigation. Besides, the steps to be taken in such projects for health and risk assessment were talked about in literature review too. [ABSTRACT FROM AUTHOR]

As an important part of carbon dioxide capture, utilization and storage (CCUS), the progress of injecting CO2 into oil reservoirs could increase the recovery rate and achieve large-scale carbon storage. It has become one of the most important carbon storage methods around the world. This paper selected the tight sandstone of the fourth member of the Quantou Formation in the southern Songliao Basin to carry out a CO2 storage physical simulation experiment. Representative samples were collected at 24 h, 72 h, 192 h and 432 h to study the CO2 water-rock interaction and to analyze the mineral composition, pore structure and the evolutionary characteristics of physical reservoir properties over time. Physical property analysis, Ion analysis, X-ray diffraction mineral analysis, QEMSCAN mineral analysis, scanning electron microscopy and high-resolution CT scanning techniques were adopted. The main points of understanding were: (i) It shows a differential evolution of different minerals following the storage time of CO2, and carbonate minerals are mainly dissolved with ankerite as a typical representation; a small amount of calcite is formed in 24 h, and dissolved in the later period; feldspar and quartz were partially dissolved; clay mineral precipitation blocked the pores and gaps; (ii) The evolution in mineral variation leads to the complexity of pore structure evolution, following a trend of "small pores decreasing and large pores increasing" with extending storage time. The final porosity and permeability ratios gradually increase from 4.07% to 21.31% and from 2.97% to 70.06% respectively; (iii) There is a negative correlation between the increasing ratio and the original physical properties of the tight stones due to the dissolution of ankerite. Relevant research could provide scientific guidance and technical support for the geological storage of CO2 in lacustrine tight continental sandstones and the development of CCUS technology. [ABSTRACT FROM AUTHOR]

For wind-solar sustainable energy systems with a large amount of abandoned wind and solar energy and carbon dioxide emissions, a power-to-gas equipment can be introduced to synthesize methane together, which is an effective way to alleviate the greenhouse effect, improve the utilization rate of new energy, and promote sustainable development. Focusing on how to perform the optimal capacity configuration of the newly introduced power-to-gas equipment more accurately and simply, this paper make progress through a more similar scenario reduction and a more accurate power-to-gas capacity configuration model. First, in view of the problem that the existing scenario reduction methods are difficult to take into account the coherent temporal characteristics and spatial amplitude characteristics, a novel multi-source-load double-layer spatiotemporal clustering algorithm is proposed. Second, in view of the problem that the power-to-gas equipment can only capture the actual carbon dioxide, a more comprehensive model considering the coupling relationship of multi-energy flows such as electricity-natural gas-hydrogen-oxygen-actual carbon dioxide-virtual carbon dioxide is proposed. The example analysis shows that the proposed strategies can reduce the error rate of the power-to-gas capacity configuration with a similar calculation amount. • Aim to reduce the error rate of power-to-gas capacity configuration. • Modeling novel multi-source-load two-layer spatio-temporal clustering algorithm. • Exploit the potential of carbon emission and electric hydrogen production. • Using typical daily scenario to simplify the calculation of capacity configuration. • Distinguish between actual and virtual carbon dioxide to refine constraints. [ABSTRACT FROM AUTHOR]

This paper aims to contribute to the search for sustainable solutions for CO 2 capture from industrial processes such as steelmaking. This is realized by exploring possibilities of a CO 2 capture from blast furnace gas using clathrates and comparing this technique to conventional absorption with monoethanolamine (MEA). First a design with pure clathrate hydrates was made to act as a reference and aid to construct a more detailed model for the semiclathrate tetra-n-butyl ammonium bromide (TBAB). Herein the capture process was modeled as a crystallization process in a bubble column like crystallization vessel. It was found that the TBAB process suffers mostly from the low capacity which requires high volume flows. Because of the low temperature, large amounts of expensive refrigerants are required (>300 MW). Because of the high pressure, a large amount of electrical power is required as well (>80 MW). Overall, the process as designed here cannot compete with the conventional MEA process. However, several options were identified that could improve the process in such a way that it could become more feasible. These include an apparently higher capacity than estimated and the use of more stable semiclathrates, hence reducing the need for expensive refrigerants. [Display omitted] • Low temperature and high pressure requirements make for a complex design. • Due to low stability, pure water hydrates are not feasible. • Due to high energy requirements TBAB semiclathres are not feasible. • TBAB semiclathrates cannot compete with the MEA process. • A higher capacity and stability are needed to compete with the MEA process. [ABSTRACT FROM AUTHOR]

Global warming has in recent years become a cause for serious concern. It is believed to result from the release of greenhouse gases into the atmosphere, particularly carbon dioxide. Upon assessing the recent developments, it can be learnt that attempts in relation to the reduction of anthropogenic carbon dioxide content and decreasing the emission of greenhouse gases appear to be among the key issues. Despite a range of technologies and approaches established over the years, the issue of separating carbon dioxide from gas streams still cannot be addressed. Notwithstanding having developed new methods, another substantial challenge identified in the area is the growth of adsorbents with relatively higher performance. It is worthy of note that they help balance an array of optimization‐needed factors which include efficiency, engineering feasibility and costs. Zeolites, metal‐organic frameworks, silica and activated carbon are among the adsorption materials which are widely discussed in the literature. Accordingly, recent studies focusing on such materials are comprehensively discussed and summarized in this review. Besides, the cost, carbon capture capacity and selectivity which are among the major concerns with respect to selecting adsorbents are compared in this paper. Furthermore, both the privileges and drawbacks of each type of adsorbent are presented in this manuscript. Despite the encouraging results achieved in this study, developing more effective adsorbents to capture carbon dioxide remains a fundamental challenge. Therefore, further innovations regarding the design and synthesis of adsorbents are essential for future applications. [ABSTRACT FROM AUTHOR]

Summary: Anthropogenic activities including the combustion of fossil fuels have led to a dramatic increase in the rate of carbon dioxide (CO2) emission in the last three decades. Since fossil‐based fuels are still the predominant energy source for this century, CO2 is a colossal problem. It is emitted as a consequence of combustion and human activities and is a major greenhouse gas (GHG) that significantly contributes to climate change and global warming, making CO2 emission a worldwide problem. The Intergovernmental Panel on Climate Change (IPCC) has proposed a 45% decrease in anthropogenic CO2 emissions by 2030, with a target of "net‐zero" CO2 emissions by 2050. Despite its harmful effects, CO2 has the potential to be used for a wide range of different industrial needs, after its capture. CO2 capture technologies are still in the early stage of development because of economic and technological issues. However, in the future, carbon capture and related application technologies and methods may become easier and more accessible due to the new developments in the materials synthesis, strategies and skills and inexpensive utilization, and functioning cost of the employed methods. Furthermore, carbon capture system (CCS) might improve the recent power plan system properties. Concerning climate change, carbon capture is deemed as a promising solution to prevent CO2 emissions. CO2 capture, storage, and utilization are garnering intensive interest from scientists worldwide. This review paper identifies and gave particular attention to the literature on the recent CO2 capture technologies, for example, adsorption, absorption, membrane, and algae‐based separation techniques for pre‐combustion, oxy‐fuel combustion, and post‐combustion periods. Aside from all of these capture technologies, the utilization and application of captured CO2 in various industrial fields such as solvents, chemicals, and fuels are evaluated. [ABSTRACT FROM AUTHOR]

This paper examines the potential for synergistic benefits of co-utilizing three waste streams of pinewood, spent fluid catalytic cracking (sFCC) catalyst, and waste CO 2 via thermochemical conversion. For this, a lab-scale fixed-bed semi-batch scale reactor facility is utilized to investigate the impact of using sFCC catalyst and its reusability on the syngas output, quality, and energy during pyrolysis and CO 2 -assisted gasification of pinewood 800–900 °C. Results are reported on the pyrolysis and CO 2 -assisted gasification of pinewood, as well as the impact of using sFCC catalyst and its reusability on syngas output, quality, and energy. Incorporating the catalyst without direct contact with the solid feedstock resulted in syngas enhancement and reusing this catalyst led to <5 wt% char formation from the gasification at 900 °C. The addition of FCC catalyst improved the total CO yield and its rate with an increase in temperature due to improved cracking of volatiles and their simultaneous reforming using CO 2. In addition, the syngas and energy yields decreased when the catalyst was in direct contact with the solid biomass which also acted as a barrier between the feedstock and gasifying agent, leading to lower CO production. Catalytic gasification at 900 °C using CO 2 provided combustible gas output that was 1.4 times higher than the feedstock mass which suggests that at least 0.4 g of CO 2 consumption for combustible gases, such as H 2 and CO. This points to the synergistic potential in co-utilization of waste streams of biomass, spent FCC catalyst, and CO 2 that provided not only waste management and energy recovery but also energy efficient carbon sequestration. Temperature programmed oxidation of the char residue left from the pyrolysis and gasification tests and coke that forms on the sFCC catalyst revealed conversion of about 0.1 g of the feedstock to coke that was significantly more resistant to oxidation than the char formed. • Investigated synergistic utilization of pinewood, CO 2 and spent FCC catalysts. • Examined pyrolysis and CO 2 -assisted gasification of pinewood and sFCCs at 800–900 °C. • Avoiding catalyst feedstock contact resulted in syngas enhancement. • CO 2 consumption of at least 0.4 g/g feedstock was converted into combustible syngas. • Reusing sFCCs for gasification resulted in coke deposition led reduction in activity. [ABSTRACT FROM AUTHOR]

CO 2 capture, utilization, and storage (CCUS) are critical technical measures to effectively mitigate the global climate change problem. However, most of the existing research has focused on the capture end and lacks in-depth analysis of subsequent processes such as compression, leading to limitations in the improvement of system economics. Therefore, a novel CCS system for a 300 MW coal-fired power plant was proposed in this paper with two strategies: (1) a CCS system integrating CO 2 refrigeration cycle (CFPP-CCS-CRC); and (2) a CCS co-generation plant integrating CO 2 refrigeration cycle (CHP-CCS-CRC). The proposed systems' performance was comparatively evaluated by applying energy, exergy, and economic (3E) analyses. The results demonstrated that at different CO 2 capture percentages (13.1 %∼72.9 %), the CHP-CCS-CRC system has improved energy utilization efficiency by 1.2 %∼5.6 % and exergy efficiency by 7.7 %∼25.8 %, compared to the conventional CCUS system (CFPP-CCS). In particular, at a percentage of 13.1 %, the combined energy consumption of the CHP-CCS-CRC system was 0.39 GJ/tCO 2 , a 79 % reduction compared to 1.87 GJ/tCO 2 of the CFPP-CCS system, which resulted in a static payback period of less than 2 years. In general, the newly proposed system features more adequate energy utilization, lower operating costs, and higher economic efficiency. [Display omitted] • A novel CCUS system coupled with CO 2 refrigeration were proposed. • The performance of the proposed systems is comparatively evaluated by 3E analysis. • The energy consumption of the proposed CCUS systems is reduced by 29.24 %–79 %. • The exergy efficiency of the proposed CCUS systems is reduced by 7.7 %–25.8 %. • The static payback period for the proposed systems is reduced to less than 2 years. [ABSTRACT FROM AUTHOR]

In this paper, we propose a multi-RREH (Remote Renewable Energy Hub) based optimization framework. This framework allows a valorization of CO 2 using carbon capture technologies. This valorization is grounded on the idea that CO 2 gathered from the atmosphere or post combustion can be combined with hydrogen to produce synthetic methane. The hydrogen is obtained from water electrolysis using renewable energy. Such renewable energy is generated in RREH, which are locations where RE is cheap and abundant (e.g., solar PV in the Sahara Desert, or wind in Greenland). We instantiate our framework on a case study focusing on Belgium and 2 RREH, and we conduct a techno-economic analysis under uncertainty. This analysis highlights, among others, the interest in capturing CO 2 via Post Combustion Carbon Capture (PCCC) rather than only through Direct Air Capture (DAC) for methane synthesis in RREH. By doing so, a notable reduction of 10% is observed in the total cost of the system under our reference scenario. In addition, we use our framework to derive a carbon price threshold above which carbon capture technologies may start playing a pivotal role in the decarbonation process of our industries. • We demonstrate PCCC technology potential for reducing RREH's CH4 production cost. • We derive a carbon price threshold for crucial industrial decarbonization. • An uncertainty analysis has been carried out on the reference scenario. [ABSTRACT FROM AUTHOR]

• Typical marine CO 2 sequestration technologies were summarized. • Environmental issues from marine CO 2 sequestration technologies were described. • Solutions to the potential environmental issues were proposed. The global warming effect resulting from excessive CO 2 emissions is getting increasingly critical and the necessary steps must be taken to collect the CO 2 emitted and find a suitable location to sequestrate. The selection of the location influences the final effect of sequestration. The ocean offers promising prospects for sequestration of CO 2 due to its vastness and the solubility of CO 2 it contains. This paper presents several marine CO 2 sequestration technologies, and their benefits and drawbacks as well as their current state of development are assessed. Furthermore, special attention has been paid to the possible environmental issues of the marine CO 2 sequestration technologies, and reasonable alternative actions and suggestions are proposed to solve the potential environmental issues. [ABSTRACT FROM AUTHOR]

As main by-product in iron and steel industry, high value-added utilization of blast furnace slag had received extensive attention. In this paper, a novelty technology was proposed for using blast furnace slag as raw material to obtain excellent CO 2 adsorbent-layered double oxides. The characteristics of layered double hydroxides and layered double oxides were investigated in detailed. Most notably, the laminate structure of layered double hydroxides collapsed and the pore structure, particle size distribution and functional groups of the sample had been greatly changed. The layered double oxides were occupied by phases of CaO, Ca 12 Al 14 O 32 Cl 2 and MgO. The transformation mechanism of the layered double oxides preparation was obtained. In addition, CO 2 concentration and temperature influencing on CO 2 adsorption of layered double oxides were studied and established a suitable kinetic model. The optimal kinetic mechanism model of CO 2 adsorption by layered double oxides was PSO. The activation energy and pre-exponential factors were 56.88 kJ‧mol−1 and 12.26 min−1, respectively. Ultimately, CO 2 adsorption capacity comparison and preliminary economic evaluation were conducted to assess the industrial feasibility of this technology. This work achieved the goals between CO 2 reduction and high value-added utilization of solid waste in iron and steel industry. [Display omitted] • Blast furnace slag used for high value-added CO 2 capture technology. • Successful transformation of slag-derived hydroxides into effective CO 2 adsorbent. • Detailed investigation of changes in structure and characteristics of the adsorbent. • Achieved CO 2 reduction and waste utilization in the iron and steel industry. [ABSTRACT FROM AUTHOR]

The present paper compared, through life cycle assessment (LCA), the production of aviation biofuel from two hydrothermal routes of microalgae cultivated in wastewater. Hydrothermal liquefaction (HTL) and gasification followed by Fischer-Tropsch synthesis (G + FT) were compared. Both routes included biomass production, hydrotreatment for biofuel upgrading, and product fractionation. Secondary data obtained from the literature were used for the cradle-to-gate LCA. G + FT had a higher impact than HTL in the 18 impact categories assessed, with human carcinogenic toxicity exerting the most harmful pressure on the environment. The catalysts were the inputs that caused the most adverse emissions. The solvent used for bio-oil separation also stood out in terms of impacts. In HTL, emissions for global warming were −51.6 g CO 2 eq/MJ, while in G + FT, they were 250 g CO 2 eq/MJ. At the Endpoint level, HTL resulted in benefits to human health and ecosystems, while G + FT caused environmental damage in these two categories, as well as in the resources category. In the improvement scenarios, besides considering solid, aqueous, and gaseous products as co-products rather than just as waste/emissions, a 20% reduction in catalyst consumption and 90% recovery were applied. Thus, in HTL, 39.47 kg CO 2 eq was avoided, compared to 35.44 kg CO 2 eq in the base scenario. In G + FT, emissions decreased from 147.55 kg CO 2 eq to the capture of 8.60 kg CO 2 eq. [Display omitted] • Gasification + Fischer-Tropsch caused more impacts than liquefaction. • The environment has suffered more harmful pressure on human carcinogenic toxicity. • The catalysts used were the inputs that most caused adverse emissions. • Liquefaction route captured 39.47 kg CO 2 eq with improvement scenario. • Gasification + Fischer-Tropsch captured 8.6 kg CO 2 eq with the improvement scenario. [ABSTRACT FROM AUTHOR]

• Synthesized innovative and efficient superbase ternary DESs to capture CO 2. • Revealed effect of temperature, pressure and alkalinity on adsorption capacity of DESs for CO 2. • Improved reaction equilibrium thermodynamic modeling (RETM) to obtain "Active DESs" model.. • Obtained the important physical properties of ternary DESs. The absorption and separation of CO 2 is one of the main strategies to reduce carbon emissions and mitigate global climate change. In this context, a series of ternary superbase/betaine-based deep eutectic solvents (DESs) were synthesized to capture CO 2 , and their density, viscosity and thermal stability were investigated. The effects of temperature, pressure, different hydrogen bond donors (HBDs) and alkalinity of the superbase on their CO 2 affinity were evaluated by the isovolumetric saturation method. The uptake of CO 2 by the DES synthesized from betaine, 1,2-propanediol and 1,8-diazabicyclo(5.4.0)undec-7-ene reached a maximum of 1.5071 mol·kg−1 at 303.15 K and a pressure of 0.187 MPa. The simultaneous chemical and physical adsorption of CO 2 by the ternary DESs was verified by FTIR spectroscopy, and the absorption mechanism was also proposed. The reaction equilibrium thermodynamic model (RETM) was improved to obtain the "Active DES" model, which was correlated with the experimentally determined CO 2 solubility. The reaction equilibrium constants and Henry's law constants were obtained for each ternary system. The ternary superbase/betaine DESs proposed in this paper are green, economical and high-performance absorbers for capturing CO 2. [ABSTRACT FROM AUTHOR]

• Ready-to-operate flue gas cleaning process with CCS for natural gas CHP. • In-depth analysis of SCR, flue gas dehydration, and CO 2 capture processes. • Two-step dehydration using condensation and TSA manage high H 2 O content. • 4-step VSA using zeolite 13X with 15 columns can produce 90 % pure CO 2 stream. • A foundation for future optimization and techno-economic analysis. This paper proposes a continuous CO 2 capture system for natural gas combined heat and power (CHP) facility and explores the potential of low-temperature vacuum-swing adsorption (VSA) process for post-combustion CO 2 capture (PCC) in the context of carbon capture and storage (CCS). Although VSA has strong potential for efficient CO 2 capture in district-scale energy systems, previous case studies have largely focused on high-emission coal combustion sources, making VSA application challenging for these conditions. We address this issue by theoretically designing a ready-to-operate flue gas cleaning process with CCS for a medium-sized 4.3 MW natural gas CHP operating in the local industry. Our in-depth analysis examines the most critical parts such as dehydration, involving condenser and temperature-swing adsorption (TSA), and CO 2 capture via VSA. The conceptual design and performance of VSA are approached by developing a mathematical model to estimate the technology size and performance. This work shows that utilising a small fraction of heat recovered from CHP-generated flue gas is sufficient to supply the necessary heat for auxiliary units, and that using natural cooling water for dehydration effectively reduces moisture (87 vol%) and energy demand for final dehydration via TSA. Furthermore, it demonstrates that 4-step VSA consisting of 15 columns using zeolite 13X can separate CO 2 with a desired purity of 90.4%, meeting the requirements for CO 2 storage and transportation onshore, at a 15.6% recovery rate. The cost of achieving high CO 2 purity without pre-pressurising the CO 2 -rich flue gas, while maintaining cycle simplicity, is discussed. Overall, our paper provides a comprehensive approach to retrofitting distract-scale power plants with CO 2 -lean emissions, presenting a ready-to-operate flue gas cleaning technology based on real operating conditions and technical restrictions, which can contribute towards decarbonisation. [ABSTRACT FROM AUTHOR]

Understanding the phase behaviour of (CO2 + water + permanent gas) systems is critical for implementing carbon capture and storage (CCS) processes, a key technology in reducing CO2 emissions. In this paper, phase behaviour data for (H2O + N2) and (CO2 + H2O + N2) systems are reported at temperatures from 323 to 473 K and pressures up to 20 MPa. In the ternary system, the mole ratio between CO2 and N2 was 1. Experiments were conducted in a newly designed analytical apparatus that includes two syringe pumps for fluid injection, a high-pressure equilibrium vessel, heater aluminium jacket, Rolsi sampling valves and an online gas chromatograph (GC) for composition determination. A high-sensitivity pulsed discharge detector installed in the GC was used to measure the low levels of dissolved nitrogen in the aqueous phase and low water levels in the vapour phase. The experimental data were compared with the calculation based on the γ-φ and SAFT-γ Mie approaches. In the SAFT-γ Mie model, the like parameters for N2 had to be determined. We also obtained the unlike dispersion energy for the (H2O + N2) system and the unlike repulsive exponent and dispersion energy for the (CO2 + N2) system. This was done to improve the prediction of SAFT-γ Mie model. For the (H2O + N2) binary system, the results show that the solubility of nitrogen in the aqueous phase was calculated better by the γ-φ approach rather than the SAFT-γ Mie model, whereas SAFT-γ Mie performed better for the prediction of the vapour phase. For the (CO2 + H2O + N2) ternary systems, both models predicted the experimental data for each phase with good agreement. [ABSTRACT FROM AUTHOR]

This paper introduces GCAM-CDR 1.0, an integrated assessment model for climate policy based on the open-source Global Change Analysis Model (GCAM). GCAM-CDR extends GCAM v5.4 by enabling users to model additional carbon dioxide removal (CDR) technologies and additional policies and controls related to CDR. New CDR technologies include terrestrial enhanced weathering with basalt, ocean liming, and additional versions of direct air capture. New CDR policies and controls include integration of bioenergy with carbon capture and storage (BECCS) into the CDR market, interregional trade in CDR, exogenous control over the rate of growth of CDR, the ability to set independent targets for emissions abatement and CDR, and a variety of mechanisms for setting demand for CDR at the regional and/or global level. These extensions enhance users' ability to study the potential roles of CDR in climate policy. [ABSTRACT FROM AUTHOR]

To improve transportation efficiency, a supercritical CO2 pipeline is the best choice for large-scale and long-distance transportation inshore and offshore. However, corrosion of the pipe wall will occur as a result of the presence of free water and other impurities present during CO2 capture. Defects caused by corrosion can reduce pipe strength and result in pipe failure. In this paper, the burst pressure of subsea supercritical CO2 pipelines under high pressure is investigated. First, a mechanical model of corroded CO2 pipelines is established. Then, using the unified strength theory (UST), a new burst pressure equation for subsea supercritical CO2 pipelines is derived. Next, analysis of the material's intermediate principal stress parameters is conducted. Lastly, the accuracy of the burst pressure equation of subsea supercritical CO2 pipelines is proven to meet the engineering requirement by experimental data. The results indicate that the parameter b of UST plays a significant role in determining burst pressure of pipelines. The study can provide a theoretical basis and reference for the design of subsea supercritical CO2 pipelines. [ABSTRACT FROM AUTHOR]

Carbon Capture and Utilization (CCU) is a viable solution to valorise the CO2 captured from industrial plants' flue gas, thus avoiding emitting it and synthesizing products with high added value. On the other hand, using CO2 as a reactant in chemical processes is a challenging task, and a rigorous analysis of the performance is needed to evaluate the real impact of CCU technologies in terms of efficiency and environmental footprint. In this paper, the energetic performance of a DME and methanol synthesis process fed by 25% of the CO2 captured from a natural gas combined cycle (NGCC) power plant and by the green hydrogen produced through an electrolyser was evaluated. The remaining 75% of the CO2 was compressed and stored underground. The process was assessed by means of an exergetic analysis and compared to post-combustion Carbon Capture and Storage (CCS), where 100% of the CO2 captured was stored underground. Through the exergy analysis, the quality degradation of energy was quantified, and the sources of irreversibility were detected. The carbon-emitting source was a 189 MW Brayton–Joule power plant, which was mainly responsible for exergy destruction. The CCU configuration showed a higher exergy efficiency than the CCS, but higher exergy destruction per non-emitted carbon dioxide. In the DME/methanol production plant, the main contribution to exergy destruction was given by the distillation column separating the reactor outlet stream and, in particular, the top-stage condenser was found to be the component with the highest irreversibility (45% of the total). Additionally, the methanol/DME synthesis reactor destroyed a significant amount of exergy (24%). Globally, DME/methanol synthesis from CO2 and green hydrogen is feasible from an exergetic point of view, with 2.276 MJ of energy gained per 1 MJ of exergy destroyed. [ABSTRACT FROM AUTHOR]

In this paper, the effect of carbon curing procedure on low reactive fly ash alkali-activated pastes was investigated. Specimens were cured with pure carbon dioxide (CO2) gas for different curing times under 4 bar pressure. Chemical and physical characteristics of the geopolymer pastes were obtained from mass monitoring, titration test, XRD, FTIR and TGA-DTG analyses. Regarding the test results, after three days of CO2 curing, the highest CO2uptake was obtained at 4.8 wt% of fly ash precursor, with carbon sequestration efficiency at 22.6%. The ratio of carbon dioxide absorbed as efflorescence to the total absorbed CO2 was measured. The results show that at early age, almost 50% of carbonated products appeared as efflorescence; however, by increasing the curing time, and after 3 days of curing, about 80% of carbon dioxide was stored in the matrix. It was found that, in all cases, carbonation curing was detrimental to the geopolymerization process due to a high amount of efflorescence and led to a reduction in the compressive strength. At 24 h and 3 days, the specimens showed a lower reduction in compressive strength in comparison to CO2 samples cured at 3 h, 6 h and 12 h. Regarding the XRD results, calcite was detected in the 24 h and 3 days specimens, which contributes to lower pore sizes due to a higher molar volume and production of silica gel that might participate in the polymerization processes and results in densified microstructures. [ABSTRACT FROM AUTHOR]

Accurately locating and quantifying carbon dioxide (CO2) leakage to the atmosphere is important for diffuse degassing studies in volcanic / geothermal areas and for safety monitoring and/or carbon credit auditing of Carbon Capture and Storage (CCS) sites. This is typically conducted by measuring CO2 flux at numerous points over a large area and applying statistics or geostatistical interpolation. Accuracy of the results will depend on many factors related to survey/data-processing choices and site characteristics, and thus uncertainties can be difficult to quantify. To address this issue, we have developed a Monte Carlo-based program (MC-Flux) that repeatedly subsamples a high-resolution synthetic or real dataset using a choice of different sampling strategies (one random and four grid types) at multiple user-defined sample densities. The program keeps track of the anomalies found and estimates total flux using two statistical and two geostatistical approaches from the literature. This paper describes the use of MC-Flux to assess the potential impact of various sampling and interpretation decisions on the accuracy of the final results. Simulations show that an offset grid sample distribution yields the best results, however relatively dense sampling is required to obtain a high probability of an accurate flux estimate. For the test dataset used, ordinary kriging interpolation produces a range of flux estimates that are centered on the true value while sequential Gaussian simulation tends to slightly overestimate values at intermediate sample spacings and is sensitive to input parameters. These results point to the need for developing new approaches that decrease uncertainty, such as integration with high-resolution co-kriging datasets that complement the more accurate point flux measurements. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2) and hydrogen (H 2) present substantial feedstock potential for advancing sustainability in the chemical industry. In this paper, a new integrated system is proposed consisting of four subsystems, including an ICT-OEC six-step Cu–Cl cycle, a CO 2 capture using monoethanolamine (MEA), an ammonia production unit, and a methanation unit. The simulation of these subsystems was carried out using Aspen Plus software. Based on literature indicating a 3-step Cu–Cl cycle producing 125 TPD of hydrogen, comparative simulations of a similar-capacity six-step Cu–Cl cycle were conducted for the current analysis. All related values correspond to it. Converting CO 2 into methane and nitrogen into ammonia holds great promise in reaching the net-zero target and fostering sustainability. A comprehensive cradle-to-gate Life Cycle Assessment (LCA) investigates the environmental impacts of ammonia and methane production using green hydrogen and CO 2. Significantly, the utilization of renewable energy sources such as nuclear, wind, and hydropower in the CO 2 refinery process generates a net negative Global Warming Potential (GWP). It was noted that the GWP value of the electrical grid could increase significantly, reaching up to 370,000 kg CO 2 eq., particularly when producing 23,277.2 kg/h of ammonia and 2141.71 kg/h of methane at a hydrogen consumption rate of 5211 kg/h (125 metric tons of H 2 per day). The significant environmental impact of the CO 2 refinery process is notably influenced by the choice of electrical grid mix as the energy source. However, in the case of photovoltaics as an energy source, the value of 0.517 kg sb eq, surpasses that of the electrical grid mix. However, nuclear energy emerges as a particularly low-GWP impact, with values of −4190 and −4140 CO 2 kg eq. for the 3-step and 6-step Cu–Cl cycles, respectively. The findings suggest that the CO 2 refinery process generates a carbon credit in both scenarios. Based on the findings of this study, policymakers have a basis for developing effective strategies to address and alleviate environmental impacts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • PEI and APTES modified MfMCNs are prepared by pre-assembly experiment. • MfMCNs contains hydroxyl and amino groups to enhance the adsorption of CO 2. • The pore size of MfMCNs decreased to 0.53–0.55 nm, which enhanced screening of CO 2. • By adding MfMCNs, the phase interface defect is improved and the separation performance of MMMs is enhanced. Traditional two-dimensional (2D) membrane fillers are prone to interfacial defects such as agglomeration and phase separation in the membrane, limiting the separation performance of membrane. In this paper, microporous carbon nanoplates (MCNs) with controllable microporous structures were functionalized with two different amine carriers of low molecular weight polyethyleneimine (PEI) and 3-aminopropyl triethoxysilane (APTES) to prepare multi-functionalized microporous carbon nanoplates (MfMCNs). It is worth noting that with the success of composite functionalization, the filling content of mixed matrix membranes is also high to a certain extent. To a certain extent, it has been demonstrated that interfacial compatibility between the polymer and the fillers has been improved. It was confirmed by characterization technology that the morphology of the fillers had not been changed, but the pore size of MfMCNs was declined to 0.53–0.55 nm because part of the amino carrier was immersed in the pore structure of MfMCNs. The gas permeability tests under dry gas and wet gas conditions show that the improvement of phase interface by MfMCNs is significant. Under the condition of a dry gas test, the CO 2 /N 2 selectivity of MfMCNs/Pebax-1.0 wt% MMMs is 76.3, which is 27 % higher than that of MCNs/Pebax-1.0 wt% MMMs. Under the moisture condition, the permeability and selectivity of MfMCNs/Pebax-1.0 wt% MMMs CO 2 are 287.72 Barrer and 79.1 separately. Compared with Pebax membrane, the permeability of CO 2 (176.6 Barrer) was rose by 62.9 %, and the selectivity of CO 2 (59.1) was rose by 33.84 %. Significantly, the best MMMs separation performance exceeds upper limit of Robeson. This provides a powerful strategy to strengthen the compatibility between inorganic materials and polymers and strengthen the performance of MMMs in CO 2 gas capture. [ABSTRACT FROM AUTHOR]