Carbon Capture Science & Technology最新文献

Mineral carbonation or mineralization of CO₂ using rocks or waste industrial materials is emerging as a viable carbon capture and storage (CCS) technology, especially for smaller and medium-scale emitters where geological sequestration is not feasible. During mineralization processes, CO₂ chemically reacts with alkaline earth metals in waste materials or rocks to form stable and non-toxic carbonates In situ mineral carbonation holds promise due to ample resources and enhanced security. However, it is still in its early stages, with higher transport and storage costs compared to geological storage in sedimentary basins. Ex situ mineral carbonation has shown promise at pilot and demonstration scales, but its widespread application is hindered by high costs, ranging from US$50-US$300/ton of sequestered CO₂. This review delves into the current progress of proposed mineralization technologies and their potential in reducing the overall cost of CO₂ sequestration. The discussion critically analyzes various factors affecting carbonation reactions, such as temperature, pressure, leaching agents, solid-to-liquid ratio, and mineralogy for geological settings relevant to the Middle East and the net-zero strategy established within Gulf Cooperation Countries (GCC). Furthermore, the potential commercialization of mineral carbonation, emphasizing the importance of reducing energy consumption and production costs to make the process economically viable is highlighted, offering directions for circular economy and mineral carbonation as a substantial carbon mitigation tool in the Middle East region. Life Cycle Assessment and Techno-Economic Analysis) was also reviewed to provide a comprehensive understanding of both the environmental and economic implications of a CO₂ capture via subsurface mineralization

The impacts of steam on hydrogenation of dual function materials (DFM) for Integrated CO₂ Capture and in-situ methanation (ICCM) is a new area requiring detailed investigations prior to industrialization. This work investigated impacts from steams on hydrogenation of Ru-Na₂CO₃/γ-Al₂O₃ DFM for ICCM that containing Na₂O adsorbent, Ru sites, and γ-Al₂O₃ support. DFM performance was examined in cyclic reactions as introducing external steam during hydrogenation, and the behaviors of adsorbed CO₂ species during hydrogenation were characterized by in-situ DRIFTS and H₂-TPSR. CH₄ selectivity decreased sharply from 84.3 % to 1.2 % as increasing external steam concentrations to 20 vol.%, and the conversion of adsorbent component decreased from 298.5 μmol g^-1 to 167.1 μmol g^-1. b-CO₃^2- and m-CO₃^2- formed at Na₂CO₃/γ-Al₂O₃ interface were the carbonate species that could be hydrogenated into CH₄, some of which were desorbed into CO₂ due to moisture-driven desorption effects. With the presence of external steam in H₂ reactants, the conversion of carbonate species is a competing process between hydrogenation and moisture-driven desorption. In ICCM reaction with external steam present, b-CO₃^2- was preferred to be desorbed into CO₂; while for m-CO₃^2-, desorption into CO₂ by steam and hydrogenation into CH₄ proceeded in parallel. Strong moisture-driven desorption effects from steam product were demonstrated in a fixed-bed reactor, which also led to rapid decrease of localized selectivity of CH₄ along bed height.

Globally, the rise in the environmental awareness on the reduction of greenhouse gas emissions has spurred the development of carbon capture and utilization (CCU) technologies, including membrane separation. Among the membrane separation technologies, dual-phase carbonate membrane is feasible for post-combustion carbon capture given its high thermal and chemical stabilities at high temperatures. The integration of carbon capture and dry reforming of methane (DRM) in a catalytic dual-phase carbonate membrane reactor to function as a single device for syngas production is an emerging area of research. This paper aims to provide a comprehensive review on the progress of the dual-phase carbonate membranes and membrane reactors in carbon capture and syngas production. The working mechanism and performance of three types of carbonate membranes in CO₂ separation from various aspects (i.e., material selection, membrane configuration, modifications on the materials, and operating conditions) are thoroughly examined. Additionally, an overview of the reactions involved (i.e., DRM, steam reforming of methane (SRM), and partial oxidation of methane (POM)) and catalyst design (i.e., nickel-based supported with metal oxides and zeolites) is provided. A detailed comparison of the performance of the catalytic dual-phase ceramic-carbonate membrane reactor using different types of catalysts for syngas production is presented. Finally, the review is concluded with a discussion of the challenges, recommendations, and future insights on the development of dual-phase carbonate membranes and membrane reactors.

Global primary energy consumption, which heavily depends on fossil fuels, is on track for depletion, with projections suggesting exhaustion by 2100. This trajectory is further compounded by the persistent rise in atmospheric CO₂ levels, currently at 420 ppm, which significantly contributes to climate change and its detrimental environmental consequences. To address this urgent challenge, various strategies have been proposed, including CO₂ capture and storage, as well as its conversion into usable fuels. Leveraging the abundance of CO₂ as a carbon source, coupled with sustainable energy resources such as solar, wind, and thermal energy, holds promise for generating value-added goods while mitigating environmental harm. This review focuses on the electrochemical reduction of CO₂, presenting a dual-pronged approach aimed at decreasing atmospheric CO₂ levels. The imperative to simultaneously combat declining atmospheric CO₂ concentrations and advance cleaner, sustainable energy sources underscores the urgency of this endeavor. Specifically, we highlight the pivotal role of diverse polymer electrolytes, encompassing cation, anion, and bipolar membranes, in facilitating electrochemical CO₂ reduction. Exploring the impact of functional groups within these membranes on CO₂ reduction reaction provides insights into potential advancements in synthesis of eco-friendly fuel from conversion of CO₂.

In the field of the CO₂ transportation for the Carbon Capture, Utilization and Storage (CCUS) process chain, several analyses show that, for a large-scale CO₂ transportation, pipeline transportation is the preferred method on land due to its lower cost. Barges also present a feasible alternative if the capture site is near a waterway. Maritime transport becomes more advantageous than pipelines, particularly over long distances and across ocean. Despite the need to liquefy CO₂ and to add temporary storage facilities for loading and unloading onto ships, beyond a certain distance at fixed CO₂ transported and plant life, ship transport optimal at pressures of 7 or 15 bar depending on the type of vessel. Impurities in CO₂, arising from various industrial processes and variable performances of capture technologies, increase energy consumption during compression and could cause corrosion risks. Specifications for CO₂ ship transport limit the concentration of certain impurities with strict thresholds. Methods for purifying CO₂, such as the two-flash system and stripping column, have been proposed to meet these specifications. The studied CO₂ liquefaction methods show that hybrid cycles, combining open cycle with Joule-Thompson expansion and closed cycle with cooling machine offer reduced energy consumption and improved CO₂ recovery compared to open or closed cycles. In the presence of the maximum threshold of impurities in the pipeline, energy consumption can nearly double from 21.8 kWh/t_CO2 to 40.9 kWh/t_CO2, with the highest recovery rising 98.1 %. This research underscores the importance of optimizing CO₂ transport strategies to facilitate the deployment of CCUS technologies.

The utilization of dual functional materials (DFMs) in integrated CO₂ capture and utilization (ICCU) has been attracted increasingly attention, with the conversion of CO₂ to CH₄ through the Sabatier reaction offering significant thermodynamic benefits. Ni, recognized for its catalytic efficiency among transition metals due to its cost-effectiveness and natural abundance while Ni-based DFMs have been favored to promote the conversion of CO₂ to value-added chemicals. In the past decades, significant efforts have been dedicated to developing more efficient Ni-based catalysts to enhance CO₂ conversion and CH₄ selectivity. This study researched the thermodynamic and kinetic aspects of ICCU and summarized the recent industrial process at first. Then, an overview of the advancements in Ni-based DFMs, including synthesis methods, support materials and promoters were provided. Next, the mechanisms of CO₂ methanation were also briefly addressed to provide a comprehensive understanding of the process. Finally, the future prospects were guided the development and application scenarios of Ni-based DFMs in the ICCU.

Post-combustion carbon dioxide (CO₂) capture/separation is considered one of the main ways to minimize the impact of global warming caused by this greenhouse gas. This work used eight mono- and dicarboxylate-based ionic liquids (ILs) to impregnate metal-organic framework (MOF) ZIF-8. This anionic effect was studied for these mostly unreported IL@MOF composites to determine its impact on gas sorption and selectivity performance. Characterization results confirmed IL impregnation into the structure of ZIF-8, along with the conservation of microporosity and crystallinity in composites. Sorption-desorption equilibrium measurements were performed, and CO₂ and nitrogen (N₂) isotherms were obtained at 303 K for ZIF-8 and IL@ZIF-8 composites. At 0.15 bar, the dicarboxylate-based composite [C₂MIM]₂[Glu]@ZIF-8 showed the highest CO₂ gas sorption, showing 50 % more sorption capacity than the best monocarboxylate-base composites at this pressure. Dicarboxylate-based composites also showed remarkable N₂ sorption in the low-pressure range. The ideal CO₂/N₂ selectivity for a typical post-combustion composition was calculated, and a trend regarding the anionic carbon chain size was observed. The composite [C₂MIM][Cap]@ZIF-8 showed nearly five times more selectivity than the pristine ZIF-8 at 1 bar of total pressure. Dicarboxylate-based composites, given their low-pressure high N₂ sorption capacity, were not as selective as their respective monocarboxylate-based IL@ZIF-8 materials with the same carbon chain size.

Composite membranes incorporating ionic liquids (ILs) within MXene demonstrate promising potential for CO₂ separation. However, studies on the separation of CO₂/CH₄ using MXene-confined ILs membranes are limited, especially in terms of understanding the mechanisms at the molecular level. In this work, the system of CO₂/CH₄ in MXene-confined ILs membranes was studied by molecular dynamic simulations. The number density results reveal that MXene stratifies the ILs between the layers, with higher concentrations of ILs near MXene and lower concentrations in the middle layer. Notably, MXene has a greater impact on cations distribution compared to anions. As the layer spacing of MXene expands from 1.5 to 3 nm, the interaction between MXene and IL weakens, while that between the cations and anions strengthens. The confined ILs enhance gas solubility capability but impede gas diffusion. CO₂ is distributed closer to anions, while CH₄ tends to be closer to cations, with the distance between CH₄ and cations decreasing as the layer spacing increases. Additionally, with the increase of layer distance, the proportion of confined ILs gradually decreases, and the gas diffusion coefficient gradually increases. Furthermore, compared to 1-Ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF₄]) and 1-Ethyl-3-methylimidazolium hexafluorophosphate ([EMIM][PF₆]), MXene-confined 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TF₂N]) is identified as the most effective for CO₂/CH₄ separation, owing to its superior CO₂ solubility and highest diffusion selectivity.

Carbon dioxide (CO₂) is a ubiquitous molecule that is essential for the existence of life on Earth. However, the ever-increasing anthropogenic CO₂ emissions in the environment have resulted in global warming-via-climate change. CO₂ is an inexpensive substrate that can be utilized to produce fuels and value-added chemicals through numerous chemical and biological processes to boost the circular economy with a negative carbon cycle in the future. Conventional technologies practiced capturing CO₂ suffer from several limitations, such as high capital costs, high energy input, complicated designs, CO₂ leakage, and kinetic limitations in various steps. To offset these limitations and negative impacts, this study assessed the emerging CO₂ capture and sequestration (CCS) technologies in value-added products that can boost the nation's economy and lower energy consumption while preserving global environmental quality. Various emerging CCS technologies, such as heterogeneous catalytic conversion, plasma technology, photocatalytic conversion, and other technologies (electrochemical or electrocatalysis, photoelectrochemical, thermo-catalysis, and biochemical and radiolysis), were discussed for efficient utilization and transformation of CO₂. In addition, it also explored how the various transformation technologies affected the characteristics, economic value, and quality of value-added chemicals/fuels. This review also covered environmental and economic implications from scientific perspectives, and lastly, the future outlook and associated challenges were discussed.

Plastic consumption has surged due to population growth and shifts in consumer behavior. Upcycling aims to address plastic waste by finding innovative reuse strategies. By integrating waste plastic into new products and materials, upcycling supports a more sustainable and environmentally friendly economic model. This reduces the overall environmental footprint, including CO₂ emissions, associated with plastic consumption. Moreover, converting plastic waste into carbon nanotubes, can effectively sequester carbon. This means that carbon is captured and stored in a stable form, preventing its release into the atmosphere as CO₂. This contributes directly to reducing net emissions. Recent interest in upcycling strategies includes producing target-oriented catalysts to reform plastic waste into carbon nanotubes embedded spent catalysts, offering potential for various applications. However, research in this area is scattered and lacks comprehensive conclusions. This review critically examines the use of spent catalysts from plastic waste pyrolysis and identifies their suitability for practical applications. It suggests focusing on the catalytic pyrolysis of plastic waste for target-oriented catalysts, as they offer good hydrogen yield and post-pyrolysis use in targeted applications. The unique structure of these catalysts enhances performance compared to commercial alternatives, but post-treatment is crucial to remove impurities for optimal performance. The upcycling of plastic waste into CNTs-metal composites substantially contributes to Sustainable Development Goals 7, 9, 12 and 13, by taking action to combat climate change and by guaranteeing access to affordable, clean, and sustainable energy. This review aims to be helpful for researchers who are currently new to the topic and want to continue research in this domain.