Carbon Capture Science & Technology最新文献

Ultra-microporous solid sorbents with high CO₂ adsorption capacities and gas selectivity are preferred for carbon capture. Here we deliver such sorbents via a combination of narrow micropores, lack of mesopores and an abundance of CO₂-philic functional groups. This was achieved by crosslinking lignin waste obtained from a local paper factory, in Lewis's acid deep eutectic solvents (DESs) such as [ChCl][ZnCl₂]₂ and [ChCl][FeCl₃]₂, varying crosslinker types and optimizing experimental parameters. Hypercrosslinked polymers (HCPs) prepared in [ChCl][FeCl₃]₂ with 1,4-dichloroxylene crosslinkers comprised quasi-unimodal, ultra-narrow micropores. At 298 K, 1 bar, and using a gas mixture comprising 15 vol.% CO₂ and 85 vol.% N₂ (similar to post-combustion flue gas), the CO₂ adsorption capacity and CO₂/N₂ selectivity of this HCP reached 18.1 cm³ g⁻¹ and 835, respectively. Deployed in temperature swing adsorption and evaluated for vacuum pressure swing adsorption, the CO₂ recovery rates of this HCP were >87 %, outperforming commercial solid sorbents such as zeolite 13X and PSAO2 HP Molsiv™. The optimization of sorbent microporosity with CO₂-philic functional groups could pave the route towards developing bio-derived solid sorbents for carbon capture.

This study evaluates the economic feasibility and environmental impacts of retrofitting a diesel-based powerhouse in the Canadian Arctic with a post-combustion carbon capture process at an active gold mining site isolated from cheaper or cleaner electrical grids. A techno-economic analysis was conducted to determine the total annualized cost (TAC) of implementing a monoethanolamine (MEA) chemical absorption process to mitigate carbon dioxide emissions. The calculated cost per tonne of CO₂ captured of $420 reflects the challenges of operating northern sites reliant on diesel fuel. Electricity generation costs, estimated at 0.44 $/kWh, are found to explain most of the variance in cost per tonne compared to other studies. A profitability model, comparing the additional annual expenditure to the current carbon tax exposure (CTE), suggests that carbon pricing alone is insufficient to incentivize investment in energy-intensive carbon capture technologies such as amine-based absorption processes. The sensitivity analysis, which evaluates profitability relative to variations in key variables, highlights the significant impact of the solvent regeneration heat demand. This major cost driver also contributes substantially to the carbon footprint of 0.55 tonnes emitted per tonne captured, as determined by a complementary life cycle assessment.

With the extensive utilization of lithium-ion battery in the electric vehicle and energy storage field, the consumption of lithium has been sharply increasing. Lithium resource occurrence area were facing increasing environmental pressure, particularly the magnesium residue (MR) produced in the lithium extraction process, and a sustainable exploitation pathway have not been established. In the framework of "net-zero", MRs were onverted to Salt lake magnesium oxide (SL-MgO) which was characterized by various elemental and surface analysis methods. Magnesium oxychloride cement (MOC) was prepared form SL-MgO and two industrial solid wastes [fly ash (FA) and phosphogypsum (PG)], and its carbon sequestration capacity was analyzed and evaluated. If all the MRs produced from the lithium extraction process were used to manufacture MOC materials for CO₂ sequestration. When the PG content was 20 %, the CO₂ sequestration capacity of the MOC was 0.29 kg/m², the compressive strength was 85.30 MPa, and the MOC neutralized 220.10 % of the CO₂ emissions from the lithium extraction process. In this procedure, evidence was found of the typical metastable carbonate products identifiable. Overall, utilizing MRs and industrial solid waste to manufacture new low-carbon MOCs may become the most direct and effective countermeasures to alleviate environmental pressure in these regions.

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.