CO2 Sequestration Capacity Research Articles

Reducing energy consumption and enhancing trapping and capacity of CO2 sequestration: The effects of pore heterogeneity and fluid properties

Sequestrating the CO2 into deep geological formations is a profound approach to reduce green-house gas and thus mitigate climate change. In this context, ceiling the energy consumption, enhancing the CO2 trapping to facilitate further dissolution and mineralization, and expanding the CO2 sequestration capacity have gained extensive interests. Here, we explore the roles of pore heterogeneity and fluid properties in optimizing energy consumption and maximizing CO2 sequestration effectiveness by computational modeling. We validate the modeling results through microfluidic experiments. We discover that placing the low Pore-Throat-Ratio layer at the middle fosters 7 % reductions of energy consumptions per pore volume, and a Ca<4.0 × 10−5 saves 8 % energy consumption per kgCO2. The High-Median-Low heterogeneous pores optimally perform not only in residual CO2 generation (22%PV) and conservation (7%PV) but also in CO2 sequestration capacity (67%PV). Regarding fluid properties, the enlarged hydrophilicity and viscosity ratio with reduced density difference and interfacial tension increase the residual CO2 and energy consumption while suppress the sequestration capacity. The presence of gravity especially when Bo > 6 × 10−5 promotes the residual CO2 generation and conservation yet burdens the energy consumptions. This work bridges the gap between energy consumption and CO2 sequestration effectiveness by uncovering the significant roles of pore heterogeneity and fluid properties.

A study on wood waste potential in Turkey

The aim of this article is to examine and assess Turkey's wood waste potential through an experimental investigation approach to serve Sustainable Development Goals (SDG) of United Nations Development Programme. While integrating entrepreneurial and architectural perspectives from two authors, the survey provides insights into the waste wood-producing sector, highlighting the gaps within the data in the existing literature. To address these gaps, after reviewing available sources in the wood-waste producing sector, the authors conducted interviews with directly involved volunteers to gather first-hand information and suggestions. Viability studies were subsequently conducted for theoretical products, comparing their potential to create value-add by utilizing wood waste capacity.The proposal for handmade, unique, products from solid wood waste demonstrated a higher added value attributed to elevated selling price expectations, albeit with limited benefits in recycling substantial amounts of wood waste. Conversely, the proposal focusing on wood-based pressboards exhibited a lower added value, influenced by competitive pressure from industrially produced boards, but demonstrated a significant capacity for CO2 sequestration. The findings of the study underscore a considerable future potential for wasted wood and its utilization in Turkey, while also emphasizing the pressing need for additional research on wood waste recycling to enhance ecological sustainability.

Investigation on coal permeability evolution considering the internal differential strain and its effects on CO2 sequestration capacity in deep coal seams

The gas adsorption/desorption-induced coal deformation effect is a significant factor governing the evolution of coalbed permeability. Current theoretical investigations typically coal bulk and fracture deformation induced by gas are equivalent, neglecting the matrix-fracture interactions. Based on internal adsorption stress, this paper proposes Internal Differential Strain Coefficient (IDSC) to quantitatively characterize the relationship between coal bulk and fracture strain under equilibrium conditions. Coupling this coefficient constructs a binary gas permeability evolution model considering matrix-fracture interactions. Through numerical simulations of CO2-ECBM processes under various internal differential strain circumstances using this model, dynamic evolution patterns of diverse parameters are obtained. The research findings indicate that along the direction of CO2 injection, matrix-fracture interactions exhibit a complex trend of initially increasing, then decreasing and then increasing, and the increase in internal differential strain levels results in a downward trend in permeability peak. Additionally, the evolutionary characteristics of CH4 recovery and cumulative CO2 storage rising with increasing internal differential strain levels were obtained on time scales using a fixed-point monitoring methodology. Inspired by the aforementioned laws, this paper discusses the macroscopic influence of burial depth on the effects of internal differential strain, providing new theoretical support for CO2 sequestration injection methods in deep coal seams.

Tailoring high-magnesium cements for enhanced carbonation hardening and CO2 sequestration

The reduction of CO2 emissions from the cement industry remains a major challenge worldwide. This study investigates the feasibility of using high-magnesium limestone to prepare high-magnesium and low-calcium cementitious materials (HM-LCCs) with improved carbonation reactivity and CO2 sequestration capacity. The carbonation reactivity, hardening properties, phase assemblage, microstructure, and pore distribution of HM-LCCs synthesized with varying proportions of high-magnesium limestone were characterized by XRD, TGA, FT-IR, SEM, and LF NMR. It is found that with increasing substitution of high-magnesium limestone, the main mineral phases in clinker transformed from C2MS2 to C3MS2 and eventually to β-C2S and MgO, along with markedly enhanced grindability. The carbonation reactivity and degree increased progressively with increasing substitution of high-magnesium limestone. Properly tailored HM-LCCs exhibited excellent strength development up to 94.56 MPa after carbonation, dense microstructure, and significantly higher CO2 uptake. This study provides new insights into developing low-carbon cement by utilizing high-magnesian raw materials. The carbonation hardening and CO2 sequestration capacity of cement can be optimized by tailoring the Mg/Ca ratio and calcium silicate phase assemblage.

CO2 sequestration by wet carbonated magnesium slag with high-content aragonite whiskers for improving cement performance as underground filling material

Magnesium slag (MS) is an alkaline waste residue from magnesium smelting processes. This study aimed to utilize the magnesium oxide in MS and adopt MgCl2 as the calcium carbonate crystal modifier to prepare high length-to-diameter ratio aragonite whiskers via wet carbonation, which can achieve high-value recovery of MS while capturing CO2 and enhancing cement as underground filling material. The effects of MgCl2 concentration on the carbonation process, composition, microstructure, and morphology were systematically investigated. With increasing MgCl2 concentration, more aragonite was obtained, reaching 94.9 % at 0.5 M MgCl2. Notably, at 0.1 M MgCl2, high length-to-diameter ratio aragonite whiskers with 16 were achieved. Introducing 1 wt% MS carbonated at optimal 0.1 M MgCl2 into cement increased the 3 d and 28 d compressive strengths by 17.8 % and 22 %, respectively. Moreover, an excellent CO2 sequestration capacity of up to 20.33 g CO2 per 100 g MS was obtained for the carbonated MS. Therefore, wet carbonated MS with high content aragonite whiskers is a promising method for MS high-value utilization while reducing cement usage and CO2 emission, as well as improving cement performance as underground filling material.

A thorough assessment of mineral carbonation of steel slag and refractory waste

Escalating industrial CO2 emissions necessitate innovative carbon capture and utilization strategies. This study explores the potential of mineral-carbonation of steelmaking slags, particularly White Slag (WS) and various Refractory Wastes (RWs), to mitigate CO2 emissions and valorize industrial wastes. Experiments were performed with waste materials from the production lines at CELSA (Barcelona, Spain). We delved into direct aqueous carbonation, evaluating the performance and characteristics of these wastes under different experimental conditions. Our findings reveal that all slags can effectively sequester CO2. This process is effective not only for pure CO2 but also for diluted flue gases under mild conditions (≤ 100 ºC, ≤ 6 bar). Specifically, WS exhibited peak CO2 sequestration capacities (SC) of 359.79 gCO2/kgslag (pure CO2) and 276.65 gCO2/kgslag (diluted flue gas). In contrast, the RWs presented different kinetic, reaching a maximum SC of 311 gCO2/kgslag after prolonged times. Given the large inhomogeneity of RWs, individual analysis of distinct RW fractions revealed significant variations in carbonation performance. Tundish RW exhibited the highest CO2 sequestration capacity, emphasizing the importance of waste source and mineral composition in the carbonation. Chemical and morphological evaluations confirmed the transformation of CaO to CaCO3, with MgO remaining largely inert. Additionally, the process indicated potential environmental benefits by reducing the mobility of toxic metals, particularly Pb, suggesting an ancillary avenue for waste treatment. This study underscores the utility of CO2 mineralization as a dual-benefit approach within the circular economy framework, offering insights into its application for sustainable waste management and CO2 emission reduction in the steel industry.

Evaluation of the Potential for CO2 Storage and Saline Water Displacement in Huaiyin Sag, Subei Basin, East China

CO2 geological storage combined with deep saline water recovery technology (CO2-EWR) is one of the most effective ways to reduce carbon emissions. Due to the complex structural features, it is difficult to use CO2-EWR technology in Huaiyin Sag, Subei basin, East China. In this study, the multi-source information superposition evaluation technology of GIS was utilized for the selection of CO2 storage sites and water displacement potential target areas in this area, which mainly focused on the sandstone reservoirs of Cretaceous Pukou Formation. Based on the results, a three-dimensional injection–extraction model was established. Various scenarios with different production/injection well ratios (PIR) were simulated. Research has shown that the suitability of the surrounding site of Huaiyin Power Plant can be divided into two levels: relatively suitable and generally suitable; the area in the generally suitable level accounts for more than 80%. At a PIR of 1, CO2 is distributed asymmetrically, whereas at PIRs of 2 or 4, CO2 is distributed symmetrically. When the number of production wells is constant, a higher injection rate results in a faster expansion rate of the CO2 plume. This means that the time taken for the CO2 plume to reach the production wells is shorter. Reservoir pressure increases rapidly after more than 60 years of CO2 injection at lower PIR values, while at higher PIRs, reservoir pressure eventually stabilizes. Higher PIR values correspond to higher gas saturation, indicating a greater capacity for CO2 sequestration with more producing wells. When PIR = 4, the total CO2 injection increased by 55.73% compared to PIR = 1. However, the extraction of saline decreases with an increase in the number of producing wells, resulting in a decrease in replacement efficiency. This study provides a theoretical basis and technical support for the implementation of large-scale CO2-EWR engineering and technology demonstration in this region.

THE POTENTIAL FOR CARBON SEQUESTRATION IN RECLAIMED MINE SOIL

Mining sector has been the central attention of the business and public policy sustainable development scheme for several years. Reclamation territories are with potential carbon sequestration capacity in degraded mining areas and can be an impeccable option for achieving sustainable development goal-13. This paper made an investigation about the presence of heavy metals in reclaimed area possibilities to improve reclaimed soils with biochar with idea to enhance ecosystem carbon pool and atmospheric CO2 sequestration capacity to offset CO2 emission and soil organic carbon losses. The results show that the carbon content in biochar is 46.6 % and would be classified in class 2 according to the International Biochar Initiative. H/C and O/C atomic ratios could be useful for restoration of degraded poor mine soils through enhanced carbon sequestration. O/C ratio is 0.085 mol mol–1 and half-life of biochar is 2795.65 years, which confirm the biochar stability. For each kilogram of biochar incorporated into the soil, 144 g of carbon were sequestrated 52,8 % CO2 emission reduction. Hence, the biochar developed in this study can be used in carbon-deficient soils with the added benefit of long-term carbon storage.

Enhancing the properties of carbonation cured gamma dicalcium silicates (γ-C2S) using biomimetic molecules

This study investigates the effectiveness of three different organic molecules to enhance the properties of carbonated gamma dicalcium silicate (γ-C2S) based cementitious system. These molecules are addressed as biomimetic molecules due to their ability to mimic the biomineralization process. Low dosages (2.5% and 5%) of L-aspartic acid (LAsp), L-glutamic acid (LGlu) and polyacrylic acid (PAA) were incorporated to the γ-C2S paste. The effects of these molecules on the microstructure, CO2 sequestration capacity and strengths of the CO2-activated γ-C2S pastes were monitored. To understand the effectiveness of molecules at different temperature, the compressive and flexural strengths of γ-C2S pastes carbonated at 25 °C and 50 °C were evaluated. It was observed that all the molecules enhanced the strength of the composites by altering the CaCO3 formation and subsequent densification of the matrix. However, the effectiveness of the molecules varies depending on the temperature. Specifically, LGlu and LAsp were found to be the most and the least, respectively, effective molecule at high temperature (50 °C) carbonation curing condition; whereas, PAA remained nearly equally effective at both temperatures.

Unveiling the Carbonation Behavior and Microstructural Changes of Magnesium Slag at 0 ℃

Magnesium slag (MS) is an industrial byproduct with high CO2 sequestration potential. This study investigates the carbonation behavior and microstructural changes of MS during wet carbonation at 0 °C. XRD, TG, FTIR, SEM, and BET techniques were used to characterize the phase composition, microstructure, and porosity of MS samples carbonated for different durations. The results showed that the main carbonation products were calcite, vaterite, and highly polymerized silica gel, with particle sizes around 1 μm. The low-temperature environment retarded the carbonation reaction rate and affected the morphology and crystallization of calcium carbonate. After 480 min of carbonation, the specific surface area and porosity of MS increased substantially by 740% and 144.6%, respectively, indicating improved reactivity. The microstructure of carbonated MS became denser with calcite particles surrounded by silica gel. This study demonstrates that wet carbonation of MS at 0 °C significantly enhances its properties, creating an ultrafine supplementary cementitious material with considerable CO2 sequestration capacity.

Utilisation of silica-rich waste in eco phosphogypsum-based cementitious materials: Strength, microstructure, thermodynamics and CO2 sequestration

Phosphogypsum-based cementitious materials (PGCM) are commonly selected as substitutes to ordinary Portland cement (OPC), however, drawbacks, such as a restricted capacity for CO2 sequestration and reduced mechanical properties upon carbonation, limit the potential applications of PGCM. This study investigates the carbonation process mechanism of PGCM and explores to modify the hydration product classes of PGCM by using two silica-rich solid wastes, which are waste glass powder (WGP) and silica fume (SF). This innovative approach resulted in an improved carbon capture capacity and enhanced mechanical properties of PGCM. The addition of SF and WGP increased the compression strength of PGCM by 15.5% and 19.0%, respectively. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were utilized to investigate the hydration mechanism of PGCM supplemented with SF and WGP, in order to gain a comprehensive understanding of their properties. The addition of SF and WGP to PGCM resulted in a 9.9% and 21.6% increase in thermal conductivity, respectively. Furthermore, the addition of SF and WGP facilitated higher CO2 sequestration rates for PGCM (49.76% and 44.05%, respectively), while after carbonation, the strength loss rates were reduced to 16.8% and 13.35%, respectively. Finally, a simple sustainability analysis showed that the utilisation of silica-rich waste in PGCM has environmental sustainability benefits.

Accelerated carbonation of alkali-activated blended blast furnace slag and wood fly ash: Carbon capture kinetics, chemical and mechanical evolutions

The influence of fly ash/slag ratio, alkaline activator silica modulus (Ms), and curing method have been evaluated on the carbonation of biomass fly ash and blast furnace slag blends. In addition to quantifying the CO2 sequestration capacity, the influence of carbonation on the chemical and mechanical properties of materials was explored to assess their durability. Results show that higher fly ash contents lead to higher CO2 diffusion, while slag limits carbonation to the surface of specimens. A higher fly ash content induces higher carbonation at Ms= 0 (as high as 0.36 mmol/g), while the most significant adsorption at a high slag content is obtained at Ms= 1.32 (as high as 0.33 mmol/g). Carbon capture and storage values as high as the pressure decay chamber recorded 0.36 mmol/g, while TGA shows the adsorption capacity of the binder as high as 3.69 mmol/g. Mechanical strength variation is proved to be a function of Ca/Si and is evaluated accordingly.

Synergistic calcium leaching and iron enrichment by indirect carbonation of thermally modified steel slag

Indirect carbonation of steel slag is an effective CO2 sequestration strategy, which is of great significance for reducing CO2 emissions of the iron and steel industry and achieving its green and low-carbon development. This paper proposed a process for high-temperature modification followed by indirect carbonation of steel slag, which enabled the separation and synergistic utilization of calcium and iron elements of the slag. The reactivity of various minerals in steel slag was initially studied at the level of ion coordination utilizing crystal structure theory. The results indicated that the O2- valence of β-Ca2SiO4 was unsaturated, resulting in high reactivity. In contrast, the O2- valence of Ca2Fe2O5 was relatively saturated, resulting in poor reactivity. The results of high-temperature modification and leaching experiments demonstrated that as the basicity of the steel slag decreased, the calcium component transformed into Ca2SiO4, while the iron component transformed into spinel minerals. When the basicity was too low, the Ca and Fe components recombined to form the poorly reactive Ca3Fe2(SiO4)3. As the basicity of the steel slag decreased, the Ca2+ leaching rate and the total iron content of leaching residue initially increased and then decreased. At a basicity of 2, both the Ca2+ leaching rate and the total iron content of leaching residue reached their maximum of 84.46% and 48.39%, respectively. This study significantly improved the Ca2+ leaching rate and the total iron content of leaching residue through high-temperature modification, thereby enhancing the CO2 sequestration capacity of the steel slag and the recovery level of iron resources The above strategy would be of great significance for promoting the green and low-carbon development of the iron and steel industry.

Synthesis of Aragonite Whiskers by Co-Carbonation of Waste Magnesia Slag and Magnesium Sulfate: Enhancing Microstructure and Mechanical Properties of Portland Cement Paste

This study focused on the synthesis of aragonite whiskers through a synergistic wet carbonation technology utilizing waste magnesia slag (MS) and magnesium sulfate (MgSO4), aiming to improve the microstructure and mechanical properties of ordinary Portland cement (OPC) paste. The influence of MgSO4 concentration on the wet carbonation process, phase composition, and microstructure of MS was investigated. Furthermore, the effect of incorporating carbonated MS (C-MS) on the mechanical properties and microstructure of Portland cement paste was evaluated. Results showed that appropriate MgSO4 concentrations favored aragonite whisker formation. A concentration of 0.075 M MgSO4 yielded 86.6% aragonite with high aspect ratio nanofibers. Incorporating 5% of this C-MS into OPC increased the seven-day compressive strength by 37.5% compared to the control OPC paste. The improvement was attributed to accelerated hydration and reduced porosity by the filling effect and microfiber reinforcement of aragonite whiskers. MS demonstrated good CO2 sequestration capacity during carbonation. This study provides an effective method to synthesize aragonite whiskers from waste MS and use it to enhance cementitious materials while reducing CO2 emissions, which is valuable for the development of a sustainable cement industry.

The impacts of CO2 mineralization reaction on the physicochemical characteristics of fly ash: A study under different reaction conditions of the water-to-solid ratio and the pressure of CO2

Utilizing fly ash (FA) directly to mineralize CO2 and injecting carbon sequestration products into goafs of coal mines is a novel and promising technology. The impact mechanisms of CO2 direct mineralization reactions on the characteristics of key groups, physical phases, surface micromorphology, particle size and pore structure of FA are discussed systematically in detail. The focus is imposed on the impacts of different reaction conditions (water-to-solid ratios and pressures of CO2). Based on the FT-IR, XRD and ESEM-EDS analysis, CO2 is transformed into carbonates of five vibrational models after mineralization and largely sequestered as calcite by portlandite, which forms a passivated layer on the FA surface. The particle size of carbonated FA particles gets smaller and less uniform, and the variation laws of the particle size at full scale are analyzed by particle size intervals. The variation process of the pore can be divided into the dissolution of FA for pore expansion, the low degree of CO2 mineralization reaction for further expanding the pore and the high reaction degree for pore shrinkage. This paper provides theoretical bases for improving the direct CO2 sequestration capacity and research directions for the subsequent application properties of carbon sequestration products.

Amine-promoted gypsum carbonation for efficient CO2 capture and selective synthesis of CaCO3 polymorph integrating with amine regeneration by bipolar membrane electrodialysis

CO2 mineralization of waste gypsum not only reduces the carbon emissions of power plants but also improves gypsum utilization by recovering high-value-added CaCO3. However, the extensive consumption of various reagents limited its development. This paper proposed an amine-promoted waste gypsum carbonation process integrating with amine regeneration by bipolar membrane electrodialysis (BMED). The alkaline amine was expected to act as a multifunctional reagent for gypsum carbonation — alkaline reagent, CO2 absorbent, gypsum dissolution promoter, and CaCO3 crystal regulator. Seven typical amines with different amino types and pKa values were selected to investigate the feasibility of this process. Results show that promising CO2 removal efficiency (>95 %) from an artificial exhausting gas, gypsum carbonation efficiency (>93 %), and CO2 sequestration capacity (>340 g-CO2/kg-gypsum) can be achieved due to the additional alkalinity, fast CO2 absorption, high CO2 concentrations, and enhanced CaSO4 dissolution in amine solutions. In addition, the interactions of amine-CO2-gypsum and the CaCO3 growth mechanism in the gas–liquid-solid system were explored. Monoethanolamine (MEA), 3-amino-1-propanol (MPA), piperazine (PZ), and 1,3-Diaminopropane (DAP) could prolong the CaCO3 precipitation due to their strong affinity for Ca2+ and CO32−. In this case, CO2 absorption by the liquid phase dominated the carbonation process in the initial 30 min for these four amines, while CaCO3 precipitation mainly occurred within 30 ∼ 120 min. Amines’ different affinities for Ca2+ and CO32− provided an approach to selective synthesis of CaCO3 polymorph: 100 % calcite by PZ, 100 % vaterite by DAP, a calcite-vaterite mixture by MEA, and a calcite-vaterite-aragonite mixture by MPA. After the carbonation process, amines were recycled from the liquid residue by BMED, which could provide OH− for amines regeneration from protonated amines, recovery of H2SO4, and decrease the solution salinity.

Influence of nesquehonite seeds on hydration and carbonation of reactive magnesia cement

Among all carbonation products of reactive magnesia cement (RMC), nesquehonite exhibited the highest CO2 amount of sequestration per molar. Inducing the nesquehonite formation may improve the CO2 sequestration capacity of RMC. In this paper, nesquehonite seeds were introduced to promote the formation of nesquehonite in RMC. The performances of RMCs with 0%, 0.5%, 1%, 1.5% and 2% nesquehonite seeds were studied and compared with that of RMC mixed with hydromagnesite seeds. It was found that the hydration of RMC could be facilitated by nesquehonite seeds, resulting in reduced setting times. The nucleation effect of nesquehonite seeds was demonstrated, resulting in increased nesquehonite formation and carbonation degree. Nesquehonite seeds combined with hydration agent can further promote the compressive strength of RMC through forming more amounts of nesqeuhonite crystals and amorphous hydrated magnesium carbonates. Compared with the hydromagnesite seeds, the nesquehonite seeds showed a more significant increase in the CO2 sequestration capacity of RMC.

Effect of Inhibitors on Hydrogen Bond Reduction and Kaolinite Dissolution for Enhanced CO2 Adsorption in Coal.

The application of an inhibitor to the remaining coal in the goaf not only prevents spontaneous combustion of the coal seam in the mining area but also greatly enhances the capacity of coal to adsorb CO2. To investigate the mechanism by which inhibitors improve the CO2 adsorption capacity of the coal seam in the goaf, we conducted swelling experiments, infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analyses to examine the microstructural changes in the adsorption of CO2 before and after inhibition. The results indicate that after inhibition, the number of hydrogen bonds between coal macromolecules decreased, and the samples exhibited approximately 5% swelling. This swelling of the coal macromolecular structure and the increased distance between coal particles create additional space for CO2 sequestration, which is a critical factor contributing to the enhanced CO2 adsorption capacity of coal. The mineral composition of coal consists of 75.6% kaolinite, and inhibition leads to a reduction in kaolinite content by 0.8-7.9%. After inhibition, the swelling and disintegration of kaolinite cause uneven stress, resulting in changes to the pore structure. Closed pores filled with kaolinite transform into open pores, and the original pores crack, forming new pores and pore channels. The dissolution of kaolinite particles increases the porosity of the coal, further facilitating gas adsorption. Among the three inhibitors tested, the most effective in enhancing CO2 sequestration by bituminous coal in the mining area was the urea solution. This study holds significant importance in improving the CO2 sequestration capacity of residual coal in goaves.

Carbonation curing of modified magnesium-coal based solid waste backfill material for CO2 sequestration

CO2 sequestration is an effective method for dealing with the global climate crisis, and carbonation curing is considered an effective method of sequestering CO2 and improving the mechanical properties of cement-based materials (CBM). Regarding modified magnesium-coal based solid waste backfill material (MB), to explore its carbonation curing performance and CO2 sequestration capacity, its uniaxial compression strength (UCS), carbonation depth, microstructure, CO2 transport performance, CO2 uptake capacity, and carbonation efficiency are analyzed and characterized using UCS tests, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) analysis. The results show that the early UCS of the MB is significantly improved by carbonation curing. The UCS at 7 days is 10.91 times higher than that of the MB without carbonation curing, and the UCS increases as the concentration and modified magnesium slag-based cementitious material (MC) content increase. Carbonation curing makes the microstructure of the MB significantly denser and reduces the porosity, pore diameter, and permeability. The formation of carbonated products such as calcium carbonate and hydration products makes the microstructure more compact, which is the main reason for the rapid increase in the early UCS of the MB. The maximum CO2 uptake capacity of the MB through carbonation curing is 14.3%, and the carbonation efficiency is up to 92.2%. Therefore, carbonation curing of MB has broad application potential in improving the UCS and sequestering CO2.

A comparative study of acid-activated non-expandable kaolinite and expandable montmorillonite for their CO2 sequestration capacity

A comparative study of acid-activated non-expandable kaolinite and expandable montmorillonite for their CO2 sequestration capacity