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This study illuminates the mineral carbonation potential of zeolite minerals. Zeolite minerals are common alteration products of basaltic rocks and are known for their ability to rapidly exchange their interstitial cations with those in aqueous solutions. A series of closed system batch reactor experiments was conducted at 60 °C by combining stilbite, a Ca-bearing zeolite, with 0.1 mol/kg w aqueous sodium carbonate solutions. The individual batch reactor experiments ran from 2 to 225 days. Scanning electron microscope images of the solids recovered from the experiments reveal the presence of extensive calcite crystals, suggesting rapid and efficient carbonation. The total mass of CO 2 mineralized during the experiments, determined from the direct analysis of the solids by thermogravimetric analysis and organic carbon analysis, equaled more than 5% of that of the original stilbite within a month. This is approximately equal to maximum CO 2 mineralization possible if all of the Ca in the original stilbite was incorporated into calcite. Chemical analysis of reacted stilbite shows that approximately 2 Na atoms were incorporated into stilbite for each Ca atom incorporated into the precipitated calcite. These observations indicate that the carbon removal by stilbite proceeded by the rapid exchange of Na for Ca in its structure. This process results in carbonation rates that are far faster than those achieved by a silicate dissolution-carbonate precipitation mechanism. These results, consequently, compel consideration of targeting subsurface mineral carbonation efforts into zeolite-rich rocks.

This study examines the potential of Saudi red mud for CO₂ sequestration through mineral carbonation and its concurrent hydrogen generation. Two batch experiments were conducted under neutral (deionized water) and acidic (1 wt% HCl) conditions at elevated temperature and pressure. Under neutral conditions, the interaction between CO₂ and red mud led to measurable mineralization, with approximately 8.3% of the injected CO₂ converted into Minerals. In contrast, the acidic system induced extensive mineral dissolution and precipitation, releasing higher concentrations of reactive elements into solution. Increasing the amount of red mud in the reaction to twice that used in the DIW case resulted in approximately twice the amount of CO₂ being mineralized. This indicates a strong relationship between red mud mass and its CO₂ sequestration capacity, highlighting that providing more reactive solid material directly enhances the system’s ability to lock CO₂ into stable carbonate minerals. Gas analysis verified hydrogen generation, along with notable hydrogen sulfide formation, particularly under acidic conditions. Overall, the findings reveal that while red mud can facilitate partial CO₂ mineralization and hydrogen evolution, its reactivity strongly depends on pH, with acid-assisted reactions enhancing mineral mobility rather than stable carbonate formation.

Carbon dioxide is a byproduct of our industrial society. It is released into the atmosphere, which has an adverse effect on the environment. Carbon dioxide management is necessary to limit the global average temperature increase to 1.5 degrees Celsius and mitigate the effects of climate change, as outlined in the Paris Agreement. To accomplish this objective realistically, the emissions gap must be closed by 2030. Additionally, 10–20 Gt of CO2 per year must be removed from the atmosphere within the next century, necessitating large-scale carbon management strategies. The present procedures and technologies for CO2 carbonation, including direct and indirect carbonation and certain industrial instances, have been explored in length. This paper highlights novel technologies to capture CO2, convert it to other valuable products, and permanently remove it from the atmosphere. Additionally, the constraints and difficulties associated with carbon mineralization have been discussed. These techniques may permanently remove the CO2 emitted due to industrial society, which has an unfavorable influence on the environment, from the atmosphere. These technologies create solutions for both climate change and economic development.

Exploring the possibility of the application of roof cutting pressure relief and filling support collaborative roadway protection technology has important forward-looking significance for deep coal mine mining. This study addresses the large deformation problems of the mining roadway in the 03 working face of a coal mine by proposing the theory of roof cutting and filling collaborative roadway protection. CO₂ mineralized filling materials were developed, and the optimal roof cutting scheme was determined through theoretical analysis and numerical simulation. Field roof cutting tests were conducted to validate and optimize the parameters, and the stress and deformation characteristics of roadway surrounding rock in fractured and unfractured areas were monitored. The results show that the optimum drilling parameters are coal pillar side tilt Angle of 15°, height of 35 m, gob side tilt Angle of 13°, height of 25 m, and the theoretical pressure relief effect is the best. When the ratio of coal gangue and fly ash is 9:1, the compressive strength of CO 2 mineralized material reaches 10.78 MPa and the residual strength is 5.40 MPa. In practical application, the collaborative protection technology significantly reduces the stress of surrounding rock in the fracturing zone by 36.08% and the displacement by 53.06%, and the stress concentration in roadway is effectively alleviated. The stability of surrounding rock is obviously improved. The research results of this paper verify the practicability and reliability of the cooperative roadway protection technology of roof cutting and pressure relief and CO 2 mineralization filling.

Long-distance migration-assisted structural trapping represents an optimal configuration for offshore geological CO₂ storage. In this study, the trapping efficiency of CO₂ was quantitatively analyzed using CMG software, taking into account aqueous solubility and geochemical reactions. The investigation focused on CO₂ migration behavior, mineralogical changes, pH and porosity variations induced by geochemical processes, and their respective contributions to overall carbon storage. Simulation results show that CO₂ tends to accumulate near the injection wells and subsequently migrates upward along the slightly dipping strata due to density differences between CO₂ and formation brine. After the injection wells are shut in, the CO₂ plume continues to migrate up-dip toward the crest of the anticline structure. A substantial portion of CO₂ remains trapped in the dipping strata due to capillary pressure hysteresis. As CO₂ dissolves into the saline aquifer, it generates H⁺ ions, which promote the dissolution of anorthite, releasing Ca²⁺ and Al³⁺ necessary for the precipitation of calcite and kaolinite over time. Results indicate that kaolinite and calcite predominantly precipitate within the aqueous phase, while anorthite is continuously dissolved throughout the simulation. The interplay of mineral dissolution and precipitation dynamically alters both pH and porosity. Anorthite is not the sole source of Ca²⁺; minerals such as dolomite and limestone can also readily contribute to Ca²⁺ availability, depending on the rock’s mineral composition. A localized pH decrease is observed along the CO₂ migration pathway. Porosity slightly decreases in the near-well zone but increases in the structurally elevated areas. The proportion of structurally trapped CO₂ increases during the injection phase but decreases during the subsequent long-distance migration phase. Residual gas trapping exhibits an initial rise followed by a decline, driven by capillary pressure hysteresis. Overall, the mechanism of long-distance migration-assisted structural trapping significantly enhances the long-term security and effectiveness of CO₂ geological storage.

Blast furnace slag (BFS) was selected as the source of Ca for CO2 mineralization purposes to store CO2 as CaCO3. BFS was dissolved using aqua regia (AR) for leaching metal ions for CO2 mineralization and rejecting metal ions that were not useful to obtain pure CaCO3 (as confirmed by XRD analysis). The AR concentration, as well as the weight of BFS in an AR solution, was varied. Increasing the AR concentration resulted in increased metal ion leaching efficiencies. An optimum concentration of 20% AR was required for completely leaching Ca and Mg for a chemical reaction with CO2 and for suppressing the leaching of impurities for the production of high-purity carbonate minerals. Increasing the liquid-to-solid ratio (L/S) resulted in the increased leaching of all metal ions. An optimum L/S of 0.3/0.03 (=10) was required for completely leaching alkaline-earth metal ions for CO2 mineralization and for retaining other metal ions in the filtered residue. Moreover, the filtrate obtained using 20% AR and an L/S of 0.3/0.03 was utilized as Ca sources for forming carbonate minerals by CO2 mineralization, affording CaCO3. The results obtained herein demonstrated the feasibility of the use of AR, as well as increasing pH, for the storage of CO2 as high-purity CaCO3.

Mineralizing CO 2 in alkaline construction materials can reduce process emissions. This study measures the effect of carbonic anhydrase on CO 2 uptake and retention in hydrated lime, Portland cement, fly ash, and slag under ambient conditions using a mass-flow-controlled CO 2 supply and gravimetric tracking. CO 2 was supplied for 1440 min for hydrated lime and cement and for 360 min for fly ash and slag, then stopped to quantify permanently retained mass. Carbonic anhydrase increased total CO 2 uptake across all materials by 71 to 89 percent. Hydrated lime reached 474.1 mg g −1 with the enzyme. Cement reached 285.9 mg g −1 . Fly ash and slag reached 308.3 mg g −1 and 312.4 mg g −1 . The fraction retained after cutoff increased for all solids and was nearly complete in several enzyme cases, while water controls showed negligible permanence. Enzyme reuse over four cycles retained 87.9 percent of the initial performance. The data support a surface-coupled mechanism in which the enzyme accelerates CO 2 hydration in the particle boundary layer, increases local carbonate availability, and drives precipitation with Ca 2+ and Mg 2+ on solid surfaces. The reaction endpoint remains unchanged; only the rate is altered. These results define material-enzyme combinations and operating conditions for enzyme-assisted mineralization in construction-relevant systems.

Concrete product manufacturing faces two coupled challenges: substantial solid waste generation and CO 2 emissions. While CO 2 mineralization can address both, conventional routes rely on high reagent use and generate wastewater, limiting sustainability. Recyclable chelating agent-assisted CO 2 mineralization offers a more sustainable alternative, yet its cycle-resolved practicality and net environmental benefits remain unclear. This study assessed the characteristics of such CO 2 mineralization processes through experiments using green chelating agent GLDA as the extractant and sludge cake collected from a concrete pole facility as the feedstock. Over ten successive reuse cycles, the efficiency of Ca extraction by the GLDA solution remained stable, yielding a 25% reduction in residue mass. The extracted Ca was selectively carbonated as CaCO 3 after heating the solution to 95 °C, mineralizing 156 g CO 2 per kg of sludge cake. A prospective, gate-to-gate life-cycle assessment (LCA) based on experimental results demonstrates a 16.1% reduction in global warming potential at concrete manufacturing plants. It also reveals a 1.2–10.0% decrease across other key environmental categories, including abiotic depletion potential (fossil fuels) and acidification potential, primarily driven by residue reduction. These findings position recyclable chelating agent-assisted CO 2 mineralization as a scalable option that couples waste minimization with permanent CO 2 storage for the concrete products industry.

Techniques for monitoring calcium carbonate and silica deposits (scale) in geothermal power plants and hot spring facilities using fiber optic sensors have already been reported. These sensors continuously measure changes in light transmittance with a detector and, when applied to field tests, require the installation of a power supply and sensor monitoring equipment. However, on some sites, a power supply may not be available, or a specialist skilled in handling scale sensors is required. To overcome this problem, we have developed a method for evaluating scale formation that is based on a batch process that can be used by anyone. In brief, this method involves depositing scale on a section of the optical fiber sensor and then fusing this section to the optical fiber and measuring it. Using this sensor, a technician in the field can simply place the sensor in the desired location, collect the samples at any given time, and send them to the laboratory to measure their transmittance. This simple and easy method was achieved by using a hetero-core type of fiber optic. This evaluation method can measure with the same sensitivity as conventional real-time methods, while its transmittance response for the sensor corresponds to the saturation index (SI) changes in the scale components in the solution due to increases in temperature and concentration. In the field of carbon dioxide capture and storage (CCS), this evaluation method can be used to quantitatively measure the formation of carbonate minerals, and it can also be used as an indicator for determining the conditions for CO2 mineral fixation, as well as in experiments using batch-type autoclaves in laboratory testing. It is also expected to be used in geothermal power plants as a method for evaluating scale formation, such as that of amorphous silica, and to protect against agents that hinder stable operation.

CO 2 capture, utilization and sequestration technology is currently a global research hotspot with increasing CO 2 emission and rising atmospheric temperatures. Flue gas desulfurization gypsum (FGDG) was used to realize CO 2 mineralization in waste NaOH lye in a pilot scale bubble tower. The effects of the ionic strength, CO 2 flow rate, reaction temperature, and liquid level in the reactor on the properties of the mineralization products and the CO 2 mineralization efficiency were investigated using thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis. The experimental results indicated that ionic strength, reaction temperature and CO 2 flow rate significantly influenced the CO 2 mineralization efficiency of FGDG. The CO 2 mineralization efficiency reached 92.15% under the optimized conditions (the ionic strength: 10 −2 mol·L −1 , CO 2 flow rate: 20 L·h −1 , reaction temperature: 60 °C, liquid level: 50 cm). The liquid level has a strong effect on the particle size distribution of mineralized products. A higher liquid level promotes the formation of mineralized products with smaller particle sizes. These products consist of a single cluster of crystals and the main component is calcium carbonate. The pilot scale results demonstrate optimized evidence for CO 2 mineralization using FGDG in waste lye. Therefore, this approach enables the comprehensive utilization of three types of waste-gas, liquid, solid- generated produced in coal-fired power plants.