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Carbon dioxide mineralization for the disposition of blast‐furnace slag is an important method for reducing CO2 emissions and simultaneously dealing with solid waste from the steel industry. However, due to the stable structures and properties of blast‐furnace slag, low mineralization reaction efficiency is a key issue in this process and hinders industrial applications. This work presents a method for enhancing the CO2 mineralization reaction by the addition of salt solutions (e.g., NaCl 1 mol · L−1) in the slurry of the blast‐furnace slag (<75 μm). The results showed that CO2 mineralization efficiency could be greatly improved with a high CO2 storage amount of ∼280 kgCO2 · tBFS−1 at a liquid‐solid ratio (L/S ratio) of 10, a temperature of 150°C and CO2 pressure of 3 MPa. The mineralization process was systematically characterized to identify the mechanism for mineralization enhancement by saline solution. The results indicated that saline solution could accelerate the dissolution of Ca2+ in blast‐furnace slag, reduce the activity of water, and lead to high acidity in the solution, and thus facilitate mineralization and improve the reaction rate. The NaCl solution was not consumed and could be recycled in the process, suggesting that this approach could use the brine and saline water as the medium for solid waste treatment and CO2 emission reduction in high energy‐consuming industries such as mineral processing, power plants, and the steel industry. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR] more...

• Biphasic DGA-PMDETA-EG system is of 2.26GJ/ton CO 2 energy consumption. • The entrainment stage and thickening stage of CO 2 rich phase are recognized. • Since the phase splitting beginning, most DGA reacts with CO 2 in the CO 2 -rich phase. Chemical absorption with organic amine solution is the most mature technology for CO 2 capture. Some biphasic anhydrous absorbents show potential in reducing regeneration energy consumption, but high viscosity of the CO 2 rich phase hinders its practical application. Alcohols are commonly employed as dilutes to reduce viscosity reducers, while its effect on CO 2 absorption and phase splitting behaviors are still unclear. In this study, the effects of alcohols on CO 2 absorption and phase-splitting of biphasic anhydrous 2-(2-Aminoethoxy)ethanol (DGA) -N,N,N′,N″,N″-pentamethyl diethylenetriamine (PMDETA) -alcohol systems are investigates. Adding alcohol reduces the viscosity of the CO 2 -rich phase, enhances desorption rate, and decreases the phase splitting time. The rich phase entrainment stage and the rich phase thickening stage, can be distinguished along with during CO 2 absorption. The majority DGA reacts with CO 2 in the rich phase since the phase splitting begins. This work may provide some basis for further biphasic absorbent design and regulation. [ABSTRACT FROM AUTHOR] more...

[Display omitted] • Catalytic performance of HDBUI and complementary mechanism of one-pot reaction promote the conversion of CO 2 and glycerol. • Glycerol, a reactant in transesterification, promotes the cycloaddition of CO 2 with propylene epoxide by hydrogen bonds. • A cycloaddition intermediate, with strong alkalinity, promotes the transesterification of glycerol with propylene carbonate. The chemical conversion of inert carbon dioxide (CO 2) into high value-added chemicals is a continuing challenge. In this work, an experimental and theoretical mechanism study is presented for one-pot synthesis of glycerol carbonate (GC) from CO 2 , glycerol (Gly), and propylene epoxide (PO) catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-enenium iodide (HDBUI) ionic liquid. 92% GC yield was obtained in the one-pot reaction through cycloaddition of CO 2 with PO to produce propylene carbonate (PC), followed by transesterification of Gly with PC to yield targeted products. Density functional theory (DFT) calculations were used to unveil the HDBUI-mediated catalytic mechanism and key catalytic species. It was revealed that the HDBUI-catalyzed cycloaddition was assisted by the hydrogen bond donor Gly, the transesterification reactant, by promoting the ring-opening of PO and the insertion of CO 2. By activating Gly hydroxyl group, alkaline HDBUI-bonded propan-1-ylium-2-yl carbonate, an intermediate in cycloaddition, catalyzed transesterification. The complementary mechanism of cycloaddition and transesterification in the one-pot provides a feasible method for utilizing inert CO 2. [ABSTRACT FROM AUTHOR] more...

This paper describes an environmentally friendly and efficient milling-assisted technology to produce soluble potassium from natural K-feldspar with the additive of calcium salts, and capture CO 2 via mineralization. The milling-assisted process could facilitate the extraction of potassium from K-feldspar under mild conditions (e.g. 30–40 °C), and mineralize CO 2 with reacted calcic slag. The milling-assisted and mineralization conditions (e.g. milling time and material ratio) were systematically investigated, reaching a maximum potassium extraction ratio of ∼80% and a CO 2 mineralization ratio of ∼5%. Characterizations indicated that the fragmentation, amorphization, and lattice distortion of the mineral particles during milling-assisted process are responsible for the enhanced K-feldspar decomposition reactions and ion-exchange reaction with calcium salt. Reaction principles of K-extraction and CO 2 mineralization are discussed, and a possible mechanism of milling-assisted process was proposed. [ABSTRACT FROM AUTHOR] more...

[Display omitted] • Phase-splitting behaviors prediction for amine-organic solvent–water system. • [RNH 3 ]+ log P and [RNHCOO]- log P models established with QSAR method. • The interactions between ions and organic solvent/water were discussed. • Work based on DFT, mathematical regression and experimental verification. Carbon capture, utilization, and storage (CCUS) has become a promising approach for relieving CO 2 effects on the environment. Moreover, CO 2 absorption by phase-splitting solvents with a low regeneration energy has the potential for industrial CO 2 capture. In this work, ionic log P of the product amine-CO 2 was modeled to predict new phase-splitting solvents at the molecule level. The density functional theory method was used for structure calculation and descriptor generation. The genetic function approximation method was used for mathematical regression. The symmetry-adapted perturbation theory and reduced density gradient method were introduced to detect interaction mechanisms between ions and solvents. Furthermore, low-ion solubility tended to appear in long-chain alcohols, branched or ring structures, and aprotic solvents. A linear the demarcation line of biphase and monophase over phase-splitting diagram was drawn based on anion log P and cation log P as 0.984 * log P anion + log P cation = − 3.46. [ABSTRACT FROM AUTHOR] more...

[Display omitted] • A facile method was proposed to mold monolithic adsorbents for CO 2 capture. • The monolithic adsorbents are versatile for multiple complex industrial scenarios due to their customizable appearance. • The adsorbents exhibit excellent CO 2 adsorption capacity, stability and regenerability. • The TEPA-MCM-550 adsorbents present superior compressive mechanical strength satisfying industrial application. Amine-functionalized solid adsorbents have significant application potential in post-combustion CO 2 capture due to the advantages of high capacity, low regeneration cost and long-term stability. Although the powdery adsorbents exhibit higher CO 2 uptake capacity, the poor strength and large pressure drop limit their practicability. Monolithic adsorbent is considered as a good choice to solve these problems, but still facing the bottle-neck of insufficient CO 2 capacity. In this work, a facile and feasible gel-casting method was proposed to fabricate monolithic adsorbents with high CO 2 capacity, excellent mechanical strength, and good cycling stability. MCM-41 with rich mesoporous structure was immobilized by polymerization of organic polymer to construct monolithic adsorbents supports with high specific surface area (~1088 m2 g−1) and mechanical strength. The 70T-MM-550 monolithic adsorbent impregnated with TEPA achieved high adsorption capacity of 151.1 mg g−1 at 75 ℃ under 1 atm pure CO 2. The monolithic adsorbents also showed good reversibility of CO 2 adsorption under mild conditions, where the adsorption capacity decreased only by 2.8% after five regeneration cycles. In addition, the radial and axial compressive strength of 70T-MM-550 is over 200 N cm−1 and 4.5 MPa, respectively. In consideration of the high CO 2 capture performance and mechanical properties of the monolithic adsorbents, the findings here open a new avenue for designing efficient monolithic CO 2 adsorbents with industrially potential. [ABSTRACT FROM AUTHOR] more...