Tuning Crystal Polymorphisms and Structural Investigation of Precipitated Calcium Carbonates for CO2 Mineralization

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• 作者：Ribooga Chang ; Dasol Choi ; Min Hee KimYoungjune Park
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2017
• 出版时间：February 6, 2017
• 年：2017
• 卷：5
• 期：2
• 页码：1659-1667
• 全文大小：736K
• ISSN：2168-0485

文摘

Mineral carbonation, which involves spontaneous reactions of CO₂ with alkaline earth metals such as calcium or magnesium, is considered one of the most attractive options to sequester CO₂ because CO₂ can be permanently stored in an inert solid forming stable inorganic carbonate. Moreover, the precipitated CaCO₃ has various potential applications in industrial areas, including adhesives, sealants, food, pharmaceuticals, paints, coating, paper, cement, construction materials, etc. In particular, it is expected that the total cost of the carbon capture and storage process could be partly offset by producing value-added CaCO₃ materials. In order to add value to the precipitated CaCO₃ produced in the ex-situ mineral carbonation process, CaCO₃’s polymorphs, as well as other properties such as particle size, shape, density, color, and brightness, must be finely tuned. Among CaCO₃’s polymorphs, calcite, aragonite, and vaterite, calcite is considered to be the most thermodynamically favorable structure at ambient temperatures. However, kinematic constraints in the crystallization induced by synthetic factors are known to significantly affect the formation of polymorphs as well. Here, we revisited the effects of the synthetic factors such as pH, temperature, feeding order, and concentration and molar ratio of Ca²⁺ and CO₃^2– on the formation of CaCO₃’s polymorphs to provide fundamental insight into how to control the polymorphism of CaCO₃ with the ultimate goal of creating value-added mineral carbonation products. ATR FT-IR spectroscopy and a powder X-ray diffraction analysis were performed on the precipitated CaCO₃ using model chemicals, K₂CO₃ and CaCl₂, and CaCO₃’s thermal stability was also investigated.