Control over crystallization of CaCO3 micro-particles by a novel CO2SM

Abstract

Different morphologies of CaCO₃ micro-particles through a hydrothermal reaction between Ca(OH)₂ saturated limpid solution and a new CO₂-storage material (CO₂SM), which was obtained from an equimolar system 1,2-ethylenediamine (EDA) + 1,2-ethylene glycol (EG) uptaking CO₂, were presented without any additives. It's worth noting that the morphologies of the CaCO₃ precipitates could be controlled as uniform sheaf-like (pure calcite) at the lower CO₂SM concentration (0.6 g L⁻¹) and homogeneous spherical-like (pure vaterite) at the higher CO₂SM concentration (40 g L⁻¹) for 1 h at 100 °C, in which the released EDA and/or EG from CO₂SM had unexpected functions as surfactants. After the precipitation of CaCO₃ crystals in 40 g L⁻¹ CO₂SM solution, the filtered solution could not only be reused to absorb CO₂, but also to prepare the same crystal phase CaCO₃ micro-particles repeatedly with the addition of Ca(OH)₂. As a result, this novel synthesis process of CaCO₃ micro-particles with CO₂SM offers an alternative way for the comprehensive utilization of CO₂.