Preparation of high surface area CaCO3 by reacting CO2 with aqueous suspensions of Ca(OH)2: Effect of the addition of sodium polyacrylate

High surface area CaCO3 was produced through the reaction between CO2 and an aqueous suspension of Ca(OH)2 with the addition of an additive, sodium polyacrylate. The surface area of CaCO3 prepared was affected markedly by the amount of additive and the solution pH when adding the additive. The CaCO3 with the highest surface area (87.7 ± 1.3 m2/g) was obtained under the conditions that the initial Ca(OH)2 concentration was 2.4 wt.%, the amount of sodium polyacrylate added was 0.2 wt.%, and the solution pH at which the additive was added was in the range of 11.4–11.1. The high surface area CaCO3 also had a high pore volume. The CaCO3 was highly reactive toward SO2, and a conversion of 0.95 was achieved when it was sulfated at 950 °C and 4000 ppm SO2 in air for 1 min. Prior calcination reduced the reactivity of this high surface area CaCO3.

Graphical abstractHigh surface area and porous CaCO3 were produced by reacting CO2 with aqueous suspensions of Ca(OH)2 with the addition of sodium polyacrylate (PAAS). A maximum surface area of 87.7 ± 1.3 m2/g was obtained when 0.2 wt.% PAAS was added into a 2.4 wt.% Ca(OH)2 suspension at pH 11.4–11.1.Figure optionsDownload full-size imageDownload as PowerPoint slide