Influence of selected CO2 absorption promoters on the characteristics of calcium carbonate particles produced by carbonation of the post-distillation liquid from the Solvay process

The aim of this work is to compare the effect of selected process parameters, gas flow rate, CO2 absorption promoter concentration and its pKa, on the precipitation of CaCO3 by the gas-liquid method using a model post-distillation liquid from the Solvay process. To ensure effective capture of CO2, the absorption promoters used were ammonia, triethanolamine and triethylamine. The Box-Behnken Design was applied to plan the experiments. The analysis of the influence of selected parameters on the course of the process and the characteristics of the obtained products was performed using the response surface methodology. In the studied range of variables, the type of absorption promoter characterized by its pKa has the most significant impact on the reaction time, polymorphic composition of the obtained CaCO3, particle size and their specific surface area. All precipitated CaCO3 samples were highly agglomerated mixture of vaterite and calcite. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

This work aimed to compare the impact of selected process parameters on the precipitation of CaCO3 by the gas-liquid method, using a model post-distillation liquid from the Solvay process. The type of absorption promoter characterized by its pKa was found to have the most significant influence on reaction time, polymorphic composition, particle size, and specific surface area of the obtained CaCO3. All precipitated CaCO3 samples were highly agglomerated mixture of vaterite and calcite.