Influence of the operation conditions on CO2 capture by CaO-derived sorbents prepared from synthetic CaCO3

•23 CaO samples for CO2 capture were prepared from synthetic CaCO3 precursors.•CaCO3 precursors are virtually nonporous and consist of aragonite and calcite.•Some CaO samples show incipient mesoporosity, remarkable carbonation and selective sulfation.•Stirring rate and surfactant % exert significant influence on the CO2 capture capacity.

In this work, a statistical experimental design is performed in order to prepare CaCO3 materials for use as CaO-based CO2 sorbent precursors. The influence of different operational parameters such as synthesis temperature (ST), stirring rate (SR) and surfactant percent (SP) on CO2 capture is studied by applying Response Surface Methodology (RSM). The samples were characterized using different analytical techniques including X-ray diffraction, N2 adsorption isotherm analysis and Scanning Electron Microscopy-X-ray Energy Dispersive Spectroscopy (SEM-EDX). CO2 capture capacity was determined by means of a thermogravimetric analyzer which recorded the mass uptake of the samples when these were exposed to a gas stream containing diluted (15%) CO2. The statistical approach used in this work provides a rapid way of predicting and optimizing the main preparation variables of CaO-derived sorbents for CO2 sorption. The results obtained clearly indicate that four parameters statistically influence CO2 uptake: SR, the square of SR, its interaction with SP and the square of SP.