New synthesis method for CaO-based synthetic sorbents with enhanced properties for high-temperature CO2 -capture

Abstract

In this paper, a new synthesis method to obtain mixed CaO/Ca12Al14O33 solids for high temperature CO2 capture is presented. The modification of a pure phase Ca3Al2O6 solid through a thermal treatment under controlled conditions leads to a high CO2 absorption capacity material, with very promising long term stability during absorption/desorption cycles. The influence of the calcination temperature during the synthesis of the Ca3Al2O6 powders, and the temperature and atmosphere applied during the thermal treatment was studied. Therefore, optimum conditions for high stabilization rate and high final CO2 absorption capacity of the sorbent could be determined. Comparison with a natural sorbent (dolomite) over 150 carbonation/calcination cycles is also included, showing a substantial improvement of the synthetic solid CO2-uptake at long term use, compared to that of natural sorbents.