Analysis of the CO 2 capture in sodium zirconate (Na 2ZrO 3). Effect of the water vapor addition

Abstract

Sodium metazirconate (Na 2ZrO 3) was synthesized, by solid-state reaction, and characterized. Water sorption experiments were performed using N 2 and CO 2 as carrier gases. In the absence of CO 2, Na 2ZrO 3 showed considerably high water vapor sorption owing to two different processes, hydroxylation and water vapor adsorption. When CO 2 was used as the water vapor carrier gas, the reactivity of Na 2ZrO 3 was found increased as a result of the reaction producing NaHCO 3 and ZrO 2. These results reveal that, at least in the measured temperature range, Na 2ZrO 3 is able to take-up 2 mol of CO 2 compared to 1 mol of CO 2 measured under dry conditions, as the final product is sodium bicarbonate (NaHCO 3). In other words, the theoretical CO 2 absorption capacity on Na 2ZrO 3 is 10.8 mmol/g, when water vapor is added. Finally, a kinetic analysis and the reaction mechanism are presented for Na 2ZrO 3 carbonation process in the water vapor presence.