Chemical Engineering Journal, Vol.236, 91-99, 2014
A study on high temperature CO2 capture by improved hydrotalcite sorbents
The effect of synthetic routes in improving the CO2 capacity of hydrotalcite based sorbents in the temperature range 300-400 degrees C has been studied. Ultrasonication and microwave irradiation of the synthesis gel during hydrotalcite precipitation leads to disruption in the layer stacking which in turn increases surface area. A correlation was observed between the increased surface area and improved equilibrium and dynamic CO2 capacity. A temperature dependent promotional effect of K2CO3 on CO2 capacity improvement was also observed. The CO2 loaded hydrotalcites were found to be regenerable by inert purge with or without evacuation at a slightly elevated temperature of similar to 450 degrees C. The dynamic CO2 capacity was found to remain stable under cyclic adsorption regeneration conditions. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Hydrotalcite;Synthesis;High temperature CO2 capture;Equilibrium uptake;Dynamic capacity;Regenerability