Kinetic study of the CO2 desorption process by carbonated Na2ZrO3 solid absorbent

A kinetic study of the CO2 desorption process by carbonated sodium zirconate (Na2ZrO3) synthesized by a liquid suspension route is presented using zirconium acetylacetonate and sodium acetate as precursors. Na2ZrO3 was characterized by XRD, SEM and TGA. Na2ZrO3 exhibited a 90% conversion during absorption with respect to the theoretical value. CO2 desorption kinetic study used three temperatures; 850, 900 degrees C and 950 degrees C and three concentrations: 5, 3 and 1% of CO2 in AT at 200 ml/min. XRD data shown only slight segregation of the precursors, which led to a small amount of ZrO2 formation in the solid product. The global rate of the decarbonation reaction of Na2ZrO3 was of first order in CO2 concentration and strongly dependent on temperature. The calculated apparent activation energy was E-A = 23.35 kcal/mol. Na2ZrO3 performance during four continuous cycles, shown an excellent thermal and chemical stability, with the material conversion remaining practically unchanged. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.