Thermodynamic Consideration on the Absorption Properties of Carbon Dioxide to Basic Oxide

Abstract

Carbon capture and storage (CCS) is a key technology for greatly reducing CO₂ emissions in the long term, and therefore a low-energy CCS process needs to be developed. This study focused on the solid absorption process using basic oxide, and thermodynamically examined the carbonation abilities of various basic oxides and compounds containing CaO, BaO or Li₂O. The CO₂ absorption and desorption behavior of these materials containing alkali earth metal oxides was investigated by measuring the weight change over a wide range of temperatures from room temperature to 1100°C in CO₂ atmosphere. It was experimentally confirmed that the partial pressure of CO₂ equilibrated with both Ba₂TiO₄ and BaCO₃ was higher than that equilibrated with both BaO and BaCO₃. The formation of compound increased the equilibrium partial pressure of CO₂ and lowered the starting temperature of CO₂ desorption.