The Research Of CaO/CaZrO₃ Hollow Spheres For CO₂ Capture

The greenhouse effect to the impact of the global climate is more and more obvious. Carbon dioxide which is the main greenhouse gas has obtained people’s continuous attention. Currently, one of the methods to deal with excessive carbon dioxide in the atmosphere is carbon dioxide capture and storage technology. In treatment of high concentration CO2 at high temperature, calcium oxide based adsorbents are widely used due to its high adsorption capacity, the large earth storage and the low cost. However, the poor reversibility performance in long cycle limits its further application.This paper focuses on enhancing the reversibility of calcium-based sorbent by introducing zirconium oxide stabilizer and establishing a stable structure. Firstly, the colloid carbon template was synthesized by hydrothermal of glucose. The influence of reaction time, concentration and temperature to prepare the template was studied. Subsequently the colloidal carbon was used to synthesize a different ratio of calcium and zirconium (1,49,99,399, and 999) of hollow adsorbent and the structure of the sorbents was characterized using XRD, SEM, TEM, EDAX and TG Then the adsorption behavior of the two metal ions on colloid carbon and the influence to the spheronization were also studied. Finally in carbon dioxide adsorption/calcination experiment, the influence of calcium/zirconium proportion (1,49,99,399,999), the elevation of temperature speed (5℃ /min,10℃/min,20℃/min), the adsorption temperature (650℃,700℃,750℃) and the calcination temperature (850℃,900℃, 950℃) to the reversibility of the sorbents were discussed.The results indicated that using 1mol/L glucose solution, after 10h under 180℃, the good carbon template could be obtained. During the preparation of the absorbent, the adsorption ability of zirconium ions was found much stronger than calcium ions and the excessive zirconium ions does not favor the formation of hollow structure. In adsorption performance test, when the elevation of temperature speed is 5℃/min, the calcium zirconium proportion is 399, the adsorption temperature is 650℃ and the calcination temperatures is 850℃, the absorbent could maintain the good reversibility. After 100 cycles more than 12000min uninterrupted test, the absorbent still could keep the good CO2 capacity.