纳米CaCO3孔径调控及其对碳酸化反应性能的影响

摘要

研究了纳米CaCO3颗粒间孔径调控对CaO与CO2碳酸化反应性能的影响.通过有机模板法制备得到一系列比表面积相近、孔径分布不同的纳米CaCO3,并考察其再生和碳酸化反应性能差异.结果表明:增大平均孔径能促进纳米CaCO3的热分解反应,并降低分解温度约15℃.将平均孔径由15 nm增大至113 nm可显著提高碳酸化反应速率和转化率.研究认为平均孔径和比表面积对碳酸化反应转化率的影响存在交互作用;比表面积小的纳米CaCO3,表现出碳酸化反应转化率受扩散控制影响较大,而比表面积较大的表现为碳酸化反应转化率以表面反应影响控制为主的规律.%The pore size modulation of nano CaCO3particles and its effect on the CaO carbonation with CO2have been studied. A series of nano CaCO3with similar surface area but different pore size distributions were prepared by organic templates, and their differences in regeneration and carbonation properties were tested. The results showed that enlarging the average pore diameter could accelerate the thermal decomposition of CaCO3, and drop the regenerate temperature by 15℃. Analogously, increasing the pore diameter from 15 nm to 113 nm could promote the CaO carbonation rate and conversion. Additionally, researches revealed that the average pore diameter and surface area had a complex affection on CaO carbonation rate and conversion. The carbonation conversion of nano CaCO3with lower surface area is mostly affected by diffusion, while the conversion of nano CaCO3with greater surface area is mainly influenced by surface reaction.