笼状纳米CaO基吸附剂碳酸化反应动力学研究

The Study of CaO Carbonation Reaction Kinetics of Cage-like Nano-CaO based CO_2 Sorbents

为了研究笼状纳米CaO基吸附剂快速段碳酸化反应特性,采用热重分析仪(TGA)考察了该吸附剂在反应温度813~933 K、CO_2分压0.01~0.02 MPa条件下的碳酸化反应。根据笼状纳米CaO基吸附剂碳酸化反应速率曲线的特点,提出了适合笼状吸附剂的划分快速段和慢速段的新判据,并用Boltzmann方程拟合了笼状纳米CaO在快速反应段的动力学方程,其计算结果与实验数据吻合较好,平均相对偏差小于5.78%。自制的笼状纳米CaO吸附剂下碳酸化反应活化能为26.66 kJ/mol,较商用纳米CaO低3.54 kJ/mol,体现了笼状纳米钙基吸附剂碳酸化反应速率优于商用纳米氧化钙的反应速率。

In order to study the carbonation reaction characteristics of the cage-like nano-CaO-based sorbent during the fast reaction segment,the carbonation reaction was experimentally investigated using thermogravimetric analysis(TGA)under the reaction temperature ranging from 813 K to 933 K and CO2 partial pressure ranging from 0.01 MPa to 0.02 MPa.According to the characteristics of the carbonation reaction rate of cage-like nano-CaO based sorbents,a new criterion was proposed to distinguish the fast and the slow reaction segment of the cage-like nano-CaO based sorbents,and the cage-shaped nano-CaO in the fast reaction segment was fitted by the Boltzmann equation.The calculated results were in a good agreement with the experimental data,and the average relative deviation was less than 5.78%.The obtained activation energy of carbonation reaction of cage-like nano-CaO based sorbents was 26.66 kJ/mol,which was 3.54 kJ/mol less than that of commercial nano-CaO sorbents indicting that the carbonation reaction rate of the cage-like nano-CaO based sorbents was better than that of commercial nano-CaO sorbents.