高浓度CO_2下CaCO_3循环煅烧试验与模拟

CaCO_3 Circulating Calcination Tests and its Simulation at a High Concentration of CO_2

建立了高浓度CO2气氛下CaCO3循环煅烧过程数学模型,利用钙基吸收剂多次循环煅烧试验对模型进行了验证,在此基础上分析了CO2浓度、吸收剂种类、粒径和循环次数等参数对CaCO3煅烧的影响。结果表明:CaCO3分解温度随气相中CO2含量的增加而增大;在高浓度CO2下,随循环反应次数的增加,吸收剂循环反应活性下降,使得所生成的CaCO3质量也随循环次数的增加而减少,致使CaCO3煅烧完全所需时间会随循环反应次数的增加而减少。

A mathematic model has been established for CaCO3 circulating calcination process at an atmosphere of high CO2 concentration and verified in multiple circulating calcination experiments by utilizing calcium-based absorbents.On this basis,the influence of a variety of parameters,such as CO2 concentration,absorbent category,particle diameter and circulating frequency etc.on CaCO3 calcination has been analyzed.The results show that the decomposition temperature of CaCO3 will increase with an increase of CO2 content in the gas phase.Under a high concentration of CO2,the circulating reaction activity of the absorbents will degrade and the quality of CaCO3 produced will become lower with an increase in the number of times of the circulating reaction,leading to a shortening of the time duration needed for a complete calcination of CaCO3 when the number of times of the circulating reaction has increased.