研究报告
张卫风,李娟,王秋华.Ca(OH)2解吸并固定混合吸收液中CO2的实验研究[J].环境科学学报,2020,40(4):1436-1442
Ca(OH)2解吸并固定混合吸收液中CO2的实验研究
- Experimental study on desorption and mineralization of CO2 in amine-rich solution
- 基金项目:国家重点研发计划项目(No.2016YFC0209300)
- 张卫风
- 华东交通大学土木建筑学院, 南昌 330013
- 李娟
- 华东交通大学土木建筑学院, 南昌 330013
- 王秋华
- 华东交通大学土木建筑学院, 南昌 330013
- 摘要:CO2化学吸收法分离纯度高,技术成熟,但能耗过高及成本是困扰该技术发展的瓶颈.在常压条件下对利用Ca(OH)2直接矿物碳酸化固定MDEA/PZ混合吸收富液中CO2进行了一系列实验研究,考察了吸收液负荷、Ca(OH)2投加量、pH、温度及搅拌速率等因素对解吸率的影响,并利用动态吸收-解吸循环实验研究了其CO2吸收性能和循环使用稳定性,最后对碳酸化反应产物进行了XRD、TEM分析.结果表明,在常压条件下,Ca(OH)2可以通过液相直接矿物碳酸化对CO2进行直接固定,并实现吸收富液的再生;随着负荷的升高及Ca(OH)2投加量、pH、搅拌速率的增大,解吸率随之增加;随着溶液温度升高,解吸率下降;经过5次动态吸收-解吸循环实验后CO2吸收量可以达到并保持在0.57 mol·L-1,显示出了良好的循环稳定性.
- Abstract:Chemical absorption is a mature technology with a feature of high separation purity. But it has bottlenecks of high energy consumption and cost, which hinder the development of this technology. To address these issues, calcium hydroxide, a fine desorption agent with low cost and energy saving, was selected to desorb and sequestrate CO2 in the rich solution under atmospheric pressure. The effects of CO2 loading, Ca(OH)2 dosage, temperature, pH and stirring rate on the desorption rate were investigated. The dynamic absorption-desorption cycle experiment was used to study the CO2 absorption performance and recycling stability. The characterization of carbonated products was also investigated applying XRD and TEM. The results showed that Ca(OH)2 could be directly immobilized by direct mineral carbonation in liquid phase under normal pressure. With the increase of loading, Ca(OH)2 dosage, pH and stirring rate, the desorption rate increased, while with the increase of solution temperature, the desorption rate decreased. After five dynamic absorption-desorption cycles, the capacity of CO2 absorption reached and remained at 0.57 mol·L-1, which showed good cyclic stability.