在固定床反应系统中对PT基准CaCO3以及安徽巢东纳米CaCO3进行多循环CCRs反应,通过计算微观参数和观察吸收剂颗粒表面形貌的变化,从微观角度解释烧结作用对吸收剂转化率的影响。结果表明,烧结使得吸收剂微观晶粒之间逐渐融合,宏观表现为颗粒之间的粘合,粒径显著增大,对循环反应中吸收剂捕获CO2的能力有较大影响。对比两种CaCO3样品颗粒表面烧结程度,纳米粉末由于团聚程度高,比表面积大,其烧结程度更为严重。
Multi-cyclic CO2 Capturing using PT CaCO3 and nano-CaCO3 powder was studied in a fixed bed. CaO and CaCO3 samples obtained in different stages of CO2 capturing were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM). The grain sizes of CaO and CaCO3 were calculated based on Scherrer formula, and the grain sizes change was used to explain the effect of sintering on the conversion and capturing capacity of CaO sorbents. The results of CaO and CaCO3 morphology showed severe sintering occurred in multi-cyclic CO2 capturing which was the main reason of CaO grains' fusion. Therefore, CaO particles started to stick together and the size of particle grew quickly. Nano-CaCO3 was easier to sintering than PT CaCO3 because of the high degree of agglomeration and huge specific surface area.