文献类型：期刊文献

英文题名：Development of a fly ash derived Li4SiO4-based sorbent for CO2 capture at high temperatures

作者：Zhang, Qi[1];Liang, Xiaoli[1];Peng, Dong[1];Zhu, Xuedong[1]

机构：[1]East China Univ Sci & Technol, Dept Chem Engn, Shanghai 200237, Peoples R China

年份：2018

卷号：669

起止页码：80

外文期刊名：THERMOCHIMICA ACTA

收录：;EI(收录号：20183905869606);WOS:【SCI-EXPANDED(收录号:WOS:000450381300010)】；

基金：This work was financially supported by the Natural Science Foundation of Shanghai [Grant No. 16ZR14082001, and the Fundamental Research Founds for the Central University [Grant No. 222201817013].

语种：英文

外文关键词：Fly ash; CO2 capture; Lithium silicates; Ca transformation

摘要：Li4SiO4-based sorbents from fly ash (FA) subjected to different pretreatments were developed for CO2 capture at high temperatures. Compared with original FA and precalcined FA, the sorbent derived from precalcined and acid leached FA (denoted as HCl/CFA-Li4SiO4) had smaller particle size and larger specific surface area. HCl/CFA-Li4SiO4 also presented an excellent CO2 capture capacity of 27.5 wt% within 25 min at 600 degrees C (approximately 2.7 times that of previously reported FA-derived Li4SiO4-based sorbents). Moreover, the transformation phenomena of the major elements Al, Fe, and Ca during cycling operations were investigated by X-ray analysis. Results show that Al and Fe species existed as LiAlO2 and LiFeO2 , respectively, which cannot contribute to the CO2 sorption performance at 600 degrees C. This phenomenon for LiFeO2 was confirmed by thermodynamic analysis with FactSage 6.4 software. Interestingly, Ca species reversibly transformed from Ca2SiO4 and CaO to Li2CaSiO4 and CaCO3 in cyclic processes.