CaO高温吸附捕集CO_2—制备CaO的钙基前驱体材料筛选  

Study on calcium precursors for CaO preparation to capture CO_2 at high temperature

作　　者：张明明[1] 计超[1] 孙泽[1] 汪瑾[1] 李平[1] 于建国[1] 

机构地区：[1]化学工程联合国家重点实验室华东理工大学,上海200237

出　　处：《中国科学：化学》2012年第3期320-328,共9页SCIENTIA SINICA Chimica

基　　金：国家高技术研究发展计划(863计划)(2008AA062302);上海市浦江人才项目(08PJ14034);上海市国际合作项目(08160704000)的资助

摘　　要：价格低廉的CaO材料在高温下能高效吸附捕集CO2气体,被认为是碳减排的有效方法之一.然而,CaO长时间循环碳酸化/煅烧解吸后,其CO2的化学吸附容量下降,稳定性较差,限制了该材料的工业应用.本文采用天然钙源(牡蛎壳和方解石等)和化学试剂(醋酸钙)为钙基前驱材料制备CaO.采用扫描电子显微镜(SEM),X射线衍射仪(XRD)和氮气吸附仪等手段对制备的CaO材料进行形貌和物理结构的分析表征;在高温和模拟的烟道气氛条件下(10%CO2和90%N2),采用热重分析仪测量CaO吸附CO2的能力和长时间循环碳酸化/煅烧解吸后的稳定性.我们经过与目前所报道的其他钙基吸附材料进行比较,并结合钙基前驱材料的市场价格,发现CaO(醋酸钙)的CO2吸附能力和稳定性较为理想,醋酸钙在高温烟气捕碳方面具有非常好的应用前景.As an abundant and cheap material, calcium oxide （CaO） is an efficient sorbent for CO2 capture at high temperature. The carbonation/calcination loop of CaO/CaCO3 is an effective process for CO2 capture and storage （CCS）. However, both the gradual decline of the CO2 capture capacity and the poor stability, because of the pore filling and pore closure at the high calcination temperature, limit the industrial application of calcium-based sorbents. In this paper, study on calcium precursors was carried out in order to obtain CaO sorbents to capture CO2 with high efficiency. The candidate materials include seashell materials （oyster shells）, natural minerals （calcite） and chemical reagents （calcium acetate hydrate）. Oyster shell powder and calcite powder were analyzed by XRD, and CaO sorbents prepared from various precursors were characterized by nitrogen physisorption apparatus. The fresh CaO sorbents and CaO after multiple cycles to capture CO2 were characterized by scanning electron microscopy （SEM）. The capture CO2 capability and the stability of CaO sorbents were investigated using a thermogravimetric analyzer （TGA）, where multiple capture cycles were carried out alternatively in the simulation flue gas （10% CO2 in N2） and in decomposition purge gas （N2）. Moreover, comparing the CO2 capture capability and the CaO stability with published works, and taking account of the market prices of precursors, calcium acetate hydrate is thought to be an economically adsorption capacity and good stability at high temperature. appropriate calcium precursor, which has acceptable CO2

关 键 词：CO2捕集 氧化钙 吸附 高温吸附 碳酸化 煅烧 

分 类 号：X701[环境科学与工程—环境工程]