三元复合钙基材料CaO-Ca_3Al_2O_6-MgO的合成及其CO_2吸附性能  

Preparation of ternary composite Ca-based material CaO-Ca_3Al_2O_6-MgO for high-temperature CO_2 capture

作　　者：张明明[1] 彭云湘 汪瑾[1] 李平[1] 于建国[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《化工学报》2014年第1期227-236,共10页CIESC Journal

基　　金：国家高技术研究发展计划项目(2008AA062302)~~

摘　　要：采用Al2O3和MgO同时掺杂改性的方法制备了CaO-Ca3Al2O6-MgO复合钙基高温吸附CO2材料。复合钙基材料孔隙发达,活性物相为CaO,惰性骨架物相为Ca3Al2O6和MgO。Ca3Al2O6/MgO质量比偏小的材料,表面微粒粒径较小。在10%(体积分数,下同)CO2和90%N2的混合气气氛下,采用热重分析仪测量了复合钙基材料吸附CO2容量、碳化反应速率以及循环碳化(670℃)/煅烧(900℃)过程的稳定性。结果发现,复合钙基材料CaO-Ca3Al2O6-MgO具有较好的吸附CO2性能,提高Ca3Al2O6/MgO质量比,合成材料的循环稳定性较好;降低Ca3Al2O6/MgO质量比,合成材料的碳化反应速率加快,CaO转化率提高。最后,通过对不同循环次数下复合钙材料的比表面积、孔径分布、微观形貌、表面元素分布,晶相、晶粒大小进行研究分析,对合成材料的失活以及掺杂物质对烧结的抑制机理进行了讨论。Synthetic sintering-resistant calcium based material for high-temperature CO2 capture was prepared by doping Al2O3 and MgO into CaO using wet chemical method. The synthetic materials with pore structure developed consist of three substances, CaO, Ca3Al2O6 and MgO. Lower mass ratio of Ca3Al2O6/MgO gives smaller grain size of the synthetic material. CO2 capture capacities and cyclic carbonation/calcination （670/900℃） stability were evaluated in thermogravimetric analyzer under the simulated 10% （vol., the same below） CO2 （90% N2）. It is found that the synthetic CaO-Ca3Al2O6-MgO material presents good performance to capture CO2 from the flue gas, and the mass ratio of Ca3Al2O6/MgO has significant effect on CO2 capture performance. Lower mass ratio leads to faster carbonation reaction rate and higher CaO conversion. Moreover, the deactivation mechanism of synthetic material and the anti-sintering mechanism of doping agents were studied through analysis of specific surface area, pore volume, micro morphology, element distribution, phase composition and grain size of CaO-Ca3Al2O6-MgO material after multicycle carbonation/calcination.

关 键 词：二氧化碳 吸附剂 失活 氧化钙 氧化铝 氧化镁 

分 类 号：TQ028.15[化学工程]