摘要
采用模板法制备了钙基中空微球,用于实现高效CO2.捕捉.借助热重分析仪在较为真实条件下研究了钙基中空微球外径、碳酸化温度对其CO2.捕集性能的影响,并借助扫描电子显微镜(SEM)、透射电子显微镜(TEM)和氮吸附分析其微观结构.最后,利用缩核模型对钙基中空微球碳酸化反应中的化学反应控制阶段进行动力学分析.结果表明,中空结构可以显著提升钙基吸收剂的CO2.捕集性能.性能最好的钙基中空微球的首次碳酸化转化率高达82.5%,相比于石灰石提升了30.7%.这是因为中空结构显著改善了孔隙结构,增大了比表面积和比孔容积.随着碳酸化温度的升高,钙基中空微球的CO2.捕集性能呈现先上升后下降的趋势,在650℃时达到最大值,碳酸化转化率高达82.5%.动力学分析结果表明,中空结构可以加快化学反应控制阶段的反应速率,并延缓反应速率的衰减,同时还可以降低反应活化能,进而对碳酸化反应起着显著的提升作用.
The templating method was used to preparation of CaO hollow microspheres for enhancing CO 2.capture performance.The effects of external diameter of CaO hollow microspheres and carbonation temperature on CO 2.capture were investigated under a relative realistic condition via a thermogravimetric analyzer (TGA).The morphologies and microstructures of sorbents were characterized using scanning electron microscopy(SEM),transmission electron microscopy(TEM),and N 2.adsorption measurement.Finally,a shrinking core model was employed to describe the chemical-reaction controlled stage of the carbonation process for CaO hollow microspheres.The results show the hollow structure can significantly enhance CO 2.capture performance of CaO-based sorbents.The initial carbonation conversion of the best CaO hollow microspheres can reach 82.5%,exceeding the reference limestone by 30.7%.It is because the hollow structure improves the porosity of the sorbents,leading to an increase in both specific surface area and pore volume.Moreover,with the increase of the carbonation temperature,the CO 2.capture performance of CaO hollow microspheres increases first,reaching a maximum carbonation conversion of 82.5% at 650 ℃,and then decreases.Furthermore,the kinetic analysis shows that the hollow structure can enhance the reaction rate of the chemical-reaction controlled stage,and slow down the decline in reaction rate.The hollow structure can also lower the activation energy.As a result,CaO hollow microspheres exhibit better CO 2.capture performance.
作者
陈健
段伦博
卞若愚
谭茗月
石田
卢欲晓
赵长遂
Chen Jian;Duan Lunbo;Bian Ruoyu;Tan Mingyue;Shi Tian;Lu Yuxiao;Zhao Changsui(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Southeast University,Nanjing 210096,China;School of Energy and Environment,Southeast University,Nanjing 210096,China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第4期757-763,共7页
Journal of Southeast University：Natural Science Edition
基金
国家重点研发计划中美清洁能源联合研究中心资助项目(2016YFE0102500-06-01)
东南大学优秀博士学位论文培育基金资助项目(YBPY1902)
国家留学基金资助项目(201806090031)
关键词
模板法
中空材料
钙循环
二氧化碳
动力学
templating method
hollow material
calcium looping
CO 2
kinetics
