摘要
甲烷化学链重整是一种利用载氧体(金属氧化物)的部分氧化能力以实现甲烷重整制取合成气的工艺,同时氧化过程中利用水蒸气氧化,还原态的载氧体在恢复晶格氧的同时分解水蒸气制氢。利用溶胶-凝胶法制备载氧体CeO_(2)/LaFeO_(3),通过X射线粉末衍射和程序升温还原等材料表征方法分析该载氧体的结构特点以及供氧能力,借助于固定床反应实验探讨了组分比例、反应温度对该载氧体反应性能的影响。实验结果表明,CeO_(2)的含量对该载氧体的供氧能力有着显著影响,合适的反应温度不仅有利于甲烷活化,而且能够促进载氧体中晶格氧的迁移,从而提高载氧体的选择性。当CeO_(2)的添加量为10%,反应温度为850℃时,该载氧体的反应性能最优,甲烷转化率可以达到94%,H_(2)选择性和CO选择性分别可以达到90%、83%。在连续的氧化-还原循环中保持稳定的反应性能和结构。
Chemical looping methane reforming is a potential route to co-produce syngas and hydrogen by using the oxygen carrier(metal oxide).The oxygen carrier CeO_(2)/LaFeO_(3) was prepared by sol-gel method,and the structure and oxygen supply capacity of the oxygen carrier were analyzed by X-ray powder diffraction and hydrogen temperature programmed reduction.The influence of CeO_(2) ratio and reaction temperature on the performance of the oxygen carrier were discussed through fixed bed reaction tests.The content of CeO_(2) had a significant effect on the oxygen supply capacity of the oxygen carrier.Increasing reaction temperature not only was conducive to methane activation,but also enhanced lattice oxygen migration in the oxygen carrier.A suitable reaction temperature could match methane activation with lattice oxygen migration,thereby improving the selectivity of the oxygen carrier.Experimental results showed that performance of the oxygen carrier was in the optimal when CeO_(2) content was 10%and reaction temperature was 850ºC.CH4 conversion rate could reach 94%,H_(2) selectivity and CO selectivity could reach 90%and 83%,respectively.The oxygen carrier 10%CeO_(2)/LaFeO_(3) could maintain stable reaction performance and structure in the redox cycles.
作者
方小杰
赵坤
赵增立
夏明珠
李海滨
FANG Xiao-jie;ZHAO Kun;ZHAO Zeng-li;XIA Ming-zhu;LI Hai-bin(School of Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Key Laboratory of Renewable Energy,Chinese Academy of Sciences,Guangdong Key Laboratory of New and Renewable Energy Research and Development,Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2021年第9期1250-1260,共11页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(51876205)
国家重点研发计划(2017YFE0105500)
广东省科技计划(2017A020216009)
广州市科技计划项目(201906010092)
中国科学院青年创新促进会(2019341)资助。
关键词
甲烷
化学链重整
合成气
载氧体
选择性
methane
chemical looping reforming
syngas
oxygen carrier
selectivity
