赤泥作为氧载体用于甲烷化学链燃烧：反应与循环性能  

Red Mud as Oxygen Carrier for Chemical Looping Combustion of Methane: Reactivity and Cyclic Performance

作　　者：邓贵先 李孔斋[2,3] 程显名 顾振华[2] 卢春强[2] 祝星 

机构地区：[1]昆明理工大学化学工程学院,昆明650500 [2]昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室,昆明650093 [3]冶金与能源工程学院,昆明650093

出　　处：《高等学校化学学报》2018年第2期327-336,共10页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号：51604137)资助~~

摘　　要：将拜耳法赤泥作为氧载体用于甲烷化学链燃烧,研究了不同预处理条件对赤泥氧载体的反应与循环性能的影响.对赤泥氧载体的物理化学性质的表征结果表明,高温焙烧导致氧载体反应活性下降,但有利于赤泥中各组分之间发生反应生成稳定的复合物(如Na_6Al_4Si_4O_(17)和Ca_2Al_2Si O_7),从而提高了赤泥氧载体的热稳定性.通过测试不同温度(800,850,900和950℃)下制备的赤泥氧载体(800-RM,850-RM,900-RM和950-RM)与CH_4的反应性能发现,900-RM的反应活性和循环性能均优于其它样品,CH_4转化率和CO_2选择性分别达到了71%和79%,说明900℃为最佳焙烧温度.在900℃下经30次redox循环后,赤泥氧载体的反应性能和物相结构未发生明显变化,表明其具有优良的循环稳定性.Chemical looping combustion（CLC）is a novel combustion technology with inherent CO_2 separation from the carbon-based fuels.The development of low-cost oxygen carrier（OC）with high reactivity and good recycl ability is the key factor for the application of CLC technology.Red mud,a byproduct from the alumina production,can be considered as an ideal candidate as a cheap OC due to the high content of iron oxide and high specific surface area.In this study,the red mud was proposed as an oxygen carrier for chemical looping combustion of methane,and the effects of calcination temperature and reaction temperature on the reactivity and cyclic performance of this OC was investigated.The physicochemical properties of the red mud were characterized by XRF,XRD,TG-DSC,BET and H_2-TPR technologies.It was found that high calcination tempe-rature result in the decrease of the OC reactivity but improve the thermal stability due to the formation of composite salts（e.g.,Na_6Al_4Si_4O_（17）and Ca_2Al_2SiO_7）via the reactions between alkali-metal oxide（Na_2O）or alkaline-earth-metal oxide（Ca O）and the inert materials（Al_2O_3and SiO_2）.Among the different red mud OCs（e.g.,800-RM,850-RM,900-RM and 950-RM,which were obtained after calcination at 800,850,900 and950℃,respectively）,the 900-RM sample shows the highest CH_4conversion（71%）and CO_2selectivity（79%）during the performance testing,indicating high activity for methane oxidation.This phenomenon suggests that 900℃is the most suitable calcination temperature.No obvious changes on the reactivity and phase structure of the red mud was observed after 30 redox cycles,which indicates that the calcined red mud OC owns excellentredox stability for CLC of methane.

关 键 词：化学链燃烧 甲烷 赤泥 氧载体 氧化还原循环 

分 类 号：O643[理学—物理化学] O614[理学—化学]