摘要
利用流化床反应器并以水蒸气作为气化-流化介质,研究了温度、反应时间、循环数对Fe2O3载氧体反应性的影响。实验表明,载氧体与煤气化产物的反应性随温度升高而增强,且温度越高,反应受化学反应控制时间越短。当温度高于900℃时,煤中碳转化为CO2的比率大于90%,载氧体体现了很好的反应性,但反应温度低于850℃时,比率小于75%。反应温度900℃时,CO2干基浓度随循环数而逐渐降低,CO、CH4浓度增加,且CH4浓度值大于CO。利用XRD、SEM分析了固体反应产物成分与微观形态结构。分析表明,Fe2O3的还原产物为Fe3O4,载氧体颗粒随循环数增加而逐渐烧结。
The reactivity of using Fe2O3 as an oxygen carrier during chemical-looping combustion（CLC） of coal has been investigated experimentally at 800℃-950℃. The experiments were carried out in a fluidized bed, where the steam acted as the gasification-fluidization medium. The reactivity of Fe2O3 as a function of the reactor temperature, reaction time, and cyclic reduction number was discussed. The reactivity of Fe2O3 oxygen carriers was enhanced as temperature increased at 800℃-950℃. Moreover, the time of chemical reaction control between the oxygen carrier and coal gasification products decreased with increased reaction temperature. When the reaction temperature was above 900℃, the rate of carbon to form CO2 was higher than 90% ; however, it was lower than 75% below 850℃. At 900℃, the dry basis concentration of CO2 decreased with increased cyclic reduction period, while that of CO and CH4 increased. Moreover, the value of the CO concentration was less than that of CH4. The performance of the reacted Fe2O3-based oxygen carriers was also evaluated using an X-ray diffraetometer and a scanning electron microscope to characterize the solid residues of oxygen carrier. The results show that Fe2O3- based oxygen carriers are only reduced to Fe3O4. With the increase of cyclic reduction period, the oxygen carrier sinters gradually.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2009年第5期513-520,共8页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(90610016)
国家重点基础研究发展规划(973计划
2006CB200302
2006CB705806)
国家高技术研究发展计划(863计划
2006AA05Z318)
关键词
化学链燃烧
Fe2O3载氧体
反应性
表面烧结
CO2分离
chemical-looping combustion
Fe2O3 oxygen carrier
reactivity
surface sintering
CO2 separation
