摘要
利用溶胶-凝胶法制备了以Fe_2O_3为活性组分,天然凹凸棒土(ATP)为惰性载体,KNO_3修饰的Fe4ATP6K1铁基复合载氧体。在高温流化床中考察了反应温度、水蒸气流量和O/C摩尔比对咖啡渣化学链气化过程的影响。结果表明,与以石英砂为床料的咖啡渣气化相比,以Fe4ATP6K1载氧体为床料的咖啡渣化学链气化对应的碳转化率由71.38%提高到86.25%。咖啡渣化学链气化的较优操作条件为:反应温度900℃、水蒸气量0.23 g·min^(-1)、O/C摩尔比1;在此操作条件下,合成气产量达到1.30 m^3·kg^(-1),氢气产量达到83.79 g·kg^(-1),氢气的平均浓度达到52.75%。通过X射线衍射(XRD)、扫描电镜-能谱(SEM-EDS)对900℃反应前后的Fe4ATP6K1进行表征,发现Fe相、K相、Si相可以发生相互作用,K以KFe Si_3O_8的形式存在于载氧体中,并且K在反应过程中有少量流失。20次氧化/还原过程中,铁基复合载氧体Fe4ATP6K1表现出较好的循环性能,碳转化率和冷煤气效率均保持在75%以上,各气体的平均浓度较稳定。
Iron-based composite oxygen carrier（OC）（Fe4ATP6K1） was prepared by sol-gel method, which features Fe2O3 as an active component, and natural attapugite（ATP） as an inert support, as well as being modified by KNO3. Effects of reaction temperature, flow rate of steam and molar ratio of O/C on chemical looping gasification（CLG） of coffee grounds were investigated in a high temperature fluidized bed using steam as gasification agent. It suggests that the Fe4ATP6K1 oxygen carrier as bed material could facilitate carbon conversion in CLG of coffee grounds from 71.38% to 86.25%, compared with that of Si O2. Under optimized conditions for CLG such as 900℃, 0.23 g·min^-1 of steam flow rate and 1 of molar ratio of O/C, up to 52.75% of average concentration of H2, 83.79 g·kg^-1 of H2 production rate, and 1.30 m^3·kg^-1 of syngas production rate were achieved. The OC samples before and after reaction at 900℃ were characterized by X-ray diffraction（XRD） and scanning electron microscope-energy dispersive spectrometer（SEM-EDS）. The interactions within phases of Fe, K and Si, and K in presence of KFe Si3O8 phase in the OCs were observed. Twenty redox cycles testing demonstrated that the Fe4ATP6K1 oxygen carrier possessed a good cyclic stability, over 75% of both carbon conversion and cold gas efficiency, while the average concentration of each gas kept almost stable.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2016年第4期1303-1312,共10页
CIESC Journal
基金
国家自然科学基金项目(21276129)
青岛市应用基础研究计划项目(14-2-4-5-jch)
山东省自然科学基金重点项目(ZR2015QZ02)~~
关键词
咖啡渣
颗粒物料
废物处理
化学链气化
铁基载氧体
合成气
流化床
coffee grounds
particle material
waste treatment
chemical-looping gasification
Fe-based oxygen carrier
syngas
fluidized bed
作者简介
张云鹏（1990-），男，硕士研究生。
联系人：郭庆杰。
