摘要
通过溶胶凝胶燃烧法合成了MnFeO3和MnFe2O4两种锰铁复合氧载体。通过原位红外实验探究其与稻草的化学链气化过程,发现其加速了稻草热解产物的析出,并通过气化反应促进CO和CO2的产生,提高了碳转化率。固定床实验结果表明MnFeO3和MnFe2O4在与水蒸气耦合气化的条件下大幅提高了合成气中H2和CO的产率,气化效率分别达到94.49%和92.76%。并通过XRD分析,发现MnFeO3和MnFe2O4在气化过程主要还原为(Fe,Mn)O,且在氧化反应后能回到初始晶相。在固定床的10次循环实验以及SEM的结果表明,MnFeO3在循环反应中逐渐形成的颗粒状多孔结构有利于维持稳定的气化效率,而MnFe2O4由于团聚和烧结作用形成了块状结构,气化效率呈缓慢下降趋势。因此,认为MnFeO3在生物质化学链气化中具有更好的适用性。
The reactivity of oxygen carriers is curial for biomass chemical looping gasification(CLG)process.Two kinds of manganese-iron composite oxygen carriers of MnFeO3 and MnFe2O4 were synthesized by sol-gel combustion method.Though the in situ infrared,CLG experiments with straw were carried out.It indicated that the ferromanganese composite oxides accelerated the release rate of pyrolysis products and enhanced the yield of CO and CO2,which promoted the carbon conversion efficiency.Further tests in fix-bed were to prove the feasibility of MnFeO3 and MnFe2O4 and the influence by coupling with steam.It showed that components of H2 and CO in syngas could be improved significantly by introducing steam and the gasification efficiency for MnFeO3 and MnFe2O4 was94.49%and 92.76%individually.The XRD analysis demonstrated that MnFeO3 and MnFe2O4 transformed to a combination of(Fe,Mn)O during the reduction process and both of them exhibit recyclable crystalline phase variation.Moreover,multiple redox tests showed MnFe2O4 exhibited a decreasing tendency of gasification efficiency because of agglomeration,its typical surface morphology changed from scattered particles to blocky structure.However,MnFeO3 formed a granular porous structure which helped to maintain a stable reactivity.Thus,MnFeO3 was considered to have better applicability in CLG process.
作者
陈智豪
廖艳芬
莫菲
刘桂才
余昭胜
马晓茜
CHEN Zhihao;LIAO Yanfen;MO Fei;LIU Guicai;YU Zhaosheng;MA Xiaoqian(School of Electric Power,South China University of Technology,Guangzhou 510640,Guangdong,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2019年第12期4835-4846,共12页
CIESC Journal
基金
国家自然科学基金项目（51676074）
广东省能源高效清洁利用重点实验室项目（2013A061401005）
关键词
生物质
气化
合成气
锰铁复合氧载体
化学链
biomass
gasification
syngas
ferromanganese composite oxygen carriers
chemical looping
作者简介
通信作者:廖艳芬(1976-),女,博士,教授,yfliao@scut.edu.cn;第一作者:陈智豪(1994-),男,硕士研究生,124164138@qq.com。
