不同生物质还原氧化铁的特性

Reduction characteristics of iron oxide by different biomass

以木屑、玉米秸秆、咖啡废渣和水解木质素4种生物质为还原剂,采用TG-FTIR联用、XRD、SEM等方法分析了各物质的化学成分及官能团构成,研究了不同生物质中碳和氢对氧化铁的还原反应特性。研究表明,生物质还原氧化铁的作用由气体和固定碳决定,其中气基还原的特征温度为806~822 K,碳还原的特征温度为1 116~1 132 K。4种生物质中,碳还原氧化铁的能力由强到弱依次是木屑>水解木质素>咖啡废渣>玉米秸秆,氢还原能力大小则为玉米秸秆>咖啡废渣>木屑>水解木质素。

Sawdust, cornstalk, spent coffee grounds and hydrolyzed lignin were used as reducing agents for iron oxide. The TG-FTIR, XRD and SEM methods were used to analyze the chemical composition, functional group and surface morphology of biomass. A comparative experiment was carried out between biomass pyrolysis alone and biomass-iron oxide mixture pyrolysis. The reduction characteristics of biomass and iron oxide were analyzed by carbon reduction and hydrogen reduction, and the ability of carbon and hydrogen to reduce iron oxide in biomass was explored. The results show that the reduction of iron oxide by biomass is mainly determined by the gases and fixed carbon produced during the pyrolysis/gasification process. The characteristic temperature of gas-based reduction iron ore powder was 806-822 K, and that of carbon reduction was 1 116-1 132 K. Among the four biomasses, the order of the ability of carbon to reduce iron oxide was sawdust>hydrolyzed lignin>spent coffee grounds>cornstalk. The order of the ability of reducing iron oxide by hydrogen was cornstalk>coffee waste residue>sawdust>hydrolyzed lignin.