生物质燃料的燃烧过程及其焚烧灰特性研究

Study on Combustion Process of Biomass Fuels and Charicteristics of Their Ashes

采用热重-差热分析法分析了秸秆、木屑生物质燃料的直接燃烧过程,研究了其焚烧灰的化学成分、晶相结构及其形貌等特性。结果表明,秸秆、木屑生物质燃料的挥发分含量高、灰分低、着火温度低、易燃烧、放热量高,其燃烧过程可分为水分蒸发、挥发分析出燃烧和固定碳燃烧3个阶段;秸秆焚烧灰中钾、钙、硫及氯含量高,木屑焚烧灰中碱金属含量低,硅、钙含量高;生物质燃料焚烧灰中的碱金属氧化物含量高导致其熔点较低、易熔融、结渣。

Direct combustion processes of biomass fuels such as stalk and sawdust are analysed using TG-DSC testing method and the characteristics of their ashes such as chemical components, structure of cysrtal phases and pattern is studied. Biomass fuels have many combustion characteristics such as high voltaic component, low residue, low iginition point, easy combustion and high liberation of heat. Their combustion process can be divised into three periods including moisture evaporation, precipitation and combustion of voltaic component and combustion of fixed carbon. Stalk ash has high content of alkali, calcium, sulphur and chloride elements, and sawdust ash has low content of alkali and high content of silica and calcium elements. Stalk ash and sawdust ash have low melting point resulting from high content of alkali salt, and are easily melted and forming into slag.