Abstract: To investigate the effects of different torrefaction parameters on the briquetting and combustion characteristics of biomass, corn straw was used as the raw material to obtain torrefaction products under varying conditions. The resulting torrefied product swere compressed  and molded without  the addition of  a binder, and  their density, water absorption,  and shatter resistance were analyzed.  Combustion tests of the molded fuel were conducted using asynchronous thermal analyzer, and key combustion parameters, including ignition temperature, burnout time, burnout temperature, and the comprehensive combustion characteristic index, were calculated. The results indicated that torrefaction enhanced  the physicochemical and combustion properties of  corn straw briquette fuel. At  a  constant torrefaction duration, an increase in temperature led to a gradual rise in molding density, a reduction in water absorption, a slight decrease in shatter resistance, an increase in ignition temperature, burnout time, and burnout temperature, and an initial increase followed by a decline in the comprehensive combustion characteristic index. Similarly, at a constant temperature, extending the torrefaction duration resulted in increased molding density, decreased water absorption, an initial increase followed by a decline in shatter resistance, and an initial rise followed by a slight decrease in ignition temperature, burnout time, and burnout temperature, while the comprehensive combustion characteristic index first declined and then slightly increased. Based on a comprehensive analysis of the effects of torrefaction parameters on corn straw briquettingcombustion performance, the optimal briquetting conditions were found to be 260 ℃ for 20 minutes, while the best combustion characteristics were achieved at 260 ℃ for 10 min.

Key words: biomass, corn straw, torrefaction, thermogravimetric analysis, combustion characteristics

摘要： 为研究不同烘焙参数对生物质成型及燃烧特性的影响，以玉米秸秆为原料，获得不同烘焙参数下的烘焙产物。在不添加黏结剂的条件下将烘焙产物压缩成型，分析其密度、吸水性和抗跌碎性，并利用同步热分析仪对成型燃料进行燃烧试验，计算其着火温度、燃尽时间、燃尽温度、综合燃烧特性指数。结果表明：烘焙可以改善玉米秸秆成型燃料的理化和燃烧特性。同一烘焙时间，随温度升高，成型密度逐步增加，吸水率下降，抗跌碎率略有下降，着火温度、燃尽时间和燃尽温度逐渐增加，综合燃烧特性指数先上升再减小；同一烘焙温度，随时间延长，成型密度增加，吸水率下降，抗跌碎率先升高再下降，着火温度、燃尽时间和燃尽温度先上升再略有下降，综合燃烧特性指数先下降再略有上升。烘焙温度为260 ℃，烘焙时间为20 min时，成型效果最好；烘焙温度为260 ℃，烘焙时间为10 min时，燃烧特性最好。

关键词: 生物质, 玉米秸秆, 烘焙, 热重分析, 燃烧特性