Thermal reaction mechanism of biomass and determination of activation energy
I.drying section
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摘要: 燥段是生物质热解的第一个过程。采用热分析仪研究了杉木木屑干燥段质量和热量的变化，推导了非等温干燥动力学模型，探讨了热质传输机理。结果表明,随着温度的升高，木屑含湿量迅速下降，80℃左右出现一个明显的失重峰；非等温干燥动力学Page模型能很好地模拟木屑干燥过程，木屑干燥活化能为12.6kJ/mol；水分传输与热量传递有紧密的耦合关系，干燥吸收的热量主要用于水分的扩散蒸发；木屑干燥需热量为426kJ/kg，模拟值与实验值吻合较好。Abstract: The first step of biomass pyrolysis corresponds to water evaporation. Thermal analysis instrument was used to determine the mass and heat change of fir wood during drying process. Non-isothermal drying kinetics model was derived to explore the mechanism of heat and mass transfer. The results show that moisture content decreases rapidly and weight loss peak appears at 80℃. Page model for non-isothermal drying kinetics can well simulate wood drying process and the drying activation energy is 12.6kJ/mol. Water and heat transfer have close relationship and the dry heat is mainly used for water evaporation. The value of heat requirement is 426kJ/kg and the simulated results show good agreement with experimental values.
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Key words:
- biomass /
- non-isothermal drying /
- activation energy /
- mass and heat transfer
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