Key Laboratory for Biomass Clean Energy of Anhui Province, University of Science and Technology of China, Hefei 230026, China.
Bioresour Technol. 2012 Mar;107:451-5. doi: 10.1016/j.biortech.2011.12.032. Epub 2011 Dec 14.
The current study presents a thermogravimetric method to determine the effective moisture diffusivity and drying kinetics of biomass. Drying experiments on poplar sawdust were performed at four temperatures (60, 70, 80, and 90°C) by a thermogravimetric analyzer (TGA). The major assumption in experimentally determining effective diffusivity by Fick's diffusion equation is that drying is mass transfer limited and temperature remains isothermal during drying. The results indicated that TGA could well achieve these determining conditions. The drying process of sawdust mostly took place in the falling rate period. Midilli-Kucuk model showed the best fit for all experimental data. The effective diffusivity values changed from 9.38 × 10(-10)m(2)/s to 1.38 × 10(-9)m(2)/s within the given temperature range, and the activation energy was calculated to be 12.3 kJ/mol.
本研究提出了一种热重法来测定生物质的有效水分扩散系数和干燥动力学。通过热重分析仪（TGA）在四个温度（60、70、80 和 90°C）下对杨木屑进行了干燥实验。通过菲克扩散方程实验确定有效扩散系数的主要假设是干燥是传质受限的，并且在干燥过程中温度保持等温。结果表明，TGA 可以很好地达到这些确定条件。木屑的干燥过程主要发生在降速期。Midilli-Kucuk 模型对所有实验数据拟合最好。在所给温度范围内，有效扩散系数值从 9.38×10(-10)m(2)/s 变化到 1.38×10(-9)m(2)/s，活化能计算为 12.3 kJ/mol。
