The understanding of complex fluidization hydrodynamics and chemical reactions in biomass fast pyrolysis fluidized bed reactors is lacking and requires further investigation. It is urgent to develop accurate mathematical models capable of describing the complex multiphase reaction system of biomass pyrolysis. A comprehensive multiscale model based on coarse-grained discrete element method (DEM)-computational fluid dynamics (CFD) was developed in open-source MFiX code. It incorporates detailed biomass pyrolysis kinetics and an intraparticle model. To validate the model, measurements were conducted in a fluidized bed pyrolyzer, including quantifying the segmental pressure drop along the height of the bed and determining the yields and compositions of gas, liquid, and solid products. The particle mixing and segregation, axial distribution and residence time, Lacey index, and pyrolysis products were investigated. The study provides experimental and theoretical foundations for designing multiphase fluidized bed reactors and advancing biomass thermochemical conversion.

中文翻译：

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耦合粗粒 DEM-CFD 和颗粒内模型用于生物质快速热解模拟和实验验证

对生物质快速热解流化床反应器中复杂流化流体动力学和化学反应的理解缺乏，需要进一步研究。迫切需要开发能够描述生物质热解复杂多相反应系统的精确数学模型。在开源 MFiX 代码中开发了基于粗粒度离散元法（DEM）-计算流体动力学（CFD）的综合多尺度模型。它结合了详细的生物质热解动力学和颗粒内模型。为了验证模型，在流化床热解器中进行了测量，包括量化沿床高度的分段压降并确定气体、液体和固体产物的产率和成分。研究了颗粒混合和偏析、轴向分布和停留时间、莱西指数和热解产物。该研究为设计多相流化床反应器和推进生物质热化学转化提供了实验和理论基础。