Gas-solid reactive flows during the biomass fast pyrolysis in a three-dimensional bubbling fluidized bed (BFB) reactor are numerically modeled via the multiphase particle-in-cell approach. The model is comprehensively validated with the experimental data regarding the bubble dynamics and product yields. Subsequently, the physical and thermal dynamics of bubbles under the condition of high-temperature biomass pyrolysis in the BFB reactor are explored. The results indicate that the axial segregation induced by size and density difference between sand and biomass results in the occurrence of preferential distribution of biomass particles, which significantly affects the spatial distributions of hydrodynamics, temperature, and species of gas-solid flows. The presence of biomass inlet results in low temperature, large density, and large aspect ratio of rising bubbles around this region. Bubble pressure and bubble temperature increase and decrease along with bed height, respectively. Pyrolysis temperature obviously affects the temperature, pressure, density of bubbles. The results are expected to shed light on the gas-solid hydrodynamics and thermochemical characteristics, especially the dynamics of meso-scale bubble structures in the reactor.

通过多相泡孔法对三维鼓泡流化床（BFB）反应器中的生物质快速热解过程中的气固反应流进行了数值模拟。该模型已通过有关气泡动力学和产品产量的实验数据进行了全面验证。随后，研究了在BFB反应器中高温生物质热解条件下气泡的物理和热动力学。结果表明，由砂和生物质之间的尺寸和密度差异引起的轴向偏析导致生物质颗粒优先分布的发生，这显着影响了流体力学，温度和气固流物种的空间分布。生物质入口的存在导致低温，高密度，以及该区域周围上升气泡的大长宽比。气泡压力和气泡温度分别随着床高度的增加和减少。热解温度明显影响气泡的温度，压力，密度。预期结果将揭示气固流体动力学和热化学特性，特别是反应器中介观气泡结构的动力学。