A model for the fast pyrolysis of anisotropic biomass particles is presented which considers bubbling dynamics within the liquid intermediate phase (metaplast) and aerosol ejection from this phase. The model employs the population balance equation and the method of moments to estimate the production rate and resultant size distribution of aerosol ejections, incorporating a detailed CRECK reaction mechanism, and considers the effect of anisotropic biomass microstructure on the intraparticle transport of mass and energy. This study investigates the impact of particle size, heating rate (heat transfer coefficient), and lignocellulosic composition on aerosol ejection. The model predicts that, at high heating rates (convective heat transfer coefficient of 359 W/m2.K), aerosols can contribute over 20% to the heavy fraction yield in bio-oil for small particles (1 mm diameter, 4 mm length). The model can predict aerosol size distribution and surface area, indicating an average size of 20 μm for bubbles and 5 μm for aerosols during increased bubble production and aerosol ejection rates. These findings are consistent with prior experimental results and provide essential information for future modeling of extra-particle reactions of the aerosols as they progress through the reactor.

中文翻译：

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模拟生物质各向异性颗粒快速热解过程中初级气溶胶的喷射


提出了各向异性生物质颗粒快速热解的模型，该模型考虑了液体中间相（后质体）内的气泡动力学和该相的气溶胶喷射。该模型采用群体平衡方程和矩量法来估计气溶胶喷射的产生速率和由此产生的粒径分布，结合详细的CRECK反应机理，并考虑各向异性生物质微观结构对颗粒内质量和能量传输的影响。本研究研究了颗粒尺寸、加热速率（传热系数）和木质纤维素成分对气溶胶喷射的影响。该模型预测，在高加热速率（对流传热系数为 359 W/m2.K）下，气溶胶对小颗粒（直径 1 毫米，长度 4 毫米）的生物油重馏分产量的贡献率超过 20% 。该模型可以预测气溶胶尺寸分布和表面积，表明在气泡产生和气溶胶喷射速率增加期间，气泡的平均尺寸为 20 μm，气溶胶的平均尺寸为 5 μm。这些发现与之前的实验结果一致，并为气溶胶在反应器中前进时的颗粒外反应的未来建模提供了重要信息。