Design and Scale-up of Reactors for Biomass Hydrolysis

这项研究使用计算模型和实验研究来提高木质纤维生物质转化为可用于生产可再生燃料和生物制品的糖的效率。目前，这些系统的运行受到混合和酶性能问题的限制，这些问题受到预处理类型、酶的类型和剂量以及生物反应器内固体物质数量的影响。我们建议使用一系列的预处理条件/选项以及生物反应器内不同的混合器/叶轮配置来收集混合和生物质转化的实验数据。我们还将使用混合微珠和粘性流体收集视频/观测数据，以评估混合情况。*同时，我们将开发一个计算流体动力学(CFD)模型来表示两相浆料(固体和液体)，考虑到反应器的几何形状、叶轮的数量和类型以及混合器的转速。CFD模型的配置将使用前面概述的实验数据进行验证。我们将创建CFD模型的稳态和暂态版本；后者可以跟踪随着生物质添加到间歇反应器系统中浆料粘度和混合随时间的变化。*经过验证后，CFD模型可用于预测不同反应器配置下的过程性能，包括不同的叶轮直径、使用轴向和径向叶轮、使用锚定搅拌器或泵周围以及不同的转速。利用经过验证的理论/数值模型进行的优化工作预计将确定/筛选关键的设计特征，然后可以通过侧重于关键/目标参数的一组较小的实验试验来验证这些特征。*从长远来看，这项工作有望促进生物质转化技术的改进，包括商业开发生产低成本可再生糖的系统。**

This research uses computational modelling and experimental studies to improve the conversion of lignocellulosic biomass into sugars that can be used to produce renewable fuels and bioproducts. Currently, the operation of these systems is limited by problems with mixing and enzyme performance, which are influenced by the type of pretreatment, the type and dose of enzymes, and the amount of solids within the bioreactor. We propose to collect experimental data on mixing and biomass conversion using a range of pretreatment conditions/options, and different mixer/impeller configurations within the bioreactor. We will also collect video/observational data using mixing beads and viscous fluids to evaluate mixing. ***In parallel, we will develop a computational fluid dynamics (CFD) model to represent the two-phase slurry (solids plus liquid), accounting for the geometry of the reactor, the number and type of impellers, and the mixer RPM. The configuration of the CFD model will be validated using the experimental data outlined previously. We will create steady state and transient versions of the CFD model; the latter can track time-dependent changes in slurry viscosity and mixing as biomass is added to the batch reactor system. ***Once validated, the CFD model can be used to predict process performance with different reactor configurations, including different impeller diameters, use of axial versus radial impellers, use of anchor mixers or pump-arounds, and different RPMs. The optimization work conducted with the validated theoretical/numerical model is expected to identify/screen for critical design features, which can then be verified with a smaller set of experimental trials focusing upon the critical/target parameters.***Long term, this work is expected to facilitate improvement in biomass conversion technologies, including commercial development of systems to produce low cost renewable sugars. **