Design and Scale-up of Reactors for Biomass Hydrolysis

这项研究使用计算建模和实验研究来提高木质纤维素生物质转化为可用于生产可再生燃料和生物产品的糖的转化率。目前，这些系统的操作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量的影响。我们建议使用一系列预处理条件/选项，以及生物反应器内不同的混合器/叶轮配置，收集有关混合和生物质转化的实验数据。我们还将使用混合珠和粘性流体收集视频/观察数据，以评估混合。 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（固体加液体），考虑反应器的几何形状，叶轮的数量和类型以及混合器RPM。将使用前面概述的实验数据验证计算流体动力学模型的配置。我们将创建CFD模型的稳态和瞬态版本;后者可以跟踪浆料粘度和混合的时间依赖性变化，因为生物质被添加到间歇反应器系统中。 一旦验证，CFD模型可用于预测不同反应器配置的工艺性能，包括不同的叶轮直径、轴向叶轮与径向叶轮的使用、锚式混合器或泵循环的使用以及不同的RPM。预计使用经验证的理论/数值模型进行的优化工作将识别/筛选关键设计特征，然后可以使用专注于关键/目标参数的一组较小的实验试验进行验证。 从长远来看，这项工作有望促进生物质转化技术的改进，包括生产低成本可再生糖的系统的商业开发。

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.