Innovative Fluidization Technologies for Green Processes

前言：沸腾床干燥广泛应用于制药、化肥、食品、农业、石化等行业的干燥过程。然而，这一能源密集型过程需要设计和运行解决方案，以最大限度地减少其能源消耗和环境足迹。沸腾床已成为生物质转化为绿色能源的有效载体。颗粒的混合和分离对沸腾床反应器的整体效率起着重要的作用。这项研究计划将开发创新的解决方案，通过引入脉冲气流来提高干燥性能。此外，基于同步加速器的X射线成像将被用来揭示流态化床内的新信息，以进一步提高能量转换。目标：具体的短期目标是：1)研究脉冲流对药物颗粒在沸腾床干燥器中鼓泡和干燥行为的影响；2)利用计算流体力学(CFD)建立干燥过程的数学模型和数值模拟；3)利用基于同步辐射的新型X射线成像技术研究包括生物质物质在内的二元混合物在沸腾床中的混合和分离。方法：首先将努力研究药物粉末在脉动辅助流态化干燥器中的干燥和鼓泡行为(目标1)。干燥实验将在配备了UofS提供的电容层析成像(ECT)系统的锥形沸腾床干燥器中进行。干燥速度将被测量，并与收集的鼓泡数据相关联。CFD，一个先进的建模和数值模拟工具，将被用来模拟有/没有脉冲流的干燥过程(目标2)。从实验中确定的干燥速度和鼓泡行为都将用于验证数值模拟。同时，基于同步加速器的X射线计算机层析成像(CT)将被用于研究含有生物质颗粒的二元混合物在沸腾床中的混合和分离(目标3)。所获得的全面知识将改善沸腾气化炉的运行。影响：拟议的研究计划将产生关于脉冲气流用于制药应用的增强型沸腾床干燥过程的全面知识。根据工作的结果，将提供优化的运行包络，以实现与该装置运行相关的能源消耗和环境足迹的减少。关于不同操作条件下混合和分离的详细信息将为各种热过程的沸腾床反应器的有效运行提供信息，目的是利用可再生生物质资源，特别是颗粒燃料生产清洁能源。我的长期目标是扩大研究计划，使化肥、食品、采矿和农业等行业的其他干燥过程受益。

INTRODUCTION: Fluidized bed drying is widely used for drying processes in the pharmaceutical, fertilizer, food, agriculture, and petrochemical industries. However, this energy-intensive process requires design and operation solutions to minimize its energy consumption and environmental footprint. Fluidized beds have been used as effective vehicles to convert biomass into green energy. Particle mixing and segregation plays an important role in the overall process efficiency of fluidized bed reactors. This research program will develop innovation solutions to enhance the drying performance by introducing pulsed gas flow. In addition, synchrotron-based X-ray imaging will be used to reveal new information within fluidized beds to further improve energy conversion. OBJECTIVES: Specific short-term objectives are to: 1) Investigate the effect of pulsed flow on bubbling and drying behaviour of pharmaceutical particles in a fluidized bed dryer; 2) Develop mathematical models and numerical simulations of drying processes using computational fluid dynamics (CFD); and 3) Investigate mixing and segregation of binary mixtures involving biomass materials in fluidized beds via novel synchrotron-based X-ray imaging techniques. METHODS: Efforts will first be placed on investigating drying and bubbling behaviour of pharmaceutical powders in a pulsation-assisted fluidized bed dryer (Objective 1). Drying experiments will be conducted in a conical fluidized bed dryer equipped with an electrical capacitance tomography (ECT) system available at the UofS. Drying rate will be measured and correlated with bubbling data collected. CFD, an advanced modeling and numerical simulation tool, will be employed to simulate the drying process with/without pulsed flow (Objective 2). Both the drying rate and bubbling behaviour determined from the experiments will be used to validate numerical simulations. In parallel, synchrotron-based X-ray computed tomography (CT) will be employed to investigate mixing and segregation of binary mixtures involving biomass pellets in a fluidized bed (Objective 3). The comprehensive knowledge obtained will improve operation of a fluidized bed gasifier. IMPACT: The proposed research program will produce comprehensive knowledge of enhanced fluidized bed drying processes for pharmaceutical applications with pulsed gas flow. Based on the outcomes of the work, an optimized operation envelope will be provided to achieve a reduction in energy use and environmental footprint associated with this unit operation. Detailed information about mixing and segregation under various operating conditions will inform efficient operation of fluidized bed reactors for various thermal processes with an aim to produce clean energy from renewable biomass resources, particularly pellet fuels. My long-term objective is to expand the research program to benefit other drying processes in fertilizer, food, mining, and agricultural industries.