Investigation of Electrostatic Charging in Various Gas-Solid Processes with Applications in Petrochemical, Pharmaceutical and Waste Management Industries

在许多气固两相过程中，颗粒在处理、运输和加工过程中会产生静电电荷，从而导致颗粒与壁面的粘连、颗粒团聚以及产生引起爆炸的高压电场。据报道，静电现象的严重负面影响出现在石油化工和制药等行业，在这些行业，一次结垢事件可能导致每天近100万美元的重大经济损失，而制药行业的干粉吸入器(由患有哮喘等肺部疾病的人使用)中的药粉团聚和沉积通过限制排放剂量降低了吸入器的效率。相比之下，静电在废物管理领域的固体分离过程中可以找到有益的应用。因此，这项研究计划的总体目标是确定防止或消除工业聚乙烯气固流化床反应器中静电荷电的方法，并阐明不同气固过程中的颗粒荷电机理，如颗粒分离和制药过程。将制定一项全面的实验计划：a)消除和减少工业气固流态化反应器中的污垢的静态控制策略。这项研究将使用最近投入使用的独特的定制化中试装置气固流态化基础设施，该基础设施能够在高达25atm的高压下运行，并配备了一种新的静电电荷测量技术。B)计算流体动力学(CFD)模型，能够预测各种气固过程中的颗粒荷电，包括沸腾床中的颗粒荷电。C)深入了解气固流态化中固体的有效进料，以在分离过程中实现更高的分离效率。D)对干粉吸入器中的药粉装填进行综合研究，以提高这种装置的药物输送效率。受过这一多学科研究项目培训的研究生和本科生的参与将有助于制药、石化和废物管理行业的研究产生直接影响，这些行业对加拿大和世界经济至关重要。

In many gas-solid processes, electrostatic charges are generated during particle handling, transport and processing in which resulting in particle-wall adhesion, particle agglomeration, and generation of high-voltage electrical fields causing explosions. The significant negative impact of electrostatic phenomenon has been reported in industries such as petrochemical where a fouling incident could result in major economic losses of nearly $1.0M/day, and pharmaceuticals where drug powder agglomeration and deposition inside dry powder inhalers (used by those who suffer from lung illnesses such as asthma) reduces the efficiency of the inhaler by limiting the emitted dose. In contrast, beneficial application of electrostatics can be found in solid separation process used in waste management sector. The overall goal of this research program is thus to determine ways to prevent or eliminate electrostatic charging in industrial polyethylene gas-solid fluidized bed reactors, as well as shed some light on particle charging mechanisms in different gas-solid processes such as those of particles separation and pharmaceuticals. A comprehensive experimental program will develop: a) Static control strategies to eliminate and reduce fouling in industrial gas-solid fluidized bed reactors. A unique custom-made pilot plant gas-solid fluidization infrastructure will be used in this study that is recently commissioned and is able to operate at high pressures of up to 25atm and houses a novel electrostatic charge measurement technique. b) A computational fluid Dynamic (CFD) model enabling the prediction of particle charging in various gas-solid processes including those of fluidized beds. c) A thorough understanding of effective charging of solids in gas-solid fluidized beds to achieve greater separation efficiencies in separation processes. d) A comprehensive study of drug powder charging in dry powder inhalers to improve drug delivery efficiency from such devices. Involvement of graduate and undergraduate students trained in this multi-disciplinary research program will assist in direct impacts of the research in pharmaceutical, petrochemical and waste management industries, sectors of vital importance to the Canadian and world economies.