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

在许多气固过程中，微粒在搬运、运输和加工过程中会产生静电荷，从而导致微粒与壁面粘附、微粒团聚，并产生高压电场引起爆炸。据报道，静电现象的重大负面影响在石油化工等行业，污染事件可能导致每天近100万美元的重大经济损失，在制药行业，药物粉末在干粉吸入器（患有哮喘等肺部疾病的人使用）内聚集和沉积，通过限制吸入器的排放剂量，降低了吸入器的效率。相比之下，静电在废物管理部门使用的固体分离过程中可以找到有益的应用。因此，本研究计划的总体目标是确定如何防止或消除工业聚乙烯气固流化床反应器中的静电电荷，并揭示颗粒分离和制药等不同气固过程中的颗粒电荷机制。一个全面的实验计划将发展：A)消除和减少工业气固流化床反应器污染的静态控制策略。这项研究将使用一个独特的定制中试工厂气固流化基础设施，该设施最近投入使用，能够在高达25atm的高压下运行，并采用了一种新的静电荷测量技术。b)计算流体动力学（CFD）模型，能够预测包括流化床在内的各种气固过程中的颗粒电荷。c)深入了解气固流化床中固体的有效充注，在分离过程中实现更高的分离效率。d)在干粉吸入器中进行药粉装药的综合研究，以提高干粉吸入器给药效率。在这个多学科研究项目中接受培训的研究生和本科生的参与将有助于对制药、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.