Fundamental Understandings of the Causes and Consequences of Chemical, Electrical and Thermal Heterogeneities in Aluminium Electrolysis Cells

对铝电解槽中化学、电和热不均匀性的原因和后果的基本了解

• 批准号: RGPIN-2022-04291
• 负责人: Dion, Lukas
• 金额: $ 2.11万
• 依托单位: Université du Québec à Chicoutimi
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765105
• 关键词: Fundamental; Understandings; Causes; Consequences; Chemical

The primary aluminium production industry is continuously trying to increase their production rate, with a reduction of their cost along with lower specific energy consumption. However, the stability of the process is becoming more and more sensitive to local variations within an electrolysis cell. These variations may be chemical (alumina distribution), thermal (energy level) or electrical (current distribution). Such imbalance lead to variations of the normal process conditions leading to negative consequences for the cell such as lower production rate, increase of energy consumption, sludge formation, or excessive production of greenhouse gases. The research program described in this proposal aims at enhancing and developing new modules for a numerical tool that would allow simulations of the heterogenous conditions in a cell and their potential consequences. The initial work on that mathematical model was performed by the applicant in previous research. The model allows the simulation of chemical and electrical variations in the cell, without any considerations for the thermal mechanisms. With this information's, the mathematical model has the ability to predict the onset of perfluorocarbon emissions during the electrolysis process. A good usage of this tool, with further refinements can provide solutions for multiple issues of the industry. There are numerous factors that play a major role in the cell heterogeneity that are not considered yet in the mathematical model. The research plan is developed with the vision to progressively introduce these elements in the model and reach more accurate prediction and pinpoint more detailed solutions to address the real conditions of industrial cells. The initial phase of the program (described in detail in this proposal) will target the thermal exchange occurring in the cell and couple the energy balance with the existing chemical and electrical modules. Further improvement, beyond the scope of this proposal will subsequently investigate the chemical, thermal and, electrical impact of operational events on the heterogeneity of the cell. A third phase will consider the impact of additives and more advanced themes such as anodic incidents and exchange mechanisms between the alumina metal pad and the electrolysis bath. The research program plan considered for the next five years includes the formation of a PhD student to integrate an energy balance into the mathematical model with indicators that can allow the evaluation of the level of severity of the imbalance observed. A master student is also considered to investigate the thermal consequences of low- and high-voltage anode effects. In both cases, the work performed will be based on theoretical concepts and experimental validation in a laboratory setup. Finally, a postdoctoral fellow will perform an extensive parametric study to pinpoint the main cause of the imbalance and propose potential and realistic solution for Canadian aluminium producers.

原铝生产行业不断努力提高生产率，降低成本并降低单位能耗。然而，过程的稳定性对电解槽内的局部变化变得越来越敏感。这些变化可能是化学变化（氧化铝分布）、热变化（能量水平）或电变化（电流分布）。这种不平衡会导致正常工艺条件的变化，从而对电池产生负面影响，例如生产率降低、能源消耗增加、污泥形成或温室气体过量产生。该提案中描述的研究计划旨在增强和开发数值工具的新模块，该模块将允许模拟细胞中的异质条件及其潜在后果。该数学模型的初步工作是由申请人在之前的研究中完成的。该模型允许模拟电池中的化学和电变化，而不需要考虑热机制。有了这些信息，数学模型就能够预测电解过程中全氟化碳排放的开始。充分利用该工具并进一步完善，可以为行业的多个问题提供解决方案。有许多因素在细胞异质性中起重要作用，但数学模型尚未考虑这些因素。该研究计划的制定目标是逐步在模型中引入这些元素，并实现更准确的预测并找出更详细的解决方案，以解决工业电池的实际情况。该计划的初始阶段（在本提案中详细描述）将以电池中发生的热交换为目标，并将能量平衡与现有的化学和电气模块结合起来。超出本提案范围的进一步改进将随后研究操作事件对电池异质性的化学、热和电影响。第三阶段将考虑添加剂的影响和更高级的主题，例如阳极事件以及氧化铝金属垫和电解槽之间的交换机制。未来五年考虑的研究计划计划包括培养一名博士生，将能量平衡纳入数学模型，并提供可评估观察到的不平衡严重程度的指标。硕士生也被考虑研究低压和高压阳极效应的热后果。在这两种情况下，所进行的工作都将基于理论概念和实验室设置中的实验验证。最后，博士后研究员将进行广泛的参数研究，以查明不平衡的主要原因，并为加拿大铝生产商提出潜在且现实的解决方案。