Competing Rates in Mixing Sensitive Processes: design fundamentals for meso-scale and transient effects

混合敏感过程中的竞争速率：中观尺度和瞬态效应的设计基础

• 批准号: RGPIN-2018-04942
• 负责人: Kresta, Suzanne
• 金额: $ 2.4万
• 依托单位: University of Saskatchewan
• 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=746872
• 关键词: Competing; Rates; Mixing; Sensitive; Processes

There are two interesting global trends to watch in chemical process engineering. In Europe, land is scarce and there is a strong commitment to process intensification. This has led to the development of micro-reactors which are extremely small (volumes of the order of micro-litres). In the global commodity chemicals market, economies of scale drive process design and "record capacity" plants are regularly commissioned. These reactor volumes are typically 1 Mega-litre. Two important industries in Canada, oil sands extraction and mineral processing, require some of the largest vessels in the world. These two industries also face difficult problems in multi-phase and partially-miscible multi-component mixing.Nano-technology has taught us that dramatic changes of scale require a shift in thinking: the physics stays the same but the dominant variables change. On moving from the litre to the micro-litre scale, the particle mass becomes negligible and tiny surface charges become extremely important. On moving from the 1L to the 1 ML scale, the blend time becomes so long relative to the key process time-scales that it is essentially infinite. At the Mega-Scale, local mixing conditions become extremely important and often dominate process performance.To successfully design and operate 1ML process vessels, clear mixing specifications are needed. This requires an understanding of how local turbulence, local segregation (injection concentration), and mixing time interact with the time scales, length scales, and concentration scales in the process. We have two test vessels which allow efficient measurement of these variables. The first has been applied to scale-down of nano-particle precipitation at very high turbulence levels; the second has allowed us to improve demulsifier performance at the Mega-Scale. Both have provided dramatic successes for our industrial partners through a better understanding of the importance of local mixing conditions. In this proposal we expand from the practical design and application of mixing principles to developing the theory which will allow modelling and prediction of mixing from the micro-litre to the Mega-Litre scale.

化学过程工程中有两个有趣的全球趋势。在欧洲，土地是稀缺的，并且有强烈的承诺对加工的加工。这导致了非常小的微反应器的发展（微电灯阶数量）。在全球商品化学品市场中，规模驱动过程的经济设计和“创纪录能力”工厂经常委托。这些反应堆的体积通常为1兆升。加拿大的两个重要行业，油砂的提取和矿产加工需要世界上一些最大的船只。这两个行业在多相和部分混合的多组分混合中也遇到了困难的问题。纳米技术学会告诉我们，规模的急剧变化需要思维的变化：物理学保持不变，但主导变量的变化变化。从升至微米尺度移动时，颗粒质量变得可以忽略不计，微小的表面电荷变得极为重要。从1L移动到1 mL量表时，相对于关键过程时间尺度而言，混合时间变得如此长，以至于它本质上是无限的。在大型尺度上，局部混合条件变得极为重要，并且经常主导过程性能。要成功设计和操作1ML工艺容器，需要清晰的混合规格。这需要了解局部湍流，局部分离（注入浓度）以及混合时间与时间尺度，长度尺度和浓度尺度相互作用。我们有两个测试容器，可以有效地测量这些变量。第一个应用于在非常高的湍流水平下的纳米粒子沉淀的缩放。第二个使我们能够在巨型尺度上提高拆卸器的性能。两者都通过更好地理解当地混合条件的重要性为我们的工业伙伴提供了巨大的成功。在此提案中，我们从混合原理的实用设计和应用扩展到开发理论，该理论将允许建模和预测从微型升级到巨型量表。