Competing Rates in Mixing Sensitive Processes: Test Cells and Models for Robust Design from the Bench Scale (1L) to the Mega-L and micro-L Scales

在化学过程工程领域，有两个有趣的全球趋势值得关注。在欧洲，土地稀缺，而且对流程集约化有着坚定的承诺。这导致了微型反应堆的发展，微型反应堆的体积非常小(体积约为微升)。在全球商品化学品市场，规模经济推动了工艺设计和“创纪录产能”工厂的定期投产。这些反应堆的体积通常为100万升。加拿大的两个重要行业--油砂开采和矿物加工--需要一些世界上最大的船只。这两个行业还面临着多相和部分混相的多组分混合的难题。 纳米技术告诉我们，规模的戏剧性变化需要思维的转变：物理学保持不变，但主导变量发生变化。从升到微升，粒子的质量变得微不足道，微小的表面电荷变得极其重要。从1L尺度移动到1ML尺度时，混合时间相对于关键工艺时间尺度变得如此之长，以至于基本上是无限的。在兆级范围内，局部混合条件变得极其重要，并且往往主导过程性能。 为了成功地设计和操作1ml工艺容器，需要明确的混合规格。必须确定本地混合条件和重要工艺速率(例如反应速率)之间的关系。两个创新的测试容器提供严格控制的混合，以满足这一需求。第一种方法已被应用于纳米粒子沉淀的规模缩小；第二种方法成功地预测了破乳剂性能在百万级的改进。在这项研究中，这些测试单元发现了两个新的应用，开发了基本理论和模型，使从微升到兆升的稳健混合设计成为可能。

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. The relationship between the local mixing conditions and the important process rates (e.g. reaction rates) must be defined. Two innovative test vessels provide tightly controlled mixing which satisfies this need. The first has been applied to scale-down of nano-particle precipitation; the second has successfully predicted improved demulsifier performance at the Mega-Scale. In this research these test cells find two new applications, developing the fundamental theory and models which will allow robust mixing design from the micro-litre to the Mega-litre scale.