Meso-mixing effects on demulsification in froth treatment: mechanisms and modeling

所有的化学工程都可以分为三个基本步骤：混合，反应和分离。虽然反应和分离已经被广泛研究了几个世纪，但（技术）混合文献只是在20世纪50年代才开始。几十年来，我们一直教导学生，过程是“充分混合”的-但我们的意思是充分混合的技术和全面的定义只出现在2009年（Kukukova等人）*混合通常是简单的或理想的，但当它作为一个问题出现时，它往往是难以捉摸的-出现在一组实验中，消失在其他明显相似的工作中。这有两个原因：第一，最近才开发出定义明确的混合测试单元;第二，混合最常见的是一个竞争速率过程-它与其他变量有很强的相互作用，不能孤立地考虑。在本提案中，将探讨将添加剂混合到稀释沥青泡沫中的初始阶段。在该方法中，如果添加剂以高浓度注入且混合不良，则在加工之前清除泡沫非常困难。如果这种添加剂在注射点进行预稀释和剧烈混合，化学品的使用可以减少一半，同时实现相同的分离。这是一个经典的介混问题，表明进料点的高局部浓度正在改变破乳剂添加剂所采取的化学作用。*新的实验工具使我们能够研究进料羽流，看看发生了什么，并确定破乳剂的命运。这是第一次有可能进行真实的现场测量。**

All of Chemical Engineering can be broken into three basic steps: mixing, reaction, and separations. While reaction and separations have been extensively studied for centuries, the (technical) mixing literature only begins in the 1950's. For decades, we have taught students that processes are "well mixed" - but a technical and comprehensive definition of what we mean by well mixed only appeared in 2009 (Kukukova et al.)****Mixing is frequently simple or ideal, but when it appears as a problem it is often elusive - appearing in one set of experiments and disappearing in other apparently similar work. There are two reasons for this: first, well defined mixing test cells have only recently been developed, and second, mixing is most frequently a competing rate process - it has strong interactions with other variables and cannot be considered in isolation.****In this proposal, the initial stages of mixing additive into diluted bitumen froth are to be explored. In this process, if the additive is injected at a high concentration with poor mixing, clean up of the froth before processing is very difficult. If this additive is prediluted and mixed vigorously at the point of injection, the chemical use can be cut in half while achieving the same separation. This is a classical mesomixing problem, indicating that high local concentrations at the feed point are changing the chemical action taken by the demulsifier additive.****New experimental tools allow us to look into the feed plume to see what is happening and determine the fate of the demulsifier. This is the first time in-situ measurements will be possible in real time.**