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“良好混合的”——但是我们所说的良好混合的技术和全面定义直到2009年才出现（Kukukova等人）****混合通常是简单或理想的，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，而消失在其他明显类似的工作中。这有两个原因：首先，定义良好的混合试验单元是最近才开发出来的；其次，混合通常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，将添加剂混合到稀释沥青泡沫的初始阶段进行探索。在这个过程中，如果添加剂以高浓度注入，混合不良，在加工前清理泡沫是非常困难的。如果在注射点对这种添加剂进行预稀释并大力混合，则在实现相同分离的同时，化学品的使用可以减少一半。这是一个经典的中混问题，表明在进料点的高浓度正在改变破乳剂添加剂的化学作用。****新的实验工具使我们能够观察饲料羽流，看看发生了什么，并确定破乳剂的命运。这是第一次现场实时测量成为可能

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.**