Managing interface composition and hydrodynamics to enhance coalescence in froth treatment

在油砂开采过程中，会产生含有~ 30wt %水和~ 10wt %固体分散在沥青（~ 60wt %）中的泡沫流。需要去除固体和水，以减轻下游过程中的侵蚀、结垢和腐蚀。在环烷泡沫处理（NFT）过程中，加入石脑油（溶剂）来降低沥青的密度和粘度，以促进水和固体的去除。加入溶剂和离心后，水和固体含量可分别保持在2.5wt%和0.5wt%以上。寻找改善水和固体去除的方法是提高Syncrude作业效果和效率的首要任务。我们之前的工作表明，改善水和固体的去除需要促进聚结，以及固体附着在水滴上，这取决于施加的压力，接触时间，溶剂的数量和化学性质，以及水相的pH值。我们假设，了解沥青组分在油水界面吸附的比例，以及导致聚结的流体动力学，我们可以制定工艺策略，以最少的溶剂和能源使用实现水和固体的最佳分离。该申请涉及3名博士和1名硕士。1名博士生将开发薄膜平衡装置，用于研究沥青薄膜的流体力学和分离压力曲线。第二个博士学位将发展吸附等温线和模型，以预测与预测聚结时间相关的界面性质。第三位博士将开发微流体装置来研究水滴在粒子存在下的聚结。一名MASc学生将致力于开发微流体装置，该装置可以评估高温下的聚结过程和界面特性，接近于NFT中使用的微流体装置。他们将分别由sacosta教授和Ramchandran教授指导，他们分别是胶体和界面以及流体动力学和微流体学领域的专家。他们的互补专业知识将得到Syncrude高级研究员专家Samson Ng博士的进一步支持，他将把实验规模的研究转化为目前正在运行的大规模工艺。

During oil sands extraction, a froth stream containing ~30 wt% water and ~10 wt% solids dispersed in bitumen (~ 60 wt%) is produced. Solids and water need to be removed to mitigate erosion, fouling and corrosion in downstream processes. In the naphthenic froth treatment (NFT) process, naphtha (solvent) is added to reduce bitumen density and viscosity to facilitate water and solids removal. After solvent addition and centrifugation the water and solids content can remain above 2.5wt% and 0.5wt%, respectively. Finding ways to improve water and solid removal is a priority to enhance the effectiveness and efficiency of Syncrude operations.Our previous work showed that improving water and solid removal requires facilitating coalescence, and solid attachment to water drops, and that this depends on the applied pressure, contact time, the amount and chemistry of solvent, and the pH of the aqueous phase. We hypothesize that understanding the ratio of bitumen components adsorbed at the oil-water interface, and the hydrodynamics leading to coalescence we can develop process strategies to achieve optimal separation of water and solids with minimum use of solvent and energy.The application involves 3 PhDs and 1 MASc. One PhD student will develop film balance devices to study the hydrodynamics and disjoining pressure curves of bitumen films. A second PhD will develop adsorption isotherms and models to predict interface properties relevant to the predicting coalescence time. A third PhD will develop microfluidic devices to study water drop coalescence in the presence of particles. One MASc student will work on developing microfluidic devices that can evaluate the process of coalescence and interfacial properties at high temperatures, close to those used in NFT. These will be supervised by ProfessorsAcosta and Ramchandran who are experts in the areas of colloids and interfaces, and hydrodynamics and microfuidics, respectively. Their complementary expertise will be further supported by Dr. Samson Ng, senior Syncrude researcher expert in translating bench-scale studies into large scale processes that are currently in operation.