Managing interface composition and hydrodynamics to enhance coalescence in froth treatment

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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.