1 CH E 534 Fundamentals of Oil Sands Extraction (Winter 2021) Assignment 4 Due date: April 16, 2021 (Friday) at 17:00. Upload your solution, in the form of a pdf file, on eClass. • No late submission...

2 questions


1 CH E 534 Fundamentals of Oil Sands Extraction (Winter 2021) Assignment 4 Due date: April 16, 2021 (Friday) at 17:00. Upload your solution, in the form of a pdf file, on eClass. • No late submission is accepted. • Handwriting assignment. • Answers without clear explanation or analysis will not be graded. • Illegible work will not be graded. Note: weight: 22.5% of final mark on assignments, i.e., maximum final mark = 9 marks. Q1(20 marks) A partially wetting particle having a water contact angle θ is located at oil-water interface as shown below. The radius of spherical particle is r, and the height of sphere cap in water is h. The surface area of a sphere cap A is2??ℎ. Surface area of a sphere cap: ?=2??ℎ 1) You are asked to derive the free energy change ∆? when the particle was moved from oil-to- water interface into the oil phase completely (as shown in graph) (10 marks). 2) For toluene (o)=water (w) interface where ??/? = 36.1 ??/? 2, please calculate the free energy change at a given contact angle ? =60°and particle radius r = 100 nm, by using the equation derived above (5 marks). 3) Given kB = 1.38 x 10-23 J/K, T=298 K, please calculate the ratio of free energy change to kBT (5 marks). Q2 (20 marks) Charges on particles and bitumen droplets control the interactions between them and hence bear important implications in bitumen production from oil sands using a water-based extraction process. The zeta potential distributions of bitumen and fines measured separately in the process water of the good processing ores are shown in the figure below. Taking this figure as your basis and considering fines being mainly clays, you are asked to: 2 1) Sketch zeta potential distribution of bitumen and fines measured separately in the processing water from poor processing ores and justify your sketch (5 marks); 2) Sketch zeta potential distribution of bitumen and fines measured together in the processing water from poor processing ores if sufficient amount of fines are present, and justify your sketch (5 marks); 3) Sketch most probable interaction energy profiles for bitumen interacting with clays in process water from good and poor processing ores, respectively (5 marks). 4) Explain the implications of your results in 2) above in the context of bitumen flotation and propose what you would do to improve bitumen recovery from the poor processing ore encountered (5 marks).