Rate of Bitumen Film Transfer from a Quartz Surface to an Air Bubble as Observed by Optical Microscopy
The rate of bitumen transfer from a bitumen-coated quartz plate to a gas bubble surface in aqueous alkaline solutions was recorded photographically. During bitumen spreading, a bulk layer followed the formation of thin bitumen films (precursor films). The bulk layer spread at the bubble surface with a velocity of about one order of magnitude less than the velocity of the precursor film. The energy of activation for spreading of the bulk layer varied from about 66 to 123 kJ/mol depending on the stage of bitumen spreading but remained constant at about 105 kJ/mol for the precursor film. Results are discussed with respect to fundamental issues associated with flo t a t i o n r e c o v e ry of heavy oils.
Robust Aqueous–Nonaqueous Hybrid Process for Bitumen Extraction from Mineable Athabasca Oil Sands
Mining and processing of Athabasca oil sands in Alberta, Canada, is a great success story of government–industry collaboration, fulfilling increased domestic and worldwide demands for oil. However, economic and environmental incentives still exist in the oil sands industry to enhance oil recovery and reduce energy consumption and water use, while minimizing green-house gas emissions and tailings ponds. The current industrial bitumen extraction processes, after surface mining, are exclusively water-based and operate at elevated temperatures, typically between 45 and 50 °C. Robust low-temperature processes, with reduced in-take of feedwater, that are less sensitive to ore characteristics are in a strong demand from both environmental and economical point of views. In response to this demand, we propose a robust aqueous–nonaqueous hybrid bitumen extraction process, in which diluent such as kerosene and naphtha is added to the oil sands prior to oil sands slurry preparation to decrease bitumen viscosity and e...
Robust solutions of inverse problems in electromagnetic non-destructive evaluation
Non-destructive testing (NDT) is the application of physical measurement technology based on energy interaction with the material and its nonconformities. The material's response is sensed by transducers and sensors which?in most cases?scan the component and document the results in inspection images. However, NDT measures a physically defined quantity or even an intrinsic property. The difference between non-destructive evaluation (NDE) and NDT is in the interpretation of the inspection data. NDE has to discuss the inspection results in terms of quality elements and characteristics which are relevant to describe the fitness of the material for use. In the case of macroscopic defects these are the kind of defect (cracklike, globular) and its size and orientation to the main stress directions; in the case of material property determination the parameters are mainly mechanical properties. Therefore, in NDE one has to solve inverse problems. The solution of inverse problems based on mathematical procedures such as integral equations is a strong developing discipline and most of the articles prepared for this special issue of the journal have the objective of discussing the latest state of the art in that field. However, practical NDE needs robust and quick solutions which are to be applied mainly online. Therefore, we present here inversion procedures based on multiple linear regression algorithms applied to inspection data. We describe the calibration procedure to fit the free parameters of the model functions and give examples of practical applications in industry.