Mixing and Settling Characterization in Low-Quality Bitumen Froth Treatment

• Author / Creator

  Saraka, Colin

• Bitumen froth is an intermediate product of bitumen upgrading which must be treated to remove solids and water. De-mineralization and de-watering occur through a settling operation in which the addition of a diluent and a demulsifier are crucial to its success. This work explores the effect of mixing variables in the addition of demulsifier, a chemical separation aid. This study probes the use of demulsifier and the effect of mixing on separation in a particularly challenging material: low-quality bitumen froth. Low-quality froth derives from low-quality bitumen ore, and is more challenging to process. Higher water and solids content and other properties, including the nature of the solids, contribute to this challenge. We use many of the same techniques used in previous studies in average-quality bitumen froth and diluted bitumen to analyze the effects of mixing variables in this new and challenging mixture. By some criteria, the mixing variables lead to expected process results: less water and solids are present in the top layer when mixing energy is high and injection concentration is low (in other words, chemical is more pre-diluted). Some unexpected results occurred as well: good mixing led to high induction time, or a long period of time after demulsifier addition before settling was detectable. Good mixing also led to lower water content in the bottom layer. Focused-beam reflectance measurement (FBRM) is an in-situ technique for particle- and droplet-size detection. It measures and counts chord lengths, which differ from diameter in that they can be read from anywhere on a spherical or non-spherical item. These chord lengths are arranged into a chord length distribution, like a drop size distribution or particle size distribution. By using FBRM, we hope to gain more understanding of the mechanisms that drive the settling process and are in turn affected by the mixing variables. This work marks the first attempt at using the FBRM to characterize mixing and settling in froth treatment.

• Subjects / Keywords

  • Bitumen froth
  • Mixing
  • Froth treatment

• Graduation date

  Fall 2017

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3S46HM0X

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.