Aggregation and sedimentation of fine solids in non-aqueous media

• Author / Creator

  Fotovati, Maryam

• A major challenge to any “solvent-based” bitumen extraction technology is the removal of suspended fine solids from the hydrocarbon medium (i.e. diluted bitumen). To address this problem, we examined how colloidal solids could be made to aggregate in a hydrocarbon medium and thus be separated by gravity settling. The model solids were micron-sized “bitumen-treated” silica particles; the oil phase was bitumen diluted in an organic solvent of variable aromatic content. On the macroscopic scale, the experiments involved quantifying the settling rates of the particles as the aromatic content of the solvent was varied. Our results showed the existence of an optimal (non-zero) aromatic content at which the solids settling rate was the highest. On the microscopic scale, adhesive forces between individual glass spheres were directly measured using the microcantilever technique (again in non-aqueous media). It was demonstrated that, in addition to being captured by asphaltene networks, the suspended solids could also homo-flocculate — and thus form aggregates and be separated — in an alkane-diluted bitumen environment.

• Subjects / Keywords

  • Inter-particle force
  • Non-aqueous
  • Colloid
  • Sedimentation
  • Silica

• Graduation date

  Spring 2011

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3TD3K

• 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.