Thin Liquid Films: WaterinBitumen Emulsions

1
Thin Liquid Films Water-in-Bitumen Emulsions

• Shawn Taylor
• NSERC Industrial Research Chair
• in Oil Sands Engineering
• Department of Chemical and Materials Engineering
• University of Alberta
• Edmonton Alberta

2
Motivation

• Water-in-oil emulsions commonly occur in the oil
  industry
• Components of bitumen
• Saturates, aromatics, resins, asphaltenes, and
  solids
• Asphaltenes are primarily responsible for
  emulsion stability

3
What is a Thin Film?
4
Motivation

• Emulsion stability depends strongly on the
  properties of the thin liquid films formed
  between two approaching water droplets.
• Study a single thin film using Thin Liquid
  Film-Pressure Balance Technique
• Investigate emulsion stability at the nanometer
  scale

5
Experimental Concept
Emulsion
6
Schematic of TLF-PBT
7
Outline of Experiments

• Determine the effect of solventbitumen ratio on
  
• Disjoining pressure
• Film Lifetime
• Solvents
• Toluene heptane
• Simulated industrial water

Diluted Bitumen Film
Water
8
Typical Film Behaviour(31 toluenebitumen)
9
Typical Film BehaviourTolueneBitumen31
10
Measured Parameters Equivalent Film Thickness

• Two surfactant layers
• liquid core
• Accuracy
• Ideal films ? 0.1 nm
• Bitumen films 0.5 nm

11
Measured Parameters Disjoining Pressure
Isotherms

• Excess pressure due to molecular interactions
  between the interfaces
• Acts normal to the interface

12
Disjoining Pressure IsothermToluene Diluted
Bitumen
13
Measured Parameters Film Lifetime

• Time from film formation to film rupture.
• A stable film will have an infinite lifetime.

14
Film LifetimeHeptane Diluted Bitumen
15
Conclusions

• Emulsion stability depends strongly on the
  properties of the thin film
• 11 TolueneBitumen
• Stable film
• 51 and 101 TolueneBitumen
• Film destabilized with dilution
• HeptaneBitumen
• Destabilized film by using aliphatic solvent