Concentrated Bitumen-in-Water Emulsification in Coaxial Mixers

Abstract

A semibatch bitumen emulsification process to generate droplet size in the submicrometer range was developed in a coaxial mixer using a high-internal-phase ratio (HIPR) step followed by dilution to the final concentration of the dispersed phase. An HIPR emulsion is characterized by nonspherical droplets shape separated by thin films due to low ratio between the continuous-and dispersed-phase concentrations. The same mixing system was used to prepare the HIPR intermediate and the eventual emulsion, based on a pitched blade turbine on the high-speed shaft and two different types of close-clearance impellers on the low-speed shaft. It was found that the most critical process stage to achieve the mean droplet size was the preparation of the HIPR emulsion. The dispersed-phase and surfactant concentrations, the close-clearance impeller rotational speed, and agitation time were identified as key process parameters to control the droplet size. These parameters were combined to provide a prediction model of the average droplet size with two dimensionless parameters, namely, the initial surfactant concentration in the continuous phase and the bitumen weighted deformation.

A low‐energy emulsification batch mixer for concentrated oil‐in‐water emulsions

“…There is a range of commercially available equipment that can be used to produce HIPR oil‐in‐water (O/W) emulsions, for example, coaxial mixers12; colloid mills13; high‐pressure homogenizers14; and static mixers 15. The production of such emulsions is also possible by the use of a complex thermodynamic mechanism, which uses the inversion phenomenon as detailed elsewhere 16.…”

Inline Bitumen Emulsification Using Static Mixers

“…This also implies that the viscous forces are dominant leading to a process operated in the laminar regime. The approach elaborated by Gingras et al 2 consists of two steps, namely the formation of the right droplet size by mixing a HIPR emulsion at an optimized composition and a water dilution stage at a concentration allowing emulsion pumpability. The HIPR emulsion is formed by gradually adding bitumen to an aqueous phase, followed by mixing during a few minutes to reach the desired droplet size range.…”

Current Research and Challenges in Bitumen Emulsion Manufacturing and Its Properties

“…This technique may produce monomodal emulsions with extremely narrow particle size distributions and small mean droplet sizes of around 1 μm. Furthermore, this technique is capable of producing concentrated and extremely concentrated bitumen emulsions (70–95%) [ 102 , 115 ]. The droplet size of the emulsions generated by this method may be easily modified by varying the rotating speed, formulation parameters, or the concentration of the dispersed phase utilized during manufacturing.…”