Demulsifier Performance in Diluted Bitumen Dewatering: Effects of Mixing and Demulsifier Dosage

Mixing conditions were explored as a possible avenue for improvement of demulsifier performance in the solvent diluted bitumen dewatering process. The effects of demulsifier bulk concentration, demulsifier injection concentration, and mixing energy on water and solids removal from the oil phase were tested. All of the experiments were carried out in a confined impeller stirred tank, which provides well-characterized mixing conditions and relatively uniform flow and turbulence. Results showed that lowering the injection concentration and increasing the mixing energy both improve demulsifier performance, allowing a 50% drop in the bulk concentration of demulsifier. This result agrees well with an earlier study by Laplante et al.(1) in which a different demulsifier was investigated. In that study, it was shown that the product of mixing time and energy dissipation rate at the feed point (the mixing energy = J) provides an alternate mixing variable.