Key Performance Indicators Reveal the Impact of Demulsifier Characteristics on Oil Sands Froth Treatment

Demulsification with ethylene oxide (EO)-propylene oxide (PO) block copolymers is a very effective technique for treating water-in-oil emulsions in the petroleum industry. In this work, two series (A and B) of EO-PO block copolymers were synthesized and studied. The demulsifiers were defined by their relative solubility number (RSN) and interfacial tension (IFT). The performance of demulsifiers was evaluated by measuring the percent water and solids contents in dilbit product and hydrocarbon (diluent/ bitumen) losses to the underflow. Demulsifiers from series B showed higher performance on dilbit dehydration and demineralization as compared to demulsifiers from series A. The higher dehydration, and demineralization efficiencies for series B demulsifiers were a result of the higher adsorption and lower IFT values at the oil/water interface. Demulsifiers from series B also showed higher hydrocarbon losses to the underflow. These higher hydrocarbon losses were associated with higher solids-removal efficiencies. The biwettable clay solids surfaces have a strong affinity for hydrocarbon components, causing increased hydrocarbon losses to the underflow.