Nanocellulose as an inhibitor of water-in-crude oil emulsion formation

Abstract

Formation of water/oil emulsions is a frequent and challenging problem to deal with during crude oil extraction and processing. Crude oil must have water contents (BS&W) below 0,5% to meet transport and export requirements. Lowering BS&W values in crude oils involve physical and chemical processes or their combinations. Chemical demulsifiers, particularly, are structurally diverse and predominantly petrochemically-derived; however, alternative surface-active compounds such as biosurfactants are nowadays the topic of active research. In this contribution, we report the use of aqueous suspensions of cellulose nanoparticles, both nanocrystals (CNC) and nanofibrils (CNF), to inhibit the formation of w/o emulsions. HLB values of 13.0 for CNF and 10.7 for CNC indicate that these materials are hydrophilic o/w emulsifying agents, and as such can also act as destabilizers for w/o emulsions. We observe, by recovered water and Near-Infrared (NIR) scattering measurements, that CNC and CNF can effectively function as inhibitors of synthetic w/o and natural w/crude oil emulsions. Aqueous suspensions of CNC and CNF decrease the amount of emulsified water, inhibiting the formation of w/o emulsions up to 75% in some cases.