Intensified demulsification and separation of thermal oxide reprocessing interfacial crud (THORP-IFC) simulants

• Main Authors: Akay Galip, Pekdemir Turgay, Shakorfow Abdelmalik M., Vickers John
• Format: Article
• Language: English
• Published: De Gruyter 2012-01-01
• Series: Green Processing and Synthesis
• Subjects: demulsification; interfacial crud; nuclear reprocessing; oil-water separation; polyhipe polymer
• Online Access: https://doi.org/10.1515/greenps-2011-0510
• ISSN: 2191-9542; 2191-9550

Reprocessing of spent nuclear fuel for the recovery of the fissionable materials (mainly uranium and plutonium), is performed by solvent extraction. Thermal oxide reprocessing (THORP) is the most widely used technique in which processing fluids gradually degrade and form stable emulsions that are referred to as interfacial crud (IFC). IFC is highly viscous and stable and its deposition in the nuclear reprocessing circuit results in blockages and plant shut-down for the recovery of IFC and cleaning of the lines. IFC is also encountered in other non-nuclear extraction processes such as crude oil production from oil wells due to the presence of naturally occurring surface active species in crude oil. In this study, we first investigated the synthesis of a non-radioactive IFC simulants and subsequently examined its demulsification behavior (separation into oil and aqueous components). It was concluded that the IFC is stabilized by surface active species, the removal of which results in the demulsification and subsequent phase separation and the prevention of the IFC re-formation. Demulsification was carried out using sulfonated, micro-porous, crossed-linked materials known as PolyHIPE Polymers (PHP). Demulsification characteristic of the hydrophilic PHP is unique compared with other demulsifiers, since the capture of surface active species is largely irreversible and hence, demulsified IFC does not reform upon mixing of the oil and aqueous phases. It is therefore possible to remove surface active species from the reaction circuit continuously.