Intensified demulsification and separation of thermal oxide reprocessing interfacial crud (THORP-IFC) simulants
Green Processing and Synthesis
Reprocessing of spent nuclear fuel for the recovery of the fi ssionable materials (mainly uranium and plutonium), is performed by solvent extraction. Thermal oxide reprocessing (THORP) is the most widely used technique in which processing fl uids 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 shutdown for the recovery of IFC and
... ery 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 fi rst investigated the synthesis of a non-radioactive IFC simulants and subsequently examined its demulsifi cation 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 demulsifi cation and subsequent phase separation and the prevention of the IFC re-formation. Demulsifi cation was carried out using sulfonated, microporous, crossed-linked materials known as PolyHIPE Polymers (PHP). Demulsifi cation characteristic of the hydrophilic PHP is unique compared with other demulsifi ers, since the capture of surface active species is largely irreversible and hence, demulsifi ed 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.