Devolatilization, often referred to as solvent recovery, is the act of removing a volatile from solids. Thermal solvent recovery offers an efficient approach to removing volatile liquids from solids under an inert environment. The schematic presented displays how indirect heat along with a low-volume counter-current nitrogen stream removes volatiles. Solvent laden feed enters the dryer, a Solidaire in this example, represented by the blue ribbon. The vessel walls are heated via steam or hot oil in the jacket, which in turn heats up and vaporizes the solvent. A heated counter-current nitrogen stream picks up the vaporized solvent, and carries it away from the solids. Though this is typically done through thermal treatment, options do exist for mechanical separation in some cases. Our Screw Press offers vapor-tight mechanical separation, whether as the entire removal step or as a preceding step to thermal recovery to minimize utility requirements.
Devolatilization not quite what you were looking for? Take a look at our other thermal and mechanical separation processes to see if there is a better fit for your application.
Selection of an appropriate method and product for devolatilization primarily depends on two factors; feed properties and product requirements. Feed properties of importance include the solvent to be removed, how much of the solvent is present, and any temperature limitations pertaining to the solids. Product requirements are primarily isolated to moisture level or desired solvent content in your final solids. Depending on these characteristics, Bepex has four primary devices for solvent extraction and recovery. The Solidaire offers high-efficiency and shorter residence times and is our most commonly used solvent recovery dryer. The TorusDisc provides longer residence times and moderate internal back-mixing, helping it achieve PPM moisture levels in the final product. Our Purge Vessel offers true plug flow and extended residence time, when precise control is necessary. If you’re looking to avoid evaporation, our vapor-tight Screw Press design provides mechanical solvent separation. Each of these products and correlating systems are available to test continuous devolatilization in our Process Development Center.