Reduction of the Residual Monomer and Volatile Organic Compounds by Devolatilization

The performance of devolatilization for cleaning industrial latexes was investigated. It was found that both steam and air saturated with water were very efficient in volatile organic compound (VOC) removal, as well as in controlling the solids content. No dependence of the VOC removed fraction on the initial VOC concentration was observed. An increase in the stripping gas flow rate improved the devolatilization efficiency because the mass transfer from the aqueous phase to the gas phase, which is the controlling step of the elimination process, was enhanced. At constant pressure, an increase in the temperature led to a higher devolatilization rate because of the increase of the Henryʹs law constant. No effect of the temperature when the system worked under boiling conditions was observed, likely because of the negligible change of the ratio of the Henryʹs law constant over the water vapor pressure under the studied range of experimental conditions. On the other hand, it was observed that the devolatilization was not efficient enough to remove highly hydrophilic and low volatile compounds.