Original Articles
Yuejin Li1,2, Wei Chen1 and Ch
Abstract
The recovery of dimethylbenzene and butyl acetate from industrial spent solvent by batch distillation was studied. The first experiment was the batch distillation of a pretreated material. The second experiment was a heterogeneous azeotropic batch distillation, and the final experiment involved removing the light and heavy parts of the industrial spent solvent oil and then separating dimethylbenzene and butyl acetate from the remaining mixture. Different types of batch distillation methods to distill from waste solvents gave different recoveries of butyl acetate and dimethylbenzenes, and the dimethylbenzene-rich fractions generally contained low concentrations of butyl acetate. Using a heterogeneous distillation process allowed the separation process to be achieved at a lower temperature than was required for the normal distillation process. Multiple distillations gave higher recoveries and concentrations of butyl acetate and dimethylbenzenes in the distillates, but obviously involved higher levels of energy consumption. The process used for a particular industrial application should be chosen to suit the actual requirements of the application.