| abstract |
For separation and recovery of dimethyl terephthalate (DMT) and ethyiene glycol (EG) from polyester waste containing foreign materials, the polyester waste is treated in EG containing a polyester depolymerization catalyst, a solid foreign material fraction floated on the surface of the resultant reaction solution is removed and the residual solid foreign material fraction is removed from the remaining solution fraction. The remaining solution fraction is distilled and concentrated and the distilled EG is recovered. A transesterification reaction catalyst and methanol are mixed into the distillation residue. The resultant reaction mixture is recrystallized and subjected to centrifugal separation to separate the reaction mixture into the DMT cake and a mixture solution, and then the cake is distilled whereby high-purity DMT is recovered. The residual mixture solution is subjected to distillation treatment for recovery of the methanol, and the distillation residue is distilled to recover EG. |