| 摘要 |
For separation and recovery of dimethyl terephthalate (DMT) and ethylene glycol (EG) from polyester (polyethylene terephthalate (PET)) waste containing foreign materials, the polyester waste is treated in EG containing a polyester depolymerization catalyst at 175 to 190 DEG C under 0.1 to 0.5 MPa, a solid foreign material fraction floated on the surface of the resultant reaction solution is removed by a floatation separation method, the residual solid foreign material fraction is removed from the remaining solution fraction by a solid/liquid separation method, the remaining solution fraction is distilled and concentrated and the distilled ethylene glycol is recovered, a transesterification reaction catalyst and methanol are mixed into the distillation residue, to cause a transesterification reaction between the residue and methanol to occur and to produce DMT and EG, the resultant reaction mixture is recrystallized and subjected to centrifugal separation to separate the reaction mixture into the DMT cake and a mixture solution, the cake is subjected to distillation purification, the distilled high-purity DMT is recovered, the residual mixture solution is subjected to distillation treatment for recovery of the methanol, and then the distillation residue is distilled to recover EG. <IMAGE> |
