Recovery of 1-Hydroxyethylpiperazine and Methyl Diglycol from a Waste Photoresist Stripper by Sequential Distillation

Abstract

In manufacturing TFT-LCD devices, a huge amount of various chemicals have been used. Including
polarizing film, liquid crystal, glass substrate, and photoresist, such compounds occupy form 60~70% of the production cost of the TFT modules. In the present work, we carried out the systemic lab-scale distillation experiments to regenerate the organic solvents from the waste photoresist stripping solution and check the product specification feasible to commercial TFT-LCD grade chemicals also build up process to separate organic solvent in distillation column. Rigorous process simulator was used to build up solvent separation
process. Finally, the best distillation sequence with optimal distillation conditions were proposed.