FEIS used to recycle MEG through thermal distillation using Dowtherm. However, the process creates residues that are categorized as hazardous waste due to high moisture and oligomers. 
To lower environmental impacts and processing costs, FEIS adopted a new method in 2024 using diaphragm pumps and centrifuges, a more effective separation technique that significantly reduced the residue by 96% and resulted in a low moisture content. The improvement reduced approximately NT$2.22 million in the cost of hazardous waste treatment. Additionally, as heating is no longer involved, the approach also cut the energy cost by approximately NT$2.08 million.