PES Membrane Performance for Triethylene Glycol (TEG) Removal of Wastewater from Natural Gas Separation Process

Abstract

In the natural gas separation plant, triethylene glycol (TEG) is used as a liquid desiccant dehydrator to absorb water vapor from the gas stream. Even though TEG can be recovered and reused in the process by evaporation and distillation, some of TEG still remains in wastewater of this recovery process. In this work, the polyethersulfone (PES-NTR 7450) membrane was chosen to test for TEG removal capacity on both cross-flow filtration and pervaporation systems. The morphology of membrane and the content of TEG were characterized by scanning electron microscope (SEM) and gas chromatography (GC), respectively. The synthesis wastewater with average TEG content of 5%, 10%, and 20% were used as feed. The increase of feed concentration was trend to increase of TEG rejection (17.49%, 43.29%, and 62.22%). In case of industrial wastewater, the average TEG content of 10.7% was monitored for feed. The high effectiveness of PES-NTR 7450 membrane to remove TEG was performed in pervaporation system. TEG rejection of 99% was achieved at the operation condition of feed temperature 28ºC and applied pressure 1 kg/cm².