Oxidative degradation of triethylene glycol

• Published in: Chemical engineering science 2024-04, Vol.287, p.119706, Article 119706
• Main Authors: Høisæter, Karen K., Buvik, Vanja, Villa Gonzalez, Susana, Vevelstad, Solrun J., Knuutila, Hanna K.
• Format: Article
• Language: English
• Subjects: Gas dehydration; Glycol stability; Monitoring; Oxidative degradation; Triethylene glycol
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2024.119706

[Display omitted] •The oxidative degradation of TEG increases with increased temperature.•The oxidative degradation of TEG increases with increased oxygen available.•Small glycols and organic acids are formed during the oxidative degradation of TEG.•Larger glycol chains formed during oxidation, indicating possible polymerization.•GC-FID and HPLC-UV can be used to quantify glycols and organic acids, respectively. Triethylene glycol (TEG) is unstable in the presence of oxygen and at high temperatures, though the degradation mechanisms occurring are not properly understood. In attempting to close some of the knowledge gaps, laboratory-scale degradation experiments have been conducted to assess the effect of temperature and oxygen on the stability of TEG. Oxidative degradation experiments with TEG were conducted. The oxidative degradation mechanism seems to change with temperature and oxygen concentration. Multiple oxidative degradation compounds of TEG were detected and quantified. These included MEG, diethylene glycol (DEG), formic acid, acetic acid, glycolic acid, formaldehyde, acetaldehyde, and water. Formic acid, MEG, and DEG are the dominant identified degradation products both at high temperatures and at high oxygen concentrations. In addition, the formation of CO2 and larger polymeric glycols was confirmed. The carbon- and mass balance indicate unidentified degradation products in the liquid and gas phases.