Investigation of the Factors and Mechanisms Affecting the Foaming of Triethylene Glycol in Natural Gas Purification

With increasing natural gas processing demands, triethylene glycol (TEG) in dehydration systems becomes contaminated by gas-carried impurities, leading to problematic foaming, degradation, and significant glycol losses that compromise operational economics, pipeline integrity, and product quality. To systematically investigate impurity effects, we conducted comprehensive single-factor TEG regeneration experiments simulating field conditions. Through precise measurements of foaming height, defoaming time, and interfacial tension, we established clear correlations between impurity types and TEG foaming characteristics. Our results demonstrate a distinct hierarchy of foaming influence: chemical additives > solid impurities > water-soluble inorganic salts > MDEA > hydrogen sulfide > hydrocarbons. Chemical additives showed the most pronounced effect on surface tension, reducing it to 31.1 mN/m at 1500 mg/L. Water-soluble inorganic salts affected foaming through combined decomposition and crystalline morphology effects, ranked as MgCl2 > NaHCO3 > KCl > NaCl > Na2SO4 > CaCl2 (MgCl2 achieving 33.8 mN/m at 2000 mg/L). Solid impurity impacts correlated strongly with particle morphology (CaCO3 > Fe2O3 > CaSO4 > ZnO > CuO > Al2O3 > FeS), stabilizing at 1.5 mg/L. Hydrocarbons showed negligible influence, while hydrogen sulfide and MDEA caused only minor surface tension reductions with limited foaming effects. Based on these findings, we propose targeted mitigation strategies for industrial implementation.