Objective Analyze the reasons for the influence of water-soluble inorganic salts as one of the main impurities on the dehydration performance of triglycol(TEG), so as to provide a basis for the quality control of TEG.

Methods By analyzing the composition and mass fraction of waste TEG water-soluble inorganic salts, nine water-soluble inorganic salts, such as NaCl, KCl, MgCl₂, CaCl₂, Na₂SO₄, NaHCO₃, FeCl₃, BaCl₂, and NaF, were determined as impurities. Under the conditions of mass fraction was 15.5 mg/g and the temperature was 182 ℃, by 50 times of cyclic regeneration and continuous heating for 48 hours, the regeneration process of cyclic regeneration of TEG and TEG retained in the reboiler was simulated, and the regeneration process of TEG was analyzed.

Results The water-soluble inorganic salt had little effect on the composition and properties of TEG under the condition of multiple cycles of regeneration, but the water content increased. However, under the condition of continuous heating and regeneration for a long time, the effective content of TEG decreased and the organic impurities increased. These organic impurities didn't meet the requirements of the TEG dehydration system, resulting in the decrease of the dehydration performance and pH value of the regenerated TEG, and the enhancement of the foaming performance.

Conclusions The influence of water-soluble inorganic salts on the properties of TEG mainly depends on the regeneration conditions, the recycling and regeneration will not affect the properties of TEG. Continuous heating for a long time at the regeneration temperature, the water-soluble inorganic salts will change the properties of TEG significantly, resulting in the decline of TEG adaptability in the dehydration system.