METHOD FOR PURIFICATION OF USED FIRE-RESISTANT TRIARYL PHOSPHATE TURBINE OIL FROM ACIDIC PRODUCTS Russian patent published in 2023 - IPC C10M175/00 

FIELD: processes for regeneration.

SUBSTANCE: processes for regeneration of used fire-resistant turbine oils based on triaryl phosphates. Method is proposed for cleaning waste fire-resistant triaryl phosphate turbine oil from acidic products by treating waste fire-resistant triaryl phosphate turbine oil with a freshly prepared solution of diazomethane in diethyl ether or methylene chloride at a temperature of 5-20°C and a 1.2-1.5-fold excess of diazomethane relative to the acid number of the used oil, followed by distillation of the organic solvent, or by treating the used fire-resistant triaryl phosphate turbine oil with a gaseous mixture of inert gas with diazomethane when the content of diazomethane in the inert gas is not higher than 7% by volume and process temperature is 25-30°C, and where, for example, nitrogen or argon is used as an inert gas.

EFFECT: simplification of the process of cleaning waste fire-resistant triaryl phosphate turbine oil from acidic products by eliminating the complex and multi-stage procedure for cleaning the oil after treatment with an alkaline solution and achieving the acid number of the oil at the fresh level, characterized by oil acid number values at ≤ 0.04 mg KOH/g.

3 cl, 2 dwg, 5 tbl