METHOD OF SYNTHESIS OF ETHANOLAMINES Russian patent published in 1999 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: process of hydroxyethylation of anhydrous ammonia is carried out in the single apparatus-reactor working in the mixing regime where parent reagents and condensed ammonia distilled out from an evaporator at 110-150 C are fed additionally. The interaction in the reactor is carried out at 40-70 C, under pressure 15-35 atm and at mole ratio OE : ammonia = 1:(15-30). Obtained mixture is fed into evaporator where distillation out of ammonia is occurred. It is necessary to maintain the pressure value in the system reactor-evaporator at equal values - at the range from 15 to 35 atm. Under these conditions of the process the reaction mixture formed has the following composition, %: monoethanol-amine 70-80; diethanolamine 17-22 and triethanolamine 3-10. Obtained mixture is fed to the separation stage. To obtain a mixture containing mainly diethanolamine the total amount of monoethanolamine obtained after the separation stage or its part is recyclized into the synthesis-reactor and the process is carried out under the same conditions but at the mole ratio OE : ammonia : MEA - 1:(15-30):(1-5). Obtained mixture of interaction products are fed to the separation stage which is carried out by the known procedure. Thus, the developed method ensures to modify the mixture composition increasing the content of mono- and/or diethanolamine depending on the demand. EFFECT: improved method of synthesis, decreased cost. 2 cl, 1 dwg, 1 tbl