HIGH-PURITY MONOETHYLENE GLYCOL PRODUCTION PROCESS Russian patent published in 2004 - IPC

FIELD: industrial organic synthesis.

SUBSTANCE: invention relates to improved process of distillation isolation of high-purity monoethylene glycol from ethylene oxide hydrolysis product by dehydration on pressure dehydration set, wherein at least one column has distillation section with at least one separation stage and wherein temperature below feeding point of pressure dehydration column is higher than 80^оС and pressure in distillation section is at least 1 bar. A part of top stream is removed from the system and the rest is dehydrated in vacuum to withdraw aqueous stream containing monoethylene glycol in concentration below 1 wt %, preferably 0.1 wt %, middle-boiling components, and low boiling components. The stream is removed from the system, probably after further processing. Remaining material is subjected to distillation purification on distillation purification column, wherein between top stream withdrawal and side withdrawal of monoethylene glycol there are from 1 to 10 separation stages disposed. Vacuum dehydration is carried out either on two vacuum dehydration columns, wherein aqueous stream is withdrawn as top stream of the second column, or on one vacuum dehydration column, wherein aqueous stream is withdrawn as side stream. Top stream of the monoethylene glycol distillation purification column is returned into middle part of vacuum dehydration column or last vacuum dehydration column.

EFFECT: simplified process and avoided use additives or supplementary equipment.

9 cl, 3 tbl, 4 dwg