METHOD FOR OBTAINING ALKYLENE GLYCOL Russian patent published in 2016 - IPC C07C31/20 C07C29/12 

FIELD: chemistry.

SUBSTANCE: invention relates to method for obtaining alkylene glycol from alkene. Method includes the following stages: i) conversion of alkene in presence of oxygen and epoxidation catalyst into respective alkylene oxide in epoxidation reactor; ii) absorption of alkylene oxide in water absorber and further desorption of said absorber to provide water flow of alkylene oxide; iii) supply of water flow of alkylene oxide near inlet pipe into carboxylation reactor; iv) conversion of water flow of alkylene oxide in presence of one or several catalysts of carboxylation-hydrolysis and carbon dioxide into flow, including respective alkylene carbonate, in one or several carboxylation reactors; v) conversion of alkylene carbonate-including flow into alkylene glycol-including flow in one or several hydrolysis reactors; vi) removal of water from alkylene glycol-including flow with obtaining flow of dehydrated alkylene glycol in one or several dehydration columns; vii) purification of flow of dehydrated alkylene glycol in one or several glycol distillation columns with obtaining flow of purified alkylene glycol product and flow of recirculation of carboxylation-hydrolysis catalyst. Start-up procedure of said method includes supply of water flows, carboxylation-hydrolysis catalyst and carbon dioxide into carboxylation reactor and provision of start-up flow, which includes alkylene glycol, in introduction point near inlet pipe, used at stage iii), or downstream from it, and discharge of alkylene glycol flow from glycol distillation column.

EFFECT: claimed method makes it possible to increase process efficiency due to improved start-up procedure.

9 cl, 4 dwg