A method for the preparation of 1,2-propanediol, dipropylene glycol and tripropylene glycol
The method for preparing 1,2-propanediol, dipropylene glycol and tripropylene glycol comprises step (a) of reacting propene with hydrogen peroxide containing nitrate in the presence of a catalyst mixture comprising a phase transfer catalyst and a heteropolytungstate in a liquid reaction mixture comp...
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Main Authors | , , |
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Format | Patent |
Language | Chinese English |
Published |
01.09.2022
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Subjects | |
Online Access | Get full text |
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Summary: | The method for preparing 1,2-propanediol, dipropylene glycol and tripropylene glycol comprises step (a) of reacting propene with hydrogen peroxide containing nitrate in the presence of a catalyst mixture comprising a phase transfer catalyst and a heteropolytungstate in a liquid reaction mixture comprising an aqueous phase with a maximum apparent pH of 6 and an organic phase; step (b) of separating the reaction mixture into an aqueous phase comprising 1,2-propanediol, dipropylene glycol, tripropylene glycol and nitrate and an organic phase; step (c) of recycling at least part of the separated organic phase to the reaction step (a); step (d) of hydrogenating the separated aqueous phase using a heterogeneous hydrogenation catalyst to provide a hydrogenated aqueous phase with a reduced nitrate content; and step (e) of recovering 1,2-propanediol, dipropylene glycol and tripropylene glycol from the hydrogenated aqueous phase by a sequential multiple step distillation. |
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Bibliography: | Application Number: TW202110138545 |