Patent ID: 7700809
Filing Date: 2010-04-20
Classification: C07C,C08G

Abstract:
1. A process for preparing tri- and tetraoxymethylene glycol dimethyl ether (POMDME n=3,4 ) by reacting formaldehyde with methanol and subsequently working up the reaction mixture by distillation, comprising the steps of: a) feeding an aqueous formaldehyde solution having a formaldehyde concentration of from 20 to 60% by weight and methanol into a reactor and reacting to give a mixture a comprising formaldehyde, water, methylene glycol (MG), polyoxymethylene glycols (MG b) feeding the reaction mixture a into a first distillation column and separating it into a low boiler fraction b c) feeding the high boiler fraction b d) feeding the low boiler fraction c e) feeding the high boiler fraction d f) feeding the organic phase e g) optionally feeding the aqueous phase e