Method for producing cyclic formaldehyde derivatives from polyoxy dialkyl ethers

Abstract

A process for preparing trioxane from trioxymethylene glycol dimethyl ether (POMDMEn=3) by converting trioxymethylene glycol dimethyl ether in the presence of an acidic catalyst and subsequent distillative workup of the reaction mixture, comprising the steps of: a) feeding trioxymethylene glycol dimethyl ether (POMDMEn=3) or a mixture comprising trioxymethylene glycol dimethyl ether into a reactor and converting it in the presence of an acidic catalyst to a mixture a comprising trioxane, formaldehyde, water, methylene glycol (MG), polyoxymethylene glycols (MGn>1), methanol, hemiformals (HF), methylal (POMDMEn=1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>1); b) distillatively separating the reaction mixture a into a low boiler fraction b1 comprising formaldehyde, water, methylene glycol, methanol, hemiformal (HFn=1), methylal and dioxymethylene glycol dimethyl ether (POMDMEn=2), and a high boiler fraction b2 comprising trioxane, polyoxymethylene glycols (MGn>1), hemiformals (HFn>1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>2); c) distillatively separating the high boiler fraction b2 into a low boiler fraction c1 comprising trioxane, and a high boiler fraction c2 comprising polyoxymethylene glycols (MGn>1), hemiformals (HFn>1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>2).

Dependencies are inferred from the claim text.