PROCESS FOR PREPARING TRIOXANE FROM TRIOXYMETHYLENE GLYCOL DIMETHYL ETHER

摘要

The invention relates to a method for producing trioxane from trioxymethylene glycol dimethyl ether (POMD- MEn=3) by reacting trioxymethylene glycol dimethyl ether in the presence of an acidic catalyst and subsequently processing the reaction mixture by distillation. The method comprises the following steps: a) feeding trioxymethylene glycol dimethyl ether (POMDMEn=3) or a mixture containing trioxymethylene glycol dimethyl ether to a reactor and reacting the substance in the presence of an acidic catalyst to give a mixture (a) containing trioxane, formaldehyde, water, methylene glycol (MG), polyoxymethylene glycols (MGn1), methanol, hemiformals (HF), methylal (POMDMEn=1) and polyoxymethylene glycol dimethyl ether (POMDMEn1); b) separating the reaction mixture (a) by distillation to give a low-boiling fraction (b1) containing trioxane, formaldehyde, water, methylene glycol, methanol, hemiformal (HFn=1), methylal and dioxymethylene glycol dimethyl ether (POMDMEn=2) and a high-boiling fraction (b2) containing polyoxymethylene glycols (MGn1), hemiformals (HFn1) and polyoxymethylene glycol dimethyl ether (POMDMEn2); c) separating the low-boiling fraction (b1) by distillation to give a low-boiling fraction (c1) containing formaldehyde, water, methylene glycol, methanol, hemiformal (HFn=1), methylal and dioxymethylene glycol dimethyl ether (POMDMEn=2) and a high-boiling fraction (c2) containing trioxane.