Disclosed is a method of producing trioxane, including: (A) preparing trioxane from a high-concentration formaldehyde aqueous solution in the presence of an acid catalyst; (B) distilling a mixture including trioxane; (C) liquefying the distilled gas mixture; (D) mixing the liquefied liquid mixture with an extraction solvent and separating the mixture into an aqueous phase and a solvent phase; (E) distilling the solvent phase to give trioxane, and mixing the aqueous phase with the extraction solvent to give a mixture, which is then separated into an aqueous phase and a solvent phase; and (F) discharging the aqueous phase separated in (E) out of the system, and recirculating the solvent phase so as to be reused in (D) and (E).

The present invention relates to a process for producing cyclic acetal comprising i) preparing a reaction mixture comprising a) a formaldehyde source in a liquid medium and b) a catalyst; ii) converting the formaldehyde source into cyclic acetals, wherein the final conversion of said formaldehyde source to said cyclic acetal is greater than 10% on basis of the initial formaldehyde source.

The present invention relates to a process for producing cyclic acetal comprising i) preparing a reaction mixture comprising a) a formaldehyde source in a liquid medium and b) a catalyst; ii) converting the formaldehyde source into cyclic acetals, wherein the final conversion of said formaldehyde source to said cyclic acetal is greater than 10% on basis of the initial formaldehyde source.

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) a formaldehyde source, b) an aprotic compound and c) a catalyst; wherein the total amount of protic compounds is less than 40 wt.-%, based on the total weight of the reaction mixture; and ii) converting the formaldehyde source into cyclic acetals.

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) a formaldehyde source, b) an aprotic compound and c) a catalyst; wherein the total amount of protic compounds is less than 40 wt.-%, based on the total weight of the reaction mixture; and ii) converting the formaldehyde source into cyclic acetals.

Method for preparing trioxane derivatives.

Method for preparing trioxane derivatives.

A composition containing (A) 58.5 to 65.5 mass % of formaldehyde, (B) 0.7 to 4.5 mass % of methanesulfonic acid; and (C) less than 0.007 mass % of a metal salt, wherein a total content of the formaldehyde (A) and the methanesulfonic acid (B) is less than 68 mass %, and the metal salt (C) contains at least one selected from a group consisting of a nitrate, a nitrite, and a persulfate.

A composition containing (A) 58.5 to 65.5 mass % of formaldehyde, (B) 0.7 to 4.5 mass % of methanesulfonic acid; and (C) less than 0.007 mass % of a metal salt, wherein a total content of the formaldehyde (A) and the methanesulfonic acid (B) is less than 68 mass %, and the metal salt (C) contains at least one selected from a group consisting of a nitrate, a nitrite, and a persulfate.

A process for preparing trioxane from methanol includes: step 1: subjecting a mixture of methanol and methylal to a reaction to obtain formaldehyde, and absorbing the formaldehyde with water to obtain a concentrated formaldehyde aqueous solution; step 2: subjecting the concentrated formaldehyde aqueous solution to cyclization to obtain a mixture containing trioxane, and passing the mixture through a trioxane concentration tower to obtain a crude trioxane product; step 3: converting a by-product and unreacted formaldehyde in the crude trioxane product into methanol, conducting dehydration through a membrane dehydration process, and subjecting a retentate to dealcoholization to obtain purified trioxane; and step 4: subjecting the remaining streams to reactive distillation to obtain a mixture of methanol and methylal at a top- and water at a bottom of the reactive distillation tower; returning the mixture of methanol and methylal to step 1; and returning or discharging the water.