processo integrado para preparar trioxano a partir de formaldeído

The invention relates to an integrated process for preparing trioxane from formaldehyde in which, in a first step, a stream A 1 comprising water and formaldehyde and a recycle stream B 2 consisting substantially of water and formaldehyde are fed to a trioxane synthesis reactor in which the formaldehyde is converted to trioxane to obtain a product stream A 2 comprising trioxane, water and formaldehyde. Stream A 2 and a recycle stream D 1 comprising trioxane, water and formaldehyde are fed to a first distillation column and distilled at a pressure in the range from 0.1 to 2.5 bar to obtain a stream B 1 enriched in trioxane, and the stream B 2 consisting substantially of water and formaldehyde. Stream B 1 is fed to a second distillation column and distilled at a pressure in the range from 0.2 to 17.5 bar to obtain a product stream C 2 consisting substantially of trioxane, and a stream C 1 comprising trioxane, water and formaldehyde. Stream C 1 is fed to a third distillation column and distilled at a pressure in the range from 1 to 10 bar to obtain the recycle stream D 1 comprising trioxane, water and formaldehyde, and a stream D 2 consisting substantially of water.