PRODUCTION METHOD FOR TRIOXANE Russian patent published in 2009 - IPC C07D323/06 

FIELD: chemistry.

SUBSTANCE: invention is related to production method for trioxane based on reaction of concentrated aqueous solutions of formaldehyde in presence of tungsten heteropolyacids, including additives of inorganic salts, in which from spent reaction mass heteropolyacid is regenerated, formaldehyde contained in spent reaction mass is removed by distillation with application of water as extractive agent, produced aqueous solution of heteropolyacid is evaporated, and after removal of formaldehyde acid is added, which is selected from the following row: nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, cationite, then extractive agent is added, such as organic dissolvent from the following group: butanol-1, butanol-2, pentanol-1, pentanol-2, cyclohexanol, octanol-1, decanol-1, 4-methyl-2-pentanone, butyl ether, benzol, nitrobenzol, ethyl acetate or their mixtures, produced extract is evaporated to initial volume of reaction mass, then heteropolyacid is transferred into aqueous phase, performing process of azeotropic distillation of extractive agent with application of water as azeotropizer, aqueous solution of heteropolyacid is exposed to extractive rectification with application of formaldehyde (50-60 wt % aqueous solution) as extractive agent, at that solution of heteropolyacid, water and formaldehyde suitable for further synthesis is produced in bottom of column.

EFFECT: syntheses on regenerated heteropolyacid indicate that it does not lose its activity, which increases its service life as catalyst.

1 cl, 2 tbl, 1 ex