Abstract: Polyacetal obtained by the polymerization of trioxane, for example, suspended in an organic solvent, in the presence of a comonomer (for example, ethylene oxide), is stabilized by hydrolysis in the heated state under pressure and then, after hydrolysis, the reaction mixture is depressurized to atmospheric pressure in order to release an aqueous phase containing the polymer and a vapor phase which contains formaldehyde and trioxane. According to the invention, the latter is recycled directly into the formaldehyde trimerization stage under reduced pressure.

Abstract: A continuous process for the manufacture of carboxylic peracids by reacting the corresponding carboxylic acid with hydrogen peroxide in the presence of a catalyst and in the presence of an inert organic liquid which is a solvent for the peracid and is capable of forming a heterogeneous azeotrope with water, removing the water present in the reaction mixture by distillation of the water/organic liquid azeotrope, and keeping sufficient water in the reaction mixture to allow the formation of an aqueous phase which is separate from an organic phase containing the organic liquid.

Abstract: A process for the recovery of carboxylic acids from mixtures containing glycol esters derived from these acids. The process comprises reacting these mixtures at boiling with water to form carboxylic acid and entraining the carboxylic acid formed by means of the water by azeotropic distillation, so as to separate off a mixture of carboxylic acid and water. This mixture is subjected to extractive distillation by means of an organic solvent which is insoluble in water and in which water is insoluble. A mixture of water and organic solvent is thereby separated from a solution of carboxylic acid in the organic solvent.

Abstract: A process for the purification of olefine oxides by subjecting a mixture containing the olefine oxides to distillation in a distillation column in the presence of a small amount of water in order to obtain olefine oxide as the distillate. A fraction of the down-flow liquid is withdrawn from the column and the withdrawn fraction is subjected to decantation, so as to separate off an aqueous phase which is discarded, and an organic phase. The organic phase is returned to the column at a point located below the withdrawal point.

Abstract: Organic solutions of percarboxylic acids are subjected to a wash by means of a dilute aqueous solution containing from 35 to 60% by weight of sulphuric acid, which if appropriate, is preceded by a preliminary wash by means of a concentrated aqueous solution containing more than 65% by weight of sulphuric acid.

Abstract: A continuous process for the manufacture of carboxylic peracids by reacting the corresponding carboxylic acid with hydrogen peroxide in the presence of a catalyst and in the presence of an inert organic liquid which is a solvent for the peracid and is capable of forming a heterogeneous azeotrope with water, removing the water present in the reaction mixture by distillation of the water/organic liquid azeotrope, and keeping sufficient water in the reaction mixture to allow the formation of an aqueous phase which is separate from an organic phase containing the organic liquid.