Process for the preparation of boric oxide by hydrolysis of methyl

Abstract

For preparing at least one boric oxide in an anhydrous or hydrated form and of general formula B.sub.2 O.sub.3, xH.sub.2 O, in which x is a number from 0 to 3, a methyl borate hydrolyzate comprising boric oxide and methanol is introduced into a distillation column is introduced the product from, at least one compound (preferably a hydrocarbon such as, e.g., 2,3-dimethyl butane or 2-methyl pentane) forming a heteroazeotrope with methanol, said heteroazaeotrope having a boiling point below that of the azeotrope formed by methyl borate with methanol and at least one compound having a boiling point higher than that of methyl borate, said compound not forming an azeotrope with a boiling point below that of said heteroazeotrope and then at the head of the column said heteroazeotrope is recovered and at the bottom of the column a suspension containing at least one boric oxide. A description is also given of a process for the oxidation of at least one saturated hydrocarbon into a product incorporating the corresponding alcohol wherein oxidation is carried out with oxygen in the presence of a boric oxide with. The oxidation product is hydrolyzed into orthoboric acid and alcohol, which is recovered by separation from the organic phase. The aqueous phase containing the boric acid is fed into a methyl borate formation zone and the methyl borate is recovered in the form of its azeotrope with methanol. The recovery of the boric oxide from said azeotrope is performed in accordance with the aforementioned process, the recovered boric oxide being recycled to the oxidation stage.