Method for preparing dihydroxy acetone by selectively oxidizing glycerin with hydrogen peroxide

Abstract

The invention discloses a method for preparing dihydroxy acetone by selectively oxidizing glycerin with hydrogen peroxide and belongs to the field of preparation of the dihydroxy acetone. The method comprises the following steps of: adding a transition metal hydrotalcite-like compound as a catalyst in 10 to 100 mass percent of glycerin aqueous solution, and controlling the dosage of the catalyst to be 5 to 20 percent of the mass of the glycerin; raising the temperature of a mixture to 25 to 90 DEG C by heating, dripping 3 to 50 mass percent of hydrogen peroxide, and reacting for 1 to 24 h; after reaction, centrifugally separating the catalyst from a reaction solution; and recovering the catalyst for reusing, and feeding the reaction solution to a liquid chromatogram for identification analysis. By using the glycerin and the hydrogen peroxide as raw materials, under the action of the transition metal hydrotalcite-like compound which serves as the catalyst, the conversion rate of the glycerin and the yield of the dihydroxy acetone are high; any acid base and any organic additive are not added in a reaction system; and the method has the advantages of high yield, low cost, no environmental pollution, easiness in separation, good repeatability, and the like.

Description

technical field

[0001] The invention relates to a method for preparing dihydroxyacetone, in particular to a method for preparing dihydroxyacetone by selectively oxidizing glycerin with hydrogen peroxide. Background technique

[0002] The increasingly scarce petroleum resources and the deteriorating environment force people to actively seek renewable clean energy to replace fossil energy, so the preparation of biodiesel from natural oils and fats has attracted much attention in recent years. In this process, for every ton of biodiesel produced, 100 kg of by-product glycerol will be produced. Therefore, in recent years, the production of glycerol has been increasing with the development of biodiesel industry, so it is urgent to find a new outlet for glycerin. Among the many uses of glycerol, the oxidation of glycerol to produce high value-added glyceric acid, glyceraldehyde, dihydroxyacetone, glycolic acid, etc. has a promising market prospect.

[0003] Among them, dihydroxya...