Method for preparing carvone from carveol by heterogeneous catalytic oxidation with molecular oxygen

Abstract

The invention relates to a method for preparing carvone from carveol by heterogeneous catalytic oxidation with molecular oxygen. A reaction system comprises carveol, a solvent, molecular oxygen and asolid catalyst; the reaction temperature is 50-200 DEG C, reaction pressure is normal pressure-1.0 MPa, the weight content of carveol in a reaction substrate is 10%-40%, liquid space velocity of the carveol solution is 0.2 h<-1>-2.0 h<-1>, and the gas space velocity is 1000 h<-1>-3000 h<-1>. The solid catalyst uses silica gel as a carrier and comprises one of noble metals such as Rh, Pd, Pt and Ru, and contained aids are one or more than two of W, Mo, Ce, La, Fe, Co, Ti, and Zr; under mild reaction conditions, carveol can be efficiently converted into carvone under the action of the solid catalyst. Catalytic activity and carvone selectivity of the solid catalyst remain basically unchanged in the 1000-hour stability test.

Description

technical field [0001] The invention relates to a reaction process and catalyst for one-step preparation of carvone by catalytic oxidation of carveol molecular oxygen under the action of a supported noble metal catalyst. Background technique [0002] The scientific name of carvone is 1-methyl-4-isopropen-6-cyclohexen-2-one, which is one of the main components of many plant essential oils, and is also the main component of the deployment of high-grade food flavors and high-grade cosmetics flavors , widely used in daily life. Carvone is also a natural antioxidant, has good antioxidant activity, and can also be used as a high-efficiency solvent in industry. Carvone has now become a bulk spice, and the demand is increasing year by year. [0003] At present, there are mainly two types of sources of carvone, natural and synthetic. Carvone extracted from natural essential oils has the disadvantages of low output and high price, and is limited by natural conditions and seasons, a...

AI Technical Summary

Problems solved by technology

However, the reaction product of this method is more complicated, the product is difficult to purify, and the catalyst cost is higher

Chinese patent CN101613263A discloses a method for preparing carvone by heating and refluxing oxidized carvone oxime with newly prepared or activated manganese dioxide. The method has less pollution, low cost and simple steps, but the product separation needs to be carried out under reduced pressure. higher

The reaction is still a homogeneous reaction in nature, and there is a problem of difficulty in separating the catalyst from the reactant, and the reaction requires a higher reaction temperature and higher energy consumption.

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