Vapor Phase Catalytic Oxidation Synthesis Of 1,4 - Naphthoquinone Vanadium Catalyst And Synthesis Technology

1,4-naphthoquinone is an important fine organic material and the pharmaceutical intermediate, and it has been widely used in the fields of medicine, dyestuff, pesticide, act.1,4-naphthoquinone was prepared by the catalytic vapor phase oxidation of naphthalene. Since nineteen twenties or thirties, the synthesis of 1,4-naphthoquinone has been studied by researchers. The method of vapor phase oxidation was simpler and easier than the liquid phase electro-oxidation, and it could applied to the large-scale industrial manufacture. The vanadium-potassium catalyst had the high activity and good selectivity to the 1,4-naphthoquinone, therefore, this catalyst was usually used in the reaction. However, in the past research, there were still some serious problems, such as the low yield of 1,4-naphthoquinone and the mass by-product of phthalic anhydride.In this paper, the optimal components of the catalyst precursor and the preparation technology of 1,4-naphthoquinone have been studied in detail, including carrier, co-catalyst, molding dimension, calcination temperature, etc. The final composition of the catalyst precursor was explained in the following sections:ammonium metavanadate (NH4VO3) as the active component; potassium bisulfate (KHSO4) and potassium sulfate (K2SO4) as the co-catalyst; anatase titanium dioxide (TiO2) as the carrier. The extruded moulding were used for the molding process of the catalysts, the best dimension was determined through the experiment. The catalyst precursor was dried for 3 h at the temperature of 100℃, and then calcined for 5 h, than the catalysts had better catalytic performance.This paper also presented the effects of the process conditions on the catalytic oxidation reaction. In this experiment, the reaction of the catalytic vapor phase oxidation of naphthalene was processed in the fixed bed reactor. The process conditions were studied including the fill volume of the catalyst, the reaction temperature, the gas hourly space velocity (GHSV) and the mass flow of naphthalene, etc. The experimental results showed that the reaction had the best effect, the conversation of naphthalene was 98.13% and the yield of 1,4-naphthoquinone was 48.46% under these optimal conditions.