Synthesis method of oil-soluble catalyst isooctyl chromate

Abstract

The invention provides a synthesis method of an oil-soluble catalyst isooctyl chromate, comprising the following steps of dissolving chromic oxide into water, dropwise adding an aqueous solution of the chromic oxide to isooctyl alcohol while stirring, controlling the reaction temperature to be 10 to 60 DEG C and the dropwise adding time to be 0.5 to 1.0h, after the adding is finished, continuously stirring to react for 0.5 to 1.5h, extracting an organic phase after the reaction is finished, wherein an obtained extract phase is the oil-soluble catalyst isooctyl chromate. When the obtained oil-soluble catalyst isooctyl chromate is applied to the cyclohexyl hydroperoxide decomposition reaction, the decomposition rate of the cyclohexyl hydroperoxide is greater than 99.0 percent, and the ketone-alcohol radio is greater than 1.2 to 1.

Description

Technical field [0001] The invention relates to a method for synthesizing a catalyst, in particular to a method for synthesizing an oil-soluble catalyst isooctyl chromate. Background technique [0002] Cyclohexane oxidation to cyclohexanone consists of the following steps: first, cyclohexane is oxidized at 155~165℃ in air to obtain a cyclohexane solution of cyclohexylhydroperoxide, and then the cyclohexane solution in the cyclohexane solution Hexyl hydrogen peroxide is decomposed into cyclohexanone and cyclohexanone at a certain alkalinity, using cobalt acetate as a catalyst, a cobalt ion concentration of 1 to 3 ppm, a volume ratio of organic phase to inorganic phase of 85:15, and a reaction temperature of 85 to 110°C. Alcohol: The product after decomposition is separated from the organic phase and the inorganic phase. The organic phase enters the alkane rectification system, and the cyclohexane is recovered at the top of the tower and sent to the oxidation kettle for recycling. ...

AI Technical Summary

Problems solved by technology

At present, there are following problems in the decomposition process of cyclohexyl hydroperoxide: in the presence of sodium hydroxide, every 1 ton of cyclohexanone is produced to produce about 0.7 tons of waste alkali solution, and the treatment not only consumes a large amount of heavy oil or natural gas, but also brings pollution to the environment. In addition, the proportion of ketone alcohol obtained after the decomposition of cyclohexyl hydroperoxide under this process is not high. Generally, the ratio of ketone alcohol to alcohol is below 1:1, which increases the load of subsequent dehydrogenation of cyclohexanol

[0003] There are two important defects in the existing homogeneous catalytic decomposition process of tert-butyl cyclohexyl hydroperoxide chromate: during the decomposition process, scales with chromium adipate as the main component will be generated, and these scales will block equipment and pipelines; The conversion rate is low, and the conversion rate is only about 92%. The decomposed material still contains about 0.5% cyclohexyl hydroperoxide. It decomposes under high acidity and high temperature conditions, and mainly produces acidic and caprolactone-based ester compounds such as adipic acid, and accelerates the free radical condensation reaction speed of alcohols and ketones and the esterification reaction speed of alcohols, forming a large amount of high Boiling matter reduces the total yield of the device, and the total yield is only about 80%.

[0004] Cyclohexyl hydroperoxide adopts the cobalt acetate heterogeneous catalytic decomposition process under sodium hydroxide alkaline aqueous solution to also have following defect: decomposition side reaction is big, and decomposition yield is low, only has about 84%; It is difficult to completely separate the hexane oil phase from the alkali-water phase containing spent caustic soda, and a certain amount of spent caustic-water phase is always entrained in the oil phase, so that fouling of spent caustic soda occurs in the rectifying tower in the subsequent process and blocks the refining process. The continuous production cycle of the distillation column and its reboiler is usually only half a year, and the total yield is only about 80%.

However, in actual industrial application, there is a large amount of scale inhibitor added, which is easy to be brought into the subsequent refining section to affect the separation of cyclohexanone and cyclohexanol