A kind of thioether oxidation method

Abstract

The invention discloses a sulfide oxidation method, which comprises continuously feeding a liquid mixture into a fixed-bed reactor, making the liquid mixture flow through the catalyst bed under oxidation reaction conditions, so as to be mixed with the catalyst bed packed in the catalyst bed. Titanium-silicon molecular sieve contact reaction, the liquid mixture contains thioether, at least one oxidizing agent and optionally at least one solvent, wherein the method also includes when the conversion rate of the oxidizing agent and / or the selectivity of the target oxidation product decreases to a certain extent , increase the weight hourly space velocity of thioether until the conversion rate of the oxidant and / or the selectivity of the target oxidation product increase to meet the requirements. The method of the present invention can maintain the conversion rate of the oxidant and / or the selectivity of the target product in a relatively high range even if it operates continuously for a long period, thereby effectively prolonging the single-pass service life of the titanium-silicon molecular sieve as a catalyst and reducing the regeneration frequency. Extend the stable operation time of the device. The method of the invention is simple and easy to implement, and is beneficial to industrial production and application.

Description

technical field [0001] The present invention relates to a kind of sulfide oxidation method. Background technique [0002] Sulfoxides are important sulfur-containing compounds. For example, dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound. It is a colorless and transparent liquid at room temperature. properties such as protons. Dimethyl sulfoxide is soluble in water, ethanol, acetone, ether and chloroform, is a highly polar inert solvent, and is widely used as a solvent and reaction reagent. Moreover, dimethyl sulfoxide has a high selective extraction ability and can be used as an extraction solvent for the separation of alkanes and aromatics. For example: dimethyl sulfoxide can be used for the extraction of aromatics or butadiene. In the polymerization reaction, it is used as a processing solvent and spinning solvent, as a synthetic solvent and spinning solvent of polyurethane, and as a synthetic solvent of polyamide, fluorochloroaniline, polyimide and pol...

AI Technical Summary

Problems solved by technology

However, with the prolongation of the reaction time, the catalytic activity of titanium-silicon molecular sieves will show a downward trend, resulting in a significant decrease in the conversion rate of the oxidant and the selectivity of the target oxidation product.

When the reaction is carried out in a fixed-bed reactor, due to the reduction of the catalytic activity of the titanium-silicon molecular sieve, the titanium-silicon molecular sieve needs to be regenerated inside or outside the reactor, resulting in shutdown of the reactor, thereby affecting production efficiency and increasing the operating cost of the device

[0005] When the regenerated catalyst is put into operation again, especially after being regenerated in the reactor, the activity of the catalyst fluctuates greatly and takes a long time to stabilize, resulting in a decrease in the selectivity of the target oxidation product, which will not only reduce the operation efficiency, and the subsequent separation and purification process is required to adjust the operating conditions, which increases the complexity of the operation; at the same time, it is also necessary to combine operations such as increasing the reaction temperature to achieve a smooth operation of the reaction, but these measures often accelerate catalyst deactivation

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