Sulfoether oxidation method

Abstract

The invention discloses a sulfoether oxidation method. The method comprises the steps that a liquid mixture is continuously fed into a fixed-bed reactor, and the liquid mixture flows through catalyst bed layers under the oxidation reaction condition to be reacted with titanium silicalite molecular sieves filled in the catalyst bed layers in a contacted mode, wherein the liquid mixture contains sulfoether, at least one oxidizing agent and at least one selectable solvent. The method further comprises the step that when the selectivity of a target oxidation product decreases to a certain degree, the content of the oxidizing agent in the liquid mixture is increased till the selectivity of the target oxidation product is raised to meet the requirement. By means of the sulfoether oxidation method, the selectivity of the target oxidation product can be maintained within a higher range even under the long-periodic continuous operation condition, therefore, the one-way service life of the titanium silicalite molecular sieves serving as a catalyst is effectively prolonged, the regeneration period of the catalyst is shortened, and the stable operation time of a device is prolonged. In addition, the sulfoether oxidation method is simple, easy to carry out and beneficial for 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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