A kind of method that catalytic hydrogenation prepares m-aminobenzenesulfonic acid

Abstract

Belonging to the field of fine chemical industry, the invention in particular relates to a method for preparation of m-aminobenzenesulfonic acid by catalytic hydrogenation. The method includes: taking sodium m-nitrobenzene sulfonate as the raw material, adding water for dissolving, boiling the mixture by activated carbon, conducting hot filtration, adjusting the pH value of the filtrate to 7.5-8.5 by a sodium hydroxide aqueous solution, employing Pt-Ru / C as a catalyst to perform hydrogenation reduction for preparation of m-aminobenzenesulfonic acid, ending the hydrogenation reduction reaction when the hydrogen pressure no longer changes, filtering out the Pt-Ru / C catalyst at the end of the reaction, firstly washing the catalyst by ethanol, then carrying out washing recycling, with the recycled catalyst being able to be applied over 50 times and still having a conversion rate and selectivity up to 99%; and subjecting the obtained filtrate to acid precipitation to pH of 2, thus obtaining a white crystal, i.e. the target product m-aminobenzenesulfonic acid. The method provided by the invention lowers the catalyst cost, improves the utilization rate of equipment, and also overcomes the problems of pollution and energy consumption in the regeneration process of the catalyst.

Description

technical field [0001] The invention belongs to the field of fine chemical industry, and in particular relates to a method for preparing m-aminobenzenesulfonic acid by catalytic hydrogenation. Background technique [0002] Aminobenzenesulfonic acid is an important chemical intermediate, widely used in the production of dyes, medicines, pesticides, developers and other industries. Industrially, the traditional methods for preparing sulfanilic acid are iron powder reduction method and electrolytic synthesis of sulfanilic acid, but these methods are replaced by catalytic hydrogenation method because of heavy pollution or cannot be recycled. [0003] Literature [Application of Modified Skeleton Nickel Catalyst in 3NBSA Hydrogenation to Prepare M-Sulphonic Acid, Shen Xiaofeng, Journal of Shenyang Institute of Chemical Technology, 2007(12), 21(4): 276-278] and [Liquid Phase Catalytic Hydrogenation Method Synthesis of 2-aminobenzenesulfonic acid, Yan Xinhuan et al., Dyestuff Indus...

AI Technical Summary

Problems solved by technology

Industrially, the traditional methods for preparing sulfanilic acid are iron powder reduction method and electrolytic synthesis of sulfanilic acid, but these methods are replaced by catalytic hydrogenation method because of heavy pollution or cannot be recycled.

[0003] Literature [Application of Modified Skeleton Nickel Catalyst in 3NBSA Hydrogenation to Prepare M-Sulphonic Acid, Shen Xiaofeng, Journal of Shenyang Institute of Chemical Technology, 2007(12), 21(4): 276-278] and [Liquid Phase Catalytic Hydrogenation Method Synthesis of 2-aminobenzenesulfonic acid, Yan Xinhuan et al., Dyestuff Industry, 2001 (4), 38 (2): 40-41] respectively used two catalysts, the modified framework nickel and the self-made palladium carbon, which were introduced in these two articles Although the method is easy to carry out the reaction, it has the disadvantages of too few times of catalyst application and high cost.

The cause of the deactivation of the catalyst is that the impurity 3,3'-diaminodiphenylsulfide will be produced during the hydrogenation reduction process of m-nitrobenzenesulfonic acid, which will cover the voids of the catalyst and greatly reduce the catalyst activity.

Chinese patent CN101817766A considers the impact of impurity 3,3'-diaminodiphenyl sulfide on the palladium carbon catalyst, after each reaction, the filtered catalyst is stirred with hydrogen peroxide to oxidize the organic sulfur-containing compound into a water-soluble After washing with water, the activity of the catalyst can be regenerated, and the number of application of the catalyst can be greatly increased. However, the disadvantage of this method is that the catalyst must be treated with hydrogen peroxide for 1-5 hours after each reaction, which is time-consuming and labor-intensive. The feeding coefficient (20 %) is low, and the utilization rate of the hydrogenation tank is greatly reduced

[0004] In summary, the prior art lacks a preparation method that is low in production cost, high in product yield, high in equipment utilization, time-saving and labor-saving, and suitable for industrialized production