A method and system for continuous production of nitrosyl sulfuric acid

Abstract

The invention discloses a method and system for continuous production of nitrosyl sulfuric acid. The method for continuous production of nitrosyl sulfuric acid comprises the following steps: sulfuric acid, water and nitric acid are continuously pumped into an acid mixing tank to obtain mixed acid, mixed acid And liquid sulfur dioxide is continuously pumped into the high gravity reactor for reaction, and finally the nitrosyl sulfuric acid product is obtained. The present invention can accurately control the amount of materials, enhance the mass transfer effect, shorten the reaction time, shorten the average residence time of materials in the reaction cycle system, reduce the loss of raw materials, reduce production costs, and the system does not produce tail gas, green Environmental friendly.

Description

technical field [0001] The invention belongs to the field of dye intermediate production, and in particular relates to a method and system for continuously producing dye intermediate nitrosyl sulfuric acid. Background technique [0002] Nitrosyl sulfuric acid is an important raw material for diazotization reaction. The diazotization reaction refers to the interaction between the diazonium component and the diazotization reagent, and the final reaction produces a diazonium salt, wherein the former is usually an aromatic primary amine, and the latter is usually nitrous acid. But nitrous acid is easy to decompose, so the diazotization reaction process usually adopts the operation mode that sodium nitrite and hydrochloric acid (or sulfuric acid) react in solution to generate nitrous acid, and nitrous acid reacts with the diazo component immediately. However, this process will produce salt in the diazotization and subsequent production process, which not only increases the proce...

AI Technical Summary

Problems solved by technology

Studies have shown that the reaction between sulfur dioxide and nitric acid is a fast and strong exothermic reaction, and nitrosyl sulfuric acid is easy to decompose. Once the local temperature reaches above 70°C, nitrosyl sulfuric acid may be decomposed quickly, which is very easy to cause safety accidents and cause environmental pollution.

In addition, the reaction raw materials have volatile components and gaseous components, so waste gases such as nitric acid mist, nitrogen oxides, carbon dioxide, and sulfur trioxide may be generated during the production process, which not only requires tail gas treatment, but also causes serious damage to the environment big impact

[0005] The Chinese patent application document with the publication number CN103435018A discloses a method and device for continuously producing nitrosyl sulfuric acid in a tower type. Sulfur dioxide gas is introduced, the reaction temperature is below 70°C, and continuous operation is achieved through pump circulation. However, this method is actually a semi-continuous process. The control of the amount of sulfur dioxide gas feed is not precise enough, and the temperature is high, which easily leads to product decomposition.

[0006] The Chinese patent application document with the publication number CN107963617A discloses a production method and system of nitrosyl sulfuric acid, which uses concentrated waste acid to absorb and reuse the tail gas in the production process of nitrosyl sulfuric acid to form a sulfuric acid solution of required concentration, and It is mixed with nitric acid to form a mixed acid; the mixed acid and sulfur dioxide-containing gas enter the reaction tower for reaction through continuous feeding, and finally obtain the finished product of nitrosyl sulfuric acid. Although this method realizes the continuous production of nitrosyl sulfuric acid and the resources of waste acid and tail gas However, the reaction time is long, the reaction temperature is high, and the reaction produces a lot of waste gas such as nitric acid mist, sulfur dioxide, sulfur trioxide, nitrogen oxides, etc., and additional tail gas treatment is required, and the steps are cumbersome

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