Preparation method of hydroxylamine sulphate

Abstract

The invention discloses a preparation method of hydroxylamine sulphate. The preparation method comprises the following steps: 1), evenly mixing the raw materials of an acid solution and oxime, rectifying in a reaction rectifying column, obtaining a mixed solution of hydroxylamine sulphate and unreacted oxime and acid in a column reactor; 2), conveying part of the mixed solution obtained in the column reactor to a stripping tower through a pump, stripping to remove an organic matter and part of water, conveying part of the mixed solution to a reactor filled with a catalyst to have a further reaction; enabling a liquid material obtained in the reaction to return to the column reactor of the rectifying column, and enabling a gaseous phase to return to the upper middle part of the rectifying column; 3), crystalizing a concentrated hydroxylamine sulphate solution flowing out from a tower kettle of the stripping tower, separating the liquid and the solid, and drying to obtain hydroxylamine sulphate.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a preparation method of hydroxylamine sulfate. Background technique [0002] Hydroxylamine sulfate is a chemical product with a wide range of uses, which can be used to synthesize pesticide raw materials, pharmaceutical raw materials, rubber additive raw materials, natural rubber stabilizers, metal treatment agents, fiber modifiers, developers, reducing agents and polymer catalysts, etc. . The traditional preparation methods of hydroxylamine sulfate mainly include nitromethane method, acetone oxime method, nitric oxide reduction method, ammonium disulfonate hydrolysis method, etc. [0003] The preparation of nitromethane requires the use of highly toxic dimethyl sulfate. When hydrolyzing hydroxylamine, the by-product is highly toxic carbon monoxide; The class is in the interface reaction, so the rate is low, the reaction time is long, and the total yield is about 75%. [0004]...

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Problems solved by technology

[0003] The preparation of nitromethane requires the use of highly toxic dimethyl sulfate. When hydrolyzing hydroxylamine, the by-product is highly toxic carbon monoxide; The class is in the interface reaction, so the rate is low, the reaction time is long, and the total yield is about 75%.

[0004] The traditional acetone oxime method first reacts with sodium nitrite and sodium pyrosulfite, acidifies with sulfuric acid to generate hydroxylamine disulfonate, then reacts with acetone, and then uses acid hydrolysis to prepare hydroxylamine. The yield is only 60%, so there is a process route Complicated, long process flow, high production cost, high raw material consumption, 6 tons of sodium sulfite and a large amount of acetone per ton of hydroxylamine, large discharge of three wastes, unstable product quality, etc.

[0005] The nitric oxide reduction method is to mix ammonia, oxygen and water vapor in a certain volume ratio, preheat to a certain temperature, and pass it into the reactor. The oxidation reaction is carried out on a platinum-rhodium catalyst, and nitric oxide can be obtained after treatment. , and then mix nitric oxide with hydrogen, and introduce it into sulfuric acid containing platinum catalyst to react to obtain hydroxylamine sulfate, with a yield of about 70%. This process requires high equipment, expensive catalyst, and difficult tail gas treatment

[0006] Although the production process of ammonium disulfonate hydrolysis method is mature, it is only suitable for large-scale factory production, the investment cost is high, and the obtained product is a mixture of ammonium sulfate and hydroxylamine sulfate. It is very difficult to separate commercial-grade solid hydroxylamine sulfate products

Although the filtrate obtained after crystallization and separation can be returned to the reaction system, there is no waste of raw materials in theory, but due to the existence of excessive inorganic acids, on the one hand, it will increase the difficulty of equipment selection, and on the other hand, it will cause high content in the crystallized hydroxylamine sulfate The high content of free acid in solid hydroxylamine sulfate will cause the following series of adverse consequences:

[0022] 1). The high content of free acid cannot be removed during the drying process, and it will also cause high moisture content. In the end, the product is particularly easy to agglomerate during storage, which is not conducive to the safe use of downstream customers;

[0023] 2). High content of free acid has higher requirements on equipment materials, which can easily cause equipment corrosion;

[0024] 3). High content of free acid will seriously damage the product quality and almost deteriorate all quality indicators

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