SU1217785A1 - Method of producing sodium sulfite - Google Patents

Description

The invention relates to methods for producing sodium sulphite used in medicine, the chemical industry and the manufacture of chemical fibers.

The aim of the invention is to increase the yield of the target product and simplify the process

The method is carried out as follows.

10-20% water solution of monoethanolamine is saturated with sulfur dioxide, solid sodium chloride is loaded into the resulting solution with stirring, after which the target product is salted out of solution with 0.4-0.5 of the initial solution, and then sodium sulfite is separated by filtration and dried.

Example. 2.5 liters of a 10% aqueous solution of MEA is treated for 35 minutes with sulfur dioxide at a flow rate of 3.84 l / min. After that, 0.665 kg of solid sodium chloride is loaded into the reactor with stirring. In order to dissolve sodium sulfite, pure monoethanol amine in the amount of 1.25 l is introduced into the solid phase in the reactor.

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0.60 kg of crystalline salt containing 97.0% Na2S03. The degree of use of sulfur dioxide in the process is 92.6%.

As can be seen from Table 1, the highest yield of sodium sulfite is reached at 283 K and the content of MEA in the solution is 10–20%. From a technological point of view, it is most appropriate to conduct the process under normal conditions, at a temperature of 298 K and atmospheric pressure.

I

Below is the effect of the volume ratio between the solution and monoethanolamine on the yield of the product in the solid phase,%:

0.4; 0.5 0.6: 0.7

73.2 80.2 75.1 70.3

The maximum product yield is achieved at a solution volume ratio: monoethanolamine of 1: 0.5. With an increase in the amount of added monoethanolamine in the hardened phases, the sodium chloride filter is released. After drying, receive

and yield is reduced.

The effect of MEA concentration and temperature on the output of NajSOj,%

Temperature, K

MEA concentration, May.%

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Editor A.Dolinich

Compiled by A. Volkov Tehred S. Migunova

Order 1071/26 Circulation 452

VNIIPI USSR State Committee for Inventions and Discoveries 4/5, Moscow, Zh-35, Raushsk nab. 113035

Branch PSh1 Patent, Uzhgorod, st. Design, 4i

0.60 kg of crystalline salt containing 97.0% Na2S03. The degree of use of sulfur dioxide in the process is 92.6%.

As can be seen from Table 1, the highest yield of sodium sulfite is achieved at 283 K and the content of MEA in the solution is 10–20%. From a technological point of view, it is most appropriate to conduct the process under normal conditions, at a temperature of 298 K and atmospheric pressure.

I

Below is the effect of the volume ratio between the solution and monoethanolamine on the yield of the product in the solid phase,%:

0.4; 0.5 0.6: 0.7

73.2 80.2 75.1 70.3

The maximum product yield is achieved with a solution volume ratio: monoethanolamine of 1: 0.5. With an increase in the amount of added monoethanolamine in tverrium, and the yield decreases.

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Proofreader E. Sirohman Subscription

Claims (2)

1. A METHOD FOR PRODUCING SODIUM SULPHITE, comprising treating an inorganic sodium salt with sulfur dioxide in an aqueous solution of an organic compound, isolating the target product in a solid phase, filtering and drying it, characterized in that, in order to increase the yield and simplify the process, as an organic compound use 1020% monoethanolamine, and the selection of the target product in the solid phase is carried out by salting out with monoethanolamine in an amount of 0.4-0.5 of the volume of the initial solution. 2. The method of pop. 1, l and m of h and w and Yu-th to I in that the inorganic salt is sodium chloride _with sodium. ® ω bm SL