Production method of food additive sodium benzoate

Abstract

The invention discloses a production method of a food additive sodium benzoate. The production method comprises the following steps: feeding crude benzoic acid into the bottom of a rectifying tower with side stream withdrawal, controlling the pressure to a range of 1 to 15 kpa, starting heating when the feed level reaches 50-80% of the height of the tower bottom, controlling the tower top temperature to a range of 160 to 175 DEG C, the temperature of the side stream withdrawal to a range of 165 to 180 DEG C and the tower bottom temperature to a range of 190 to 240 DEG C, adjusting the reflux ratio to a range of 0.3 to 1.5, and obtaining refined benzoic acid from a tower top discharge outlet; adding the refined benzoic acid to an aqueous solution containing a sodium compound for neutralization to obtain a sodium benzoate solution, and then decolorizing the sodium benzoate solution with activated carbon and carrying out filtering, drying and dehydrating to obtain the food additive sodiumbenzoate. The production method of the food additive sodium benzoate is simple and convenient to operate with no need for complicated and tedious melting crystallization step, thereby saving a largeamount of energy and a large number of operations for separation and greatly reducing the production cost; and the production method is more conducive to industrial production.

Description

technical field [0001] The present invention relates to the preparation method of sodium benzoate, specifically refer to a kind of production method of food additive sodium benzoate. Background technique [0002] Sodium benzoate, as the sodium salt of benzoic acid, is odorless or has a slight smell of benzoin. It can be partially converted into active benzoic acid in acidic foods. The antiseptic mechanism is the same as that of benzoic acid. Because it is more soluble in water than benzoic acid and stable in the air, it has a strong inhibitory effect on yeast and bacteria, and is widely used in food, medicine and feed. [0003] Benzoic acid is as the main raw material of sodium benzoate, and its impurity content directly affects the product quality of sodium benzoate. Before the present invention, the common production process of benzoic acid is: petroleum toluene obtains the oxidized liquid containing benzoic acid after catalytic oxidation, and after the oxidized liquid is...

AI Technical Summary

Problems solved by technology

Therefore, with the present production process, only the mode of rectification can't produce the qualified food grade sodium benzoate raw material

[0005] Before the present invention, the Chinese invention patent with the patent number of 201010568840.X disclosed a method for refining benzoic acid. This method obtains benzoic acid with high purity by melting and crystallization, and has low energy consumption, low pollution, no solvent, and easy operation. Low temperature and other advantages, but also has its limitations: first, it needs to be purified in stages, each stage needs to improve the purity of the material, the crystallization part of any stage is used as part of the initial solution of the next stage, and the remaining raffinate is sent to the front One stage, when the material reaches the required purity and the raffinate meets the discharge requirements, they are collected and discharged separately

The melting crystallization and purification process of benzoic acid is generally divided into three stages, and each stage requires four steps of circulation, crystallization, sweating, and melting, and the overall steps are lengthy

Second, the longer operation steps make the melt crystallization operation time longer, and the production efficiency is not high

Third, if the presence of polymer impurities exceeds 1%, the speed and efficiency of crystallization separation will be seriously affected, resulting in a large amount of raffinate produced by the melting crystallization method, which requires the use of post-treatment processes

The 4th, crystallization method is that industrial benzoic acid is purified, and impurity is enriched in the raffinate, usually only has about 97% benzoic acid content in the raffinate, is lower than industrial benzoic acid quality index, causes yield lower

Fifth, the falling film crystallizer and its ancillary equipment used in the crystallization process are relatively expensive, requiring an investment of tens of millions, and the cost of this step increases by about 1,000 yuan / ton

[0006] Therefore, adopting rectification to add melting, crystallization etc. to purify benzoic acid, can cause long production process, many equipments, high energy consumption, directly affect the production cost of food additive sodium benzoate

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