Neutralization method of citric acid

Abstract

The invention provides a neutralization method of citric acid, comprising the following steps: neutralizing once degerming clear solution of the citric acid with calcium carbonate and/or calcium hydroxide to pH 2-5 to generate precipitate containing citrate; carrying out solid-liquid separation and washing solid phase to obtain a solid phase containing the citrate, a liquid phase is solution containing the citric acid; secondarily neutralizing the solution containing the citric acid with the calcium carbonate and/or calcium hydroxide to pH 3-9 to generate the precipitate with the citrate; allowing the solid phase containing the citrate after separation to return for once neutralization, and allowing the liquid phase without the citric acid after separation to be discharged; and adding sulfuric acid into the solid phase containing the citrate obtained by once neutralization for acidolysis reaction to obtain acidolysis solution of the citric acid and calcium sulfate precipitate. The neutralization method of the invention has the advantages of good product quality, a small quantity of consumed water volume, small load on solid-liquid separation equipment and the like.

Description

technical field [0001] The invention relates to a method for extracting citric acid, in particular to a method for extracting and separating citric acid in fermentation broth by using a calcium salt method, which belongs to the field of food chemical industry. Background technique [0002] Citric acid is an organic acid widely used in beverage, food and pharmaceutical industries. my country is a major producer of citric acid, with more than 20 production plants, and the output has exceeded 700,000 tons. The extraction methods of citric acid at home and abroad are mainly calcium salt method, chromatography, membrane separation method and extraction method. [0003] The disadvantages of the traditional calcium salt method are: firstly, each ton of citric acid consumes about 0.85 tons of sulfuric acid and 0.85 tons of calcium carbonate, and the consumption of auxiliary materials is high; second, it produces about 2 tons of solid waste calcium sulfate; third, the specific surfac...

AI Technical Summary

Problems solved by technology

[0003] The disadvantages of the traditional calcium salt method are: firstly, each ton of citric acid consumes about 0.85 tons of sulfuric acid and 0.85 tons of calcium carbonate, and the consumption of auxiliary materials is high; second, it produces about 2 tons of solid waste calcium sulfate; third, the specific surface area of ​​calcium citrate precipitate Large, adsorbed impurities, resulting in a large amount of washing water, high consumption of hot water, the highest neutralization yield can only reach 94%, and the yield is low; Fourth, the highest acidity after acidolysis of citric acid can only reach about 40%, and the energy consumption of concentration high

[0004] The disadvantages of the chromatography process are: first, the high investment in equipment and auxiliary facilities; second, the pre-treatment of materials is more complicated, consumes a lot of money, and costs a lot

[0005] The disadvantages of electrodialysis are: first, high investment in equipment and auxiliary facilities; second, high power consumption and high production costs

[0006] The disadvantages of the extraction method are: first, the product quality is poor; second, the product cannot be used in the food and pharmaceutical industries due to the residue of the extractant