Process for preparing citrate salt from mother liquor for citric acid production

Abstract

The invention discloses a technique for preparing citrate by utilizing mother liquor produced by citric acid, which comprises the following steps: a. industrial citric acid is obtained by concentrating, crystallizing, and separating mother liquor after citric acid is purified; b. the mother liquor after industrial citric acid is separated is respectively concentrated, crystallized and separated again for a plurality of times until the concentration of Fe<+3> of the final mother liquor is bigger than 200ppm; K value of easily carbon compound is bigger than 2.0; the mother liquor is retreated in the former working procedure; c. industrial citric acid is treated with 732 type cation exchange resin column; the effluent liquid is neutralized with sodium carbonate or potassium carbonate to obtain sodium citrate or potassium citrate; the technique for preparing citrate by utilizing mother liquor produced by citric acid has the advantages that not only the mother liquor is treated well, but also impurities are removed in the processing procedure to get the citrate product, thus improving economic benefits of the whole enterprise.

Description

(1) Technical field: [0001] The invention relates to a process for preparing citrate, in particular to a process for preparing citrate from mother liquor produced by citric acid. (two) background technology: [0002] At present, in the process of producing citric acid by fermentation, when the citric acid solution obtained by fermentation is concentrated, crystallized, separated and refined, high-grade citric acid (that is, the easy-carbon compound κ value in 1.0g of citric acid≤ 1.0, Fe +3 Concentration ≤ 10ppm) and suboptimal citric acid (that is, the κ value of easy carbon compounds in 0.75g citric acid ≤ 1.0, Fe in 1.0g citric acid +3 Concentration ≤ 10ppm); and the mother liquor after separation of the above two types of citric acid is due to its high impurity content, the citric acid produced, its Fe +3 Concentration > 30ppm, exceeding the product quality standard by more than three times; easy carbon compound κ value > 1.5, exceeding the product quality standa...

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Problems solved by technology

[0002] At present, in the process of producing citric acid by fermentation, when the citric acid solution obtained by fermentation is concentrated, crystallized, separated and refined, high-grade citric acid (that is, the easy-carbon compound κ value in 1.0g of citric acid≤ 1.0, Fe +3 Concentration ≤ 10ppm) and suboptimal citric acid (that is, the κ value of easy carbon compounds in 0.75g citric acid ≤ 1.0, Fe in 1.0g citric acid +3 Concentration ≤ 10ppm); and the mother liquor after separation of the above two types of citric acid is due to its high impurity content, the citric acid produced, its Fe +3 Concentration > 30ppm, exceeding the product quality standard by more than three times; easy carbon compound κ value > 1.5, exceeding the product quality standard by 1.5 times, failing to meet the citric acid quality standard, and having to return to the previous process for reprocessing, and the returned amount generally reaches the fermentation broth 20-25% of the total amount, so it needs to consume a lot of manpower, material resources and energy, while the total yield of citric acid is reduced, which affects the overall economic benefits of the enterprise

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