PRODUCTION OF CITRIC ACID

摘要

The process comprises i) subjecting said citric acid fermentation broth to evaporation to produce a concentrate with a citric acid concentration of at least 80% of the saturation value at the evaporation temperature; ii) subjecting such concentrate to an extraction operation with a recycled amine extractant citric acid solution in which the citric acid concentration is below the equilibrium value which corresponds to the broth concentrate at the extraction temperature, to produce a more concentrated amine extractant citric acid solution and an aqueous citric acid raffinate; iii) withdrawing the aqueous extraction raffinate from said extraction operation, bleeding off a small fraction thereof and recycling the balance to the said evaporation; iv) withdrawing the said concentrated amine extractant citric acid solution extract and back- extracting it with water to obtain an aqueous citric acid solution and a depleted amine extractant citric acid solution the concentration of which is below the equilibrium value which corresponds to the broth concentrate; and v) recycling said depleted amino extractant citric acid solution to the extraction operation.