Patent · US Expired

Production of citric acid

US4994609A · kind A · utility

13Cited by
4References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 6, 1990
Grant dateFeb 19, 1991
Priority date
Expiry dateJun 6, 2010

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C51/48
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

Recovery of citric acid from a citric acid fermentation broth. The process comprises PA1 (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; PA1 (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 aqueous citric acid raffinate; PA1 (iii) withdrawing the aqeuous extraction raffinate from said extraction operation, bleeding off a small fraction thereof and recycling the balance to the said evaporation; PA1 (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 PA1 (v) recycling said depleted amine extractant …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.