Urea → Citric Acid

Beteiligte Stoffe

Reaktionsschritte

A 5% aliquot of this actively growing inoculum is then added to a large fermenter containing the following ingredients per liter of sterilized medium: 4.7 g. of urea, 0.001 g. of thiamine hydrochloride, 180 g. of C14 -C16 n-paraffins and 0.375 g. of KH2PO4 (sterilized separately). The fermentation medium is stirred for 144 hours (6 days) at 1725 rpm, 4.0 S.C.F.H.G. (standard cubic feet of air per gallon per hour) and a temperature of 26° C. The fermentation yield of citric acid monohydrate is 225 grams per liter. Early in this six-day run the pH levels off of its own accord at about 2-3 and no adjustments are necessary. After the 6 days, the solids and mycelium are removed by filtration and the filtered fermentation broth concentrated under vacuum at 45° C. to 40° Baume. The crystals of citric acid which are formed after standing overnight are removed by centrifugation. Second and third crops of citric acids are recovered by concentrating the mother liquors under vacuum to 45° Baume at 75° C. The total recovery of free citric acid is approximately 50% by weight. Residual product in the final mother liquor is lastly recovered as the monosodium salt by neutralizing with sodium hydroxide and concentrating under vacuum.

Herkunft & Nachweise