Claims
- 1. A method for the recovery of solid sodium, potassium or ammonium tri-citrate which comprises the steps of:
- a) providing an aqueous solution of citric acid;
- b) adding Na.sub.2 Co.sub.3, NaHCO.sub.3, KOH, K.sub.2 CO.sub.3, NH.sub.4 OH, (NH.sub.4).sub.2 CO.sub.3 or KHCO.sub.3 to the solution in sufficient quantity to convert the citric acid to tri-sodium, potassium or ammonium citrate thereby raising the pH of the solution to a level within the range of about 6.5 to 8.0;
- c) adding an alcohol having 1 to 5 carbon atoms to the solution in an amount sufficient to provide a volume ratio of alcohol to the solution of at least about 3.7 to 1 to precipitate the sodium, potassium, or ammonium citrate; and
- d) recovering the precipitated sodium, potassium or ammonium citrate.
- 2. The method of claim 1 wherein the alkali metal or ammonium containing base or salt is Na.sub.2 Co.sub.3, NaHCO.sub.3, KOH, K.sub.2 CO.sub.3, NH.sub.4 OH, (NH.sub.4).sub.2 or KHCO.sub.3.
- 3. The method of claim 1 wherein the alkali metal or ammonium containing base or salt is NaOH.
- 4. The method of claim 1 wherein the alcohol is ethanol.
- 5. The method of claim 1 wherein the solution is maintained at the reflux temperature of the added alcohol.
- 6. The method of claim 1 wherein the ratio of alcohol to the solution is in the range of from about 3.7:1 to 8.0:1.
- 7. A method for the recovery of solid tri-sodium citrate dihydrate which comprises the steps of:
- a) providing an aqueous solution of citric acid containing at least 50% citric acid on a weight basis;
- b) adding NaOH to the solution in sufficient quantity to convert the citric acid to tri-sodium citrate and raise the pH of the solution to a level of from about 6.5 to 8.0;
- c) adding ethanol to the solution in an amount sufficient to provide a volume ratio of alcohol to the solution of from about 3.7:1 to 8:1 while maintaining the solution at the reflux temperature of the ethanol to precipitate the tri-sodium citrate;
- d) recovering the precipitated tri-sodium citrate by liquid/solid separatory techniques; and
- drying the recovered tri-sodium citrate sufficiently to form the dihydrate.
Parent Case Info
This is a continuation of application Ser. No. 732,658, filed May 10, 1985, now abandoned.
Non-Patent Literature Citations (1)
Entry |
Shen, JAOCS, vol. 61, No. 6 (Jun. 1984) pp. 1126-1130. |
Continuations (1)
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Number |
Date |
Country |
Parent |
732658 |
May 1985 |
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