Process for treating a liquid
AssigneeReilly Industries, Inc.
InventorsFrancis H. Verhoff, Sanet Grond, Fadl Hendricks, Lakshminarayanan Pattabiraman Raman
Life of this patent
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Abstract
A process for treating a liquid comprising subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step. From the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution, is obtained.
Claims24
A process for treating a liquid, which process comprises
- subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a molecular weight similar to that of citric acid, to nanofiltration in a filtration step;
- obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution the permeate including 80 or more percent of the citric acid originally in said liquid;
- and
- concentrating the permeate by subjecting it to crystallization without treating the permeate to remove the remaining less desirable component prior to the crystallization.
A process for treating a liquid, which process comprises
- providing a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, and cations;
- removing cations from said liquid to form a cation-depleted liquid;
- subjecting said cation depleted liquid to nanofiltration in a filtration step;
- obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution;
- concentrating the permeate by subjecting it to crystallization in at least one crystallizer, with citric acid crystals and mother liquor being produced in the crystallizer;
- separating the citric acid crystals from the mother liquor;
- treating at least a portion of the mother liquor to recover citric acid therefrom;
- and
- recycling at least a portion of the recovered citric acid to upstream and/or down stream of the filtration step.
A process for treating a liquid, which process comprises
- subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a molecular weight less than that of citric acid, to nanofiltration in a filtration step;
- and
- obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution the permeate including 80 or more percent of the citric acid originally in said liquid.
Dependencies are inferred from the claim text.