Abstract:
According to the process for producing amino acid or salt thereof in the present invention, in the adsorption step, an amino acid-containing aqueous solution is fed into a pressure tight column so that a free amino acid is adsorbed on a carbonate-type anion exchange resin packed in the pressure tight column. Subsequently, in the elution step, eluent liquid containing a hydrogen carbonate ion and/or a carbonate ion is injected into the pressure tight column in a pressurized state to elute the amino acid adsorbed on the anion exchange resin and simultaneously to regenarate the anion exchange resin into the carbonate-type. In the case of purifying an acidic amino acid, an aqueous ammonium carbonate solution is employed as the eluent liquid. In the case of purifying a neutral amino acid, an aqueous carbonic acid solution, an aqueous hydrogen carbonate solution, an aqueous ammonium hydrogen carbonate solution or an aqueous ammonium carbonate solution is employed as the eluent liquid. Further, a breakthrough liquid discharged from the adsorption step is optionally concentrated to remove the volatile carbonate acid component and ammonium component from the breakthrough liquid. Thus, the solid content in the breakthrough liquid can be reduced.
Abstract:
Process for preparing monodisperse weakly basic or optionally strongly basic anion exchangers of the poly(meth)acrylamide type, the ion exchangers themselves and their use.
Abstract:
A method and apparatus for producing deionized water by passing water to be treated through a deionizing and water treatment system having carbon filtration and beds of packed ion exchange resins, specifically including beds of mixed anion resins, so that sediment and impurity ions are removed as adsorbed on the ion exchange sites of the resins and a method of regenerating the ion exchange resins after having its ion-exchanging and adsorbing abilities lowered.
Abstract:
Process for preparing monodisperse weakly basic or optionally strongly basic anion exchangers of the poly(meth)acrylamide type, the ion exchangers themselves and their use.
Abstract:
A process based on ion exchange with separated beds is disclosed for the deionization of substances that are not stable in the presence of strongly acidic cation exchangers, wherein the solution to be deionized is contacted with a first bed consisting of a basic anion exchanger in the form of hydrogen carbonate and subsequently with a second bed, connected in series, consisting of a weakly acidic cation exchanger in hydrogen form.
Abstract:
The recovery of iodide from chemical process wastewater is accomplished by loading the wastewater containing iodide onto a strongly basic anion-exchange resin in free-base form; eluting the sorbed iodide from the resin with aqueous strong acid (e.g., hydrochloric acid); loading the iodide-rich cuts onto a weakly basic anion-exchange resin in free-base form; and eluting the sorbed iodide with aqueous base (e.g., sodium hydroxide). The recovered iodide typically has sufficient purity to permit its re-use in the chemical process.
Abstract:
Anion-exchange compositions are provided comprising anion-exchange functional groups comprising at least a first and a second nitrogen group, wherein the first nitrogen group is a quaternary amine and the second nitrogen group is selected from the group consisting of primary, secondary, tertiary or quaternary amines. Methods of making and using the compositions are also provided.
Abstract:
The invention is for a process of removing acid salt contaminants from a resin solution. The process comprises providing an organic solution of a phenolic resin having a portion of its phenolic hydroxyl groups condensed with an acid halide in the presence of a base catalyst. The organic solutions is then contacted with a strong acid cation exchange resin and a base anion exchange resin for a time sufficient to remove essentially all of said acid salt contaminants. Acid salt contamination is reduced to a level below normal detection limits.
Abstract:
THE INVENTION DISCLOSED HEREIN RELATES TO A NOVEL PROCESS FOR THE ISOLATION AND PURIFICATION OF CONJUGATED ESTROGENS BY BRINGING EQUINE PREGNANCY URINE OR, ALTERNATIVELY, AN AQUEOUS EXTRACT DERIVED FROM EQUINE PREGANCY URINE OR, ALTERNATIVELY, AN AQUEOUS EXTRACT DERIVED FROM EQUINE PREGNANCY RUINE, INTO CONTAC WITH AN ANION EXCHANGE RESIN, THEREBY ABSORBING SAID CONJUGATED ESTROGENS ON SAID RESIN, AND ELUTING THE RESIN WITH AN AQUEOUS ALCOHOL ELUTING SOLVENT CONTAINING CHLORIDE IONS. CONJUGATED ESTROGENS DERIVED FROM EQUINE PREGANCY URINE (PMU) HAVE BEEN USED FOR MANY YEARS IN ESTROGENIC PREPARATIONS.
Abstract:
BY PRETREATMENT OF A STRONG BASE QUATERNARY AMMONIUM ANION EXCHANGE RESIN WITH AN AQUEOUS SOLUTION OF A CHELATING AGENT, MORE EFFICIENT ELUTION OF THYROXINE THEREFROM IN BIOLOGICAL ISOLATION AND ANALYTICAL PROCEDURES IS ACHIEVED. A FURTHER IMPROVEMENT IS ACHIEVED BY PRETREATMENT OF THE RESIN WITH NITRIC ACID.