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AssigneeYissum Research & Development Co. of Hebrew Univ. of Jeru.
InventorAvraham M. Baniel
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The invention provides a process for the separation of a strong mineral acid from other species present in an aqueous solution and the recovery thereof. The process comprises the steps of: (a) bringing an aqueous solution containing the mineral acid to be separated into contact with a substantially immiscible extractant phase, whereupon the mineral acid to be separated selectively and reversibly transfers to the extractant phase; (b) separating the two phases; and (c) backwashing the extractant phase with an aqueous system to recover substantially all the mineral acid contained in the extractant phase. The special extractant phase used comprises a strong organic acid which acid is oil soluble and substantially water immiscible both in free and in salt form, an oil soluble amine which amine is substantially water insoluble both in free and in salt form and a carrier solvent for the organic acid and amine, the molar ratio of the organic acid to amine in the extractant phase being between about 0.5:2 and 2:0.5.
A process for the separation of a strong mineral acid from other species present in an aqueous solution and the recovery thereof under reversible conditions which obviate the consumption of chemicals for regeneration comprising the steps of:
A process for the separation and recovery of nitric acid from an aqueous solution thereof comprises contacting said solution with a homogeneous solution of tertiary trilaurylamine and dinonylnaphthalene sulfonic acid in xylene, the equivalent ratio of said amine and said acid being from 1:1 to 1:1.1, and recovering said nitric acid from the organic phase by contacting the latter with water.
Dependencies are inferred from the claim text.
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Of solutions which are liquid: applications, solvents used
Separation
Term ended 28 Mar 2000 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a process for the separation of a strong mineral acid from other species present in an aqueous solution and the recovery thereof. More particularly the present invention relates to a process for the separation of a strong mineral acid from other species present in an aqueous solution including the separation of strong mineral acids from each other using a two liquid phase extraction process involving an immiscible extractant phase.
Two phase systems comprising an aqueous phase and an immiscible phase are known in the art and used in a variety of processes of separation and of reaction. Separations can lead to concentration of a constituent present in low concentration in the aqueous phase or provide a step in the recovery of one constituent out of many initially present in an aqueous phase.
Reactions are achieved by displacing an equilibrium which exists in an aqueous phase through the selective transfer to the solvent phase of one of the species which participate in the equilibrium. In all cases the usefulness of the two phase systems resides in the ability of the solvent phase to extract selectively constituents out of the aqueous phase and such two phase systems are already known and used in the art.
5 ml of a 0.4 N solution of a tertiary trilaurylamine (TLA) (Sold by General Mills, Inc. as Alamine 304) in xylene was mixed with 5.5 ml of a 0.4 N solution of dinonylnaphthalene sulfonic acid (HDNNS), obtained by adjusting SYNEX DN-052 of King Industries, Inc. with the addition of xylene. The homogenous organic phase that was obtained was equilibrated with gentle agitation with 2 ml 1 N HNO.sub.3. After settling, separation and analysis, it was established that the aqueous phase was 0.64 N in HNO.sub.3.
The organic phase was then equilibrated with 2 ml of H.sub.2 O. After separation the acidity in the aqueous phase was 0.27 N.
With two more successive equilibrations with 2 ml of H.sub.2 O each, the combined aqueous phases were found to contain practically the full 2 meqs of HNO.sub.3 originally contained in the 2 ml 1 N HNO.sub.3.