REMOVAL OF THERMAL STABLE SALTS FROM ORGANIC SOLVENTS

• US 20130098245A1
• Filed: 01/29/2011
• Published: 04/25/2013
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Thyssenkrupp Uhde GmbH (Thyssenkrupp AG)
• Original Assignee: Thyssenkrupp Uhde GmbH (Thyssenkrupp AG)
• Inventors: Menzel, Johannes
• Granted Patent: US 9,427,696 B2
• Time in Patent Office: Days
• US Class Current: 95/205
• CPC Class Codes: B01D 1/14 with heated gases or vapours or liquids in contact with the liquid
• CPC Class Codes: B01D 2252/204 Amines
• CPC Class Codes: B01D 3/14 Fractional distillation or use of a fractionation or rectification column
• CPC Class Codes: B01D 3/143 by two or more of a fractionation, separation or rectification step
• CPC Class Codes: B01D 3/148 in combination with at least one evaporator
• CPC Class Codes: B01D 3/38 Steam distillation
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents

Abstract

A Method for removing salts, which cannot be thermally regenerated in a temperature range from 0°-200° C., from organic solvents in aqueous solution by evaporation, wherein the normal boiling point of the organic solvents is higher than water. The organic components contained in the solvent and the salt-like components which are contained in the organic components are enriched by evaporating water and a portion of the organic components in a liquid phase which is formed in a first container. The salt-like components are concentrated in the liquid phase which is forming in the second container, and a partial stream of the liquid phase which is formed in the second container is discharged from the second container.

Claims

1. A process for removal of salts thermally non-regenerable in a temperature range from 0°

C. to 200°

C. from organic solvents in an aqueous solution by evaporation, the normal boiling point of organic solvents being higher than that of water, and by enriching the organic constituents existing in the solvent as well as the salt-like constituents existing therein in a liquid phase forming by evaporation of water and a portion of the organic constituents of a first tank, and discharging an evolving vaporous phase from the first tank,

wherein

the liquid phase formed in the first tank is passed into a second tank, water in vaporous and/or liquid form being passed into the second tank, water and another portion of the organic constituents contained in the solvent being evaporated and forming a vaporous phase which is discharged from the second tank, said salt-like constituents being enriched in concentration in the liquid phase forming in the second tank, and wherein a partial stream of the liquid phase formed in the second tank is discharged from the second tank.

2. The process according to claim 1, wherein the salt concentration of the liquid phase formed in the first tank is determined, and in that the liquid phase of the first tank is passed into the second tank as soon as the concentration of salt-like constituents of the liquid phase to be carried over has reached a maximally admissible concentration at which the salt-like constituents are still soluble in the liquid phase.

3. The process according to claim 2, characterized in that wherein the liquid phase of the first tank is passed into the second tank as soon as a concentration of the salt-like constituent in the liquid phase of 5 to 35% by wt., preferably 5 to 25% by wt., and more particularly preferably 5 to 15% by wt., and most preferably 8 to 12% by wt., is achieved.

4. The process according to claim 1, wherein the salt concentration of the liquid phase formed in the second tank is determined, and a partial stream of the liquid phase is discharged from the second tank as soon as the concentration of salt-like constituents of the liquid phase to be discharged has reached a maximally admissible concentration at which the salt-like constituents are still soluble in the liquid phase.

5. The process according to claim 4, wherein a partial stream of the liquid phase is discharged from the second tank as soon as a concentration of the salt-like constituent in the liquid phase of 25 to 65% by wt., preferably 40 to 65% by wt., and more particularly preferably 45 to 65% by wt., and most preferably 55 to 65% by wt., is achieved.

6. The process according to claim 1, wherein the first tank and/or the second tank is externally heated and/or cooled.

7. The process according to claim 1, wherein water is provided in the second tank already before the liquid phase formed in the first tank is carried over into the second tank.

8. The process according to claim 1, wherein merely a concentrated salt solution depleted in organic constituents is produced as wastewater that encompasses the liquid phase formed in the second tank.

9. The process according to claim 1, wherein merely a partial stream of a main circulating stream of an industrial plant encompassing an organic solvent burdened with thermally stable salts is supplied to the first tank.

10. The process according to claim 1, wherein the vaporous phases of the first and/or second tank formed by evaporation are returned into a main circulating stream of an industrial plant.

11. The process according to claim 1, wherein the liquid phase formed in the first tank is continuously passed on to the second tank, and water in vaporous and/or liquid form is continuously passed into the second tank, and in that by way of a controlled supply or discharge of heat, water and portions of the organic constituents contained in the solvent are continuously evaporated, thus forming a vaporous phase which is discharged from the second tank, said salt-like constituents being enriched in concentration in the liquid phase forming in the second tank, and wherein a partial stream of the liquid phase formed in the second tank is continuously discharged from the second tank and forms a wastewater stream which encompasses a concentrated salt solution depleted in organic constituents, and wherein the vaporous phases of the first and/or second tank which are formed by evaporation are returned into a main process stream of an industrial plant.

12. The process according to claim 1, wherein a strong base is supplied to the first tank and/or the second tank.

13. The process according to claim 1, wherein first a removal of CO₂ and/or H₂S and/or HCN and/or mercaptans from flue gases is carried out.