Desalination of high chloride salt absorbed porous beads

Patent metadata

Field	Value
Publication number	US-12390791-B2
Application number	US-202218061399-A
Country	US
Kind code	B2
Filing date	Dec 2, 2022
Priority date	Apr 8, 2022
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A method of recovering desalinated activated alumina (AA) beads from a composition including salt laden (high salt absorbed) activated alumna (AA) beads and free anions and free cations, comprising the step of electrodialysis of the composition to reduce salt content of the activated alumina (AA) beads to produce a stream comprising the desalinated activated alumina (AA) beads.

First claim

We claim:

1. A method of recovering desalinated activated alumina (AA) beads from a composition comprising salt laden activated alumna (AA) beads and free anions and free cations, wherein the salt of the salt laden activated alumna (AA) beads comprises a chloride salt, comprising:
electrodialysis of the composition to reduce chloride salt content of the activated alumina (AA) beads to produce a stream comprising the desalinated activated alumina (AA) beads,
wherein the activated alumina (AA) beads have a D50 median particle size of 0.5 mm to 5 mm,
wherein the composition comprises a mixture of the salt laden activated alumina (AA) beads, liquid water and electrolyte, wherein the chloride salt forms the free anions and free cations in the water, wherein the cations comprise alkali metal ions and the anions comprise chloride ions and optionally potassium ions;
subjecting the mixture of activated alumina, liquid water, and electrolyte to the electrodialysis in an electrodialysis device by running an electric current through the mixture of activated alumina, liquid water, and electrolyte to remove the anions and the cations from the mixture to produce the desalinated activated alumina having reduced concentration of chloride salt absorbed on the activated alumina relative to concentration of chloride salt absorbed on the salt laden activated alumina prior to the electrodialysis, wherein the electrodialysis device comprises an anode and a cathode; and
separating the desalinated activated alumina beads from liquid of the mixture;
optionally repeating the process to reuse the liquid to extract chloride from an additional batch of salt laden activated alumina (AA) beads,
wherein the electrodialysis device comprises one or more of the group consisting of
a) at least one electrodialysis cell configured so that a cation exchange membrane separates at least one anolyte product region, containing the desalinated activated alumina beads, from a catholyte region,
b) a diluate chamber and a concentrate chamber between the cathode and the anode, and
c) a diluate chamber containing the anode and a concentrate chamber containing the cathode; and
separating the desalinated activated alumina beads from liquid of the mixture;
optionally repeating the process to reuse the liquid to extract chloride from an additional batch of salt laden activated alumina (AA) beads.

2. The method of claim 1 ,
wherein the salt laden activated alumina (AA) beads may have greater than 5,000 ppm by weight chloride anion on a dry basis; and
wherein the desalinated activated alumina (AA) beads may have less than 5,000 ppm by weight chloride anion on a dry basis.

3. The method of claim 1 wherein the electrodialysis device comprises a diluate chamber and a concentrate chamber between the cathode and the anode; and
wherein the salt laden activated alumina are placed in the diluate chamber,

wherein the water and the electrolyte are placed in the diluate chamber and the concentrate chamber.

4. The method of claim 1 wherein the electrodialysis device comprises a diluate chamber containing the anode and a concentrate chamber containing the cathode; and
wherein the chloride salt laden activated alumina beads are placed in the diluate chamber, wherein the water and the electrolyte are placed in the diluate chamber and the concentrate chamber.

5. The method of claim 1 , wherein the electrodialysis is done using an electrodialysis cell without a cation exchange membrane between an anode and a cathode.

6. The method of claim 1
wherein the electrodialysis device comprises at least one electrodialysis cell configured so that a cation exchange membrane separates at least one anolyte product region, containing the desalinated activated alumina beads, from a catholyte region.

7. The method of claim 1 , wherein the activated alumina beads have a volume mean diameter, or a mean length, of particle size of 0.5 mm to 5 mm.

8. The method of claim 1 , wherein the electrodialysis is performed at a current density in the range from about 1 to about 10 kA/m 2 .

9. The method of claim 1 , wherein material of the cathode is steel, nickel, graphite, titanium, coated titanium or activated nickel.

10. The method of claim 1 , wherein material of the anode is lead, graphite, coated titanium, lead oxides, tin oxide, tantalum, or combinations thereof.

11. The method of claim 1 , wherein the chloride salt laden activated alumina beads are pre-wetted before the electrodialysis in water, before being added to the electrodialysis device.

12. The method of claim 1 , wherein the alkali metal ions are collected as an alkali metal hydroxide-containing aqueous catholyte, and wherein the chloride ions form hydrochloric acid and/or chlorine gas.

13. A method of recovering desalinated activated alumina (AA) beads from a composition comprising salt laden activated alumna (AA) beads and free anions and free cations, wherein the salt of the salt laden activated alumna (AA) beads comprises a chloride salt, comprising:
electrodialysis of the composition to reduce chloride salt content of the activated alumina (AA) beads to produce a stream comprising the desalinated activated alumina (AA) beads,
wherein the activated alumina (AA) beads have a D50 median particle size of 0.5 mm to 5 mm,
wherein the composition comprises a mixture of the salt laden activated alumina (AA) beads, liquid water and electrolyte, wherein the chloride salt forms the free anions and free cations in the water, wherein the cations comprise alkali metal ions and the anions comprise chloride ions and optionally potassium ions;
subjecting the mixture of activated alumina, liquid water, and electrolyte to the electrodialysis in an electrodialysis device by running an electric current through the mixture of activated alumina, liquid water, and electrolyte to remove the anions and the cations from the mixture to produce the desalinated activated alumina having reduced concentration of chloride salt absorbed on the activated alumina relative to concentration of chloride salt absorbed on the salt laden activated alumina prior to the electrodialysis, wherein the electrodialysis device comprises an anode and a cathode;
wherein anolyte comprising the salt laden activated alumina beads and water is added into the electrodialysis device;
wherein catholyte comprising the water is added into the electrodialysis device;
wherein the electrolyte comprises tetraethylammonium tetrafluoroborate, and wherein the electrolyte is added to the salt laden activated alumina beads and the water in the electrodialysis device, and
separating the desalinated activated alumina beads from liquid of the mixture;

optionally repeating the process to reuse the liquid to extract chloride from an additional batch of salt laden activated alumina (AA) beads.

14. The method of claim 13 , wherein temperature in the anolyte is in a range from about 50 to about 100° C.

15. A method of recovering desalinated activated alumina (AA) beads from a composition comprising salt laden activated alumna (AA) beads and free anions and free cations, wherein the salt of the salt laden activated alumna (AA) beads comprises a chloride salt, comprising:
electrodialysis of the composition to reduce chloride salt content of the activated alumina (AA) beads to produce a stream comprising the desalinated activated alumina (AA) beads,
wherein the activated alumina (AA) beads have a D50 median particle size of 0.5 mm to 5 mm, wherein the electrodialysis is done using an electrodialysis cell with a cation exchange membrane between an anode and a cathode.

Assignees

• Knauf Gips Kg

Inventors

• Li Qinghua
• Chen Xiaoyan

Classifications

• C01F7/021

  After-treatment of oxides or hydroxides · CPC title

• C04B2111/0062

  Gypsum-paper board like materials · CPC title

• C01P2006/80

  Compositional purity · CPC title

• C01P2004/60

  Particles characterised by their size · CPC title

• B28B19/0092

  to webs, sheets or the like, e.g. of paper, cardboard · CPC title