Divided electrochemical cell and low cost high purity hydride gas production process

Patent metadata

Field	Value
Publication number	US-9738982-B2
Application number	US-201514822299-A
Country	US
Kind code	B2
Filing date	Aug 10, 2015
Priority date	Dec 20, 2007
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

This invention is an apparatus and a method for continuously generating a hydride gas of M 1 which is substantially free of oxygen in a divided electrochemical cell. An impermeable partition or a combination of an impermeable partition and a porous diaphragm can be used to divide the electrochemical cell. The divided electrochemical cell has an anode chamber and a cathode chamber, wherein the cathode chamber has a cathode comprising M 1 , the anode chamber has an anode comprising M 2 and is capable of generating oxygen, an aqueous electrolyte solution comprising a hydroxide M 3 OH partially filling the divided electrochemical cell. Hydride gas generated in the cathode chamber and oxygen generated in the anode chamber are removed through independent outlets. M 1 can be selenium, phosphorous, silicon, metal or metal alloy, M 2 is metal or metal alloy suitable for anionic oxygen generation, and M 3 is NH 4 or an alkali or alkaline earth metal.

First claim

The invention claimed is:

1. An apparatus for generating a hydride gas of M 1 comprising:
a divided electrochemical cell comprising:
(a) tubular housing wherein at least part of the tubular housing comprising M 2 ;
(b) an electrical insulator bottom;
(c) an electrical insulator top lid comprising a cathode gas outlet, an anode gas outlet and a water inlet;
(d) a divider that divides the divided electrochemical cell into a cathode chamber and an anode chamber, wherein the divider is electrically insulated from anode and cathode circuits;
(e) the cathode chamber comprising a cathode selected from the group consisting of a solid rod of M 1 and a fixed bed of M 1 granules, and the cathode gas outlet;
(f) the anode chamber comprising an anode that is part of tubular housing comprising M 2 , the anode gas outlet and the water inlet;

an aqueous electrolyte solution partially filling the cathode chamber and the anode chamber comprising a hydroxide M 3 OH;
a first control valve connected with the cathode gas outlet;
a second control valve connected with the anode gas outlet; and
a third control valve connected with the water inlet;
wherein
the cathode and the anode are at least partially immersed in the aqueous electrolyte solution;
the cathode, the anode and the divider are spaced apart;
M 1 is selected from the group consisting of selenium, phosphorous, silicon, antimony, arsenic, lead, cadmium; and combinations thereof;
M 2 is a metal or a metal alloy suitable for anionic oxygen generation selected from the group consisting of nickel, copper, stainless steel, aluminum, and combinations thereof; and
M 3 is NH 4 or a metal selected from the group consisting of alkali and alkaline earth metals.

2. The apparatus of claim 1 , wherein the M 3 OH is selected from the group consisting of NaOH, KOH, LiOH, CsOH, NH 4 OH and combinations thereof; and the M 3 OH in the aqueous electrolyte solution ranges about 2% to about 45% by weight.

3. The apparatus of claim 1 further comprising a heat transfer jacket covering the tubular housing of the divided electrochemical cell; wherein the heat transfer jacket comprises an inlet and an outlet for circulating cooling fluid.

4. The apparatus of claim 1 wherein the divider is at least partially extends into the aqueous electrolyte solution to prevent mixing of an anode gas with a cathode gas; and is selected from the group consisting of a solid impermeable partition; and a combination of a solid impermeable partition and a porous permeable diaphragm wherein pore size in the porous permeable diaphragm is smaller than gas bubbles generated in the anode chamber and the cathode chamber to prevent mixing of the gas bubbles.

5. The apparatus of claim 1 wherein M 1 is arsenic; and M 2 is nickel.

6. A method for generating a hydride gas of M 1 using the apparatus of claim 1 ; comprising
supplying an electric power to the divided electrochemical cell;
controlling a differential pressure ΔP=Pc−Pa by using the first and the second control valves; wherein Pc is a pressure in the cathode chamber and Pa is a pressure in the anode chamber;
allowing the differential pressure ΔP increase;
releasing gas generated in the cathode chamber through the cathode gas outlet as the hydride gas;
releasing gas generated in the anode chamber through the anode gas outlet; and
closing the control valves.

7. The method of claim 6 wherein the divider is at least partially extends into the aqueous electrolyte solution to prevent mixing of an anode gas with a cathode gas; and is selected from the group consisting of a solid impermeable partition; and a combination of a solid impermeable partition and a porous permeable diaphragm wherein pore size in the porous permeable diaphragm is smaller than gas bubbles generated in the anode chamber and the cathode chamber to prevent mixing of the gas bubbles.

8. The method of claim 6 wherein the M 3 OH in the aqueous electrolyte solution ranges about 2% to about 45% by weight, and the M 3 OH is selected from the group consisting of NaOH, KOH, LiOH, CsOH, NH 4 OH and combinations thereof.

9. The method of claim 6 wherein the electric power is supplied through a constant current density ranging from about 100 to about 15,000 A/m 2 ; or a constant voltage V ranging from about 2 to about 15 volts; Pc and Pa range from about 50,000 to about 500,000 Pa; ΔP ranges from about 1 to about 10,000 Pa; the divided electrochemical cell is operated at a temperature ranging from about 15° C. to about 100° C.; and water is added to the anode chamber continuously or batch-wisely.

10. The method of claim 6 wherein M 1 is arsenic; and M 2 is nickel.

11. An apparatus for generating a hydride gas of M 1 comprising:
a divided electrochemical cell comprising:
(a) a U-shaped tubular housing at least partially comprising M 2 ; wherein
one side of the U-shaped tubular housing forms a cathode chamber;
the other side of the U-shaped tubular housing forms an anode chamber; and
bottom part of the U-shaped tubular housing comprises an electrical insulator connecting the cathode chamber and the anode chamber while not allowing mixing of a cathode gas with an anode gas;

(b) the cathode chamber comprises a cathode selected from the group consisting of a solid rod of M 1 and a fixed bed of M 1 granules, and an electrical insulator top lid comprising a cathode gas outlet;
(c) the anode chamber comprises an anode that is the other side of the U-shaped tubular housing comprising M 2 , and an electrical insulator top lid comprising a anode gas outlet and a water inlet;

an aqueous electrolyte solution comprising a hydroxide M 3 OH partially filling the cathode chamber and the anode chamber;
a first control valve connected with the cathode gas outlet;
a second control valve connected with the anode gas outlet;
a third control valve connected with the water inlet; and
wherein
the cathode and the anode are immersed in the aqueous electrolyte solution;
M 1 is selected from the group consisting of selenium, phosphorous, silicon, antimony, arsenic, germanium, lead, cadmium; and combinations thereof; and
M 2 is a metal or a metal alloy suitable for anonic oxygen generation selected from the group consisting of nickel, copper, stainless steel, aluminum, and combinations thereof; and
M 3 is NH 4 or a metal selected from the group consisting of alkali and alkaline earth metals.

12. The apparatus of claim 11 further comprising a heat transfer jacket covering the tubular housing of the divided electrochemical cell; wherein the heat transfer jacket comprises an inlet and an outlet for circulating cooling fluid.

13. The apparatus of claim 11 , wherein the M 3 OH in the aqueous electrolyte solution ranges about 2% to about 45% by weight.

14. The apparatus of claim 11 wherein the M 3 OH is selected from the group consisting of NaOH, KOH, LiOH, CsOH, NH 4 OH and combinations thereof.

15. The apparatus of claim 11 wherein M 1 is arsenic; and M 2 is nickel.

16. A method for generating a hydride gas of M 1 in a divided electrochemical cell comprising (a) a U-shaped tubular housing at least partially comprising M 2 ; wherein one side of the U-shaped tubular housing forms a cathode chamber; the other side of the U-shaped tubular housing forms an anode chamber; and bottom part of the U-shaped tubular housing comprises an electrical insulator connecting the cathode chamber and the anode chamber while not allowing mixing of a cathode gas with an anode gas; (b) the cathode chamber comprises a cathode selected from the group consisting of a solid rod of

Assignees

• Air Prod & Chem
• Versum Mat Us Llc

Inventors

• Machado Reinaldo Mario
• Tsirukis Athanasios Georgios
• Hartz Christopher L
• Leenhouts James Robert
• Schulze William F

Classifications

• C25B9/08

  Chemistry & Metallurgy · mapped topic

• Y02E60/366

  Cross-Sectional Technologies · mapped topic

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C23C16/4488

  by in situ generation of reactive gas by chemical or electrochemical reaction · CPC title

• C25B9/16

  Chemistry & Metallurgy · mapped topic