Electrolyzers

Patent metadata

Field	Value
Publication number	US-2024035172-A1
Application number	US-202318360326-A
Country	US
Kind code	A1
Filing date	Jul 27, 2023
Priority date	Jul 28, 2022
Publication date	Feb 1, 2024
Grant date	—

Abstract

Disclosed herein is an electro-synthesizer unit comprising a first compartment comprising a cathode and a first electrolyte, a second compartment comprising an anode and a second electrolyte and a third compartment comprising a third electrolyte. The unit is configured to produce acid and base solution at desired concentrations. Also disclosed are methods of using the electro-synthesizer unit and producing the acid and base solution at desired concentrations.

First claim

1 . An electro-synthesizer unit,
wherein the electro-synthesizer unit is a flow unit comprising:
a first compartment comprising:
a first inlet configured to receive a first flow of a first electrolyte solution;
a cathode;
the first electrolyte solution that is in electrical and fluid communication with the cathode; wherein a pH of the first electrolyte solution is about 6≤pH≤15.5;
wherein the cathode is configured to generate a hydrogen gas and a hydroxide;
one or more outlets configured to remove the generated hydrogen gas and/or a base solution comprising the generated hydroxide from the first compartment;

a second compartment comprising:
a second inlet configured to receive a second flow of a second electrolyte solution;
a third inlet configured to receive a stream comprising a hydrogen gas;
an anode; and
the second electrolyte solution that is in electrical and fluid communication with the anode; wherein a pH of the second electrolyte solution is about −1.5≤pH≤8;
wherein the anode is configured to oxidate the hydrogen gas to generate hydrogen ions;
an outlet configured to remove an acid solution comprising the generated hydrogen ions from the second compartment; and

a third compartment positioned between and in fluid communication with the first compartment and the second compartment, wherein the third compartment is separated from the first compartment with one or more cation exchange membranes and is separated from the second compartment with one or more anion exchange membranes;
wherein the third compartment comprises:
a fourth inlet configured to receive a third flow of a third electrolyte solution;
the third electrolyte solution, wherein a pH of the third electrolyte solution is about 4≤pH≤10; and
an outlet configured to remove the third electrolyte from the third compartment.

2 . The electro-synthesizer unit of claim 1 , wherein the stream comprises the hydrogen gas generated in the first compartment.

3 . The electro-synthesizer unit of claim 2 , wherein the stream comprising the generated hydrogen gas is directly fed from the first compartment to the second compartment.

4 . The electro-synthesizer unit of claim 1 , wherein the stream comprises a hydrogen gas provided from an external source.

5 . The electro-synthesizer unit of claim 1 , wherein each of the first, second and third compartments are defined by two or more plates.

6 . The electro-synthesizer unit of claim 1 , wherein the second inlet of the second compartment extends into a first channel and the third inlet extends into a second channel, such that the first channel is positioned between the anion exchange membrane and a first surface of the anode and the second channel is positioned abut a second surface of the anode.

7 . The electro-synthesizer unit of claim 1 , wherein the generated in the first compartment hydrogen gas and the base solution comprising the generated hydroxide is removed from the same outlet or wherein the generated hydrogen gas stream and the base solution comprising the generated hydroxide are removed from separate outlets.

8 . The electro-synthesizer unit of claim 1 , wherein the first and/or the third compartments each have a width of about 0.01 to about 500 mm.

9 . The electro-synthesizer unit of claim 6 , wherein the first channel present in the second compartment and/or the second channel present in the second compartment each has a width of about to about 500 mm.

10 . The electro-synthesizer unit of claim 1 , wherein the anode comprises a gas diffusion layer.

11 . The electro-synthesizer unit of claim 10 , wherein the anode further comprises a hydrogen oxidation catalyst layer.

12 . The electro-synthesizer unit of claim 10 , wherein the gas diffusion layer comprises a carbon-based gas diffusion layer, a fluorocarbon-based gas diffusion layer, a hydrophobic material comprising a plurality of pores, or any combination thereof.

13 . The electro-synthesizer unit of claim 11 , wherein the hydrogen oxidation catalyst layer comprises one or more Pt group metal (PGM) or alloys thereof-based catalysts, PGM-free catalysts, and any combination thereof.

14 . The electro-synthesizer unit of claim 1 , wherein the cathode comprises a Pt group metal or their alloys based electrode, a Ni— and its alloys-based electrode, a NiFe-based electrode, NiTi-based electrode, steel-based electrode, transition metal sulfates-based electrode, transition metal phosphide-based electrode, Fe-based catalysts, carbon-based materials, or any combination thereof.

15 . The electro-synthesizer unit of claim 1 , wherein the cation and/or anion exchange membranes are polymer reinforced, wherein the polymer is inert to the first, second, and/or third electrolyte solutions.

16 . The electro-synthesizer unit of claim 1 , wherein the third electrolyte solution comprises one or more inorganic salts.

17 . The electro-synthesizer unit of claim 16 , wherein the one or more inorganic salts comprise chlorides, sulfates, nitrates, phosphates, citrates, formates, lactates, tartrates, malates, fumarates, oxalates, succinates, gluconates, ascorbates, acetates of alkaline metals and/or alkaline-earth metals, or mixtures thereof.

18 . The electro-synthesizer unit of claim 1 , wherein the first electrolyte solution comprises a base comprising one or more of sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide, amine-based bases, sodium acetate, or any combination thereof.

19 . The electro-synthesizer unit of claim 1 , wherein the second electrolyte solution comprises an acid comprising one or more of hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfurous acid, sulfuric acid, nitric acid, phosphorous acid, phosphoric acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, formic acid, acetic acid, carbonic acid, or any combination thereof.

20 . The electro-synthesizer unit of claim 1 , wherein the first electrolyte further comprises one or more inorganic salts comprising chlorides, sulfates, nitrates, phosphates, citrates, formates, lactates, tartrates, malates, fumarates, oxalates, succinates, gluconates, ascorbates, acetates of alkaline metals and/or alkaline-earth metals, or mixtures thereof.

21 . The electro-synthesizer unit of claim 1 , wherein the second electrolyte further comprises one or more inorganic salts comprising chlorides, sulfates, nitrates, phosphates, citrates, formates, lactates, tartrates, malates, fumarates, oxalates, succinates, gluconates, ascorbates, acetates of alkaline metals and/or alkaline-earth metals, or mixtures thereof.

22 . The electro-synthesizer unit of claim 1 , wherein the first electrolyte, the second electrolyte, and/or the third electrolyte each has a flow rate of about 1 to about 5,000,000 mL/h.

23 . The electro-synthesizer unit of claim 1 , wherein when the pH in the first compartment is 8 to about 15.5, and wherein the pH in the second compartment is about −0.5 to about 6, the base solution removed from the one or more outlets of the first compartment has a molarity of greater than to about 20 M and the acid solution removed from the outlet of the second compartment has a molarity of greater than 0 to about 10 M.

24 . A system comprising one or more of the electro-synthesizer units of claim 1 .

25 . The system of claim 24 , wherein two or more electro-synthesizer units are present, and two or m

Assignees

• Univ Johns Hopkins

Inventors

• Wang Chao
• Shen Hao
• Zhou Chengao

Classifications

• C25B13/04

  characterised by the material · CPC title

• C25B1/22

  Inorganic acids · CPC title

• C22B3/06

  in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions} · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• B01D2251/604

  Hydroxides · CPC title