# US 12,601,073 B2 · H2 dryer for power plant using electrolyzer

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- Number: US 12,601,073 B2
- Document ID: US12601073B2
- Status: Granted
- Kind: B2
- Application number: 17/895,560
- Filed: 2022-08-25
- Published: 2024-02-29
- Granted: 2026-04-14
- Earliest claimed: 2022-08-25
- Assignees: Mitsubishi Power Americas, Inc.
- Applicants: Mitsubishi Power Americas, Inc.
- Inventors: Todd Eric Carlson; Leif Hsieh
- Web page: https://patentgrep.com/patent/US12601073B2

## CPC

- C25B 15/02: Process control or regulation
- B01D 53/261: {by adsorption}
- C25B 1/04: by electrolysis of water
- Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A system for drying hydrogen in a hydrogen production facility comprises an electrolyzer for producing a flow of hydrogen gas, a drying device configured to remove moisture from the flow of hydrogen gas, a compressor configured to receive the flow of hydrogen gas from the drying device, and a recirculation line connected to output of the compressor to recirculate at least a portion of the flow of hydrogen gas from the compressor to the drying device. A method of drying hydrogen in a hydrogen production facility comprises producing a flow of hydrogen gas with an electrolyzer, drying the flow of hydrogen gas with a drying device, compressing the flow of hydrogen gas from the drying device with a compressor, and recirculating at least a portion of the flow of hydrogen gas from the compressor to the drying device to maintain pressure distribution within the drying device.

## Claims

### Claim 1

A system for drying hydrogen in a hydrogen production facility, the system comprising:
an electrolyzer for producing a flow of hydrogen gas;
a drying device configured to remove moisture from the flow of hydrogen gas;
a compressor configured to receive the flow of hydrogen gas from the drying device;
a recirculation line connected to output of the compressor to recirculate at least a portion of the flow of hydrogen gas from the compressor to the drying device;
a valve located in the recirculation line; and
a controller configured to operate the valve based on an operating state of the electrolyzer.

### Claim 2 (depends on 1)

The system of claim 1, further comprising:
a first pressure sensor configured to sense pressure of hydrogen gas entering the compressor; and
a second pressure sensor configured to sense pressure of hydrogen gas leaving the compressor.

### Claim 3 (depends on 1)

The system of claim 1, further comprising:
a cooler configured to cool the flow of hydrogen gas from form the compressor before entering the recirculation line; and
a hydrogen storage system configured to receive the flow of hydrogen gas from the compressor downstream of the recirculation line.

### Claim 4

A method of drying hydrogen in a hydrogen production facility, the method comprising:
producing a flow of hydrogen gas with an electrolyzer;
drying the flow of hydrogen gas with a drying device;
compressing the flow of hydrogen gas from the drying device with a compressor; and
recirculating at least a portion of the flow of hydrogen gas from the compressor to the drying device to maintain pressure distribution within the drying device.

### Claim 5 (depends on 4)

The method of claim 4, further comprising modulating the portion of the flow of hydrogen gas from the compressor that flows to the drying device based on output of the electrolyzer.

### Claim 6 (depends on 5)

The method of claim 5, further comprising:
operating the electrolyzer in a turndown mode such that volumetric flow from the electrolyzer is less than a capacity of the compressor; and
recirculating sufficient flow of hydrogen gas from the compressor to the drying device to provide volumetric flow through the compressor at the capacity.

### Claim 7 (depends on 5)

The method of claim 5, further comprising stopping recirculation of the portion of the flow of hydrogen gas from the compressor when the electrolyzer is operating at full capacity.

### Claim 8 (depends on 4)

The method of claim 4, further comprising:
cooling the flow of hydrogen gas from the compressor before recirculating the portion of the flow of hydrogen gas from the compressor; and
storing compressed hydrogen gas in a storage system after compressing the flow of hydrogen gas from the drying device.

### Claim 9

A controller for operating a hydrogen production facility comprising an electrolyzer, the controller comprising:
a pressure sensor interface for receiving input signals from a compressor configured to receive a hydrogen output from the electrolyzer;
a kickback valve interface for providing an output signal to a kickback valve that controls recirculation between output of the compressor an inlet of a hydrogen dryer; and
memory having stored therein instructions for:
operating the kickback valve based on compressor suction pressures received at the pressure sensor interface;
operating the electrolyzer to produce the hydrogen output; and
operating a drying device that receives the hydrogen output from the electrolyzer.

### Claim 10 (depends on 9)

The controller of claim 9, wherein the instructions for operating the kickback valve comprise increasing the recirculation as the hydrogen output of the electrolyzer decreases.

### Claim 11 (depends on 9)

The controller of claim 9, further comprising:
a first pressure sensor configured to sense pressure of hydrogen gas at an inlet of the compressor; and
a second pressure sensor configured to sense pressure of hydrogen gas at an outlet of the compressor.

### Claim 12 (depends on 9)

The controller of claim 9, further comprising the kickback valve.

### Claim 13 (depends on 10)

The controller of claim 10, wherein the controller further comprises instructions for stopping recirculation of the hydrogen output from the compressor when the electrolyzer is operating at full capacity.

### Claim 14 (depends on 9)

The controller of claim 9, wherein the instructions for operating the kickback valve comprise modulating the kickback valve.

### Claim 15 (depends on 9)

The controller of claim 9, wherein the drying device comprises a beaded adsorption bed.

### Claim 16 (depends on 9)

The controller of claim 9, wherein the controller further comprises instructions for controlling operation of a storage system to store hydrogen gas from the drying device.

### Claim 17 (depends on 9)

The controller of claim 9, wherein the controller further comprises instructions for operating a cooling device to cool flow of the hydrogen output from the electrolyzer before entering the compressor.

### Claim 18 (depends on 9)

The controller of claim 9, wherein the controller further comprises instructions for operating the compressor to compress the hydrogen output at a fixed volumetric flow rate.

### Claim 19 (depends on 9)

The controller of claim 9, wherein the controller further comprises instructions for operating the electrolyzer in a turndown mode where volumetric flow from the electrolyzer is less than a capacity of the compressor.

### Claim 20

A controller for operating a hydrogen production facility comprising an electrolyzer, the controller comprising:
a pressure sensor interface for receiving input signals from a compressor configured to receive a hydrogen output from the electrolyzer;
a kickback valve interface for providing an output signal to a kickback valve that controls recirculation between output of the compressor an inlet of a hydrogen dryer;
memory having stored therein instructions for:
operating the kickback valve based on compressor suction pressures received at the pressure sensor interface;
a first pressure sensor configured to sense pressure of hydrogen gas at an inlet of the compressor; and
a second pressure sensor configured to sense pressure of hydrogen gas at an outlet of the compressor.