High Pressure Water Electrolysis

Through a special material choice and optimization, high pressure water electrolysis allows the generation of hydrogen at pressures of up to 5 MPa. The processes under development attempt to find an appropriate capacity optimization that will also allow a problem free connection of the electrolyser with a fluctuating current supply (e.g. Wind or PV connection for isolated plants). A development work to mention is that being carried out by GHW (Gesellschaft für Hochleistungswasserelektrolyse) for the commercialization of a high performance electrolyser with output pressures up to the 5 MPa level. The goal of these efforts is to reach, along with the high output pressure, an appropriately optimized operating efficiency applicable to strongly varying loads. In the field of small capacity units (under 100kW), vHS has the appropriate equipment to offer.

Table B-1 Present electrolyzer development [96]

Electrolyser Type

Anode (A) Cathode

(C)

Efficiency

(V)

Cons.

m3 H2)

Remarks

Alkaline (2030% KOH)

Ambient pressure

77-80

1.84 -2.25

1.3-2.5

4.3-4.9

Com. large-scale prov. tech., simple, low eff., corrosive electrolyte

80°C, ambient pressure

83

1.8

3

4.3

Norsk Hydro, >400 kW, capacity 100-400 Nm3/h

90°C, 3.2 MPa

79

1.7

4

4.2

Lurgi, 25 MW, capacity 5100 Nm3/h

30-85°C, 0.3 - 0.9 MPa

69

3.5

5.0

Hysolar 350 kW

100°C; 0.11 MPa

87

1.7

5

4.0

Research center Jülich, Hysolar 10 kW

110°C, 0.5 MPa

90

1.7

5

3.9

Hydrogen system, <100 kW, commercial 5-10 kW

Advanced alkaline (25-40 % KOH)

(A): Ni (C): Ni

90-145°C, < 4 MPa

80-90

1.5 - 3.0

3.8 - 4.3

Lab scale, prototype, com. potential, severe cor. at higher temp.

120°C

1.5

2.5

3.8

Research center Jülich, 10 kW

Inorganic Membrane alkaline (1415% NaOH)

(A):spinel oxide

(C):NiS

90-120°C < 4 MPa

82-91

1.6-1.9

1.6 -1.9

3.6-4.0

Lab scale, prototype, non-noble metal cat., membrane perf. needs to be demonstrated

Solid polymer (Nafion)

(A): Ti, (C): carbon with Pt

100-130°C, < 4 MPa

85-90 88

1.4 - 2.0 1.7

2.5-20 10

100 kW, compact, non-cor. elect., noble metal cat, exp. membrane GIRI, Osaka, production rate 1.3 Nm3/h

Intermediate temp Molten Carbonate (KOH/NaOH)

(A): Ni (C): Ni

300-600°C

82-91

1.3-1.4

>2

simple double cell configuration

High-

temperature (solid Y2O3 stab. ZrO2)

NiO,

1000°C,< 3MPa

90-100

0.95-1.3

10

3.5

Very small lab scale, non-cor. Electr., severe material & fabrication problem

Living Off The Grid

Living Off The Grid

Get All The Support And Guidance You Need To Be A Success At Living Off The Grid. This Book Is One Of The Most Valuable Resources In The World When It Comes To When Living Within The Grid Is Not Making Sense Anymore.

Get My Free Ebook


Post a comment