Modular electrolyzer unit to generate gaseous hydrogen at high pressure and with high purity

1. An electrolyzer unit ( 100 ) to generate gaseous hydrogen from water via electrolysis, comprising:

at least one electrolyzing cell ( 24 ) to perform the electrolysis of water;

a cathode plate ( 4 ) and an anode plate ( 9 ) sandwiching the at least one electrolyzing cell ( 24 ) and arranged in close contact with opposite sides of said at least one electrolyzing cell ( 24 );

a cathode insulation plate ( 3 ) arranged over the cathode plate ( 4 ) in close contact with the cathode plate ( 4 );

an anode insulation plate ( 10 ) arranged over the anode plate ( 9 ) in close contact with the anode plate ( 9 );

a cathode-side endplate ( 1 ) arranged over the cathode insulation plate ( 3 ) in close contact with the cathode insulation plate ( 3 ), said cathode-side endplate ( 1 ) is provided with a water inlet ( 1 b ), a hydrogen outlet ( 1 a ), and a water/oxygen outlet ( 1 b ′);

an anode-side endplate ( 12 ) arranged over the anode insulation plate ( 10 ) in close contact with the anode insulation plate ( 10 );

wherein individual ones of the at least one electrolyzing cell ( 24 ) are defined by a first two-component bipolar plate assembly ( 25 ) and a second two-component bipolar plate assembly ( 25 ′) arranged adjacent to one another and comprise:

a first component ( 25 a ) of the first bipolar plate assembly ( 25 ) to act as cathode of a respective cell;

a second component ( 25 b ) of the second bipolar plate assembly ( 25 ′) to act as anode of said respective cell, the second component ( 25 b ) being complementary to the first component ( 25 a ), wherein cavities ( 26 ) are formed in said first and second components ( 25 a , 25 b );

a proton conducting membrane ( 5 ) arranged between said first and second components ( 25 a , 25 b ), wherein the proton conducting membrane ( 5 ) comprises a catalyst-coated membrane, and is sandwiched between titanium-frit plates ( 14 , 15 ) on both sides, wherein the titanium-frit plates ( 14 , 15 ) are made of titanium particles of different average particle size by pressing, wherein said titanium particles are coated with a catalyst, said catalyst being a nanoparticulate catalyst;

a first channel sealing assembly ( 13 ) to provide fluid communication therethrough between a water receiving cavity of the first component ( 25 a ) and said water inlet ( 1 b ) through a water transport channel ( 13 b ) and to provide a sealing of the membrane ( 5 );

a second channel sealing assembly ( 13 ) to provide gaseous communication therethrough between a hydrogen receiving cavity of the first component ( 25 a ) and said hydrogen outlet ( 1 a ) through a hydrogen transport channel ( 28 );

a third channel sealing assembly ( 13 ) to provide gaseous communication between an oxygen receiving cavity of the second component ( 25 b ) and said oxygen outlet ( 1 b ′) through a water/oxygen transport channel ( 29 ) and to provide a sealing of the water receiving cavity and the hydrogen receiving cavity.

2. The electrolyzer unit ( 100 ) according to claim 1 , wherein a cathode-side pressure chamber ( 2 b ) is formed between the cathode-side endplate ( 1 ) and the cathode-side insulation plate ( 3 ), and

an anode-side pressure chamber ( 11 b ) is formed between the anode-side endplate ( 12 ) and the anode-side insulation plate ( 10 ).

3. The electrolyzer unit ( 100 ) according to claim 2 , wherein the cathode-side pressure chamber ( 2 b ) is formed in a plate ( 2 ) inserted between the cathode-side endplate ( 1 ) and the cathode-side insulation plate ( 3 ).

4. The electrolyzer unit ( 100 ) according to claim 2 , wherein the anode-side pressure chamber ( 11 b ) is formed in a plate ( 11 ) inserted between the anode-side endplate ( 12 ) and the anode-side insulation plate ( 3 ).

5. The electrolyzer unit ( 100 ) according to claim 1 , wherein a hydrogen/oxygen recombiner element ( 30 ) is arranged within the water receiving cavity and the oxygen receiving cavity.

6. The electrolyzer unit ( 100 ) according to claim 5 , wherein the hydrogen/oxygen recombiner element ( 30 ) is a mesh.

7. The electrolyzer unit ( 100 ) according to claim 6 , wherein the mesh is provided in the form of a platinum coated titanium mesh.

8. The electrolyzer unit ( 100 ) according to claim 1 , wherein the at least one electrolyzing cell ( 24 ) at most ten electrolyzing cells.

9. The electrolyzer unit ( 100 ) according to claim 1 , wherein the channel sealing assemblies ( 13 ) comprise a body ( 13 a ) with a longitudinal through bore ( 13 b ) formed therein and first and second O-rings ( 17 ) arranged at the upper and lower edges of the body ( 13 a ) around said through bore ( 13 b ).

10. A hydrogen generator ( 200 ) comprising a water source ( 105 ), a hydrogen outputting means, an oxygen outputting means and at least one electrolyzer unit ( 100 ) according to claim 1 in fluid communication with the water source ( 105 ), and in gaseous communication with the hydrogen outputting means and the oxygen outputting means.

11. The hydrogen generator ( 200 ) according to claim 10 , wherein a mechanical water separator ( 110 ) is inserted between the electrolyzer unit ( 100 ) and the hydrogen outputting means.

12. The hydrogen generator ( 200 ) according to claim 11 , wherein a thermal water separator ( 120 ) is inserted between the mechanical water separator ( 110 ) and the hydrogen outputting means.