1. PEM electrolyzer assembly process
Take a semi-automatic assembly line as an example:
1) 3 people/line (3 people per line)
2) Use 30mm 316 stainless steel as the end plate.
3) Use PPS-40GF as the binding material of MEA, and use compression belts or tie rods to fasten.
1. Brief description of processing process
1) Raw materials: processed BP, sealant, processed MEA, etc.
2) Equipment: manipulator, conveyor belt, screen printing machine, UV furnace, hot press, hydraulic press, test bench
3) Process: BP - Printed sealant - MEA - Printed sealant - UV curing - 3 manual stacking and hot pressing - Pressing - Installing the shell and other firmware - Adjustment and testing
2.Cost calculation under different scales
2.PEM BP production process
1. Brief description of processing process:
1) Raw material: surface-hardened (nitrided) 316 stainless steel coil (most of them currently use titanium plates)
2) Process: blanking - stamping - chemical cleaning - cleaning - surface plasma treatment - finished product
3) Equipment: punching and blanking machines, stamping dies, plasma nitriding furnaces, chemical cleaning pools, and ordinary cleaning pools.
2.Cost analysis of electrolyzers with different powers:
3. Production of MEA
1.Cathode:
1) Raw materials: PEM membrane with protective layer, catalyst slurry (platinum)
Note: Currently, most PEMs used for hydrogen production through water electrolysis are perfluorosulfonic acid membranes. The preparation process is complex and has long been monopolized by American and Japanese companies, such as Chemours Nafion™ series membranes, Dow XUS-B204 membranes, Asahi Glass Flemion® membranes, and Asahi Kasei. Aciplex®-S membrane, etc. Among them, Chemours Nafion™ series membranes have the advantages of low electronic impedance, high proton conductivity, good chemical stability, mechanical stability, and gas permeability prevention. They are currently the most commonly used proton exchange membranes for electrolytic hydrogen production.
2) Equipment: coating machine, drying oven, scanner, visual identifier (quality inspection), conveyor belt
3) The process is as follows:
Coil material - catalyst coating - drying and curing - quality inspection - next process
2.Anode
1) Raw materials: base membrane (used to undertake the anode catalytic layer), anode catalyst slurry (DSA-mixture of iridium oxide, titanium oxide, etc.)
2) Equipment: coating machine, drying oven, scanner, visual identifier (quality inspection), conveyor belt
3) The process is as follows: (The initial raw material is PET and other films that undertake the catalytic layer)
Undertake film rolls - coating of catalytic layer, drying and curing - visual system quality inspection - next process
3. CCM synthesizes the final MEA
1) Raw materials: cathode layer (with PEM membrane and catalytic layer) coated in the previous process, anode layer processed in the previous process (catalytic layer attached to the base film)
2) Equipment: conveyor belt, hot pressure roller, scanner, visual recognition system (quality inspection)
3) The process is as follows:
4. Powder metallurgy production of GDL layer
1. Raw materials: copper, stainless steel, molybdenum and other metal powders (currently titanium felt, carbon felt and other routes are available)
2. Equipment: powder mixing device, metal powder compaction equipment, tooling mold, sintering device
3. The process is as follows:
Metal powder - stirring and mixing - compaction and shaping - sintering into felt
Note: Currently, titanium felt is mostly used as anode; carbon felt is mostly used as cathode. Another picture of metal powder sintered GDL is as follows:
(a) SEM image of GDL
(b) Photomicrograph at 1cm size
5. PEM single cell structure
Cathode Plate
Anode Plate
Frame: MEA frame (similar to fuel cells)
MEA Cell: Membrane Electrode Group
Seals: sealing components
Porous Ti GDL:PTL or titanium felt diffusion layer (GDL)
6. BOP (Blance of Plant)
1.Power supply
1) Power supply
2) DC voltage/current sensor.
2. Deionized water system
1) Oxygen separator
2) Circulation pump
3) Various valves, pipes, etc.
4) Instruments (pressure, flow, temperature, conductivity, etc.)
5) Control system
3. Hydrogen production drying system
1) Hydrogen separator
2) Valves, instruments (pressure, temperature, flow, etc.), pipelines, etc.
3) Control system
4. Cooling and drying system
1) Plate heat exchanger
2) Cooling pump
3) Instruments, valves, pipelines, etc.
4) Dry condenser
5.Others
Compressed air, nitrogen, combustible gas detectors, ventilation systems, etc.
The approximate cost structure of the above BOP is as follows:
Conclusion:
Through the above core components of PEM hydrogen production, as well as the material composition and processing technology of the entire system, as well as a simple cost analysis of different scales, can we simply understand the basic path to increase efficiency and reduce costs of PEM in the future?