Design, Development and Testing of Hydrogen Purifier System

through the technique of Electrochemical Separation and

optimize the setup based on the plate design

Senior Project PresentationSpring 2015

Project Goal

• The main goal of this project is to create a system through electrochemical separation that filters pure hydrogen from the dirty gas inlet and optimize the assembly adapting the best plate design.

Reason for the need

• Limited non impurity tolerance for PEM fuel cell is the reason for the need of pure hydrogen.• The performance of the PEM fuel cell tremendously reduces when the inlet gaswhich is hydrogen has impurities with it.• That brings in the need for the inlet gas of the PEM fuel cell as pure as possible.

How is it different from fuel cell ?

• The design, setup and working of the hydrogenpurifier system is comparable to that of the hydrogen fuel cell except that • The current is produced in the fuel cell whereas, current is passed to the purifier.• Inlet to the fuel cell is pure; inlet to the purifier is dirty• Fuel cell has 2 inlets and 2 outlets; purifier has 1 inlet and 2 outlets.

How it works ?

• The functioning of the purifier is mainly because of the property of the MEA which actually pures the hydrogen through selective transmission from the impurities.

• The process is accelerated through the supply of current as an external source forcing the reaction.

• Thus, the passed current enables the movement of the hydrogen from the dirty gas flow to permeate through MEA and reach the top plate forming pure hydrogen.

Plate setup

The reaction on the MEA

My second goalBest and the rest

• The second goal of this project was to find out the best plate design among the 4 different design options.

1. 1 pattern flow field.2. 3 pattern flow fields.3. 5 pattern flow fields.4. 7 pattern flow fields.

• The design of the flow fields also affect the performance of the purifier system.

• The proton exchange process which happens in the MEA is considerably a slow process. So the inlet gas needs adequate time to react with the MEA so that the entire inlet gases reach to the other side with minimal losses. This can be controlled by proper flow field design techniques.

• The amount of time the gas flows in the plate is called the retention time.

Achieving proper retention time is a optimization process.

Result expectations

• The expected result was that, the hydrogen purifier will have a better performance when it uses plates, made of 7 flow field pattern as compared to the regular 1 flow pattern.

• The project was started with the hope that creating more flow lines and increasing the retention time will increase the performance of the purifier.

• Expectations Experiments Conclusions

On what certain basis to conclude

• Firstly, fair comparison should be carried out when all the plates were tested. • Just altering between plates, keeping other variables unaltered, the same test should be performed.Voltage: Any voltage difference occured in the setup is acceptable.Current: 1 Amps.Inlet gas: Same mixture (3:1 H2:N)Inlet pressure: 5 psi.

Sample size: Same (1 ml)

GC Sensitivity : 1: 20

GC settings : Same Injector: 150˚C, Detector: 200˚C, Column:90˚C, Constant flow rate.

Reader movement: 1 mm/sec

Time measured: 30 minutes after passing the current.

Torque: 60 inch pounds.

Tools and apparatus: Remains the same

Criteria of judgment:Implicit reference:

The measurement of pressure in the pure hydrogen outlet is an implicit indication or reference of the design of the plate.

Better the plate design greater the retention time.

Greater the retention time increased availability of time, for the inlet dirty gases to react with MEA. Hence, higher the pressure attained in the pure hydrogen outlet side.

Conclusion note: Better plate High pressure accumulation.

Explicit reference:• The readings of the GC (Gas Chromatography) are an explicit reference to the design aspect of the plate.

• In the dirty gas outlet, if any hydrogen is found or detected, it is due to the lack of time the inlet gases were prone to.

• Insufficient time for the gases to react with MEA or for the proton exchange reaction causes into direct bypass to the dirty outlet without taking part in the actual reaction.

• So when a sample of the dirty gas outlet is analyzed on the GC, at a specific time, it should show less percentage of hydrogen content.

• Better plate design minimal hydrogen content in the dirty outlet port.

Purifier Plate design

Drilling the guide pins, inlet and outlet ports

End Plates

Unused ports are closed

Thermal Spraying the Purifier Plates

2 Gauges used

Dirty Gas outlet

Purifier assembly

Picture of the used tools

Multimeter ReadingsResistance in Ω (Ohms)

Collector – Plate 1 Plate 1 – Plate 2 Plate 2 - Collector Collector - Collector

1 pattern 0.4 35.56 0.3 37.4

3 pattern 0.6 74.2 0.5 85.7

5 pattern 1.2 221.5 0.9 230.4

7 pattern 1.5 174.4 0.2 190.8

The tank mixture consists of H2 and Nitrogen

Current supplied

Checking the inlet gauge pressure of the purifier

Flow alterations

Channel Design

JB weld to attach the bridge

Applied weld and set to dry

Coated, bridged and filed plates

Pressure readings of 1 pattern

Pressure readings of 3 pattern

Pressure readings of 5 pattern

Pressure readings of 7 pattern

Gas Chromatography

1µl Syringe

Pure Hydrogen Sample Test

Mixture of 3:1 H2 - N

1 pattern plate

5 pattern plate

7 pattern plate

Clogged Syringe

The peaks of 3 pattern plate

Obstacles faced

• Materials: Stainless Steel.• Failure of CNC Machines: Tool failure.• Machine capability: 9 hours with monitoring.• Creating entry and exit holes.• Insufficient availability of tool length to drill

the plates. or the diameter of the Colet. • Narrow angles: 19 degree.• Lack of harder drill bit.

• Making the end plates.• Alignment of the guide pins and clamp pins.• Creating bridge, JB weld and drying.• Altering to new designs.• Spraying the plates before bridging.• Employing the suitable fittings that fits into both high

scale and low scale requirements with provisions to take samples.

• Ensuring the right proportions in the mixture gas.

Conclusion

• I conclude my project presentation with the point that the 7 flow pattern plate design came out to be the best out of the other available options that were tested.Higher the number of flow lines, more efficient the assembly is, as it accumulates or creates higher pressure in the pure hydrogen outlet for the same given time.More production of desired gas at a faster rate.• Result came out as expected

Acknowledgements

Guidance and support• Dr. Hazem Tawfik ( Course instructor)

Active involvement, dedication and technical assistance• Dan Weinman (Technical Specialist)• Robert Adolfson (Junior in MET)• Daniel Boss (Junior in MET)

Special thanks too Alex Pereira o Tom

• Project Presented by,

Pragadeesh Ravichandran, B.S METFarmingdale State College