Stephanie Noble
Advisor: Professor Benziger
REU Partner: Chelsea Bonetti
Goals and Motivation
Optimizing a Hydrogen Pump to Conserve Energy
WHAT:
1. Confirm theoretical performance of previous Multi-Stage Pump.
2. Design and optimize our own Multi-Stage Pump.
i.
Efficient/Effective
ii.
Portable
iii. Minimal Energy Loss
WHY:
1. Obtain un-polluted fuel (H2) and pure waste (CO2)
2. Prove theoretical high energy efficiencies with multi-stage
design.
How a Hydrogen Pump Works
A Chemical Perspective
3H2/
CO2
Process
• Gases Enter
Protons Cross Membrane
•
Electrochemical Pumping Process
Leftover Gas Exits
•
•
Cathode
x H2
e-
(3-x)H2/
CO2
In a Multi-Stage pump, these pass to
the next stage.
New CO2/H2 Ratio.
H+
Cathode
•
Polymer
Electrolyt
e
Anode
•
Hydrogen/Carbon Mix
Anode
•
H+
(3-x) - y
H 2/
CO2
Polymer
Electrolyte
e-
y H2
Why a Hydrogen Pump?
A Comparison with the Conventional System
Efficiency of Operation of Hydrogen
Pump
100
HYDROGEN PUMP
Single-Stage
• Advantages
•
Percent(%)
90
80
70
•
60
50
•
40
•
30
20
Disadvantages
•
10
High Degree of Separation
Low Temperature Operation
Acts as a Pump
0
•
•
Lower Efficiency
Serpentine flow
•
Hydrogen Recovery (%)
Energy Efficiency (%)
•
(previous models)
BUT!... Multi-Stage
• Same Advantages
•
Higher Theoretical Efficiency
Assembly of a Hydrogen Pump
Brief Procedure
Wash
Nafion
H2O2, H2O, and
H2SO4
Coat
Nafion
Spray Pt/C
catalyst mix
Size Pieces
Membrane,
Gasket, and
Electrode
Assemble
Important to
ensure optimal
results!
Connect
to External
Controls
MFCs, Power
Supply/Arbin
Linear Hydrogen Pump
Design Challenges and Final Product
STRENGTHS:
• Durable
• Thorough Mixing
• Ease-of-use
WEAKNESSES:
• Difficult Screw Insulators
• Weak Luer Locks
•Uneven Pressure Distribution
Our Design: Efficiency
Efficiency, Extent of Separation vs. Voltage
0.6
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
0.2
0.1
0.1
0.1
0
0
0.4
0.3
0
0.5
Voltage
Extent
of Sep'n
Efficienc
y
0
1
0.35
1
0.9
0.8
0.8
0.8
0.7
0.7
0.6
0.6
0.7
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.3
0.2
0.2
0.2
0.1
0.1
0.1
0
0
0.2
0.95
0.55 Voltage 0.75
0
1
0.5
0.4
Efficiency
0.4
0.6
Extent of
Voltage
Sep'n
0
0.8
1
1
0.9
0.9
0.8
0.8
0.7
0.7
0.6
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
CH = 2
0.1
0.1
0
0
0
0.2
0.4
Voltage
0.6
0.8
Efficiency
0.5
0.7
0.9
Extent of Separation
0.6
0.7
Efficiency
Extent of Sep'n
0.7
0.8
0.9
More efficient than Commercial
Current @ 0.8 V and Pure H2:
Our Design: 1.31 A
Commercial: ~0.7 A
Efficiency
0.9
0.8
0.8
Extent of Sep'n
Extent of Separation
0.9
1
Commercial (CH = 2)
0.9
C/H = 1
1
1
Efficiency
C/H = 0 (Pure H2)1
1
Optimization Parameters
Customizing a Single Unit
Current vs. Voltage
(Different C/H Ratios)
Why is there an optimum voltage?
• Hydrogen can only cross the membrane so fast
•Limiting diffusion to and across the membrane
What controls where the optimum occurs?
• Rate at which Hydrogen contacts the
Membrane
• Feed: C/H Ratio, Flow rate
Data Analysis
Analytical Program
Set
Parameters
Analyze
Data
Set
Optimum
Values of
Each Stage
Data Analysis
Optimization Program
• Prepare Program Parameters
• Determine desired trends.
• Feed Condition  Optimal Voltage
• Fit with parameters determined experimentally.
• Design Program
•
•
Report Optimal Voltage from Trend
Alter Feed Conditions based on Previous Stages
Conclusion
What’s next?
Separate-Stage Design
•
Increased effectiveness, durability, and ease-of use
Program for Multi-Stage Analysis
•
•
Observe efficiency/operation of both individual stages and
Overall Process
Separate Program for Optimizing a Single Stage
Confirmation of Theoretical Process
•
Observed similar trends
•
•
However, more Conclusive Results TBD
Our Design and Program facilitate future Confirmation
Professor Jay Benziger
May Jean Cheah
Eric Gauthier
Xuemei Wu
PRISM/PCCM
PEI Grand Challenges Program