Hydrogen Production Progress Update
October 5, 2011
22.033 Fall
Rebecca Krentz-Wee Derek Sutherland Ben Nield
Lauren Chilton
Presentation Outline
● Objectives
■ Hydrogen economy viable?
● O p t i o n s
■ Steam Methane Reforming (SMR)
■ Westinghouse Sulfur Process (WSP)
■ Water Electrolysis (ES)
■ HT Steam Electrolysis (HTSE)
■ Sulfur-Iodine (S-I)
■ Br-Ca-Fe (UT-3)
● Comparison
■ Bacteria / Urine
Hydrogen economy viability?
Chemical Properties
● Difficult to contain in gaseous forms
● Parasitic energy losses
● Cryogenics required for best storage
● Safety concerns
Infrastructure Overhaul
● Multi-billion dollar distribution framework required
C o n c l u s i o n : A hydrogen economy is not technically or economically viable in the relatively near future.
Engineering Objectives
Hydrogen Production 0.1 kg/s a t S T P
Required Temperature < 8 0 0 C
Power Consumption < 150 MW
Environmental Impact
Zero Greenhouse Emissions
Options - Steam Methane Reforming
● Currently used commercially
● Input temperature: 700-800 C
● 70% efficien t
● By-product: CO 2
Konopka, Alex J., and Gregory, Derek P. "Hydrogen Production by Electrolysis: Present and Future." Institute of Gas Technology, Chicago IL. IECEC 1975 Record.
Options - Westinghouse Sulfur Process ( W S P )
800 o C
Courtesy of Edward J. Lahoda. Used with permission .
Options - Water Electrolysis
|
Polymer Electrolyte Membrane |
80 - 100 o C a t P a t m |
|
Alkaline Electrolyzers |
100 - 150 o C a t P a t m |
Konopka, Alex J. and Gregory, Derek P. Hydrogen Production by E lectrolysis: Present and Future. Institute of Gas Technology, Chicago, Illinois 60616. IECEC 1975 Record.
Options - Water Electrolysis
Efficiency
Process Overall 75% 25-45%
Production Rate
Energy Generation 30%
K onopka, Alex J. and Gregory, Derek P. Hydrogen Production b Ele ctrolysis: Present and Future. Institute of Gas Technology, C hicago, Illinois 60616. IECEC 1975 Record.
Options - HT Steam Electrolysis
S t e a m
Konopka, Alex J. and Gregory, Derek P. Hydrogen Production by E lectrolysis: Present and Future. Institute of Gas Technology, Chicago, Illinois 60616. IECEC 1975 Record.
HTSE Process
H2O+2e->H2+O
Chemically stable electrolyte
Hydrogen and Oxygen released through porous material
Hydrogen
S t e a m
Electrolyte
P o rous cathode Porous anode
U.S. DOE factsheet for high-temperature electrolysis
HTSE Advantages
● High efficiency (enthalpy of steam vs water)
● No pollutants
● Uses reactor heat
● Simple chemistry
● Improvement with temperature
H T S E T h e r m o d y n a m i c s
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Options - Sulfur-Iodine Cycle
850 C 450 C
Courtesy of Elsevier, Inc., http://www.sciencedirect.com . Used with permission.
Options - Sulfur-Iodine Cycle
Advantages
● Commercial scalability
● No greenhouse emissions
● Cheap reactants
Disadvantages
● Very high temperatures required (850 C +)
● Material concerns due to aggressive chemistry
● Heat exchanger design limitations at high temperatures
● Process efficiency limited to roughly 34-37%
Options - Br-Ca-Fe (UT-3) Process
Hydrogen Separation Unit
Heat Input Heat Input
Oxygen Separation Unit
F e Reactor Unit
Ca Reactor Unit
Hydrogen
Oxygen
Bromine Hydrobromic
Acid
A. Aochi et al., Economical and technical evaluation of UT-3 th ermochemical hydrogen production process for an industrial scale plant. Int. J. Hydrogen Energy , 14(7):421–429, 1989.
Options - Br-Ca-Fe (UT-3)
Advantages
● Can occur at a lower temperature than the sulfur-iodine process
● Commercially scalable method of hydrogen production
● No greenhouse gases produced
Disadvantages
● Efficiency limited to ~ 40%, but a soft limit
● Material concerns, though not as prominent as SI
● Higher temperature than core output is required
Options - Bacteria
● Dark fermentation is most commercially viable approach of bacterial hydrogen production.
Advantages
● Low temperatures required
● Limited material concerns
Disadvantages
● Uncertainty on scalability due to limited research
● Expensive strains required
● Contamination concerns
● Large volume of bacteria mixture required
Options - Urine
● Breaking down urea into hydrogen
● Storage and transport of human waste
● Hydrolyzes over time-->fast process needed
● Large volume of waste needed
Comparison of Processes
|
Process |
Materials |
T e m p [ ° C ] |
Pressure [atm] |
Efficiency [%] |
F e a s i b i l i t y |
|
E S |
W a t e r , Electrolytes, Anode/Cathode |
~100 |
1 |
25-45 |
drastic scaling needed |
|
H T S E |
Ceramics |
500+ |
1 |
90+ |
only small scale |
|
S I |
Ceramics |
850+ |
1-10 |
34-37 |
commercially viable, but too high temp |
|
S M R |
Nickel catalyst |
700-800 |
1-3 |
70 |
commercially viable, but polluting |
|
UT-3 |
Ceramics |
760 |
1 |
40+ |
commercially viable |
Final Decision: UT-3 Process
● Well demonstrated over three decades
● Minor material concerns
● Commercially viable
● Reasonable temperatures required
● No greenhouse emissions
● Relatively cheap reactants
Next Steps
● Scale/capacity
● Hydrogen storage/reserves
● Material concerns
● Transportation to biofuels
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22.033 / 22.33 Nuclear Systems Design Project
Fa ll 2011
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