solid oxide fuel cells and applications to ecological ... · solid oxide fuel cells and...
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Solid Oxide Fuel Cells and Applications to Ecological System Engineering
Dr. Sepideh Faraji
Chemical Engineering DepartmentCSULB
December 2011
Opening questionsWhat is air pollution?
Wh t th ff t f i ll ti b d ?What are the effects of air pollution on our body?
Is there any air pollution in California?
Background
Air pollution is a major problem in California.
Air pollutants are the by-products of the combustion of
fossil fuels:fossil fuels:
- Toxic gases such as CO
- Greenhouse gases such as CO2
O t d i ll tiOne way to reduce air pollution:
- using alternative energy (fuel cells)
What is fuel cell?• Fuel cell is a device that converts the chemical energy
from a fuel into electrical energy.
• The following reaction takes place in a fuel cell:
H2 + 0.5 O2 H2O + heat
• Fuel cells are different from batteries!batteries!
Picture from Wikipedia
Fuel cell applications
Fuel cell applications
Picture from http://www.iepm.com/business_oppty.htm
Different types of fuel cells
Electron ElectronElectron Electron
ElectrolyteA dC th d
ElectrolyteA dC th dAnode
H2
Cathode
O2
Anode
H2
Cathode
O2Oxygen Hydrogen
Water
Solid Oxide Fuel Cell (SOFC) Proton Exchange Membrane (PEM) f l llfuel cell
SOFC
• Advantages: ElectronElectron
• High efficiency
• Cheap ElectrolyteA dC th d
• Fuel flexibility
• Disadvantages:
Anode
H2
Cathode
O2 Oxygen• Disadvantages:
• High temperatures Water
• Slow startup time
SOFC
Where does hydrogen come from?
H d k
ElectronElectron
• Hydrogen tank
• Other hydrocarbons: ElectrolyteA dC th d
- methanol, natural gas, …Anode
H2
Cathode
O2 Oxygen
How to produce hydrogen from other
h d b ?Water
hydrocarbons?
• Reaction in anode:
CH4 + O2 CO2 + 2H2
SOFC challengesAnode reaction: ElectronElectron
ElectrolyteA dC th d
hydrocarbon + O2 CO2 + H2
A perfect catalyst for this reaction
has not been found yet:
Anode
H2
Cathode
O2 Oxygeny
• Cost of catalyst
O ti t t f t l t• Operating temperature of catalyst
• Catalyst lifetime Water
Research objectives• Investigate different catalysts for hydrogen
production:production:
1 Pt based catalysts1. Pt-based catalysts
2. Ni-based catalysts
• Investigate the lifetime of the catalysts• Investigate the lifetime of the catalysts
Experimental• Ni/CeZrO2 and Ni/Al2O3 catalyst preparation:
• Incipient wetness impregnation method (15 wt% Ni)p p g ( )
• Catalysts were not reduced
• Pt-Ni/CeZrO2 and Pt-Ni/Al2O3 catalyst preparation:
• Incipient wetness impregnation method (0.2 wt% Pt and 15 wt% Ni)
• Catalysts were not reduced
Experimental
Reduction of new catalysts(Heating up the catalyst in H2)( g p y 2)
Pt-Ni is active at lower temperatures.
New catalysts(Heating up the catalyst in CH4+CO2)( g p y 4 2)
Pt-Ni is active at lower temperatures.
The effect of catalyst on reaction at 800°C
P Ni/Al O l i bl• Pt-Ni/Al2O3 catalyst is very stable.
• Pt-Ni/Al2O3 catalyst shows highest conversion and H2/CO ratio.
The effect of temperature on reaction
• Operating temperature affects methaneOperating temperature affects methane conversion and H2/CO ratio.
• Pt Ni/CeZrO catalyst shows highest conversion• Pt-Ni/CeZrO2 catalyst shows highest conversion and H2/CO ratio at 600 °C.
Conclusions• Pt-Ni/CeZrO2 catalyst shows a very promising
performance at 600 °C.performance at 600 C.
• Pt increases the reducibility of Ni particles in the bimetallic catalystbimetallic catalyst.
Future Direction• New catalyst support with high surface area.
• Hydrogen production from renewable resources:• Hydrogen production from renewable resources:- Ethanol reforming at low T.
Waste glycerol reforming at low T- Waste glycerol reforming at low T.
AcknowledgementsAcknowledgements• California State University, Long Beach
•University of Kansas
• MEL chemicals
Q i ?Questions ?