Solid Oxide Fuel Cells and Applications to Ecological System Engineering Dr. Sepideh Faraji Chemical Engineering Department CSULB December 2011
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 ?