Propane steam reforming for fuel cells
Download
1 / 17

PROPANE STEAM REFORMING FOR FUEL CELLS - PowerPoint PPT Presentation


  • 111 Views
  • Uploaded on

PROPANE STEAM REFORMING FOR FUEL CELLS. By Tamika Brown. e -. e -. H 2. H 2. H 2. H 2. H 2. H 2. H 2. O 2. O 2. O 2. O 2. O 2. O 2. O 2. H 2 O. H 2 O. H 2 O. H +. H +. What is a Fuel Cell, and how does it work?. A fuel cell is an electrochemical device

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' PROPANE STEAM REFORMING FOR FUEL CELLS' - yuri


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

What is a fuel cell and how does it work

e-

e-

H2

H2

H2

H2

H2

H2

H2

O2

O2

O2

O2

O2

O2

O2

H2O

H2O

H2O

H+

H+

What is a Fuel Cell, and how does it work?

  • A fuel cell is an electrochemical device

  • that combines hydrogen fuel and oxygen

  • from air to produce electricity and water.

  • In a Polymer Electrolyte Fuel Cell, Hydrogen ions form at the anode, and

  • diffuse through the electrolyte and react

  • with oxygen at the cathode.

  • Anode: H2→ 2H + (aq) +2e-

  • Cathode: ½ O2 + 2H + (aq) + 2e- → H2O (l)

Anode

Cathode

Electrolyte


Uses of fuel cells
Uses of Fuel Cells

  • Transportation:

    • Phosphoric Acid Fuel Cell

      • Anode: H2(g) →2H + (aq) + 2e-

      • Cathode: ½ O2 (g) + 2H+ (aq) + 2e- → H2O(l)

  • Portable:

    • Proton Exchange Membrane Fuel Cell

      • Anode: H2(g) → 2H + (aq) + 2e-

      • Cathode: Cathode: ½ O2 (g) + 2H+ (aq) + 2e- → H2O(l)

  • Stationary:

    • Solid Oxide Fuel Cells

      • Anode: H2(g) + O2→ H2O(g) + 2e-

      • Cathode: ½ O2 (g) + 2e- → O2-


Fuel cell uses
Fuel Cell uses

  • Fuel Cell transit buses in Chicago (Ballard Corp)

    • Anode: H2(g) → 2H + (aq) + 2e-

    • Cathode: ½ O2 (g) + 2H+ (aq) + 2e- → H2O(l)

  • Energy Research Corp.

    • Anode: H2(g) + 2CO3 → H2O(g) + CO2(g) + 2e-

    • Cathode: ½ O2 (g) + CO2 + 2e- → 2CO3


Hydrogen
Hydrogen

  • Hydrogen is the most abundant element in the universe

  • No known sources of gaseous hydrogen

  • Hydrogen generated from another energy source such as petroleum or from water through electrolysis

    • energy (electricity) + 2 H2O ->  O2  + 2 H2

      SO HOW DO WE GENERATE AN ADEQUATE SUPPLY OF HYDROGEN FOR FUEL CELLS . . . . .


Fuel processor reformer
Fuel Processor/Reformer

  • Reformers convert hydrocarbon fuels into hydrogen

  • Steam and/or oxygen along with a catalyst are needed

  • Carbon dioxide is a byproduct

Electric Power Conditioner

Air

Fuel

Exhaust

Fuel

Processor

Spent-Gas

Burner

Fuel Cell

Stack

Air

H2

Thermal & Water Management


3 types of reactions
3 Types of Reactions

*Steam Reforming:

  • Hydrocarbon+ Steam + catalyst → H2 + CO2

  • Partial Oxidation Reforming:

    • Hydrocarbon + Oxygen + catalyst → H2 + CO2

  • Autothermal Reforming:

    • Hydrocarbon + Oxygen + Steam + catalyst → H2 + CO2


  • Why choose steam reforming
    Why choose Steam Reforming?

    • Tailor to application

      • Ex. This particular investigation focuses on stationary uses such as power plants and industrial plants

    • Partial Oxidation (POx) can be tailored to meet certain vehicle regulatory standards

    • Autothermal Reforming (ATR) is a thermal balance between (POx) and Steam Reforming


    What is hydrocarbon source
    What is Hydrocarbon Source?

    • Liquefied Petroleum Gas (LPG),

    • Consists mainly of propane, propylene, butane and butylenes in various mixtures.

    • In the U.S. the mixture is mainly propane.


    Why choose lpg
    Why choose LPG?

    • LPG can be used in the home, commercial businesses, industry, and transportation

    • The residential and commercial markets where LPG is used make up about 50% of the world total LP gas retail sales


    Fuel processor reformer1
    Fuel Processor/Reformer

    Hydrocarbon + H2O(g) + catalyst → H2 + O2

    1.Inlets to Reactor

    a) Water → Steam

    b) Fuel (liquid) → Vapor

    c) Fuel (gas)

    d) Air (POx or ATR)

    e) Catalyst

    2. Reactor

    a) Sampling ports

    3. Analytical Train

    a) CO/CO2 detector

    b) Mass flow indicator


    What are the goals of experimentation
    What are the Goals of Experimentation?

    • Explore how operating conditions affect the reaction kinetics

      • Variables: temperature, flow rates, catalyst

    • Data from reactor model → kinetics → full scale reactor design for commercial use


    Challenges of reforming process
    Challenges of Reforming Process

    • Flow Rates:

      • High efficiency is desired at faster flow rates

        • Waste less fuel and energy, less catalyst

  • Cost:

    • Parts can be expensive, as well as precious metal coated catalysts.

  • Catalyst:

    • Catalyst needs to withstand impurities such as sulfur, but also produce the most amount of hydrogen possible

  • Temperature:

    • High efficiency needs to be achieved at lower temperatures

      • Less of a hazard, cost of parts is cheaper, and less energy is needed to maintain system


  • Challenges continued
    Challenges Continued

    • Response times:

      • Don’t want to have to wait periods of time for hydrogen to be produced in order for fuel cell to start working.

    • Durability:

      • Catalyst and Reformer need to be durable

    • Coking:

      • Carbon deposits in the reformer

        • This causes clogging in the system

  • Interference of components in fuel mixture

    • Alkenes interfere with alkane reforming

      • This is a problem for LPG, because it is not a homogenous mixture


  • Conclusion
    Conclusion

    • If we switch to a hydrogen economy

      • More efficient than combustion

        • Less air pollution (NOx, SOx, COx)

      • Easily transportable

      • Save money (less imports)

    • Fuel Reforming for Fuel Cells is an intermediary technology for the production of hydrogen until a renewable source of energy can be discovered.


    Acknowledgments
    Acknowledgments

    I would like to thank John Kopasz for giving me the opportunity to participate in this and other research projects. I would like to thank Dan Applegate for his knowledge and helpfulness. I express sincere gratitude to Laura Miller for her patience, time, and wisdom. Last but not least, I would like to thank the U.S. Department of Energy for giving students a change to grow scientifically as well as professionally.


    References
    References

    • “What is a Fuel Cell.” Fuel Cells 2000. 2 March 2004.

    • http://www.fuelcells.org/whatis.htm

    • Carter, David, “Fuel Cell Power: What’s taking so long?”

    • IPMI 25th International Precious Metals Conference, June 9-12, 2001.

    • “Electrolysis: Obtaining hydrogen from water: The Basis for a Solar-Hydrogen Economy.” 4 April 2005. http://www.nmsea.org

    • “Chicago’s Fuel Cell Buses Mobilized.” Hydrogen Newsletter Winter 1998: Hydrogen Buses. 4 April 2005. http://www.hydrogenus.com/advocate/ad31cta.htm

    • “Pocket-size PEMs.” Pocket-size PEMs. 4 April 2005. http://www.memagazine.org/backissues/february2000/features/pems/pems.html

    • Miller, Laura, “Safety Review for Long Term Test Reactor CMT50-0006-EP-Rev 08 NEPA Document ER-281.” February 17, 2005 pp. 1-15.

    • Laura, Miller, “Science Careers in Search of Women Conference.” March 10, 2005.

    • “What is Propane?” Alternative Fuels Data Center: What is Propane?” 23 March 2005. http://www.eere.energy.gov/afdc/altfuel/whatisprop.html.

    • “What is LP Gas?” World LP Gas Association. 29 March 2005. http://www.worldpgas.com/mainpages/aboutpgas/whatislpgas.php.


    ad