1. Van Ortega Cayetano Shama Karu Sean McKeown Themistoklis Zacharatos Advisor: Dr. Woo Lee Plasma Specialist: Dr. Kurt Becker Powered by: Project NTP

2. Why Fuel Cells? Environmental Effects –Reduction of automobile greenhouse gas emissions by 50% –Cut down on smog and acid rain –Reduce noise pollution Social Ramifications –Reduction of energy imports –Lower energy costs Applications –Batteries –Transportation –Power Plants

3. Introduction to Plasma: Plasmas are an equilibrium of ions and electrons within a confined space. Different characteristics of plasmas are produced with various means of energy applications.

4. Categories of Plasmas: Various plasmas: –Homogeneous Plasma –Arc Discharge (lightning) –Thermal Plasma –Non-Thermal Plasma (NTP) (fluorescent tubes) Few variations among plasmas: –Electron density –Thermal energy –Energy consumption

5. Cause of Variations: Pressure Voltage Material of electrodes Type of gas Means of plasma production (plasma source)

6. Goals: Obtain a clear understanding of plasma Breakdown Methane at a lower temperature than the current conventional methods using NTP Improve on previous year

7. Production of Plasma: A commonly used method of generating and sustaining NTP is through an electric field. –Two parallel electrodes are applied with voltage to form a capacitive discharge

8. Breakdown of Methane: Methane steam reforming: CH 4 + 2H 2 O CO 2 + 4H 2 CH 4 + H 2 O CO + 3H 2 Temperature: 600–1300K with Ni/Ca/Carbon – based catalyst Methane plasma reforming: x CH 4 + e - C 2 H 2 + 3H 2 + e - C 2 H 4 + 2H 2 + e - C 2 H 6 + H 2 + e - C 2 H 2 + H 2 + e - Temperature ~ 300K C 2 H 4 + H 2 + e -

9. Plasma Reformation of Methane: Reference: Yu. Gerasimov, T.A. Graecheva, Yu. Lebedev:Chim. Vys. Energii, vol. 17, pp 270 (1983) Reaction occurs largely by free radical pathways. Endothermic reaction shows diminishing returns: high efficiency at low energies, but very little benefit at higher energy. Several competing pathways for reaction (some with similar energies) means more analysis will be required. Initiation: CH 4 + e - CH 3 · + H · + e - Propagation: CH 3 · + CH 4 C 2 H 6 + H · H · + CH 4 CH 3 · + H 2 Termination: H · + H · H 2 CH 3 · + H · CH 4 CH 3 · + CH 3 · C 2 H 6 Temperature ~ 300K

10. Glass Pipette Anode Cathode AC HV + Network Plasma Region Gas Flow Spectroscopy, Gas Chromatography Pure He or Ar He/N 2 or Ar/N 2 He/Ar + N 2 + CH 3 OH 1 kV, 50 W 250 kHz Reference: Prof. Becker The Plasma Reactor: Dielectric Barrier Discharge at/above Atmospheric Pressure

11. Design Considerations: Explanation of previous design: Constriction of gas flow through the plasma source. The constriction can also take the form of a wide slit -- or a straight row of holes. Gas Flow Current designs are being modeled from this perspective.

12. Gas Flow Constricts gas flow Narrow space conducive for plasma discharge Requires sealant for joints Assembly needs stability (brace) Requires interface with mass flow meter “Hourglass” Design

13. Multi-tube Design Rigid Narrow space necessary for plasma discharge Requires interface with mass flow meter Capillary tubes Quartz tubing

14. Current design focus: (Planar Design)

15. Gas Chromatograph: Problem –We are detecting 100- 1000 ppm of hydrogen –Previous Column detected methane not H 2 Solution –New Column can detect in 100s of ppm of H 2 –Gas sampler will prevent loss of material

16. Mass Flow Controller Mass Flow Controller Mass Flow Controller NH 3 Ar CH 4 Plasma Source-SD Plasma Source-Grad Schematic Diagram of Gas Flow: GC

17. Construct a new source Experiment with ratio of methane to argon flow Experiment with pressure and flow rate of gas mixture Work with RF generator to optimize H 2 output –Tune frequency –May not need carrier gas Elemental analysis by Gas Chromatography (GC) –GC automation Future Plasma Research:

18. Gantt Chart:

19. Expenses:

20. Summary of Experimental Results with Cold Plasma: Physics Department: Experiments with He/Ar+N 2 +CH 3 OH –Gas temperature between 350 – 380 K range –Increase in CO, OH, and CH emissions, indicating a (partial) plasma-induced break-up of CH 3 OH –Very weak H emission –Needs improvement for controlling methanol content –May require more energetic electrons Reference: Prof. Becker Summer CVD Lab experiment: Total flow-rate of Ar/MeOH mixture was 151.8cc/min Methanol concentration before entering plasma to be 1.29% Conclusion: GC detector not sensitive enough to detect such a small concentration Agrees with experiments done by the Physics Department

21. Summary of Experiment Attempting to Crack Methanol from Pipette Design: Flow-rate of pure Argon was 140cc/min Flow-rate of Ar/MeOH was 11.8cc/min Total flow-rate was 151.8cc/min Power in was approximately 150W Methanol concentration before entering plasma to be 1.29% Conclusion: GC detector not sensitive enough to pick up such a small concentration Agrees with experiments done by the Physics depart.