Modeling Plasma-Based Methane Reformation: Gas Flow Design and Chemistry Analysis
This project investigates gas flow design considerations in plasma sources, focusing on the constriction methods that influence methane decomposition. Current modeling approaches, including hourglass and multi-tube designs, highlight the need for stability and integration with mass flow meters. We explore methane (CH4) reformations under various conditions, revealing that low-energy inputs yield high conversion rates due to free radical reactions. The project also includes a Gantt chart for outlining the timeline, with estimated weekly hours dedicated to research and analysis.
Modeling Plasma-Based Methane Reformation: Gas Flow Design and Chemistry Analysis
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Presentation Transcript
Project NTP Van Ortega Cayetano Shama Karu Sean McKeown Themistoklis Zacharatos Advisor: Dr. Woo Lee Plasma Specialist: Dr. Kurt Becker Powered by:
Gas Flow 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, which works well for large-scale applications. Current designs are being modeled from this perspective.
“Hour glass” Design Gas Flow • constricts gas flow • narrow space necessary for plasma discharge • requires sealant for joints • assembly needs stability (brace) • requires interface with mass flow meter
Multi-tube Design Quartz tubing Capillary tubes • rigid • narrow space necessary for plasma discharge • requires interface with mass flow meter
Plasma Chemistry – the CH4 Decomposition Reaction Table 12.3: Considered gross reactions for the plasma conditions given in Table 12.2. Constant: Reaction: V1 2 CH4 + e- C2H2 + 3H2 + e- V2 2 CH4 + e- C2H4 + 2H2 + e- V3 2 CH4 + e- C2H6 + H2 + e- V4 CH4 + e- C2H2 + H2 + e- V5 CH4 + e- C2H4 + H2 + e-. E1 Cwall + 2 H2 + e- CH4 + e- E2 Cwall + .5H2 + e- .5 C2H2 + e- E3 Cwall + H2 + e- .5 C2H4 + e- E4 Cwall + 1.5H2 + e- .5 C2H6 + e-.
Experiment - from “Low-Temperature Plasma Physics” by Hippler, Pfau, Schmidt, and Schoenbach Reference: Yu. Gerasimov, T.A. Graecheva, Yu. Lebedev: Chim. Vys. Energii, vol. 17, pp 270 (1983)
Reformation of CH4 to obtain H2 • The referenced experiment (previous slide) analyzed the conversion of methane to its elements under different power inputs and energy concentrations. Showed diminishing returns: the endothermic reformation reaction has a high rate-per-unit-energy at low energy inputs. • In most atmospheric-pressure non-equilibrium discharges the desired chemical changes are due to free radical reactions rather than to the direct action of electrons or ions (Low Temperature Plasma Physics, pp. 337) • Reaction kinetics will require more analysis, to understand the effect of free radicals on methane reformation.
Gantt Chart – November Time per week: 20-25 hrs
