Session: 11-18-01: Fundamental Issues in Fluid Mechanics/Rheology of Nonlinear Materials and Complex Fluids/Plasma Flow

Paper Number: 165320

Calibrating Low Temperature Plasma System for Gas Conversion Processes 

An experimental rig for plasma conversion of gases was established consisting of a high voltage power supply and an electrode system developed for generating dielectric barrier discharges (DBDs). A previously reported reactor is used which can be operated in Plasma Liquid Gas (PLG) mode or non-PLG mode. In the PLG mode, at least one liquid electrode is utilized to support the plasma discharge. In non-PLG mode, no liquid electrode is used; a standard metal electrode is used. For both cases, the system is operated at atmospheric pressure in air samples containing atmospheric levels of CO₂ or higher as supplied via a compressed CO₂ tank. With the electrical parameters in part dependent on the load, calibration of the system is performed to establish a range of operating parameters that can be expected from the coupled power supply and electrode orientation. Key instrumentation includes an oscilloscope, high voltage probe, and current probe. The present work is a foundation for a wider range of experiments exploring the electricity-driven conversion of gases. Instead of thermal processes, the approach here is to use plasmas. One gas of interest is carbon dioxide (CO₂) for upgrading to chemicals deemed more valuable. Instrumentation supporting assessment of CO₂ and its concentration in plasma-treated samples includes a glass cell for collecting gas samples for analysis via FTIR spectrometer, and a gas analyzer connected to a laboratory PC for assessing CO₂ concentration. The high voltage electrode system reported in a previous study, was a 1-inch tall, 1.5-inch diameter aluminum rod covered by a 1/8” quartz disc. In non-PLG mode, the ground electrode is an uncovered (i.e., no quartz) aluminum rod of the same dimensions. In PLG mode, this electrode would be a liquid like tap water. For the PLG case, the gas analyzer used here is also capable of measuring H₂O concentrations if needed for quantifying any vaporization of water. The power supply is capable of a range of voltages, currents, and frequencies (dependent on the load). With the power supply connected to the set of electrodes, the voltage, current, and frequencies are calibrated to establish the operating conditions for the DBD. Calibration of the plasma system without and with the presence of a liquid electrode is described and conducted as part of this study, to establish clear operating parameters for supporting the conversion of gases. The direct comparison of the PLG mode utilizing at least one liquid electrode, vs. the non-PLG mode, will lay the foundation for exploring new types of gas phase reactions useful for energy and gas conversion.

Presenting Author: Christos Potamianos The Cooper Union

Presenting Author Biography: Master's of Engineering student at The Cooper Union

Authors:

Christos Potamianos The Cooper Union
Jude Pizzone The Cooper Union
Kamau Wright Cooper Union