Arc Characteristics of Various Alcohol Solutions in Water Plasma with a Tunable Mist Generation

Water plasma with tunable mist generation was introduced to investigate arc characteristics using four different solutions: water, 1-propanol and 2-propanol, and ethanol solutions. The influence of physical properties such as vapor pressure, surface tension, and viscosity on the arc characteristics was discussed in detail. The arc fluctuation with voltage was distinctly observed using a high-speed camera equipped with an oscilloscope. The arc temperature was estimated using an optical emission spectrometer based on the Boltzmann plot method. The arc fluctuation in all experiments corresponded to the restrike mode. Mean arc voltage and frequency were the lowest when using only water due to higher surface tension and lower vapor pressure, which was also observed in arc existence probability. The arc temperature of water was the highest. This results from a lower decomposition energy. The opposite tendency was confirmed when using ethanol solutions. In particular, the effect of vapor pressure on arc characteristics was distinctly confirmed between alcohol solutions. Based on the results, the water plasma developed with a tunable mist generation system would be a feasible strategy for wastewater treatment.