Decomposition of Ethylene Using Dual-Polarity Pulsed Dielectric Barrier Discharge

Abstract

Ethylene (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) gas promotes the aging of some kinds of fruits and vegetables such as persimmon, banana, and cucumber. Decomposition of ethylene using nonthermal plasma is effective for keeping freshness of fruits and vegetables in the transportation container. The ethylene was decomposed into gas stream using a dielectric barrier discharge (DBD) reactor driven by dual-polarity pulse generator that consisted of four insulated gate bipolar transistors and a pulse transformer. The output voltage of the pulse generator was 10 kV in amplitude, 1 kilopulse/s in repetition rate, and 50 μs in rectangular pulsewidth. The 200 ppm ethylene was diluted with dried air and was employed as simulated gas of the transportation container. The gas mixture was fed into the DBD reactor for the evaluation of the decomposition efficiency. The ethylene concentration decreased to less than 1 ppm after the DBD treatment at 30 J/L in input energy. The energy efficiency for ethylene decomposition was around 50 g/kWh and was almost independent of the initial ethylene concentration. The decomposition efficiency increased with increasing oxygen content of the background gas. The byproducts were analyzed by a Fourier transform infrared spectrometer. The results showed that the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O and CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> were mainly produced after the decomposition of the ethylene by the DBD plasma.