Decomposition Characteristics of Acetone in a DC Corona Discharge at Atmospheric Pressure

Abstract

Decomposition characteristics of acetone in a DC corona discharge generated between a multi-needle and a plane electrodes in nitrogen-oxygen mixtures at atmospheric pressure are investigated mainly by infrared absorption spectroscopy in this work. It is found that CO₂, CO, CH₄, HCHO, HCOOH and HCN are the by-products of acetone in the corona discharge, and that CO, CH₄, HCHO, HCOOH and HCN are intermediate products, which tend to be decomposed in the corona discharge. CO₂ is found to be the major and end-product. It is also found that acetone is chiefly inverted to CO₂ via CO at high oxygen concentration (20%) and via CO and CH₄ at relatively low oxygen concentration (0.2%), in addition to the direct conversion from acetone to CO₂. As the oxygen concentration increases, the percentages of carbon atoms contained in deposit on the plane electrode and the wall of the discharge chamber increases. Further, the decomposition process of acetone is deduced from the examination of rate constants for the reactions in the gaseous phase.