Removal of Acetaldehyde and Skatole in Gas by a Corona-Discharge Reactor

A corona-discharge reactor, called a deposition-type reactor, was applied to remove acetaldehyde and skatole from nitrogen and an oxygen−nitrogen mixture. In the removal from nitrogen, acetaldehyde and skatole are negatively ionized and removed by depositing at the anode surface. In simultaneous removals of acetaldehyde and skatole, it is found that skatole has a higher reactivity of electron attachment than acetaldehyde. In the removal of acetaldehyde from an oxygen−nitrogen mixture, 40 molecules of acetaldehyde were removed by one electron. The reason for the extremely high removal efficiency is considered to be based on the ozone reaction and the formation of negative-ion clusters. Stabilization energies of the negative-ion clusters were estimated by ab initio molecular orbital calculation. Skatole was removed from a nitrogen−oxygen mixture perfectly with extremely low discharge current by the ozone reaction. Simultaneous removals of acetaldehyde and skatole from a nitrogen−oxygen mixture suggest that coexisting skatole inhibits the removal of acetaldehyde.