Indoor air cleaning using a pulsed discharge plasma

The purpose of this paper is to develop a high-efficiency air-cleaning system for air pollutants such as tobacco smoke found in indoor environments. The authors investigated the basic characteristics of treating particulate matter and acetaldehyde (CH₃CHO) in a one-pass test using a pulse generator and a plasma-driven catalyst reactor, both of which are attachable to an air conditioner. Using a circulation test, the decrease in acetaldehyde concentration was measured in a closed vessel where the reactor had been placed. The removal efficiencies of particulate matter and acetaldehyde in the one-pass test (residence time of 10 ms) were 70% and 27%, respectively. In the circulation test, 98% of the suspended particles were collected after 2 min of operation and the acetaldehyde concentration decreased by 70% after 50 mins. It is believed that the TiO₂ catalyst is excited by plasma-induced high-energy particles (electrons, photons, and metastable molecules), resulting in an enhanced pollutant removal. These test results indicate that the combination of plasma with TiO₂ is a potential alternative in treating the pollutants in environmental tobacco smoke