Regular Article

Nanosecond pulsed dielectric barrier discharge plasma-catalytic removal of HCHO in humid air

Key Lab of Materials Modification by Laser, Ion and Electron Beans (Dalian University of Technology) Ministry of Education, Dalian 116024, P.R. China

^a e-mail: wangwenc@dlut.edu.cn

Received: 4 September 2016
Revised: 30 December 2016
Accepted: 5 April 2017
Published online: 19 May 2017

Abstract

Non-thermal plasma (NTP) has been regarded as a promising method for the removal of a wide range of low concentration volatile organic compounds (VOCs). In this paper, nanosecond pulsed and alternating current dielectric barrier discharge plasmas synergistic catalyst are utilized for removal of formaldehyde (HCHO) in humid air. Working gas is 1% H₂O/21% O₂/78% N₂ with 154 ppm HCHO over total flow rate of 50 mL/min. Specific energy density (SED) are 32.5 JL^-1, 35.8 JL^-1 and 1069.2 JL^-1 at power consumption of 0.325 W, 0.3 W, 8.9 W for removal of 67%, 63.8% and 73.8% HCHO when using bipolar nanosecond pulsed, unipolar nanosecond pulsed and AC dielectric barrier discharge (DBD) plasma, respectively. The removal efficiencies of HCHO using nanosecond pulsed DBD plasma increase approximately 10 ~ 20% when the packed-bed Al₂O₃ pellets exist and can reach up to almost 100% when TiO₂ nanoparticles are used while the effect of CeO₂ nanoparticles is a bit poor. Analysis indicate that OH radical and O atom play main role for removal HCHO and the gas temperature is a significant factor for its influence on rate constants of HCHO with active particles.