Formaldehyde removal with plasma

The performance of removing the formaldehyde by Alternating Current corona discharge plasma is studied. The high-frequency Alternating Current power supply, ceramics rings as the packing media carrier, two types of typical ferroelectric-barium titanate and sodium nitrite as the packing media are applied in the experiment. The relations between removal efficiency of formaldehyde and voltage of power supply, flow velocity are mainly investigated and the effects of non-packing media, sodium nitrite packing media and barium titanate packing media on the removal efficiency of formaldehyde are also studied in the experiment. The power supply parameters 8,9,10,11 and 12 kV and the gas velocity parameters 35 mm/s, 47 mm/s, 58 mm/s and 70 mm/s are studied. The results show that the formaldehyde could be removed efficiently by high-frequency power supply corona discharge. It is also found that the removal efficiency of formaldehyde can be enhanced with higher voltage of power supply and small flow velocity; the removal efficiency is higher with barium titanate media packed than with sodium nitrite media packed, both are better than without media packed. At the same time, the mechanism of removal efficiency of formaldehyde is discussed based on the experimental results. The removal of HCHO depends on two mechanisms (a) collision between electrons and HCHO molecules and (b) reactions between gas-phase radicals and HCHO molecules.