Uneven Dielectric Barrier Discharge Reactors for Diesel Particulate Matter Removal

Abstract

Uneven dielectric barrier discharge (DBD) reactors driven by positivenegative pulse plasma discharges were investigated for particulate matter (PM) removal from a diesel engine. Two kinds of uneven alumina plates and three kinds of uneven stainless steel plates were used to assemble six kinds of uneven DBD reactors of discharge gaps 0.4-1.0 mm. The experimental results show that PM from diesel engines can be removed using the uneven DBD reactors. The maximum PM removal was 67% at 300 W energy injections using the DBD reactor of 0.4 mm gap distance. PM removal increased with decreasing gap distance. The energy efficiency using the uneven DBD reactor of a shorter gap distance was higher than that using the uneven DBD reactor of a longer gap distance as the uneven DBD reactor of a shorter gap distance has a higher PM deposition rate. The energy efficiency was typically in a range of 3-10.6 g/kWh at an energy density of 2-16 J/L. A comparison of this study with reports given by other research groups is given.

Experimental investigation on diesel PM removal using uneven DBD reactors

“…In the time range of 0-25 min, the PM concentrations sampled at the outlet of the DBD reactor are less than 10 4 particles/ cm 3 at energy densities of 2.7, 2.0, and 2.8 J/L. The PM concentration sampled at the outlet of the DBD reactor at an energy density of 0 J/L (from time 25-30 min) is at a level of 6 Â 10 4 particles/cm 3 . The PM concentration sampled at the inlet of the DBD reactor from time 55-59 min is at a level of 6 Â 10 4 particles/cm 3 .…”

“…Typical waveforms of discharge voltage and current have been reported elsewhere. 3 The energy injection rate P d (W) from the pulse power supply was calculated using Eq. 1 over one positive voltage pulse of one pulse repetition.…”

“…The PM concentration sampled at the outlet of the DBD reactor at an energy density of 0 J/L (from time 25-30 min) is at a level of 6 Â 10 4 particles/cm 3 . The PM concentration sampled at the inlet of the DBD reactor from time 55-59 min is at a level of 6 Â 10 4 particles/cm 3 . The concentrations of PM sampled at the outlet of the DBD reactor are obviously lower than that sampled at the inlet of the DBD reactor.…”

“…Recently, the authors have developed an uneven dielectric barrier discharge (DBD) reactor driven by a pulse power supply for the removal of particulate matter (PM) emitted from a diesel engine. 2,3 The uneven DBD reactor was operated at an energy density as low as a value of 2-16 J/L. The energy efficiency (defined as the amount of removed PM per kW h electric power) of the DBD reactor achieved a level of 3-10.6 g/kWh, indicating that such a plasma PM removal method has potential for the practical use to remove PM from diesel engines.…”

Influence of non-thermal plasma after-treatment technology on diesel engine particulate matter composition and NOx concentration

“…Furthermore, emission reduction in diesel engines at low temperature is important in some special applications of diesel engines such as mining industries where exhaust cooling occurs for safety reasons. In comparison with the numerous publications on NO x treatment by plasma (Lebouvier et al 2011;Vinh et al 2012;Arai et al 2004;Jolibois et al 2012;Mohapatro and Rajanikanth 2011;Chae 2003;Yoshida et al 2009), a limited amount of research has investigated particulate matter (Ye et al 2005;Thomas et al 2000;Babaie et al 2013) and most of it has emphasised PM mass reduction only (Yao et al 2006;Fushimi et al 2008). In this paper, the effect of plasma technique on particulate matter constitutes (soot, SOF and sulphates) and NO, NO 2 and N 2 O emission concentrations have been studied.…”