Effect of nonthermal plasma with different ozone concentrations on the oxidation and removal of different components in particulate matter

Experimental evaluation of the effect of ozone treatment on the oxidation and removal of dry soot deposits of the exhaust gas recirculation system

“…Moreover, as the graph shows, the higher atmosphere temperature, the greater mass reduction was achieved, reaching a reduction of the 52.1% when the atmosphere temperature was fixed in 140 °C. The comparison with the results of the atmospheres with 30 gO 3 /m³ and 50 gO 3 /m³ revealed that, in agreement with recent studies [ 27 , 30 ], this effect was more marked when higher ozone concentrations were considered. In this manner, the deposit mass reduction achieved with 30 and 50 gO 3 /m³ at 100 °C was 27.1% and 35.8%, respectively, while at 140 °C, the mass loss was 78.5% and 91.8%, respectively.…”

“…This effect, that was observed both in the fouling samples that were exposed to the ozone atmosphere at 90 °C and at 140 °C, revealed an increase of the volatility of the deposit. The reaction of ozone with the surface functional groups of the deposit resulted in the breakdown of C–C bonds, as well as the generation of carbon and oxygen-functional groups, leading to the formation of more volatile species [ 27 , 28 , 67 ]. Moreover, the presence of OH groups in fouling, due to the more reactive capacity of chemisorbed oxygen, also facilitated its removal from the deposit during oxidation [ 68 , 69 ].…”

“…The use of pollution control devices, as Diesel Particulate Filters (DPF) or Exhaust Gas Recirculation (EGR) systems, have been effective technologies in helping ICEs meet the new rigorous pollution standards and reduce their impact on the air quality [ 25 , 26 ]. The NTP technique has also been employed to regenerate these antipollution systems and the third category is composed of the studies of Shi et al [ [27] , [28] , [29] ], Pu et al [ 30 ] or Kuwahara et al [ 31 ], that evaluated the effectiveness of this technique on the oxidation and removal of the particulate matter deposited in DPFs, and those carried out by Li et al [ 32 ], Shi et al [ 33 ] or Chen et al [ 34 ], that assessed the suitability of NTP to the regeneration of EGR coolers. Through the evaluation of different operating conditions, these studies indicated that ozone exposure produced the decomposition of the fouling layer, however the oxidative and removal potential of the ozone injection process can vary depending on the specific conditions under which the deposits were generated.…”

Air Purification Performance Analysis of Magnetic Fluid Filter with AC Non-Thermal Plasma Discharge

“…As the magnetic fluid plays the role of the discharge electrode as well as the collection electrode, it achieves two-stage PM collection. Possible methods for the treatment of the collected PM include the replacement of the magnetic fluid, oxidation via O3 injection [30,31], or oxidation via the OH radicals and O3 generated during NTP In this study, taking advantage of both positive and negative corona discharges, a high AC voltage is applied to the electrodes. With the application of the alternating voltage, NTP discharge occurs from the spikes of the magnetic fluid.…”

“…As the magnetic fluid plays the role of the discharge electrode as well as the collection electrode, it achieves two-stage PM collection. Possible methods for the treatment of the collected PM include the replacement of the magnetic fluid, oxidation via O 3 injection [30,31], or oxidation via the OH radicals and O 3 generated during NTP discharge. The generated OH radicals and O 3 also contribute to proofing against mold and bacteria in air purification [27].…”