Real diesel engine exhaust emission control: indirect non-thermal plasma and comparison to direct plasma for NOX, THC, CO, and CO2

Abstract

Recently, diesel engine exhaust emission control by non-thermal plasma (NTP) technology has been shown to be promising. However, carbon and soot deposition on the inner surface of the NTP reactor for direct plasma processing decreased the efficiency of the plasma process throughout the experiments. In the present work, the feasibility of indirect plasma processing was investigated as an innovative and novel method compared to direct plasma processing. Air was directed through an NTP at an applied voltage of V P-P = 7 kV and a flow rate of 1-4 L/min, and then, it was combined with engine exhaust gas at a flow rate of 5 L/min. In this case, the maximum conversion of NO X was 64.9% at 4 L/min. However, for direct plasma processing at 5 L/ min, NO conversion was 58%, which proves that the indirect NTP process can decrease NO X concentration effectively. The maximum conversion for unburned hydrocarbon (UHC), carbon monoxide (CO) and carbon dioxide (CO 2 ) was obtained as 2%, 4% and 0.7% at 4, 2 and 3 L/min in indirect plasma processing; While their remove rate for direct plasma processing was 16.3%, −0.5% and 13.2%, respectively.

Insight into Nanoparticle-Number-Derived Characteristics of Precharged Biodiesel Exhaust Gas in Nonthermal Plasma State

“…The PM reduction when activating the NTP charger is already well described as a result of particle number. Meanwhile, the NO x reduction through the plasma chemistry reactions of the molecule dissociation is by electron collision in the discharge plasma, as described by these following equations and Furthermore, other reactions also occurred in a moist environment, , following these equations and From the experimental results, the NTP charger in this experimental study can reduce NO x covering 21.5–34.3% for D100 and WCO fuels in both loads, which is a lower removal efficiency compared to that in the previous research. , The lower removal efficiency for this NTP system is because of two main reasons. The first reason is a gas residence time in the NTP device .…”

“…From the experimental results, the NTP charger in this experimental study can reduce NO x covering 21.5−34.3% for D100 and WCO fuels in both loads, which is a lower removal efficiency compared to that in the previous research. 42,43 The lower removal efficiency for this NTP system is because of two main reasons. The first reason is a gas residence time in the NTP device.…”

Experiment Study on the Exhaust-Gas Heat Exchanger for Small and Medium-Sized Marine Diesel Engine

“…The number of fishing vessels in China ranks first globally. As the main power source of the ships, marine diesel engines have a thermal efficiency of 40% to 45% [1][2][3], but more than half of the heat is discharged in the form of cylinder liner water and exhaust gas, of which exhaust gas heat accounts for 20%-35% of the total calorific value of diesel, and the exhaust gas temperature is 200°C-400°C under full working condition [4][5][6]. On the other hand, the offshore fishing cycle of fishers driving small and medium-sized fishing vessels to sea is about 7-10 days.…”

Red mud and foundry sand industry wastes for reducing NOx in plasma activated diesel exhaust

“…The existing catalyst-based converters and adsorbent based techniques are becoming expensive owing to the short life, dependency on noble metals, more vulnerability to acidic coating, bulk usage of adsorbents etc. In this regard the application of non-thermal plasma or electric discharge plasma for pollution control aided by additional technique is slowly gaining popularity in the past few years [3][4][5][6][7]. The success in capturing dust particles in electrostatic precipitators by high voltage discharge motivated the researchers to explore the chemistry aspect of discharge in abating the gaseous pollutants in exhaust.…”