Performance evaluation of PM, NOx, and hydrocarbon removal in diesel engine exhaust by surface discharge-induced plasma.

Diesel engines are characterized by low CO2 emissions and high fuel efficiency. However, their exhausts contain nitrogen oxides (NOx), particulate matter (PM), and hydrocarbons (HC) that require removal by aftertreatment. A novel low-temperature plasma-based aftertreatment method has been developed for the simultaneous removal of NOx, PM, and HC. NOx could be reduced by reacting with HC and CO in the exhaust gas. The particle and gas concentrations in the exhaust are measured using a scanning mobility particle sizer, a NOx analyzer, and a total hydrocarbon analyzer. The treatment performance is evaluated using the resulting measurements. The diesel engine is operated under 0%, 25%, 50%, and 75% loads (maximum output of 2 kW), and the exhaust gas is mixed with N2 + O2 (13%) gas. The power is adjusted to provide 100, 200, 300, and 400 W input power during the plasma reactor treatment. The aftertreatment removal of NOx, PM, and HC is evaluated, and the engine exhibits a removal efficiency of 70% for NOx, 98% for PM, and 67% for HC at 75% engine load and an input power of 100 W.