An experimental study on neutralization of non-thermal plasma oxidized diesel engine combustion exhaust NOx gases with hydrated lime filter

A neutralizing procedure for non-thermal plasma (NTP) oxidized nitrogen oxides (NOx) in diesel engine combustion exhaust gases is experimentally investigated. The NTP process converts NO to NO₂ and nitric acid (HNO₃) gases in the condition of enough residual oxygen (O₂) and water vapor content, such as diesel engine combustion exhaust gases. To reduce the produced poisonous gases, additional chemical treatments are required with no more costs. A suitable chemical treatment may be a neutralization of HNO₃ by hydrated lime pieces, which are widely used as manure in gardening and farming. The experiments are conducted to evaluate the neutralization of oxidized exhaust gases by the NTP, and by a chemical treatment reactor cascading an AC discharge type NTP equipment with the hydrated lime filter. The experimental results show the reduced NOx and HNO₃ characteristics for the diesel engine combustion exhaust gases and the quantitative removal effects are discussed.