Development of Clean Diesel Engine with Plasma-Assisted Aftertreatment System (Achievement of System Energy Efficiency of 385 g (NO2)/kWh Using Nonthermal Plasma and EGCR)

The authors realize a new prototype of plasma-assisted environmental protection aftertreatment system using atmospheric-pressure nonthermal plasma combine processes for super clean diesel engines. This system does not use any rare or precious metal catalysts and harmful ammonia or urea solution. A NOx aftertreatment system, using nonthermal plasma (NTP) reduction and exhaust gas components recirculation, is investigated. A pilot-scale system is applied to a stationary diesel engine using A type of heavy oil fuel. In this system, NOx is first removed by adsorption, and subsequently, the adsorbent is regenerated by thermal desorption. The desorbed high-concentration NOx is reduced by using nitrogen NTP with low flow rate. Moreover, NOx re-circulated into the engine intake reduces NOx emission. In the present experiments, a very high system energy efficiency of 385 g (NO2)/kWh is achieved in the NOx reduction test. The developed system demonstrates excellent energy efficiencies to meet the most recent international regulation of marine diesel engine exhaust gas.