Investigation of a pulsed corona reactor for heavy-duty diesel engine emissions reduction

Meeting manufacturer heavy-duty diesel engine emissions reduction goals without relying on some form of exhaust aftertreatment is becoming increasingly difficult. The inverse relationship that exists between NO _x and particulate emissions is particularly problematic for engine modification-based approaches. New techniques, or combinations of techniques, which promise the simultaneous reduction of these two pollutants are needed. One alternative approach currently under investigation is the pulsed corona reactor (PCR). The PCR utilizes an atmospheric-pressure, nonthermal plasma discharge to generate chemical radicals and other active species in a flowing gas volume, thereby facilitating a conversion of entrained pollutants into potentially less harmful by-products. A series of detailed experiments was performed at SwRI to explore the technical viability of this technology for the treatment of heavy-duty diesel engine exhaust. The specific energy consumption of the reactor, the chemical removal efficiencies for each pollutant species and a complete analysis of the relevant reaction by-products is presented for a wide variety of engine conditions. The outlook for commercial application, as well as a discussion of concerns and outstanding research issues is included