Diesel Engine Emission Control Using Pulsed Corona Plasma-Wet Chemical Hybrid Process

Abstract

The plasma-wet chemical hybrid process for NOx removal from the flue gas emissions is extremely effective and economical in comparison with the conventional selective catalytic reduction system. A series of experiments using the plasma-wet chemical hybrid system are performed to control NOx from the diesel engine emission. The operation characteristics and optimum operation for plasma and chemical reactors are investigated in regard to reaction products such as N 2 O, CO, CO 2 , HNO 3 and NO 3 -as well as NOx removal efficiency using the pulsed corona and barrier type packed-bed plasma reactors. The oxidation from NO to NO 2 without reducing NOx concentration (i.e., minimum reaction byproducts) and with least power consumption is the key for the optimum reactor design. The produced NO 2 is totally converted to N 2 and Na 2 SO 4 with Na 2 SO 3 scrubbing. The hybrid reactors followed by the chemical reactor achieved extremely low operating cost and around 90 % NOx removal efficiency with small amount of byproducts.

Performance evaluation of semi-dry flue gas desulfurization and denitration from flue gas of a glass melt using nonthermal plasma combined process

“…In contrast, the highly efficient and energy-conserving atmospheric nonthermal plasma using plasma-chemical hybrid process (PCHP) has been extensively investigated as a technique for the removal of NOx in combustion gases released from boilers, diesel generators, and garbage incinerators (Yamamoto et al, 2000;Oda et al, 1998;Fujishima et al, 2005;Okubo et al, 2006;Cha et al, 2007;Yoshida et al, 2009;Hayakawa et al, 2016;Kuwahara et al, 2016;Chang et al, 2004;Zhou et al, 1992;Dinelli et al, 1990;Chang et al, 1998). Furthermore, highly efficient exhaust gas treatment can reportedly be achieved using the wet plasma-chemical hybrid treatment technology, which combines the plasma process that oxidizes NO in the combustion exhaust gas released from boilers using ozone (O3) generated by atmospheric nonthermal plasma and the process involving the reductive removal of NO2 generated from oxidation using an aqueous Na2SO3 solution (Sano and Yoshioka, 2003;Fujishima et al, 2010).…”

Continuous operation of commercial-scale plasma–chemical aftertreatment system of smoke tube boiler emission with oxidation reduction potential and pH control

“…The laboratory-scale nonthermal plasma-chemical hybrid process for NO x removal from a stationary emission source such as a boiler, power generator, and incinerator has been investigated over the years and demonstrated to achieve a nearly complete NO x removal with negligible reaction byproducts [1][2][3][4][5][6]. Moreover, the operating cost for the plasma-chemical hybrid system is approximately 15 times more economical than the conventional SCR process [3].…”