Diesel NO_x aftertreatment by combined process using temperature swing adsorption, NO_x reduction by nonthermal plasma, and NO_x recirculation: Improvement of the recirculation process

摘要

NO_x emitted from a stationary diesel engine generator was treated with a hybrid system comprising NO_x reduction by nonthermal plasma (NTP) and temperature swing adsorption (TSA) driven by engine waste heat. TSA produces a low-volume gas mixture of N_2 and highly concentrated NO_x, which is effectively reduced by NTP treatment. Improved treatment performance and efficiency are achieved by re-injecting the NTP-treated gas mixture into the engine intake. The system comprises two switchable adsorption chambers; the operation of this system was simulated by using a one-chamber system. The maximum energy efficiency for NO_x treatment is 200g(NO_2)/kWh. The respective contributions of NTP and injection of N_2 and NO_x to the performance were theoretically analyzed. The analysis predicts that high energy efficiency and high NO_x-removal efficiency can be simultaneously achieved with this system but miniaturization of the adsorption chambers will be a challenge.