Pulsed plasma promoted adsorption/catalysis for NOx removal from stationary diesel engine exhaust

A detailed laboratory study on the removal of oxides of nitrogen (NO_x) from the exhaust of a stationary diesel engine was carried out using pulsed electrical discharge promoted adsorbent/catalytic processes. In this study, the filtered exhaust from the diesel engine is made to pass through a combination of plasma reactor and adsorbent/catalytic reactor connected in series. This combination is referred to as cascaded process. In the cascaded plasma-adsorbent process, the plasma treating filtered exhaust was cascaded with adsorbents (MS-13X/Activated alumina/Activated charcoal). The cascaded plasma-adsorbent process exhibits a superior NO_x removal characteristic compared to the individual processes-plasma or adsorbent processes. In the cascaded plasma-catalyst process, the plasma treating filtered exhaust was cascaded with activated alumina catalyst. For the purpose of investigation, both two-stage and four-stage cascaded plasma-activated alumina catalyst processes were separately studied. The synergy effect and limitation of two-stage process and improved performance of four-stage process are explained. Further, experiments were conducted at room temperature as well as at higher temperatures