Study on Synergy Between Plasma and Composite Industry Wastes in Catalyzing HC Removal in Diesel Exhaust

The increased usage of diesel in the past 20 years, particularly in developing countries like India, has resulted in serious concerns in abating gaseous pollutants such as oxides of nitrogen (NO_X) and hydrocarbons (HC). On the other hand, the growing metallurgical processing industries leave behind tons of solid waste, making waste management a bigger issue. In the current work several industry wastes have been tested under discharge plasma environment for their catalytic properties in the removal of HCs from diesel exhaust. To explore the benefit of metal oxide components, present in industry wastes, a new approach was proposed in this work wherein two industrial wastes were blended to form a composite waste which was then powdered and bound to form pellets. Four such composite waste-based pellets, namely red mud + iron tailing, iron tailing + lignite ash, lignite ash + copper slag and red mud + oyster shells, were tested for their catalytic properties under plasma environment. Exhaust emanating from a 6 HP engine is sampled and studied for HC removal in a pulsed plasma reactor embedded with composite wastes. The pellets being porous in nature, studies were also conducted for HC adsorption by cascading composite wastes with plasma alone while treating the exhaust. All the composite wastes exhibited good plasma catalysis in HC removal (58–73%) when compared to that with plasma alone (31%). Further, there is a marked difference between plasma adsorption and plasma catalysis by a factor of 1.75–2.2 indicating synergy between plasma and metal oxides present in composite wastes while catalysing HC removal.