Dielectric barrier discharge cascaded with red mud waste to enhance NOx removal from diesel engine exhaust

Red mud is a waste by-product generated during the processing of bauxite, the most common ore of aluminium. With the presence of ferric oxide, high surface area, resistance to poisoning and low cost, red mud made itself a good alternative to the existing commercial automobile catalyst. The cascading of dielectric barrier discharge plasma with red mud improved the NO_X removal from diesel engine exhaust significantly. The DeNO_X efficiency with discharge plasma was 74% and that with red mud was 31%. The efficiency increased to 92% when plasma was cascaded with red mud catalyst operating at a temperature of 400°C. The NO_X removal was dominated by NO₂ removal. The studies were conducted at different temperatures and the results were discussed.