Executive Summary : | Diesel exhaust contributes a major portion of nitrogen oxides (NOx) and volatile organic compounds (VOC) to the atmosphere. Controlling NOx in diesel exhaust is a challenging task due to the presence of soot, moisture and oxides of sulfur which may damage any DeNOx catalysts/adsorbents decreasing its functionality and life span. In addition to NOx, VOC present in diesel exhaust is also of major concern, as it leads to ground level ozone and photochemical smog. At present, only a part of VOC is controlled by using catalysts and the rest goes unabated. The usage of adsorbents for VOC removal from stationary sources is still a far-fetched option. While usage of catalyst is a well-established technique for cleansing petrol engine exhaust, it is not very efficient for diesel exhaust. On the other hand, the usage of adsorbents for NOx treatment in diesel exhaust is limited to stationary exhaust cleaning. However, the issues, such as, poisoning of the adsorbents by formation of acidic HNO2/HNO3 on the surface of adsorbents, desorption of the adsorbents, pretreatment of exhaust for oxidising NO to NO2 by catalysts which in turn increases the overall cost (that of catalysts + adsorbents) etc., poses a limitation on the usage of adsorption techniques. For VO treatment, the usage of adsorbents is still in its infancy. Of late, high voltage electrical discharge based non-thermal plasma is being considered for the treatment of oxides of nitrogen and other hazardous air pollutants at the laboratory level. In this proposal, studies will be conducted to correctly interpret the meaning of the term, ‘reduction of NOx’ by quantifying all the higher oxides of nitrogen as well as acidic compounds of nitrogen. This wasn’t the case earlier. An attempt will be made to explore possibility of using the solid waste red mud generated from Aluminium industry as a potential adsorbent/catalyst for treating NOx/VOC from diesel engine exhaust. A new dimension to managing solid industrial waste when employed in hybrid mode with high voltage electrical discharges can be expected as a possible outcome of this proposal. |