Environmental applications of high power accelerators

High power DC accelerators in the power range 50-600 kW have been employed in recent years in some countries on experimental basis for Flue Gas and Wastewater treatment. A 3 MeV, 30 kW DC accelerator, built indigenously by Accelerator and Pulse Power Division, BARC at Electron Beam Centre, Kharghar, will undergo commissioning trials shortly. Experiments on Flue Gas treatment by EB will be conducted in active collaboration with BHEL, Ranipet at beam parameters of 1 MeV, 5 kW. Flue gas will be simulated by first producing carbon dioxide from the combustion of LPG and then diluting it with air. External cylinders of SO2, NO, NH3 will be used to introduce these gases into the main flow in a controlled manner by using mass flow controllers realizing concentrations of SO2, NH3 in the range 500-2500 ppm and NO 100-500 ppm. Humidity and temperature will be controlled to optimize removal process. The flue gas will pass through a water-cooled reaction vessel of dimension 100 cm (length) x 35 cm (width) x 100 cm (depth) fitted with a 50 μm thick Titanium foil window at the top to allow beam electrons to pass through and interact with the Flue Gas. The production of high density of oxidizing OH free radicals, which react with the pollutants to produce sulphuric acid and nitric acids, results in high throughput. The acids are neutralized by ammonia in the moist environment to produce the useful fertilizers ammonium sulphate and ammonium nitrate. Prior to experiments, simulation work has been carried out with the software package CKS for our experimental parameters and it indicates highly efficient simultaneous removal of SO2 and NO2 at a dose of 15kGy