Electron beam treatment of gas stream containing high concentration of NOx: An in situ FTIR study

Abstract

The NOx removal from gas stream by electron beam (EB) technique under flow through condition was investigated using two different reactors. Initially reactor type I was fabricated to investigate the NOx removal performance, based on its performance, the reactor type II was designed for further investigation on NOx removal efficiency. The influence of the applied current, O2, water vapour and gas flow rate on the removal of NO and NOx was studied. The FTIR spectrum of the NO gas samples acquired after EB irradiation indicated the formation of NO2 and N2O. It was observed that the NOx concentration could be reduced to 95% from the initial NO concentration of 1000ppm using reactor type II. The possible removal mechanism of NOx under EB irradiation is discussed. It is inferred that the EB irradiation accelerate the reduction of NO to N2 and O2 in the absence of O2. Addition of O2 and water vapour in the NO/N2 gas stream was found to influence the oxidation and reduction reaction, respectively under EB irradiation. The Na2SO3 scrubbing of the gas increased the NOx removal performance during EB processing. The N2O was observed to form mainly by the reduction of NO2 during EB irradiation.