Prediction and inhibition of the N2O accumulation in the BioDeNO x process for NO x removal from flue gas.

Abstract

BioDeNO x process, which combines the advantages of the chemical absorption and biological reduction processes, is regarded as a promising candidate for NO removal from the flue gas. In the BioDeNO x , N2O was accumulated in the process of the biological reduction of FeII(EDTA)-NO. In this work, the pathway of the FeII(EDTA)-NO reduction was investigated and a mathematic model was developed to evaluate and predict the accumulation of N2O. Furthermore, parametric tests such as the effects of the C/N ratio (molar ratio of carbon/nitrogen), electron donor, and sulfite concentrations on N2O accumulation were investigated. Experimental results revealed that N2O accumulation was inhibited with a high C/N ratio (2.4), sufficient electron donor, and a low sulfite concentration. In addition, compared with the inorganic electron donor (FeII(EDTA)), the organic electron donor (glucose) was beneficial for microorganism metabolism and N2O accumulation inhibition. This work will provide significant insight into the inhibition of N2O accumulation during the operation of BioDeNO x and advance this novel process for the industrial application.