TG–MS analysis of nitrogen transformation during combustion of biomass with municipal sewage sludge

Municipal sewage sludge can be chosen as an inhibitor to solve the problems related to alkali metal during biomass combustion. Emission of NOx and N2O is an important factor for the co-combustion of biomass with municipal sewage sludge. Thermogravimetry–mass spectrometry was adopted to study nitrogen transformation during the co-combustion of the blends. In this paper, the release characteristics of nitrogen-containing species of the blends during heating process are mainly studied. The yields of main nitrogenous gases (HCN, NH3, NO and HNCO) decrease by mixing biomass with municipal sewage sludge during the heating process. The decrease rate is significant when municipal sewage sludge share changes from 0 to 30 %. The co-combustion of corn straw and cotton stalk mixed with sludge releases less nitrogenous gases than that of wheat straw mixed with sludge.