Effects of Pressure on Coal-nitrogen Conversion during the Pyrolysis and Gasification of Loy Yang Brown Coal

摘要

Effects of pressure on the formation of HCN and NH_3 during the pyrolysis and gasification of Loy Yang brown coal in steam were investigated using a pressurised drop-tube/fixed-bed reactor. NH_3 yield increased with increasing pressure during both pyrolysis and gasification, providing further evidence that the availability of H and other radicals controls the hydrogenation of char-N into NH_3 that is the main route of NH_3 formation. The corresponding HCN yield appears much less sensitive to changes in pressure. Our results indicate that direct conversion of HCN into NH_3 on char surface during pyrolysis and gasification of brown coal is unlikely to be an important route of NH_3 formation.