The release of nitrogen species during pyrolysis of model chars loaded with different additives

Effect of iron and calcium compounds on nitrogen distribution during pyrolysis of carbazole char up to 950 °C has been studied in a quartz fixed-bed reactor. It was found that impregnated iron and calcium compounds facilitate the carbazole nitrogen to turn into N2, the nitrogen remaining in char and the amount of evolved HCN and NH3 are lower than those without additives. The impregnated iron sharply decreases the evolution of NH3; it also suppresses the HCN formation during pyrolysis. The impregnated calcium also shows some effects on reduction of NH3 and HCN, but its catalytic effect is lower than that of iron. To investigate the super catalytic effects on NH3 reduction, iron was introduced into different supporters. It was found that iron loaded in different supporters show quite different catalytic effects on NH3 reduction, which means that supporters strongly affect the catalytic effects of iron.