Nitrogen transformation in chemical looping combustion of sewage sludge

The experiments were conducted in a bench-scale fluidized-bed reactor. To improve the reactivity of hematite, cement was added. The results show that cement-modified hematite possessed a higher reactivity, leading to an increase in carbon conversion of sewage sludge. Nevertheless, the NO emission also increased as compared to hematite alone. The rise of fuel reactor temperature can intensify both carbon conversion and NO emission. Meanwhile, the rise of steam content can increase carbon conversion and decrease NO emission. Approximately 0.286%-0.768% of nitrogen measured was NO, which is lower than the value in sewage sludge air incineration process.