Volatile‑N\nBehavior in Oxygen Carrier Aided\nSolid Waste Combustion Using a Two-Stage Fluidized Bed Reactor

Oxygen\ncarrier aided combustion (OCAC) represents an innovative\napproach to enhancing the efficiency and stability of solid waste\ncombustion. This technology substitutes traditional inert bed materials\nwith metal oxides, which can significantly influence NO<sub><i>x</i></sub> formation during redox processes. This study investigates\nthe in situ and ex situ effects of both reduced and oxidized ilmenite\nore (OC) on the conversion of volatile nitrogen (volatile-N) from\nfour different fuels using a two-stage bubbling fluidized bed reactor.\nExperimental results show that reduced OC can promote the reduction\nof NO from pyrolysis gas, with reductions of 2.11% for sawdust (SD),\n88.23% for torrefied leather (LT), 25.18% for waste tires (WT), and\n92.98% for bituminous coal (BC), while the reduced OC increases the\nformation of HCN and NH<sub>3</sub> in pyrolysis process. Oxidized\nOC can directly oxidize HCN and NH<sub>3</sub>, leading to an increase\nin NO by 2.80% for SD, 21.57% for LT, 15.19% for WT, and 9.92% for\nBC. These patterns were consistent in both in situ and ex situ experiments.\nThis suggests that OCAC technology is most effective at lower oxygen\nconcentrations. Overall, these insights advance our understanding\nof the potential pathways for volatile-N conversion in solid waste\ncombustion facilitated by OCAC, highlighting critical operational\nparameters that influence the chemistry of volatile-N in solid waste\ncombustion.