Effects of <scp> NH ₃ </scp> co‐firing ratios on performance of a 500 <scp> MW _e </scp> pulverized coal combustor using a compartment model

Abstract This study developed a 1D compartment model with 21 continuous stirred tank reactors to evaluate NH 3 co‐firing (0%–30%) with bituminous coal (BC) and Ninh Binh anthracite (NB) in a 500 MWe pulverized coal (PC) combustor, advancing low‐emission power generation for using Vietnam's coal resources. The model employs 341 reactions, including 117 nitrogen‐related, and accurately predicts combustion performance and emissions. Without NH 3 co‐firing, BC and NB show comparable combustion, with NB's higher fixed carbon (61.8 wt.% vs. 54.7 wt.%) driving faster heat release. At 10% NH 3 , NO x emissions remain stable (123.6–126.5 ppm vs. 122.3–125.5 ppm at 0%), the pathway favouring N 2 O conversion to N 2 . At 30% NH 3 , NO x increases significantly (639.8 ppm for BC, 565.7 ppm for NB) due to the NH 3 ➔ NH 2 ➔ HNO ➔ NO pathway, amplified by the BC's higher volatile matter (29.5 wt.% vs. 13.3 wt.%). CO 2 emissions decrease by 28.2% for BC and 28.0% for NB, leveraged by NH 3 's carbon‐free nature. However, increased NO x emissions at 30% NH 3 indicate trade‐offs which require further investigation. This model can be used for evaluating NH 3 co‐firing ratios in industrial‐scale combustors, balancing NO x control and CO 2 reduction while elucidating emission formation pathways.