Ammonia-coal co-combustion

as a new low-carbon technology

has garnered significant attention for its potential to reduce carbon emissions compared to traditional coal combustion. However

the interaction between ammonia and pulverized coal in co-combustion remains unclear

and issues such as ignition

flame stability

and burnout in combustion with high ammonia blending ratio have yet to be resolved. In this work

we use a flat flame burner experimental platform and employ SEM-EDS and thermogravimetric analysis to systematically investigate the effects of NH3 co-firing ratio (0 to 0.6) and oxygen concentration (0.1

0.15

0.2) on the combustion behavior of pulverized coal particles. The results indicate that as the NH3 co-firing ratio increases

the particle size of coke decreases

the temperature of maximum weight loss rate reduces

and the carbon content first increases and then decreases. This is attributed to the rise in flame temperature

enhanced heat transfer

and rapid release of volatiles

which increase the fragmentation stress of char particles. Smaller particles react more rapidly

causing the third stage of the thermogravimetric curve to change from a single peak to a double peak

with a lower peak temperature. Meanwhile

increasing the oxygen concentration enlarges the surface porosity of particles

slightly raises the carbon content

increases the temperature of maximum weight loss rate

and shifts the thermogravimetric process toward the high-temperature region. At an NH3 co-firing ratio of 0.4 and an oxygen concentration of 0.2

the particle reaction temperature is the lowest

indicating that the co-combustion activity and combustion rate are optimal. This study provides critical insights into the synergistic combustion mechanisms of ammonia-coal co-combustion and offers valuable guidance for optimizing operating parameters in practical boiler systems

thereby facilitating the promotion and application of low-carbon combustion technologies.