• • Blending biomass with coal gasification fine slag (CGFS) increased volatile combustion rates by 3–5 times compared to single-component fuels, enabling faster energy release and improved combustion efficiency.
• • Co-combustion of biomass and CGFS reduced NOx and CO emissions by over 50% relative to pure CGFS, addressing environmental concerns associated with CGFS disposal.
• • Increasing biomass blending ratio accelerated volatile release and shortened burnout time, but elevated NO emissions due to higher volatile nitrogen content, necessitating a trade-off between combustion rate and NOx control.
• • Biomass type significantly influenced combustion: rubber tree material exhibited intense pyrolysis and high mass loss rates, while bark-derived volatiles produced flame temperatures up to 1600 °C with prolonged duration, affecting pollutant formation patterns.