Co-combustion of wheat straw and camphor wood with coal slime: Thermal behaviour, kinetics, and gaseous pollutant emission characteristics

Highlights: • Thermal behaviour of wheat straw, camphorwood, coal slime and its blends were studied. • The effects of co-combustion on NO and SO₂ emissions were investigated. • Co-combustion with biomass improved the combustion performance of the blends. • Notable interactions were found during the co-combustion process. • Addition of biomass could reduce the emission of NO and SO₂ from coal slime. The disposal of coal slime has attracted increasing attention due to its increasing production and consequent environmental pollution. The co-combustion with biomass is a promising method for the treatment of coal slime. However, there are only a few studies on coal slime and biomass co-combustion. This study investigated the co-combustion characteristics and gaseous pollutant emissions of coal slime with camphor wood and wheat straw. The results showed that there are significant interactions between biomass and coal slime during the co-combustion process. The addition of biomass reduced the ignition and burnout temperature and enhanced the combustion stability of the blends. Meanwhile, the addition of biomass inhibited the emission of NO and SO₂ from the blends. Moreover, the kinetic analysis showed that the activation energies of biomass char and coal slime combustion stage decreased with increasing biomass content, indicating that biomass's addition improved the combustion reactivity of the blended fuel. The results provide basic knowledge regarding the thermal behaviour and emission characteristics of coal slime and biomass co-combustion. It was established that co-firing is beneficial for the clean and efficient utilisation of coal slime.