Abstract: Co-combustion of organic solid waste in coal-fired boilers is an effective approach to realize low-carbon development of coal power. This paper systematically reviewed the research progress regarding stable combustion and pollution control during co-combustion of organic solid waste in coal-fired boilers. The combustion characteristics of various organic solid wastes, co-combustion modes, and their impacts on boiler operation and pollutant formation were analyzed. Special attention was paid to the generation and emission characteristics of typical pollutants under co-combustion conditions, the influences of co-firing parameters on flue gas purification systems together with corresponding regulation strategies, as well as the physicochemical properties and resource recovery pathways of fly ash generated after co-combustion. Co-combustion delivers prominent carbon reduction benefits: every 5% increase in biomass blending ratio cuts coal consumption by 1.0-3.0 kg per ton of steam produced, yet the blending ratio should not exceed 20%. Nevertheless, co-combustion brings notable risks of “pollution transfer”. Co-firing biomass tends to raise alkali metal contents in fly ash and increase PM1 emissions. Co-firing sewage sludge elevates heavy metal concentrations in flue gas, while co-firing high-chlorine organic solid waste significantly raises the formation risks of hydrogen chloride (HCl) and dioxins. Targeted countermeasures including blending ratio adjustment, temperature control and air distribution optimization are required for regulation. This review can provide theoretical references and technical support for the clean and efficient application of organic solid waste co-combustion technologies in coal-fired boilers, facilitating the green transition of coal power and energy recovery of organic solid waste.

Key words: coal, organic solid waste, co-firing, stable combustion, pollutant, fly ash