Impact of additives in mitigating ash-related problems during co-combustion of solid recovered fuel and high-sulfur coal

Environmental concerns and the generation of municipal solid waste (MSW) continues to increase linearly to the population growth. The co-firing of solid recovered fuel (SRF) can substitute for fossil fuels and minimize waste disposal in landfills. However, SRF contains chlorine and alkali components that may cause issues related to ash deposition on boiler surfaces. This study aims to investigate the impact of additives during the co-firing of SRF and high-sulfur coal, specifically in mitigating the ash deposition propensities. The primary fuels used in this investigation are SRF and high-sulfur coal. Various additives, including aluminosilicate (Al–Si), aluminum (Al), and magnesium (Mg)-based compounds, are examined for their effectiveness in reducing ash deposits. The research employs a combination of theoretical calculations, experimental methods, and observation of ash melting behavior, for various scenarios of additive dosages (0.10 and 1.00 wt%). The findings revealed that using Al–Si and Al-based additives at a dosage of 0.10 wt% results in cleaner test probe surfaces and fewer melting spots than other additives. Consequently, incorporating Al–Si and Al-based additives at a dosage of 0.10 wt% exhibits promising potential for mitigating ash deposition issues during co-firing of a mixture comprising of 15 wt% SRF and 85 wt% high-sulfur coal.