The individual and interactive effects of acid and basic oxides on ash fusibility during oxy-biomass combustion with recycled SO2

Ash-melting problems induced by alkali metals and recycled SO2 are one of the major obstacles to oxy-biomass combustion, which depend heavily on the contents of acid or basic oxides in ash particles. In this study, the individual effects of acid or basic oxides as well as their interactions on ash melting performance of corn straw were explored. The results showed that the individual effects of SiO2 to Al2O3 (Si/Al) or acid to basic oxides (A/ B) ratios on the ash fusion temperatures (AFTs) were nonlinear due to the eutectic melting of minerals. A regression model was established by response surface methodology to reveal the interactive effects of Si/Al and A/B ratios on ash slagging, in which softening temperature (ST) was the response factor. In comparison with the Si/Al ratio, the influence of the A/B ratio on ST was more significant. Furthermore, based on the regulation strategy obtained through the regression model, after modifying the ratios of Si/Al and A/B to 8 and 1.0 simultaneously, all the AFTs were dramatically increased and the ash slagging was alleviated effectively during oxy-biomass combustion with recycled SO2.

Automated summary

The study examined the effects of acid or basic oxides and their interactions on ash melting in oxy-biomass combustion. A regression model revealed that the A/B ratio had a significant impact on softening temperature (ST). By modifying the Si/Al and A/B ratios, the ash fusion temperatures (AFTs) were increased and ash slagging was effectively alleviated during combustion.