Control of slagging and fouling during co-firing of solid recovered fuel and high-sodium coal using aluminum and magnesium-based additives

The objective of this study is to evaluate the effect of additives in mitigating slagging and fouling during co-combustion of solid recovered fuel (SRF) and high-sodium coal in a lab-scale drop tube furnace. 85 wt% high-sodium coal and 15 wt% SRF were used as a benchmark sample, while the effectiveness of aluminum, magnesium, and aluminosilicate additives were evaluated at various dosages (0.10 and 1.00 wt%). The results revealed that aluminum and magnesium additives at a dosage of 1.00 wt% have a significant effect in reducing ash deposition, indicated by lower Na and K elements. In comparison, the aluminum additives showed better results than the magnesium additive, at the same dosage of 1.00 wt%, revealed by the result of cleaner probe surface and the presence of significant amount of angular solid particles with high Al element, while the use of 1.00 wt% magnesium additive showed a slightly cleaner probe surface with the presence of high Mg in the ash particles. Meanwhile, the others do not overcome ash deposition problems, indicated by rougher probe surface. Moreover, ash morphology also shows the domination of spherical and adhered fine particles, with the presence of Na and K elements in the ash particles.