Fine Ash Formation and Slagging Deposition during Combustion of Silicon-Rich Biomasses and Their Blends with a Low-Rank Coal

Some silicon-rich mineral additives are known to be capable of capturing volatile elements evolved during combustion and, thus, may be used to mitigate ash-related problems (e.g., particulate matter emissions, fouling/slagging, and corrosion). Considering that silicon is also rich in some biomasses (e.g., rice husk), this work aims to explore how co-firing various silicon-rich biomasses with coal would affect fine ash formation and slagging deposition. Combustion experiments of individual biomasses, a low-rank coal, and their blends were conducted on a drop-tube furnace in simulated air and at 1300 °C. The fine ash was collected by a Dekati low-pressure impactor, and the high-temperature slags were collected by uncooled mullite tubes. The particle size distributions of fine ash were obtained. The morphology and composition of fly ash and the slags were carefully characterized by a scanning electron microscope equipped with an energy-dispersive spectrometer. The results indicate that the particle size dist...