Effects of biodegradable- and non-biodegradable-rich waste separation on ash deposition behaviour during coal and refuse-derived fuel co-combustion

The potential impact of ash deposition during the combustion of separated biodegradable- and non-biodegradable-rich waste of refuse-derived fuel (RDF) was evaluated in this study. Theoretical prediction, drop tube furnace experimental combustion, and ash observation were performed to comprehensively investigate their ash deposit behaviour. The results show that high CaO and Cl in RDFs result in severe sintering and rust in the metal surface. The high ash deposit weight and aggregated sticky particles are observed during single-firing RDFs. Furthermore, adding 5 wt% of biodegradable-rich RDF or mixed RDF to coal has a less significant effect on ash deposition. However, several aggregate particles and metal degradation are observed during the combustion of mixed coal with the addition of 5 wt% non-biodegradable-rich RDF. The high Cl in non-biodegradable-rich RDF affects the ash deposition behaviour significantly. This research provides valuable insights into optimising coal-RDF co-combustion, especially with separating biodegradable- and non-biodegradable-rich RDFs.