Pyrolysis and char reactivity of a poor-quality refuse-derived fuel (RDF) from municipal solid waste

• Increasing both heating rate and peak temperature led to more reactive RDF chars.
• The co-pyrolysis of the RDF and two-phase olive mill waste was also investigated.
• The reactivity of resulting chars increased in the presence of RDF.
• The carbonization efficiency of TPOMW was improved in the presence of RDF.
• Results motivate further studies on the use of this RDF as pyrolysis additive.

The present study focuses on analyzing the pyrolysis and combustion behaviors of a refuse-derived fuel (RDF), which is generated in a MSW treatment plant located in Zaragoza (Spain). Pyrolysis experiments were carried out in a TGA apparatus and a fixed-bed reactor at different peak temperatures (400 and 600 °C) and heating rates (5 and 40 °C min− 1). The reactivity towards oxygen of produced chars was also measured in the same TGA device at a heating rate of 10 °C min− 1 and a final temperature of 800 °C. Pyrolysis results were significantly affected by peak temperature and heating rate. The found effect of peak temperature on char and fixed-carbon yields as well as on measured properties (H:C and O:C ratios, BET surface area and average pore diameter) was in agreement with previous studies. However, the effect of heating rate, especially on the release rate of volatiles, could be explained by a change in the pyrolysis reaction scheme. The RDF-derived chars obtained at the highest heating rate showed a higher reactivity in air. In addition, an increase in peak temperature also led to a higher reactivity. This result can indicate that the carbon present in the RDF-derived char is dispersed within an ash matrix containing a high number of active sites, the distribution of which could be improved when heating rate (and, to a lesser extent, peak temperature) is increased. The addition of 10 wt.% RDF to two-phase olive mill waste prior to slow pyrolysis led to an apparent increase in the carbonization efficiency as well as to an enhancement of the resultant char's reactivity in air.

Figure optionsDownload as PowerPoint slide