Drying kinetics of RDF: Experimental investigation and modeling

Abstract

Abstract. An experimental study was performed to determine the drying characteristics of an oversized fraction of RDF alternative fuel using a laboratory scale hot air dryer at a variety air temperatures and a constant air velocity. For this research the industrial RDF was derived from a Regional Municipal Waste Treatment Facility near the city of Kraków, Poland. The samples of RDF were prepared in two forms: ovesized (unmodified condition) and shreded in a two-drum crusher. In addition, the RDF was sorted into three groups of samples: paper, plastic, textiles. Each form of RDF and each group of samples were dried in hot air dryer at temperatures of 50, 70 i 90 °C and a constant air velocity of 1,5 [m·s]. The loss of the the samples mass were measured in a continues manner until the equilibrum moisture content was reached. The effective moisture diffusivity [m 2 ·s -1 ] and activation energies [kJ·mol -1 ] was amounted. The analysis of the course of moisture content change concludes that that the drying of the RDF alternative fuel occured mainly in the II period of the process during which the transport of water content was carried out by diffusion. And, to a lesser extent, with the surface heat transfer in II period. Based on the calculated data there was a model determined which presented the best possible matching of the course of moisture content change.

Evolution of pyrolysis and gasification as waste to energy tools for low carbon economy

“…Non‐reactive drying at approximately 100°C is the next stage. The temperature in this phase remains practically invariable until the critical water content (5%–10%) is reached (Bergman et al, 2005; Słomka‐Polonis et al, 2018). Further heating of feedstock results in a reactive drying process, where the remaining bound water is removed.…”

The Prediction of Calorific Value of Carbonized Solid Fuel Produced from Refuse-Derived Fuel in the Low-Temperature Pyrolysis in CO2

“…The plastics waste, which is one of the predominant components of RDF/SRF mixture (constitute ≈30–50%, sometimes reaching over 80%) [ 24 ] is made from other polymers than the above-mentioned RDF components, and its thermal degradation takes place at 400–600 °C (PE, PET, PE plastic). PVC material is less thermally stable and starts to be degraded at ≈250 °C [ 25 ].…”