Steam gasification of refuse-derived fuel (RDF): Influence of process temperature on yield and product composition

The opportunity of using refuse-derived fuel (RDF) to produce fuel gas seems to be promising, and particular attention has been focused on alternative process technologies such as pyrolysis and gasification. Within this frame, present work relates to experimental tests and obtained results of a series of experimental surveys on RDF gasification with steam, performed by means of a bench-scale rotary kiln plant at different process temperatures, using thermogravimetry (TG) and infrared spectrometry (Fourier transform infrared, FTIR) to characterize the incoming material and online gas chromatography to qualify the gaseous stream. Experimental data show that the gas yield increases with temperature and, with respect to the gas composition, the hydrogen content increases, mainly at the expense of the other gaseous compounds, which highlights the major extension of secondary cracking reactions into the gaseous fraction at higher temperature. Syngas obtained at processing temperatures of 950 degrees C or higher seems to be suitable for producing hydrogen for ammonia synthesis or for fuel cell applications, whereas, at lower processing temperatures, it seems usable for Fischer-Tropsch synthesis. The low organic content of solid residue does not suggest any other exploitation of the char apart from the landfilling.