Devolatilization of Polypropylene Particles in Fluidized Bed
Armando Vitale, Alessandro Antonio Papa, Stefano Iannello, Erwin Ciro, Arda Hatunoglu, Valerio Corradetti, Nicola Rovelli, Pier Ugo Foscolo, Andrea Di Carlo
Abstract
Gasification of plastic waste is an emerging technology of particular interest to the scientific world given the production of a hydrogen-rich gas from waste material. Devolatilization is a first step thermochemical decomposition process which is crucial in determining the quality of the gas in the whole gasification process. The devolatilization of polypropylene (a key compound of plastic waste) has been investigated experimentally in a bench-scale fluidized bed reactor. Experimental tests were carried out by varying two key parameters of the process—the size of the polypropylene spheres (8–12 mm) and temperature (650–850 °C). Temperature shows the highest influence on the process. Greater molecular cracking results were more pronounced at higher temperatures, increasing the production of light hydrocarbons along with the formation of solid carbon residue and tar. The overall syngas output reduced, while the H2 content increased. Furthermore, a pseudo-first-order kinetic model was developed to describe the devolatilization process (Eapp = 11.8 kJ/mol, A1 = 0.55 s−1, ψ = 0.77).