Three-dimensional computational fluid-dynamic simulation of polypropylene steam gasification

Among the recycling techniques, gasification allows to obtain a hydrogen-rich gas from polypropylene (PP), a widely used thermoplastic material. In this work, devolatilization and steam gasification tests of PP were conducted in fluidized bed reactors. The results show a gas yield of 1.3 and 3.0 Nm 3 /kg PP , and a tar content of 117.3 and 20.9 g/Nm 3 from devolatilization and gasification, respectively. Experimental results provide an overall overview of this process, able to produce a syngas with an H 2 -content of 50 vol% dry . Experimental data coupled with kinetic analysis were used to develop a computational fluid dynamic model (CFD) capable of describing both thermal degradation and subsequent gasification reactions. Although some discrepancies on water conversion and H 2 /CO ratio probably related to the influence of steam in radical chain-scission the model allows to describe gas production and hydrocarbons evolution providing important support for modeling and sizing of fluidized bed reactors on an industrial scale. • Kinetic law of polypropylene devolatilization in fluidized bed reactor is obtained. • Thermochemical valorization of polypropylene is deeply analyzed. • H 2 -rich syngas is obtained during steam gasification. • Devolatilization and gasification kinetics are tuned by experimental data. • An effective computational fluid dynamics model for scaling-up is developed.