Analysis of hydrogen production potential from waste plastics by pyrolysis and in line oxidative steam reforming

A study was carried out on the valorization of different waste plastics (HDPE, PP, PS and PE), their mixtures and biomass/HDPE mixtures by means of pyrolysis and in line oxidative steam reforming. A thermodynamic equilibrium simulation was used for determining steam reforming data, whereas previous experimental results were considered for setting the pyrolysis volatile stream composition. The adequacy of this simulation tool was validated using experimental results obtained in the pyrolysis and in line steam reforming of different plastics. The effect the most relevant process conditions, i.e., temperature, steam/plastic ratio and equivalence ratio, have on H₂ production and reaction enthalpy was evaluated. Moreover, the most suitable conditions for the oxidative steam reforming of plastics of different nature and their mixtures were determined. The results obtained are evidence of the potential interest of this novel valorization route, as H₂ productions of up to 25 wt% were obtained operating under autothermal conditions.