Impact of Plastic Composition on the Performance of the Integrated Process of Pyrolysis and Oxidative Steam Reforming for Hydrogen Production

The pyrolysis and oxidative steam reforming (P-OSR) of different types of plastics (HDPE, PP, PET and PS) has been carried out in a two reactor system provided with a conical spouted bed reactor (CSBR) and a fluidized bed reactor (FBR). The effect plastic composition has on the oxidative steam reforming step has been analyzed using two space time values (3.1 gcatalyst min gplastic − 1 and 12.5 gcatalyst min gplastic − 1 ) at a reforming temperature of 700 ◦C, S/P ratio of 3 and ER of 0.2 (optimum conditions for autothermal reforming). The different composition of the plastics leads to differences in the yields and compositions of pyrolysis products, and consequently in the performance of the oxidative steam reforming step. High conversions (> 97 %) have been achieved by using a space time of 12.5 gcat min gplastic − 1 , with H2 production increasing as follows: PET ≪ PS < HDPE ≤ PP. A maximum H2 production of 25.5 wt% has been obtained by using PP, which is lower than that obtained in the process of pyrolysis and in line conventional steam reforming (P-SR) of the same feedstock (34.8 wt%). The lowest H2 production (10.5 wt%) has been achieved when PET was used due to the high oxygen content of this plastic. The results obtained in this study prove that P-OSR performs very well with different feedstock, thereby confirming the versatility and efficiency of this process to produce a hydrogen-rich gas.