Parametric study on the steam reforming of phenol-PET solution to hydrogen production over Ni promoted on Al2O3-La2O3 catalyst

Abstract

Production of hydrogen from plastic waste could be a prospective key to the ecological problems resulted from waste. To further explore the process, a 32-runs parametric study on the steam reforming of Polyethylene terephthalate (PET) dissolved in phenol was conducted in a fixed bed reactor using Ni over La2O3-Al2O3 support. The five factors studied were temperature (A), feed flow rate (B), mass flow (C), phenol concentration (D), and concentration of PET solution (E), whereas the responses were phenol conversion (Y1) and hydrogen selectivity (Y2). From the result, it was observed that significant influence resulted for all the main independent variables on the dependent variable of Y1 and Y2 with the range of 47.24–97.6% and 49–70.96%, respectively. Moreover, the Y1 and Y2 responses have influenced by some interaction variables like AC, CD, CE, ACE, and BCE. As evident from the design, initial variables such as 800°C, 0.10ml/min feed flow rate, 10 SCCM mass flow, 10wt.% of phenol in the feed, and 7% PET concentration were the best preliminary conditions that formed maximum Y1 (94%) and Y2 (71%) responses. However, analyses on the product composition revealed that high amount of aliphatic branched-chains along with moderate amount of cyclic compounds were produced from steam reforming of PET-phenol. Due to the short retention time of the compounds on the catalysts bed, the aromatization of PET cracking products was small.