Catalytic hydropyrolysis of a model municipal waste plastic mixture over composite USY/SBA-16 catalysts

Hydropyrolysis of a model municipal waste plastic mixture is studied using in-house composites of zeolite USY with mesoporous SBA-16. Three different TEOS/USY weight ratios such as 0.75, 0.92, and 1.2 are employed in the synthesis of the composite catalysts. For the comparison, a composite USY with mesoporous SBA-15 and a mesoporous Al-SBA-16 are also prepared. The catalysts are characterized by using SEM, TEM, EDX, XRD, N₂-BET, FTIR, and py-FTIR. Hydropyrolysis performance of the catalysts is studied in a stirred autoclave reactor at initial cold hydrogen pressure of 20 bar and at three reaction temperatures of 375 °C, 400 °C, and 425 °C. The effect of residence time on the hydropyrolysis performance of the catalysts is also studied. The characterization results revealed that the crystallinity decreases with an increase in TEOS/USY ratio. It is found that the composites of USY/SBA-16 delivered more conversion and liquid yield compared to their parent USY catalyst.