Preparation of Al₂O₃ Nanoparticles via Fluidized Roasting and Their Application in the Pyrolysis of Spent Mulching Film for Hydrocarbon Production

Plastic waste poses serious environmental challenges, and converting it into valuable carbon resources without using noble metal catalysts is vital for sustainable development. In this study, nano-α-Al2O3 was synthesized through a one-step fluidized roasting process of AlOOH, producing particles with a regular nanometer-scale grain size to enhance the catalytic activity. Comprehensive characterization techniques, including X-ray powder diffraction, scanning electron microscopy, and nitrogen adsorption-desorption isotherms, confirmed that nano-α-Al2O3 (L1200) exhibited a smaller nanoparticle size of 125 nm, a higher surface area, and superior thermal and chemical stability compared to the control sample (G1200), prepared via static roasting, which had a particle size of 202 nm. L1200 exhibited outstanding catalytic efficiency in processing spent mulching film (SMF), achieving an oil yield of 65.54 wt % under optimized conditions of 450 °C and a reaction time of 30 min. Py-IR analysis revealed a higher B acid content in L1200, which contributed to its superior performance in SMF conversion. This study highlights the potential application of nano-α-Al2O3 as an efficient, cost-effective catalyst for the conversion of sustainable plastic waste into clean energy.