Pyrolysis of an LDPE-LLDPE-EVA copolymer mixture over various mesoporous catalysts

The aim of the present work was to study the performance of mesoporous catalysts in the catalytic cracking of an LDPE+LLDPE+EVA copolymer. Mesoporous catalysts, including MCM-41, Nano-MCM-41, Al-Nano-MCM-41, MMZ-ZSM-5 and Meso-MFI, were applied for this reaction. Also, microporous HZSM-5 was used for a comparison. All of the catalysts showed higher decomposition abilities than thermal decomposition. The catalytic conversion of the LDPE+LLDPE+EVA copolymer was highest with the use of Meso-MFI due to its pore size and strong Brönsted acidity, with high selectivity for lower olefin and gasoline range hydrocarbon. Both MMZ-ZSM-5 and Al-Nano-MCM-41 have an acid site that induced the decomposition reactions, and thus, produced compounds with lower carbon numbers in liquid products. MCM-41, which exhibits no acidity, showed a similar distribution of liquid products to that via thermal cracking, while Nano-MCM-41 showed better catalytic cracking ability due to its high surface area.