Pyrolysis of polypropylene over a LZ-Y52 molecular sieve: kinetics and the product distribution

The present work demonstrates the decomposition kinetics of polypropylene in the presence of LZ-Y52 molecular sieve. The pyrolysis was performed at different heating rates in the temperature range 30–600 °C in an inert atmosphere. The kinetics parameters were calculated by applying Ozawa–Flynn–Waal, Tang–Wanjun, and Coats–Redfern (modified) methods. The activation energy ( E a ) and frequency factor ( A ) were found in the range of 52.44–74.50 kJ mol −1 and 1.5 × 10 −2 to 9.05 × 10 8 min −1 , respectively. Based on the activation energy data, all three methods agreed well. Moreover, pyrolysis was performed at 350–390 °C in a pyrolysis chamber and the conditions were optimized for maximum oil production. A 10% catalyst amount, at 370 °C, nitrogen flow rate 16 mL/min, and reaction time 60 min were the optimum conditions during experimental work. The products collected were analyzed by gas chromatography/mass spectrometry. In the case of thermal degradation, no oil was obtained; however, thermo-catalytic degradation resulted in more than 40% oil at 370 °C for 1 h. Fuel properties of the oil obtained were determined. These properties were in good agreement with standard values and therefore it has potential applications for replacing fuel oil.