(473f) A Study of Metal Supported ZSM-5 and Y Zeolite for Microwave-Induced Degradation of Low-Density Polyethylene

Pyrolysis of plastic has been a topic of research because it was proposed as an alternative to landfilling and mechanical. This method is more energy efficient for conversion of plastics to high valued products such as olefins and aromatics. Recently, the use of microwave for degradation of plastic has been a novel technology to solve the waste plastic problem. The benefit of using microwave is its rapid and selective heating of catalyst. In this research, low density polyethylene was pyrolyzed using Fe promoted HZSM-5 catalyst in a microwave batch reactor. The reaction took place at 300°C for 30 minutes with N₂ flowing at 30 mL/min for an inert environment. Volatiles and condensate percentage were collected and compared between samples. The composition of these products was also investigated, with the gas composition for Fe supported zeolite Y and H-ZSM5 through time shown in the provided image. Overall liquid and gas composition will also be discussed. These profiles were compared to those reported in literature in terms of gas percentage with temperature ranging from 400-550°C. Plastic to catalyst ratio will also be varied to observed difference in the products. Based on product distribution results, interpretations can be made to maximize desirable products such as aromatics and olefins.

Unlike conventional heating, catalyst particles directly interact with the electric (or alternatively magnetic) field component of electromagnetic radiation, generating heat (so, the microwave heating is also known as dielectric heating). Thus, microwave heating occurs via two different mechanisms of dipolar polarization and Maxwell-Wagner polarization. It was observed that H-ZSM5 catalyst with and without some transition metal supported failed to reach the desired temperature due to low absorbance to microwave. A study on dielectric properties of the plastic and different catalysts will be conducted. Coupled with the selective heating, dielectric property can elucidate the heating mechanism of microwave on these materials.