Effect of Zeolite Catalyst on the Pyrolysis Kinetics of Multi-Layered Plastic Food Packaging

Abstract

Pyrolysis is gaining more significance as a technology used to produce alternative fuels and chemicals. This study dealt with the catalytic pyrolysis of a realistic waste mixture of multi-layered plastic food packaging. The thermal behavior, kinetic parameters, and kinetic model of multi-layered plastic food packaging pyrolysis were determined to show its potential for process scale-up. In particular, we aimed to evaluate the effect of a ZSM-5 zeolite catalyst, modified with iron(III) oxide. The pyrolysis process on this decagonal structure was investigated using thermogravimetric analysis under nitrogen flow at four heating rates ranging between 40 and 600 °C. The kinetic study was conducted using the model-free isoconversional Friedman method as well as advanced statistical analysis to determine the reaction mechanism of the process. The thermal decomposition occurred in the range of 350–510 °C, with a mass loss greater than 90%. The kinetic study revealed a complex pyrolysis process, which consisted of three decomposition stages, diffusion, and Avrami-Erofeev reaction types. The activation energy values determined by the Friedman method rose with the degree of conversion, from 127 kJ mol−1 at 0.01 to 219 kJ mol−1 at 0.95. The doping of the catalyst lowered the activation energy of the reaction by 44% and 8% in the first and second stages, respectively, and increased the acidity of the zeolites, thus enhancing the reactivity on the surface of the catalysts. Lower activation energy meant less energy was required to heat the pyrolysis reactor since the onset temperature of sample decomposition was reduced.

Thermal Stability and Kinetics of Degradation of Moxonidine as Pure Ingredient vs. Pharmaceutical Formulation

“…According to the ICTAC protocols, the use of model-free isoconversional methods is recommended over model-fitting methods, and the integral methods of FWO and Kissinger-Akahira-Sunose and the FR differential method are by far the most frequently utilized methods for the kinetic analysis of solid-state degradation processes [28].…”

“…Kinetic analysis represents an analytical method based on the data obtained from various thermal analysis techniques (thermogravimetry and differential scanning calorimetry) and it serves as an important investigational method in the pharmaceutical research [10,[25][26][27], among other scientific fields [28][29][30], leading to crucial information on stability, degradation mechanisms of the investigated compounds, and even shelf-life.…”

Catalytic Pyrolysis of Plastic Waste and Molecular Symmetry Effects: A Review

“…However, the selection of the zeolite has to be focused on target selectivity, which further implies that HZSM-5 zeolite enhances the production of olefins, whereas hierarchical Beta and HY zeolites promote the production of middle distillates [110]. In addition, the kinetics of the plastic pyrolysis reaction, in the presence of the ZSM-5 zeolite catalyst, modified with iron (III) oxide, was recently investigated [111]. The improvement of the reactivity on the catalyst's surface is due to the doping of the zeolite with iron.…”

Influence of Natural Zeolites on the Thermal Decomposition of Multi-layered Plastic Waste

“…According to the UNEP statistic, about 36% of all produced plastic are applied in packaging sector (UNEP). In Europe, 40% of 55 Mt of plastics is produced only for packaging [1]. Multi-layered plastic is mostly used for food packaging, personal hygiene products (e.g., shampoo, conditioner) [2].…”

“…The thickness of multi-layered plastic food packaging differs from 30 µm to 1 mm. Also, the number of the layers varies between 3 and 20 [1]. Multi-layer plastic improves properties of packaging, like barrier performance, which leads to longer shelf-life.…”