Catalytic Pyrolysis of Copper-Incorporated Nylon Fishing-Net Waste: Thermal Behavior, Evolved-Vapor Analysis, Kinetics, Thermodynamics, and Artificial Neural Networks

Abstract

In this research, the catalytic pyrolysis properties, kinetics, thermodynamic characteristics, and composition of the vapor evolved from the thermal decomposition of copper-incorporated nylon fishing net (CuFN) waste were investigated. The analysis was performed on CuFN composed mainly of nylon and copper (3 wt.%) as an anti-corrosion element. A comparative catalytic study was conducted using two types of zeolite catalysts, ZSM-5 (CuFNz) and Y-type (CuFNy). Reaction complexity in the presence of both catalysts was investigated through linear and nonlinear kinetic approaches, along with estimation of the relevant thermodynamic parameters. In addition, a well-trained artificial neural network was used to predict the catalytic thermal decomposition properties of both batches under untested heating conditions. Thermogravimetric results indicated that the catalyst type moderately influenced the decomposition profiles, with CuFNz achieving complete decomposition at 495 °C (44 wt.%), compared to 475 °C (52 wt.%) for CuFNy. Also, the type of catalyst did not affect the functional groups in TG-FTIR, which showed two main peaks at 1712 cm−1 (Carbonyl group) and 2933 cm−1 (C-H stretching band), but the alkyl C-H band was dominant in the case of CuFNy. Meanwhile, gas-chromatography–mass-spectrometry results indicated that caprolactam (88.21%) was a major GC compound in the CuFNz sample and 5-Cyano-1-pentene (70.43%) was dominant in the vapor of the CuFNy sample. However, the presence of the catalyst increases the complexity of the reaction, reflected by higher pyrolytic activation energies of 244.8 kJ/mol (CuFNz) and 296.3 kJ/mol (CuFNy). Moreover, the mysterious catalytic thermal decomposition of CuFN was fully recognized by the optimized ANN algorithm with R = 1. The study demonstrates that catalytic pyrolysis can convert CuFN into valuable products, including caprolactam using a ZSM-5 catalyst and 5-Cyano-1-pentene using a Y-type catalyst, potentially leading to significant environmental and economic benefits.