Kinetics and thermodynamic analysis of pyrolysis of paper waste

The pyrolysis of paper waste can be a viable energy recovery and waste management strategy. However, the complex reaction involved in the process makes it difficult to understand the underlying decomposition mechanism and predict the final product yield. The kinetic and thermodynamic analysis of pyrolysis of paper waste can provide valuable insights into the complex nature of reactions, energy consumed, and the spontaneity of the process. This study aims to predict the kinetic and the associated thermodynamic parameters of paper waste pyrolysis using model-based (Coats-Redfern) and model-free techniques (Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose and Vyazovkin). The pyrolysis of paper waste is carried out in a thermogravimetric analyzer, with varying heating rates of 5, 10, 15, and 20°Cmin⁻¹ and temperatures ranging from 30 to 800 °C. We have utilized the kinetic compensation effect and Criado master plot method to enhance the accuracy of the results. The best-fitted reaction model for the experimental data has been selected based on the coefficient of determination values and quality of fit (%) obtained for each reaction model. The findings indicate that the Zhuravlev diffusion model is the best-fitted model with the coefficient of determination values (R² > 0.94) for region I (235–429 °C) and (R² > 0.99) for region II (429–597 °C). The apparent activation energy values for the best-fitted reaction vary from 124 to 131 kJ/mol for region I and 2.5 to 37 kJ/mol for region II. The apparent activation energy values obtained using different methods exhibited a high degree of similarity.

Graphical abstract