Catalytic pyrolysis of algae: kinetics and thermodynamic analysis

Abstract

Pyrolysis characteristics of the algae biomass collected from local source in the presence of HZSM-5 catalyst was investigated using Thermogravimetric analyzer (TGA) in this study. Multi-components of carbohydrates, proteins, lipids and other component dissociation in algae sample taking place at different stages at varying temperature condition was confirmed as per the multi-step DTG curve. The average activation energy, and pre-exponential factor for the pyrolysis reaction were analyzed using the isoconversional integral methods such as, Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Starnik and Coats Redfern (SCR) methods, and differential isoconversional method of the Kissinger method. The stages of multi-component dissociation was evident consistently in the kinetic and thermodynamic properties analyzed in this study. The diffusion kinetic model fits well into the pyrolysis zone based on the master plot method. The thermodynamic properties including, change in enthalpy, Gibbs free energy, and entropy of the pyrolysis reaction confirms the complex nature of the pyrolysis reaction.