Pyrolytic degradation of lignin via in situ Copper catalyst: Kinetic modeling and Analysis

The untapped giant for clean energy production, Lignin, holds tremendous potential for sustainable energy production. Metal impregnation can effectively generate bio-oil and carbon hybrids by pyrolysis with metal recovery in char. Pyrolysis experiments of pure lignin and Cu impregnated lignin were performed to validate the kinetic and thermodynamic parameters. Kinetic study of raw and Cu impregnated lignin was performed by modeling with Friedman, FWO, Kissinger, and Starink isoconversional process at distinct heating rates of 10 to 25⁰Cmin-1 to estimate the optimal condition of pyrolytic degradation in both situations. The average activation energy for raw and metal-impregnated lignin was 220.829 and 154.9961 KJ/mol, respectively, and was maximum with the Fwo method. The metal-impregnated lignin resulted in a lower activation energy requirement than raw lignin. The ΔH and ΔG values are maximum for raw lignin compared to metal-impregnated lignin, which signifies a higher energy requirement for breaking the reactant bonds.