Vapor-Phase Cracking of Eugenol: Distribution of Tar Products as Functions of Temperature and Residence Time

Knowledge of the product distribution and kinetics of the secondary vapor-phase cracking of biomass tar is crucial for the design and optimization of biomass thermochemical conversion processes, such as fast pyrolysis, gasification, and combustion. In this study, we have examined the distribution of condensable tar products from the vapor-phase cracking of eugenol, a model-fuel compound representative of the lignin structural entities found in biomass. Pyrolysis experiments were investigated at different temperatures (300–900 °C) and residence times (τ = 1 and 3 s) in a non-isothermal laminar-flow reactor operated at atmospheric pressure. Tar products were analyzed using gas chromatography with mass spectrometric detection. Eugenol conversion commenced rapidly above 350 °C at τ = 3 s and above 400 °C at τ = 1 s. Complete conversion was attained at 550 and 600 °C at τ = 3 and 1 s, respectively. A numerical model incorporating laminar-flow, non-isothermal temperature profile and pseudo-unimolecular kinetics...