Numerical Simulation of Heat Transfer and Heterogeneous Chemical Reactions in a Biomass Particle During Pyrolysis

Abstract

Heat transfer and heterogeneous chemical reactions in a biomass particle during pyrolysis were investigated using numerical simulation. The radiation heat transfer through the pores and the secondary tar cracking exhibited considerable e ects on the results including the intraparticle temperature pro le and the product yields. Time course of the temperature at the center of biomass particle didn’t depend on the lignin content of the biomass. However, the higher lignin content of biomass resulted in the higher yields of tar and solid and the lower yield of gas at the setting temperatures between 673 and 1073 K. The Arrhenius plot of the maximum gas generation rate exhibited two regimes having di erent activation energies regardless of biomass type. These two regions may be attributed to cellulose and hemicellulose decomposition at lower temperatures and lignin decomposition at higher temperatures, respectively. The maximum gas generation rate depended on the volume of the particle below a certain particle size (3.5 mm), and depended on the external surface area of the particle above 3.5 mm.