Experiments and modeling of fixed-bed debarking residue pyrolysis: The effect of fuel bed properties on product yields

highlights
• We investigate the effect of fuel bed properties on pyrolysis yields with a model.
• The model describes fixed-bed pyrolysis of Norway spruce debarking residue.
• The model is calibrated with experimental data of debarking residue pyrolysis.
• Particle size affects intraparticle tar cracking, but not extraparticle cracking.
• Low porosities increase liquid yield but does not affect solid yield.

This paper presents a study on the fixed-bed pyrolysis of debarking residue obtained from Norway spruce. Analysis is based on the dynamic model of packed bed pyrolysis which was calibrated by determining appropriate reaction rates and enthalpies to match the model predictions with the experimental data. The model comprises mass, energy and momentum equations coupled with a rate equation that describes both the primary and secondary pyrolysis reactions. The experiments used for the model calibration determined the yields of solid, liquid and gaseous pyrolysis products as well as their compositions at three distinct holding temperatures. Subsequently, the dynamic model was used to predict the product yields and to analyze the underlying phenomena controlling the overall pyrolysis reaction in a fixed-bed reactor.