Simulation and Thermodynamic Evaluation of Woody Biomass Waste Torrefaction
Thiago da Silva Gonzales, Simone Monteiro, Giulia Cruz Lamas, Pedro Paulo Oliveira Rodrigues, Mario Siqueira, Luis A. Follegatti–Romero, Edgar A. Silveira
Abstract
High Resolution Image Download MS PowerPoint Slide Torrefaction is a thermochemical pretreatment that enhances biomass properties, improving energy density, decomposition resistance, and hydrophobicity, making it a viable alternative as biofuel. This study performed a thermodynamic assessment of the torrefaction process for urban forest waste, integrating experimental data with two-step reaction kinetic modeling to evaluate the torrefaction product yields and properties using Aspen Plus software. The process was modeled with a yield reactor, employing the Peng–Robinson equation to describe vapor-phase behavior and empirical correlations to predict solid-phase properties. Simulations were validated against experimental data for temperatures between 225 and 275 °C, achieving an absolute deviation of less than 5%. Energy consumption ranged from 368 kJ·h –1 for light torrefaction to 1853 kJ·h –1 for severe torrefaction. Process irreversibility varied from 326 kJ·h –1 (3% exergy destruction) in light torrefaction to 3993 kJ·h –1 (16% exergy destruction) in severe torrefaction. The research provides a robust model for torrefaction scale-up that is adaptable to diverse biomass feedstocks and process conditions, highlighting its potential for optimizing energy use and improving sustainability in biomass utilization.