Analysis of the performance and products in the torrefaction of sugarcane bagasse with different particle sizes

Abstract

The torrefaction of sugarcane bagasse particles was evaluated using standard thermogravimetric equipment (TGA) and in a torrefaction reactor explicitly designed for this work. Different particle sizes (fine, large, and unground bagasse) were torrefied to examine any potential effect of particle type and size on the devolatilization process. The custom-designed reactor allowed measurement of the mass and temperature of the particle and the condensable volatiles captured through a condensation unit held at −12 °C during torrefaction. Final products of the process (liquids, solids, and gases) were measured and characterized to understand and analyze the processes occurring in the sugarcane biomass during torrefaction. A two-step kinetic model was fitted to experimental data on fine particles to get the kinetic parameters. A particle model was developed to understand the dynamics of biomass heating and conversion under isothermal conditions. Results of tests for large particles show an effect of particle size on the process of decomposition of the biomass. The large unground biomass showed the lowest mass loss among evaluated particles. The torrefaction process resulted in significant thermal impact for fine particles, having the highest center temperatures, devolatilization, and changes in the O-H group with FTIR tests.