Torrefaction and Combustion of Ligno-Cellulosic Biomass

AbstractTorrefaction of biomass and ligno-hemicellulosic compounds followed by combustion of torrefied samples was conducted by using a TGA. Cellulose exhibited highest thermal stability during torrefation at 473K. Hemicellulose attained 48% decompositionafter torrefaction at 523K while lignin decomposition was limited to 65% after torrefaction at 573K. Co-torrefaction ligno-hemicellulosic compounds followed a similar trend for torrefaction behavior of biomass samples. Morphology changes in torrefied cellulose and biomass were notable on fiber shrinkage basis while hemicellulose disintegrated into smaller. However, no significant morphology change was observed on lignin. HHV increased with the increase in torrefaction temperature however torrefaction at 573K resulted into decrease in HHV for biomass and co-torrefied ligno-hemicellulosic compounds. Optimal torrefaction temperature was observed to be 523K where average mass loss of 34% resulted in energy yield of 75%. Torrefied samples exhibited slightly slower combustion than pyrolyzed samples. Combustion reactivity of torrefied biomass, hemicellulose, cellulose and lignin were realized to be 15%/min, 21%/min, 18%/min and 14%/min, respectively