Reaction kinetics of the thermal decomposition of cellulose and hemicellulose in biomass materials

摘要

Sugar cane bagasse, wheat straw, pine and cotton wood pyrolysis was studied by TGA in argon at heating rates of 5 and 20°C/min. The DTG ( dm/dt) peaks associated with the components of an untreated plant material are relatively wide and strongly overlap each other. A reduction in the amount of inorganic ions in the samples by simple water or dilute acid washing procedures resulted in sharper peaks with a better separation. The thermal decomposition of the major biomass components was described, more or less formally, by first order reactions and the DTG curves of the biomass samples were approximated by a linear combination of first order reactions. Good fits between the calculated and the experimental data and good reproducibility of the model parameters were achieved. The kinetic model applied here may serve as a starting point to build more complex models capable of describing the thermal behavior of plant materials during a thermal or thermochemical processing or burning. Theoretically, there is also a possibility to utilize this sort of calculation in the quantitative analysis of the cellulose and hemicellulose content of the lignocellulosic materials.