Effects of cellulose, hemicellulose, and lignin on the combustion behaviours of biomass under various oxygen concentrations.

The combustion behaviours of three components, namely hemicellulose, cellulose, and lignin, and four types of biomass, namely rice straw, bamboo, peanut shell, and chestnut shell, were examined in a drop tube furnace set at 1273 K, in O/N atmospheres containing 21-100% O. Radiant energy analysis technology was employed to infer the temperatures of the samples. The results show that the ignition mechanisms of cellulose and hemicellulose change at 30% and 70% O, respectively, and the lignin particle ignites homogeneously at 20-30% O, heterogeneously at 50% O, and hetero-homogeneously at 70-100% O, respectively. The changes in the ignition mechanisms of biomass particles with lignin content > 10% and < 10% under a certain oxygen concentration depend considerably on the lignin and cellulose contents in the biomass particle, respectively. The expansion of biomass particles with lignin content > 10% and < 10% during combustion process are caused by lignin and hemicellulose, respectively.