Abstract:

TGA was employed to investigate several kinds of typical biomass materials (namely,eucalyptus bark,eucalyptus leaves,eucalyptus branches,straw,bagasse and sugarcane leaves) in South China through pyrolysis and combustion experiments.The results show that (1) as compared with wood- based materials (eucalyptus barks,eucalyptus leaves,eucalyptus branches),herbal materials(straw,bagasse and sugarcane leaves)are of better per-formance in the ignition process and the liberation of volatile compounds due to their simple material structure; (2) herbal materials,however,have a short burnout time in terms of the fixed carbon and the residue,with a low com-bustion loss which accounts for only 20% of the overall weight loss and a greatly decreasing combustion intensity in the later stage; (3) three types of eucalyptus materials are found to be of different combustion characteristics due to their different compositions; (4) eucalyptus leaves are easy to ignite and their more crude protein and crude fat bring about a wider combustion temperature range and a lower combustion intensity; (5) eucalyptus branches have advantage in terms of the combustion intensities of the volatiles and the fixed carbon,indicating that they are of more stable combustion in the furnace; (6) eucalyptus barks have a long combustion duration but possess no advantage in terms of the ignition and the combustion intensity; and (7) bagasse and sugarcane leaves possess a short combustion duration but show a good synthetic combustion performance.In addition,a non- isothermal kinetic analysis method (Coats- Redfern) is adopted to evaluate the pyrolysis and combustion processes of all the materials,thus obtaining the corresponding kinetic parameters.

Key words: biomass, pyrolysis, combustion, kinetic characteristic