Pyrolysis behavior of cellulose,xylan and lignin

The difference of pyrolysis characteristic among cellulose,xylan and lignin was studied by TG and heat radiation reactor.Xylan has a lower thermal stability than cellulose,and decomposes at 217℃~390℃.Cellulose has a higher onset temperature of pyrolysis and lower yield of char compared with xylan and lignin,and decomposes in a rather narrow temperature range.Lignin decomposes over a broad temperature range from 227℃ to 550℃ with a char yield of 42% which is the highest of the three fractions.The trend of bio-oil yield from the three components with temperature is the same,which increases firstly and then decreases.The bio-oil yield from cellulose is the highest of the three fractions,but it is lest stable.The bio-oil from xylan and lignin shows a higher thermal stability.The char yield for cellulose,xylan and lignin decreases with temperature rise,and finally closes to a constant value about 1.5%,22% and 26%.The gas yield increases with temperature rise,but the contents of the gas are different according to the different fraction.