Abstract:

The pyrolysis behaviors of wood and its three chemical components（cellulose，hemicellulose and lignin）were investigated in a thermo-gravimetric analyzer（TGA）. Meanwhile，the thermo-gravimetric behavior of liquefied residues under same liquefaction conditions were also studied. Regarding thermal stability，TGA results showed that lignin was the most difficult one to be pyrolyzed，hemicellulose was the easiest one，and cellulose was in the middle. The thermal degradation of wood was considered as the sum of the thermal degradations of each individual chemical component. It was achieved in a step-wise manner，i.e. hemicellulose breaken down first at 236～333 ℃，cellulose next at 332～383 ℃ and lignin at 250～630 ℃. Lignin was the most susceptible wood component to the liquefaction reaction among the three main wood components，then hemicellulose，and cellulose at last. In the liquefaction process，the rapid liquefaction stage was mainly attributed to lignin and hemicellulose，which were easily and firstly liquefied，while the second stage，characterized by the slow decrease of residues，mainly depended upon the progress of cellulose liquefaction.