Comparative study of the thermal decomposition of pure cellulose and pulp paper

The thermal decomposition of pure cellulose, either powder or paper, and of pulp Kraft paper was studied by thermogravimetry, differential scanning calorimetry, thermal volatilisation analysis and characterisation of the degradation products. Depolymerisation of the pure cellulose with production of levoglucosan takes place at high heating rates. At low heating rates autocatalytic dehydration of the cellulose with char production predominates, as shown by kinetic treatment of thermogravimetric data. Both mechanisms simultaneously contribute to the thermal decomposition of the Kraft paper independently of the heating rate, with the largest production of char. Pure cellulose produces more levoglucosan than Kraft paper on thermal decomposition, which gives furanic compounds as secondary degradation products. A larger amount of volatile carbonylic compounds is formed on thermal decomposition of the Kraft paper.