Abstract:With the aim to study the performance regulation and mechanism of different biochar-based biomasses, cellulose, hemicellulose and lignin were used as the raw materials to prepare biochar by pyrolysis in vacuum atmosphere furnace. The results manifested that the pyrolysis temperature of cellulose and hemicellulose ranged from 300℃ to 500℃, and the yields of biochar decreased from 35.38% (cellulose), 46.28% (hemicellulose) to 20.93%, 29.40%, respectively. Meanwhile, the pyrolysis temperature range of lignin was 300~600℃, and the yields of biochar decreased from 81.22% to 51.53%. Moreover, the effect of pyrolysis temperature on C, H, O and N contents of prepared biochar were similar in the three feedstocks. The content of C raised up gradually according to the temperature increase, while the contents of H, O, N decreased gradually. Detailly, the content of C increased from 69.42%, 72.92%, 54.75% to 96.39%, 77.26%, 67.97% for cellulose, hemicellulose and lignin, respectively. The effect of pyrolysis temperature on the content of ash, volatile, fixed carbon and the calorific value was basically the same in the three feedstocks. The volatile relatively decreased, and the ash, fixed carbon and calorific value increased gradually. Specifically, the volatile from the cellulose, hemicellulose and lignin fell to 7.63%, 5.52%, 14.41% from 50.67%, 44.89%, 39.99%, respectively. The fixed carbon increased from 47.95%, 55.03%, 35.41% to 90.18%, 94.11%, 53.70%, respectively. The calorific value rose to 34602.52kJ/kg, 33965.15kJ/kg, 24142.62kJ/kg from 25652.58kJ/kg, 26681.81kJ/kg, 21173.29kJ/kg, respectively. The significant effect of pyrolysis temperature on the specific surface area and pore size distribution of the prepared biochar was observed for lignin, however, insignificant effect was shown for cellulose and hemicellulose. The optimal surface area and pore volume of the biochar produced from cellulose and hemicellulose was obtained at 500℃, and the lignin was at 600℃. Besides, when the pyrolysis temperature was at 500℃, the iodine adsorption value of the biochar from cellulose and hemicellulose reached their respective maximum values at 422.46mg/g and 115.06mg/g. Meanwhile, at the pyrolysis temperature of 600℃, the iodine adsorption value of the biochar from lignin reached the maximum point of 460.35mg/g.