Thermogravimetric analysis (TGA) result of BW at heating rate of 10°C/min was showed in Fig. 1(A). This figure evidenced that about 70% weight loss occurred at the end of pyrolysis (700°C). Corresponded to such weight loss, differential weight (%/min) versus temperature profile exhibited an asymmetric curve, which had a sharp peak, a weak shoulder, and a long tail. The peak appeared at about 350°C, which was the fastest weight loss rate of BW pyrolysis. Such peak was believed to be contributed by maximum decomposition rate of cellulose component (Hu et al., 2016). The TG/DTG profiles were further transferred to conversion form, which were given in Fig. 1(B). As can be observed from this figure, weak shoulders appeared at about 300°C. And the tail covered higher temperature range of 400°C-700°C.