Table 1 show details on the yield of chars, as well as approximate analysis (moisture, volatile matter, and ash content)
produced under different environment conditions. The results indicate that there are no significantly changed on the yield of the three chars, in which CCA700 yielded only about 6-9% higher than CFN700 and CCN700. As reported by Masek et al. [31], the decrease in yield of biochar is due to the none severe pyrolysis conditions that enhance the biomass decomposition. The results indicated that there are no drastic changes on the surface of the chars at different environment conditions.