During pyrolysis, the C, O, H, and other elements were converted into volatile components and escaped from the carbon residue . The main constituents of the volatile components include CO, CO2, and methane. As shown in Fig. , CO and CO2 were the major constituents of the pyrolysis gas, while other components, methane, hydrogen, and hydrocarbons, were kept at shallow levels throughout the pyrolysis process. The formation of CO and CO2 started when the pyrolysis temperature attained 300 ℃. After 25 min of pyrolysis, the production of these two gases reached the maximum, then gradually decreased to 0 until 60 min, which indicated the completion of carbonization. Next, to quantitatively analyze the influence of pyrolysis temperature on hydrogen production, 20 g of ZMS was pyrolyzed at 300-400 o C, followed by gasification at 900 o C with 5 mL/min of steam supply. The experimental groups were noted as 900-5-300, 900-5-350, and 900-5-400, respectively. Although the yield of biochar decreased with increasing pyrolysis temperature , the hydrogen yield did not show an obvious change (Fig. ). This finding suggested that, although the biochar yield was lower, the larger specific surface area formed at higher pyrolysis temperature allowed more thorough contact between the steam and the biochar, leading to a more complete gasification process and a higher hydrogen yield.