When sleam to biomass ratio (S/B) is smaller than 0.37, the H2 content rises with the increasing of the S/B, but the H2 content decreases slowly when it is larger than 0.37.

• 发现在水蒸气和生物质比率(S/B)小于0.；37时，氢的百分含量随S/B的增大而增加，S/B大于0