Figure 2.
SEM images of raw rye straw under 50 and 200 or 500 magnification (a), rye straw after pretreatment with water at 121 °C and 1 h (b), rye straw after pretreatment with 5% sulfuric acid at 121 °C and 2 h (c) and 10% sulfuric acid at 121 °C and 1 h (d) and 10% sulfuric acid at 121 °C and 2 h (e).


