High-solid pretreatment of corn stover using urea for enzymatic saccharification.

The aim of this research was to study a high-solid pretreatment of corn stover using urea. Effects of solid loading (30-70%), temperature (60-80 °C), time (2-14 d), ratio of urea to corn stover (1:10-1:1), and ratio of soybean flour to corn stover (1:40-1:10) on enzymatic saccharification were investigated. Generally, the glucose and xylose yield increased as the reaction temperature, time, and ratio of urea to corn stover increased. Urea enhanced enzymatic saccharification at a relatively high-solid loading and low temperature. The results showed that 80 °C for 10 d with urea to corn stover ratio of 1:1 and 50% solid loading are optimum treatment condition to achieve high glucose recovery and enzymatic saccharification efficiency. Under optimum condition, 97.24% glucan and 61.63% xylan were preserved in the treated corn stover, and the maximum enzymatic saccharification efficiencies of 84.11% and 78.54% were achieved for glucose and xylose, respectively.