Wet explosion pretreatment of sugarcane bagasse for enhanced enzymatic hydrolysis

Wet explosion pretreatment of sugarcane bagasse was investigated in pilot-scale with the aim of obtaining the highest possible sugar yield after pretreatment. The temperatures used were 155, 170, 185 and 200 °C with or without addition of oxygen (0.6 MPa pressure). Enzymatic hydrolysis of washed solid cakes was carried out using two loadings of enzyme mixtures as enzyme protein (EP) on cellulose was 12.4 and 22.0 g kg−1. After hydrolysis, a pretreatment temperature of 185 °C with oxygen yielded the highest glucose concentration of 573.9 ± 4.5 g kg−1 TS and a glucose yield of 87.4 ± 0.7% of the theoretical maximum value. Pretreatment at 200 °C with oxygen exhibited enhanced enzymatic efficiency but lower xylose recovery and formation of the degradation products such as acetate, furfural and HMF of 7.6, 3.3 and 1.0 g L−1, respectively. In the hydrolysis, the total sugars (glucose + xylose) yielded at 185 °C and 200 °C with oxygen were 615.9 ± 4.5 and 584.5 ± 3.1 g kg−1 TS, respectively.