Effect of glycerol pretreatment on component recovery and enzymatic hydrolysis of sugarcane bagasse

Sugarcane bagasse was cooked with aqueous glycerol (40-80% (w/w)) either in presence of NaOH or H2SO4, or without any chemicals, at 190oC, 10% biomass load and for one to four hours. The pretreatments resulted in cellulose-enriched fibres and in solubilisation of lignin and xylan. Cellulose recovery was higher in pretreatments with NaOH addition and without any chemicals, than in those with H2SO4. Xylan solubilisation was almost complete in all the H2SO4-assisted treatments, whereas in the other experiments it decreased with the increase of glycerol concentration and increased with pretreatment time. Lignin solubilisation increased proportionally to glycerol concentration. For all the conditions, the pretreatment improved the enzymatic hydrolysis of cellulose and residual xylan. The highest overall cellulose convertibilities were achieved in the pretreatments without chemicals (85-94%). The convertibility decreased with time for the acidic pretreatments, and increased slightly for the other ones.