ORGANOSOLV PRETREATMENT WITH COMMERCIAL AND CRUDE GLYCEROL TOGETHER WITH FeCl3 OF THE CORN STRAW AND CORN COB BIOMASSES, BOTH INDIVIDUALLY AND MIXED

Organosolv pretreatment with glycerol was applied to the corn straw and corn cob biomasses individually and mixed. The reactions were carried out to improve the amount of FeCl3 catalyst, the use of crude glycerol, and eliminate the steps of washing and drying the pretreated biomass before it was subjected to enzymatic hydrolysis. The results indicated that the straw and cob behaved very similarly in the different pretreatment situations, with the condition using 0.0125 mol L–1 of FeCl3 being considered the best for both. It was evident that the FeCl3 catalyst reduces the recalcitrance of biomasses, acting in the removal of hemicellulose and lignin to the pretreatment liquor. The 50% cob + 50% straw mixture, pretreated according to the best condition, provided sugar release analogous to that of the biomasses individually. Excellent cellulose recovery was obtained (98.2%), in addition 99.2% of hemicellulose and 89.5% of lignin were removed using commercial glycerol with 0.0125 mol L–1 of FeCl3. From 1 kg of 50% cob + 50% straw in natura, 360.9 g of glucose was obtained in 24 h of hydrolysis. The application of crude glycerol was promising, and the pretreated biomass can be subjected directly to enzymatic hydrolysis, without washing and drying.