Debottlenecking high-solids concentration enzymatic hydrolysis: ball-milling tumbling reactor and use of surfactants

Enzymatic hydrolysis (EH) is one of the key steps in the second generation ethanol production process. The main challenges of EH are long reaction time, low yield at high-solid concentration and the high cost of enzymatic cocktail. It is known that the use of additives such as surfactants may alter the behavior of cellulolytic enzymes on lignocellulosic material increasing the reaction yield. Also the use of ball-milling during enzymatic hydrolysis has being claimed to carry out fiber comminution leading to high hydrolysis yield. Ball-milling enzymatic hydrolysis reactor (BMER) and use of surfactant were investigated in the EH of 20% (w/v) of hydrothermal pretreated sugarcane bagasse (pSCB) using a cellulolytic enzyme cocktail at 10 to 20 FPU/g pSCB. BMER was employed with different number of beads (0 to 30 stell sphreres/20 g pSCB) and surfactant Tween 80 (S) was tested at different concentration (0 to 20 mg S/100 g pSCB). Increasing of glucose yield (from c.a.30% up to 60%) were observed with the use of either, 10 FPU/g pSCB and 15 stell sphreres/20 g pSCB or 20 FPU/g pSCB and 5 mg S/100 g pSCB. It was demonstrated that both strategies may be advantage for pSCB enzymatic hydrolysis. The combinatorial effect of both strategies also was performed and discussed.