Research paperMechanical pretreatment of biomass - Part I: Acoustic and hydrodynamic cavitation

- Acoustic and hydrodynamic cavitation were examined as mechanical pretreatments.
- Acoustic cavitation of microcrystalline cellulose showed significant gains over no treatment.
- Hydrodynamic cavitation increased the enzymatic digestibility of both raw and lime-treated sugarcane bagasse.
- The energy cost of hydrodynamic cavitation is too expensive to be economical.

Acoustic and hydrodynamic cavitation were examined as suitable mechanical pretreatments for lignocellulosic biomass. Microcrystalline cellulose and lime-treated sugarcane bagasse were subjected to acoustic cavitation, whereas raw and lime-treated sugarcane bagasse were subjected to hydrodynamic cavitation. Acoustic cavitation successfully increased microcrystalline cellulose enzymatic digestibility by 37% compared to no acoustic cavitation treatment; however, there was no significant effect on lime-treated sugarcane bagasse. Hydrodynamic cavitation increased the enzymatic digestibility of both raw and lime-treated sugarcane bagasse. Best results were obtained using cavitation treatment of bagasse followed by lime treatment; the 3-d enzymatic digestion increased by 46% when compared to lime treatment only.