Comparison of the impact of ionic liquid pretreatment on recalcitrance of agave bagasse and switchgrass

Lignocellulose represents a sustainable source of carbon for transformation into biofuels. Effective biomass to sugar conversion strategies are needed to lower processing cost without degradation of polysaccharides. Since ionic liquids (ILs) are excellent solvents for pretreatment/dissolution of biomass, IL pretreatment was carried out on agave bagasse (AGB-byproduct of tequila industry) and digestibility and sugar yield was compared with that obtained with switchgrass (SWG). The IL pretreatment was conducted using ([C2mim][OAc]) at 120 and 160 °C for 3 h and 15% biomass loading. While pretreatment using [C2mim][OAc] was very effective in improving the digestibility of both feedstocks, IL pretreatment at 160 °C resulted in higher delignification for AGB (45.5%) than for SWG (38.4%) when compared to 120 °C (AGB-16.6%, SWG-8.2%), formation of a highly amorphous cellulose structure and a significant enhancement of enzyme kinetics. These results highlight the potential of AGB as a biofuel feedstock that can produce high sugar yields with IL pretreatment.

► Assessment of the potential of agave bagasse as a biofuel feedstock using ionic liquid (IL) pretreatment.
► The total sugar yield was higher for agave bagasse (AGB) than for switchgrass (SWG).
► The initial enzymatic hydrolysis rate was lower for AGB than for SWG.
► Pretreatment resulted in higher delignification for AGB (45.5%) than for SWG (38.4%).
► XRD patterns showed highly crystalline peaks for AGB which decreased with pretreatment.