Blending agave bagasse with leading bioenergy feedstocks in ionic liquid pretreatment: impact on enzymatic digestibility and biomass structure

Lignocellulosic biomass has great potential to produce fuels and chemicals as a low cost and renewable feedstock for bioconversion. Reducing biomass recalcitrance is required through a pretreatment step to increase sugar production where a sustainable process should be achieved. Leading bioenergy feedstocks were selected based on high availability and heterogonous composition from three large categories, woody biomass, agroindustrial residues and energy crops. Recently, agave bagasse (AGB - byproduct of Tequila industry) have demonstrated its potential as a biofuel feedstock. This study aims to assess the impact of agave bagasse in ionic liquid pretreatment during processing along with leading bioenergy feedstocks (corn stover, pine wood, sugarcane bagasse and switchgrass) in terms of sugar production, delignification and structural changes. Four different biomass blends based on an increasing AGB content using 20% (1:1:1:1:1), 40% (4:1.5:1.5:1.5:1.5), 60% (6:1:1:1:1) and 80% (8:0.5:0.5:0.5:0.5) were used. Both, pure feedstocks and blends were subjected to an IL pretreatment, which was conducted separately and in triplicate at 140°C for 3h using a 10 % (w/w) biomass loading using 1-ethyl-3-methylimidazolium acetate. Subsequent enzymatic saccharification with a normalized enzyme loading per gram of glucan using enzyme mixtures CTec2 and HTec2 were performed. Pretreated biomass were characterized to obtain crystallinity index by powder X-ray diffraction (XRD), molecular level understanding of delignification by Raman spectroscopy, surface morphologies by confocal fluorescence microscopy, and wet-chemistry techniques.