Ternary aqueous ionic liquid system for the pretreatment of mixed agave bagasse and municipal solid waste

The production of biofuels and chemicals from lignocellulosic feedstocks is an important alternative to conventional petroleum-derived products. One of the major obstacles in lignocellulose conversion is overcoming biomass recalcitrance for enzymatic hydrolysis and downstream fermentation through pretreatment while still maintaining a sustainable and economically viable process. Recently, ionic liquid (IL) pretreatment using 1-ethyl-3-methylimidazolium acetate ([C₂mim][OAc]) have demonstrated the potential of agave bagasse (AGB) as a biofuel feedstock that can produce high saccharification kinetics and sugar yields. The presence of water (up to 50wt%) have shown to improve saccharification yields along with other advantages such as a facilitated recovery of pure IL, lower amounts of IL employed on the process and a less viscous solution formed which leads to a facilitated biomass processing. This study aims to assess the effect of a ternary aqueous system, mixing [C₂mim][OAc], 1-butyl-3-methylimidazolium acetate ([C₄mim][OAc]) and water at 14 selected ratios, with the only constraint defined as water usage set at 50%. IL pretreatment was conducted for AGB, municipal solid waste (MSW) and a mixture of both feedstocks at 120°C for 3 hrs and 10% biomass loading with subsequent enzymatic saccharification. Pretreated materials were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and wet-chemistry techniques.