Tuesday, April 30, 2013
Exhibit Hall
Development of biofuels and chemicals from lignocellulosic feedstocks is an important alternative to conventional petroleum-derived products. However, lignocellulosic biomass is recalcitrant to effective enzymatic hydrolysis because of its structural complexity. In plants, calcium oxalate deposition is common. Members of more than 215 plant families accumulate crystals within their tissues. Oxalate-producing plants, which include many crop plants, accumulate oxalate in the range of 3-80% (w/w) of their dry weight. As much as 90% of the total calcium of a plant can be found as the oxalate salt (CaOx). Crystals have been observed in virtually all the tissues of a plant. Agave bagasse (AGB) was used as a model because of its high level of calcium oxalate and with proven results as a potential biofuel feedstock. To study the effect of calcium oxalate in AGB and understand the physicochemical changes in function of pretreatment, AGB was submitted to a calcium oxalate extraction process using HCl at 80ºC for 30 min, recovered the extracted biomass and used as a low CaOx-AGB. Both biomass samples, untreated and extracted AGB were used with two different techniques the novel pretreatment using ionic liquid 1-butyl-3-methylimidazolium chloride [Bmim][Cl], and oxidative delignification using hydrogen peroxide (because of its highly reactive reaction of CaC2O4 with strong oxidizers). To understand the degree of influence that calcium oxalate results in the pretreatments and its subsequent enzymatic hydrolysis, the physicochemical changes in pretreated biomass were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and standard wet chemistry techniques.