Tuesday, May 3, 2011
Alkali and oxidative treatments of lignocellulose are well-established in chemical pulping and bleaching. However, their application for pretreatment technologies optimized for liberating carbohydrates as a substrate for biofuels production is different in several regards and requires further research before they can be used in cellulosic biofuels processes. This work will present research results of alkaline hydrogen peroxide (AHP) pretreatment scaled-up from the bench scale, the optimized utilization of input chemicals for an industrially relevant process for pretreating herbaceous plants, and the characterization of soluble inhibitors to enzymatic hydrolysis and fermentation that are released during pretreatment. Scale-up will be performed to better characterize the limitations, capabilities, and potential of stirred tank reactors for AHP pretreatment. For economic feasibility, pretreatment must be done at higher solids loadings; therefore, input chemical utilization must be optimized by determining the consumption of alkali and hydrogen peroxide at high solids concentrations. An understanding of the relationship between NaOH: H2O2: Biomass and enzymatic digestibility will be developed to determine economically feasible conditions for AHP pretreatment. Hydrolyzates from AHP pretreated biomass contain polymeric hemicellulose and lignin, as well as acetate, aromatics, and potentially aliphatic and aromatic oxidation products; the identification of potential inhibitors will be determined using LC-MS and LC-MS/MS.