Deconstruction of corncob by steam explosion pretreatment: Correlations between sugar conversion and recalcitrant structures

In this work, acid-catalyzed steam explosion was carried out as a pretreatment to hydrolyze hemicellulose and increase the enzymatic digestibility of corncob. Pretreatment conditions were varied to achieve structural alterations in a wide range: type of acids (sulfuric acid and oxalic acid), acid concentration (0.1-1.5 wt.%) and pressure (1.0-1.8 MPa). The pretreated residues were analyzed by chemical analysis, surface area measurement and x-ray diffraction. Biomass and cellulose crystallinity, lignin content and specific surface area were obtained and their correlations with sugar conversion were compared. The results suggested that these parameters were coupled together and they explained in part the diversity of the literature data that improves understanding of steam explosion pretreatment.