Use of hardwoods in an integrated biorefinery: Modelling of the pretreatment process and papermaking potential

Pretreatment of hardwood can dissolve some of its hemicellulose, which can be used as a feedstock solution for biofuels and bioproducts within the context of a wood based biorefinery. It is well known that most pretreatment methods accelerate subsequent pulping and bleaching reactions. This study reports models developed for predicting several aspects of the impact of pretreatment on the properties of unbleached kraft pulps produced from sample hardwoods: sugar maple (A. saccharum) and eucalyptus (E. globulus). The kappa number was correlated with the severity of pretreatment using a first order approximation of the delignification kinetics. The resulting correlation could be applied to the delignification of pretreated hardwood chips of both the species. Other properties of pulps were modeled with pretreatment and pulping variables using principal component analysis. Multivariable linear regression (MVLR) models were established for the pulp yield, viscosity, composition, cationic demand of fibers, tensile index, tear index, stiffness and air resistance.