PHENOMENOLOGICAL KINETICS OF COMPLEX-SYSTEMS - MECHANISTIC CONSIDERATIONS IN THE SOLUBILIZATION OF HEMICELLULOSES FOLLOWING AQUEOUS STEAM TREATMENTS

The solubilization of hemicelluloses from a lignocellulosic matrix is generally described by two parallel first-order reactions. In this paper we develop a phenomenological description that relates the kinetic parameters associated with the hydrolysis of the glucosidic bond to linear free energy correlations of the Leffler type. Such a description has resulted in the correct prediction of the acid hydrolysis kinetics of a number of substrates including the published data on Populus tremuloides and Betula papyrifera and our own work on corn stalks and Stipa tenacissima. The key advantage of our approach is that it facilitates the obtention of kinetic data for a given substrate with fewer experimental points than frequently used in isothermal experiments.