Kinetic modeling of hardwood prehydrolysis. Part II. Xylan removal by dilute hydrochloric acid prehydrolysis

Journal Article · Sun Jun 01 04:00:00 EDT 1986 · Wood Fiber; (United States)

OSTI ID:5296553

Connor, A H; Libkie, K; Springer, E L

A study was made of the kinetics of xylan hemicellulose removal with 0.10 M HCl at 120 degrees C from quaking aspen (Populus tremuloides), paper birch (Betula papyrifera), American elm (Ulmus americana), red maple (Acer rubrum), and southern red oak (Quercus falcata). The mathematical model developed in Part I to describe the kinetics of xylan removal by water prehydrolysis of these species could be used to model xylan removal with dilute hydrochloric acid. Xylan removal could thus be modelled as the sum of two parallel first-order reactions - one fast and one slow. However, unlike the case with water prehydrolysis where the rate constants for the fast and slow reaction processes could be correlated with each other, they could not be correlated for HCl prehydrolysis. Instead, these constant values determined for each species clustered about average values for all the species as a whole. A single set of parameters determined from a nonlinear least squares fit of the experimental prehydrolysis data for all the species as a whole to the model could be used to describe the course of xylan removal from all the species. The fact that one set of parameters could be used suggests that the same reactions are taking place on prehydrolysis and the chemical structure and physical morphology of the xylan hemicellulose were essentially the same in the species studied and probably in all temperate hardwood species. The model thus provides a good approximation of xylan removal from any temperate hardwood with dilute hydrochloric acid at the reaction conditions studied. 20 references.

• Research Organization: USDA Forest Service, Madison, WI
• OSTI ID: 5296553
• Journal Information: Wood Fiber; (United States), Journal Name: Wood Fiber; (United States) Vol. 17:4; ISSN WOOFA
• Country of Publication: United States
• Language: English

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ACID HYDROLYSIS
ASPENS
BIRCHES
CARBOHYDRATES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CORRELATIONS
DECOMPOSITION
HEMICELLULOSE
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
HYDROLYSIS
INORGANIC ACIDS
KINETICS
LYSIS
MAPLES
MATHEMATICAL MODELS
OAKS
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
REACTION KINETICS
REMOVAL
SACCHARIDES
SOLVOLYSIS
TREES
WOOD
XYLANS