title: Kinetic modeling analysis of maleic acid-catalyzed hemicellulose hydrolysis in corn stover.
abstract: Maleic acid-catalyzed hemicellulose hydrolysis reaction in corn stover was analyzed by kinetic modeling. Kinetic constants for Saeman and biphasic hydrolysis models were analyzed by an Arrhenius-type expansion which include activation energy and catalyst concentration factors. The activation energy for hemicellulose hydrolysis by maleic acid was determined to be 83.3 +/- 10.3 kJ/mol, which is significantly lower than the reported E(a) values for sulfuric acid catalyzed hemicellulose hydrolysis reaction. Model analysis suggest that increasing maleic acid concentrations from 0.05 to 0.2 M facilitate improvement in xylose yields from 40% to 85%, while the extent of improvement flattens to near-quantitative by increasing catalyst loading from 0.2 to 1 M. The model was confirmed for the hydrolysis of corn stover at 1 M maleic acid concentrations at 150 degrees C, resulting in a xylose yield of 96% of theoretical. The refined Saeman model was used to evaluate the optimal condition for monomeric xylose yield in the maleic acid-catalyzed reaction: low temperature reaction conditions were suggested, however, experimental results indicated that bi-phasic behavior dominated at low temperatures, which may be due to the insufficient removal of acetyl groups. A combination of experimental data and model analysis suggests that around 80-90% xylose yields can be achieved at reaction temperatures between 100 and 150 degrees C with 0.2 M maleic acid.
authors.affiliation: Agricultural and Biological Engineering, Laboratory of Renewable Resources Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Lu
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Mosier
mesh_terms: D006868:Hydrolysis; D007700:Kinetics; D008298:Maleates / Q000378:metabolism*; D008962:Models, Theoretical; D011134:Polysaccharides / Q000378:metabolism*; D013696:Temperature; D014994:Xylose / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism*
chemical_list: D008298:Maleates; D011134:Polysaccharides; C007916:hemicellulose; C030272:maleic acid; D014994:Xylose