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.

Application of Response Surface Methodology to Optimize Alkali Concentration, Corn Stover Particle Size, and Extruder Parameters for Maximum Sugar Recovery

“…A comprehensive comparison of various pretreatment methods employed on corn stover is listed in Table 4. It could be observed from the table that dilute acid (Yan et al, 2009), maleic acid (Lu & Mosier, 2008), lactic and/ acetic acid (Xu et al, 2009), controlled pH hot water (Mosier et al, 2005), steam (Bura et al, 2009), and steam explosion ) had comparable yield of this extrusion pretreatment. The present results were higher than dilute sulfuric acid Zhu et al, 2009), formic acid (Xu et al, 2009a), soaking in ethanol and aqueous ammonia , and steam explosion (Mosier et al, 2005); however, it was lower than dilute acid (Zhu et al, 2005), inorganic salt-FeCl 3 (Liu et al, 2009), cellulose solvent and organic solvent based lignocelluloses fractionation (Zhu et al, 2009).…”

Maleic Anhydride Treated Wood: Effects of Drying Time and Esterification Temperature on Properties

“…According to a study realized by Chuan-Fu et al (2007), a temperature of 101 °C corresponds to the beginning of the first stage of thermal degradation of the wood components. The degradation of hemicellulose to xylose (yield 80 and 90%) by maleic acid (0.2 M concentration) in the presence of temperature starts at (Lu and Mosier 2008). This explains the sample mass loss, and is the reason of ASE loss in the shrinkage test considering that hemicellulose represents around 27 ± 2 % of the dry mass of Nord-American softwood (Stevanovic and Perrin 2009).…”

Kinetic study of pentosan solubility during heating and reacting processes of steam treatment of green bamboo

“…The simple pseudo-homogeneous irreversible first order kinetic equation (Jensen et al, 2008;Lu and Mosier, 2008) used to describe the rate of hemicellulose hydrolysis during the acidic or hydrothermal pretreatment of lignocelluloses is defined as…”

“…Understanding the kinetics of hemicellulose hydrolysis is extremely important for testing mechanisms, process control, and optimization during hydrothermal and steam pretreatment of lignocellulosic feedstock (Abatzoglou et al, 1992;Brennan and Wyman, 2004;Lu and Mosier, 2008;Springer, 1966;Zhao et al, 2012;Zhu et al, 2012a). The published models that delve into the solubility of hemicelluloses (mainly pentosan) can be divided into two categories: the homogeneous pseudo-first-order model (Aguilar et al, 2002;Saeman, 1945) and the biphasic reaction model that incorporates fast (easy) and slow (difficult) hydrolyzing fractions (Kobayashi and Sakai, 1956;Maloney et al, 1985;Zhao et al, 2012;Zhu et al, 2012a).…”

“…Likewise, if there is no uniform severity factor which can conclude the heating and reacting processes during chemical pretreatment, the different efficiency in removing pentosan between non-isothermal steam and hydrothermal treatments cannot be thoroughly compared. Moreover, data on the concentrations of xylo-oligomers, xylose, and inhibitors used to determine the kinetic constants in the aforementioned models mostly originate from measurements in the liquid phase (Jensen et al, 2008;Lu and Mosier, 2008). But measuring all degraded products is not feasible (Zhao et al, 2012).…”