Physicochemical Characterization of Wheat Straw during a Continuous Pretreatment Process

Abstract

The changes occurring during the depolymerization of lignocellulosic biomasses are not yet fully understood. Synchrotron micro-Fourier transform infrared (m-FTIR), Raman spectroscopy (RS), X-ray diffraction (XRD), and X-ray fluorescence (XRF) were applied for better characterization of wheat straw fibers during a continuous pretreatment process in terms of conditioning (C), extrusion (E), steam explosion (SE), and enzymatic hydrolysis (EH). m-FTIR revealed functional groups as phenylpropanoid polymers, ethers, and aliphatic alcohol. RS detected acetoacetate, methyl and phenol groups after SE. The crystallinity index and silica content were also determined.

Characterization of poly-hydroxybutyrate/luffa fibers composite material

“…Bands at 1592 cm -1 were indicative of the C=C stretching of the aromatic ring (NagarajaGanesh and Muralikannan 2016). Those at 1454 cm -1 could be attributed to C-H deformation stretching in either lignin or xylan molecules, the main component of hemicelluloses (Chen et al 2018;Molina-Guerrero et al 2018). At 1372 cm -1 , bands indicated C-H bending (Seki et al 2013), and at 1157 cm -1 bands corresponded to C-O-C ring vibrational stretching (Kesraoui et al 2016).…”

“…The O-H stretching vibrations for cellulose, hemicellulose, and lignin can be assigned at 3335 cm -1 (Chen et al 2017), while the peak at 2900 cm -1 corresponds to C-H stretching vibrations in both cellulose and hemicellulose (Fiore et al 2014;Chen et al 2017). The absorbance peaks at 1415 and 1033 cm -1 are attributed to O-H in-plane bending vibrations and C-O stretching vibrations, respectively (NagarajaGanesh and Muralikannan 2016; Molina-Guerrero et al 2018). The band at 895 cm -1 features the characteristic β-glycosidic linkage between anhydroglucose units (Oh et al 2005;Molina-Guerrero et al 2018).…”

“…The absorbance peaks at 1415 and 1033 cm -1 are attributed to O-H in-plane bending vibrations and C-O stretching vibrations, respectively (NagarajaGanesh and Muralikannan 2016; Molina-Guerrero et al 2018). The band at 895 cm -1 features the characteristic β-glycosidic linkage between anhydroglucose units (Oh et al 2005;Molina-Guerrero et al 2018). Lignin in fibers can be correlated with different bands.…”

Sustainable preparation of oxidized graphitic material from wheat straw using a deep eutectic solvent for superactivity of cellulase

“…of carboxylic acid) for the regenerated material suggests the oxidation of the hydroxyl groups of the components of native wheat straw. 44,45 Other bands between 1634 and 1600 cm −1 , which correspond to the aromatic skeletal vibrations of lignin, 46 shift to 1591 cm −1 in the regenerated material. Such a shift along with the high intensity of the band supports CvC to be a major group in the oxidized graphitic material.…”

Kinetic Parameter Determination for Depolymerization of Biomass by Inverse Modeling and Metaheuristics

“…Vegetal biomass (VB) is an alternative for biofuel production. VB is mainly composed of cellulose, hemicellulose, and lignin and can be transformed into different products through four fundamental stages: (i) conditioning, (ii) depolymerization or enzymatic hydrolysis, (iii) fermentation, and (iv) the downstream process [1,2]. In this context, the depolymerization stage is the most expensive, and predicting the reaction behavior is essential to achieve a higher reaction yield.…”