Characterization of liquefied wood residues from different liquefaction conditions

Abstract

ABSTRACT:The amount of wood residue is used as a measurement of the extent of wood liquefaction. Characterization of the residue from wood liquefaction provides a new approach to understand some fundamental aspects of the liquefaction reaction. Residues were characterized by wet chemical analyses, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The Klason lignin content of the residues decreased, while the holocellulose and a-cellulose contents increased as the phenol to wood ratio (P/W) increased. A peak at 1735 cm-', which was attributed to the ester carbony1 group in xylan, disappeared in the FTIR spectra of the residues from liquefied wood under a sealed reaction system, indicating significantly different effects of atmospheric versus sealed liquefaction. The crystallinity index of the residues was higher than that of the untreated wood particles and slightly increased with an increase in the P/W ratio. The SEM images of the residues showed that the fiber bundles were reduced to small-sized bundles or even single fibers as the P/W ratio increased from 1/1 to 3/1, which indicated that the lignin in the middle lamella had been dissolved prior to the cellulose during liquefaction. 63 2007 Wiley Periodicals, Inc.

Synthesis and Characterization of Phenol Formaldehyde Novolac Resin Derived from Liquefied Mountain Pine Beetle Infested Lodgepole Pine Barks

“…[34,35] The more intense peak at 1 215 cm À1 attributed to C-C, C-O, and C5 5O stretch indicated that more phenol-lignin complex in the residues from HCl catalyzed bark liquefaction than the residues from H 2 SO 4 catalyzed bark liquefaction, which was also consistent with the results that the residues from HCl catalyzed bark liquefaction had a higher lignin content. The peak at 1 168 cm À1 due to the C-H in-plane deformation in guaiacyl with a stronger intensity in the residues from HCl catalyzed bark liquefaction also supported that H 2 SO 4 can more effectively liquefy the lignin than HCl.…”

“…Lignin was reported as the most reactive components in phenol liquefaction and had the tendency to undergo secondary condensation reactions, while cellulose was reported as the most resistant components in phenol liquefaction. [3,9,10,[23][24][25]34] Early View Publication; these are NOT the final page numbers, use DOI for citation !! efficient to give a higher yield of liquefied bark than HCl catalyzed bark liquefaction.…”

Synthesis and Characterization of Composite Material Based on Modified Phenolic Resin

“…The resins and their fractions do not absorb at these frequencies. Therefore, the polycondensation reaction probably proceeds by addition across the C=C double bond and condensation across the aldehyde group [19][20]. Figure 1 shows the Differential Scanning Calorimetry (DSC) thermogram for phenolic oligomers.…”

Liquefaction behaviour of twelve tropical hardwood species in phenol

“…The characteristic peaks associated with lignin (1510 cm -1 , 1610 cm -1 , 1460 cm -1 and 1220 cm -1 ) have also shown marked reduction in the wood residues particularly obtained with 1:2 and 1:3 liquid ratios. Pan et al (2007) has also reported disappearance of peak at 1735 cm -1 , attributed to the ester carbonyl group in xylan, in the FTIR spectra of the residues from liquefied wood. They observed reduction in the Klason lignin content and increase holocellulose and α-cellulose contents as the phenol to wood ratio (P/W) increased.…”