Pyrolysis of lignin and IR analysis of residues

Pasquali, Clara E. López; Herrera, H.

doi:10.1016/s0040-6031(97)00059-2

Cited by 99 publications

(58 citation statements)

References 3 publications

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“…This observation may be attributed to mass and heat transfer effects. Similar lower values of activation energy of lignin decomposition have been reported in the literature [41][42][43][44][45]. Similarly, the cellulose and extractives decompositions of NGS and NGL biomass obeyed the same reaction order of 5, whereas NGT followed 7 and 11 reaction orders for cellulose and extractives.…”

Section: Resultssupporting

confidence: 85%

Comprehensive Characterization of Napier Grass as a Feedstock for Thermochemical Conversion

et al. 2015

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Study on Napier grass leaf (NGL), stem (NGS) and leaf and stem (NGT) was carried out. Proximate, ultimate and structural analyses were evaluated. Functional groups and crystalline components in the biomass were examined. Pyrolysis study was conducted in a thermogravimetric analyzer under nitrogen atmosphere of 20 mL/min at constant heating rate of 10 K/min. The results reveal that Napier grass biomass has high volatile matter, higher heating value, high carbon content and lower ash, nitrogen and sulfur contents. Structural analysis shows that the biomass has considerable cellulose and lignin contents which are good candidates for good quality bio-oil production. From the pyrolysis study, degradation of extractives, hemicellulose, cellulose and lignin occurred at temperature around 478, 543, 600 and above 600 K, respectively. Kinetics of the process was evaluated using reaction order model. New equations that described the process were developed using the kinetic parameters and data compared with experimental data. The results of the models fit well to OPEN ACCESSEnergies 2015, 8 3404 the experimental data. The proposed models may be a reliable means for describing thermal decomposition of lignocellulosic biomass under nitrogen atmosphere at constant heating rate.

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Section: Resultssupporting

confidence: 85%

Comprehensive Characterization of Napier Grass as a Feedstock for Thermochemical Conversion

et al. 2015

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“…These two are characteristic bands for lignin compounds. Similar to a previous IR spectral study of lignin pyrolysis, 70 it was observed that the predominant intensities of syringyl and guaiacyl groups disappear first with an increase of pyrolysis temperature. This indicates that the mechanism of lignin pyrolysis initially includes the loss of ether linkages.…”

Section: Analysis Of Lignin Pyrolysis Productssupporting

confidence: 86%

Kinetics and reaction chemistry for slow pyrolysis of enzymatic hydrolysislignin and organosolv extracted lignin derived from maplewood

et al. 2012

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The kinetics and reaction chemistry for the pyrolysis of Maplewood lignin were investigated using both a pyroprobe reactor and a thermogravimetric analyser mass spectrometry (TGA-MS). Lignin residue after enzymatic hydrolysis and organosolv lignin derived from Maplewood were used to measure the kinetic behaviours of lignin pyrolysis and to analyse pyrolysis product distributions. The enzymatic lignin residue pyrolyzed at lower temperature than that of organosolv lignin. The differential thermogravimetric (DTG) peaks for pyrolysis of the enzymatic residue were more similar to the DTG peaks for pyrolysis of the original Maplewood than DTG of the organosolv lignin. The condensable liquid volatile products were collected from a Pyroprobe reactor with a liquid nitrogen trap. The primary monomeric phenolic compounds were guaiacol, syringol, and vanillic acid. However, only 14-36 carbon% of the sample could be detected by GC-MS. Over 60 carbon% of the condensable products were heavy tar molecules that are not detectable by GC-MS. These heavy tar molecules are the primary products from pyrolysis of lignin. Intermediate solid samples were also collected at various pyrolysis temperatures and characterized by elemental analysis, FT-IR, DP-MAS 13 C NMR, and TOC. The methoxy groups and ether linkages decreased and the non-protonated aromatic carbon-carbon bonds increased in the solid residues as the pyrolysis temperature increased. The carbon content of the initial lignin feed (derived from enzymatic hydrolysis) and the solid polyaromatics residue (obtained at 773 K) was 58 wt% and 74 wt% respectively. This polyaromatic residue contained about 69 wt% of the original lignin feed. The solid polyaromatics undergo further slow decomposition accompanied by a constant release of carbon dioxide as the pyrolysis reaction continues. The pyrolysis of the enzymatic lignin residue was modelled by two reactions in series. In the first pyrolysis step the lignin was decomposed with an apparent activation energy of 74 kJ mol -1 and a heat of reaction of -8,780 kJ kg -1 . The second pyrolysis step had an apparent activation energy of 110 kJ mol -1 and a heat of reaction of -2,819 kJ kg -1 . Lignin pyrolysis has lower activation energies and higher heats of reaction than cellulose pyrolysis.

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“…On the other hand, it is interesting to compare the activation energy obtained in this study with the values found in the literature. In this study the activation energy values for the Klason lignin were in the range of 158-166 kJ/mol, while the values found in the literature for the Klason lignin varied from 12.5-89 kJ/mol [16][17][18] . This great difference may be caused by erroneous assumptions of the first order reaction by other authors.…”

Section: Thermogravimetric Analysismentioning

confidence: 53%

Materials produced from plant biomass: part III: degradation kinetics and hydrogen bonding in lignin

Poletto

Zattera

2013

Mat. Res.

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In this study Klason lignins from Eucalyptus grandis (LEUG) and Pinus taeda (LPIT) were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using the Kissinger method. Thermogravimetric results showed that LPIT had higher thermal stability and also higher activation energy than LEUG. FTIR results showed that the average strength of intermolecular interactions and enthalpy of hydrogen bond formation among the phenolic groups are higher for LPIT than for LEUG. The results demonstrated that differences between thermal stability and degradation mechanisms might be associated with differences in hydrogen bonding in lignin.

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Pyrolysis of lignin and IR analysis of residues

Cited by 99 publications

References 3 publications

Comprehensive Characterization of Napier Grass as a Feedstock for Thermochemical Conversion

Comprehensive Characterization of Napier Grass as a Feedstock for Thermochemical Conversion

Kinetics and reaction chemistry for slow pyrolysis of enzymatic hydrolysislignin and organosolv extracted lignin derived from maplewood

Materials produced from plant biomass: part III: degradation kinetics and hydrogen bonding in lignin

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