Mechanism study of wood lignin pyrolysis by using TG–FTIR analysis

Liu, Qian; Wang, Shurong; Zheng, Yun Wu; Luo, Zhongyang; Cen, Kefa

doi:10.1016/j.jaap.2008.03.007

Cited by 832 publications

(402 citation statements)

References 32 publications

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“…DRIFTS spectra of the pristine lignin (PKL) and lignin torrefied at 300°C for 1 hour using a heating rate of 3°C/min (TL). Peak assignments adapted from references [26,27]. .…”

Section: Discussionmentioning

confidence: 99%

“…2. Aliphatic C−H appears in the region 3000−2800 cm −1 , C=O groups produce a peak at 1700 cm −1 , aromatic rings produce peaks at around 1600, 1510, 1465 and 1430 cm −1 , syringyl groups produce a peak at 1370 cm −1 , guaiacyl groups produce a peak at 1270 cm −1 and C−O from methoxy groups appears at 1120−1050 cm −1 [26,27]. Torrefaction causes a reduction in all the peaks in the region 1600−900 cm −1 .…”

Section: Characterization Of Pristine and Torrefied Ligninsmentioning

confidence: 99%

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Evaluation of hydrochars from lignin hydrous pyrolysis to produce biocokes after carbonization

Castro-Dı́az

Uguna

Florentino

et al. 2017

Journal of Analytical and Applied Pyrolysis

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Hydrochars were obtained after hydrous pyrolysis of a pine Kraft lignin using different reaction conditions (temperature, water content and residence time) and the residues were characterized through a wide range of analytical techniques including high-temperature rheometry, solid-state 13 C nuclear magnetic resonance (NMR), thermal gravimetric analysis (TGA), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and field emission scanning electron microscopy (FE-SEM). The results indicated that an increase in reaction temperature, an increase in residence time or a decrease in water content reduces the amount of fluid material in the residue. The hydrous pyrolysis conditions studied were not able to increase the maturation of lignin, which would result in an increase in the resolidification temperature, but reduced the amount of mineral matter in the hydrochar produced. On the other hand, the hydrochars obtained from pristine lignin, torrefied lignin (300°C, 1 hour) and their 50:50 wt.%/wt.% blend at temperatures of 350°C after 6 hours using 30 ml of water had lower ash contents (<2 wt.%) than the parent lignin (2.5 wt.%) and a high rank good coking coal (10 wt.%). However, the reactivity of the resulting biocokes (>45%) is excessively high compared to that of the good coking coal (10%) and the microstrength of the biocokes (R 1 <1%) is much lower than that of the coal (R 1 =17%). These findings could be rationalized by the high total porosity (>39%) and high microporous surface areas (>400 m 2 /g) of the biocokes and high alkalinity index of the lignins (>27%) compared to those of the coke (27% and 145 m 2 /g) and coal (0.6%), respectively. Furthermore, the biocoke derived from the hydrous pyrolysed torrefied lignin did not agglomerate, which could not be explained by changes in the chemical properties of the material and requires further investigation.

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“…DRIFTS spectra of the pristine lignin (PKL) and lignin torrefied at 300°C for 1 hour using a heating rate of 3°C/min (TL). Peak assignments adapted from references [26,27]. .…”

Section: Discussionmentioning

confidence: 99%

Section: Characterization Of Pristine and Torrefied Ligninsmentioning

confidence: 99%

Evaluation of hydrochars from lignin hydrous pyrolysis to produce biocokes after carbonization

Castro-Dı́az

Uguna

Florentino

et al. 2017

Journal of Analytical and Applied Pyrolysis

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show abstract

“…Greater signals of ketones, aldehyde, and carboxyl C observed in FT-IR spectra are indicative of depolymerization products derived from lignin (35) and cellulose (36). Volatile compounds such as anhydrosugars, pyrans, and furans are typical transformation products (37)(38)(39).…”

Section: Transition Chars -Volatile Dissociation Products Forming Amomentioning

confidence: 99%

Dynamic Molecular Structure of Plant Biomass-Derived Black Carbon (Biochar)

Keiluweit

Nico

Johnson

et al. 2010

Environ. Sci. Technol.

2,430

124

1,222

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“…Várhegyi et al 53 reported relatively small activation energies of 34-65 kJ mol -1 for various milled wood lignins. Liu et al 54 developed a reaction model based on the two-step reaction pathway similar to the one proposed by current study (Fig. 8) In our work, TGA experiments were performed under both dynamic and constant temperature conditions to measure the kinetic behaviour of lignin pyrolysis.…”

Section: Kinetic Parameters and Heats Of Reaction For Lignin Pyrolysismentioning

confidence: 99%

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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Mechanism study of wood lignin pyrolysis by using TG–FTIR analysis

Cited by 832 publications

References 32 publications

Evaluation of hydrochars from lignin hydrous pyrolysis to produce biocokes after carbonization

Evaluation of hydrochars from lignin hydrous pyrolysis to produce biocokes after carbonization

Dynamic Molecular Structure of Plant Biomass-Derived Black Carbon (Biochar)

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

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