Real-time evolved gas analysis by FTIR method: an experimental study of cellulose pyrolysis

Li, S; Lyons-Hart, J; Banyasz, Joseph L.; Shafer, Kenneth H.

doi:10.1016/s0016-2361(01)00064-3

Cited by 208 publications

(137 citation statements)

References 27 publications

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“…In the second sub-stage, between 300 and 400 °C, the emitted compounds are mainly due to the pyrolysis of sisal cellulose: CO, CO 2 , H 2 O, glycol, formaldehyde, methanol, formic acid and ketone, assigned tentatively to 2-butanone, as well as hydroxyacetaldehyde which starts to be generated in the previous stage. The latter compound may appear as a product of decomposition of cellulose by a competitive route to the formation of levoglucosan, the main component of cellulose tar [60,67]. The low amount of hydroxyacetaldehyde emitted during the pyrolysis of sisal cellulose suggests a route of decomposition different from that of the microcrystalline cellulose studied in this work, in which this compound was not observed.…”

Section: Analysis Of the Gases Emitted By Hot-washed Sisal Fibermentioning

confidence: 65%

“…Furthermore, differently than in the case of the pure biopolymers, a triplet band centered at 858 cm -1 is observed during the decomposition of sisal, denoted by an asterisk in Fig. 6, which is assigned to hydroxyacetaldehyde, (OH)CH 2 C(O)H) [60]. It is known that the absorbance at a specific wavenumber is linearly dependent on the concentration of gas, so the changes in absorbance reflect the tendency of concentration variation of the different gas species, provided that the FTIR procedures are the same [35,42].…”

Section: Ftir Analysis Of Gases Evolvedmentioning

confidence: 88%

“…Nevertheless, CO 2 is mainly formed in the early stages of the pyrolysis of cellulose. Li et al [60] found that formaldehyde formation is favored by a lower purge flow and by longer residence times, which would explain its formation through secondary reactions. They explain that at high temperatures, near 550 °C, formaldehyde decomposes to generate CO and H 2 , which is consistent with the observation of Shen et al Various ketones have been proposed and detected at the primary decomposition and pyrolysis of cellulose.…”

Section: Ii) Cellulosementioning

confidence: 99%

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Comparison of thermal behavior of natural and hot-washed sisal fibers based on their main components: Cellulose, xylan and lignin. TG-FTIR analysis of volatile products

et al. 2014

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Abstract:This paper presents in a comprehensive way the thermal behavior of natural and hot-.washed sisal fibers, based on the fundamental components of lignocellulosic materials: cellulose, xylan and lignin. The research highlights the influence exerted on the thermal stability of sisal fibers by other constituents such as non-cellulosic polysaccharides (NCP) and mineral matter. Thermal changes were investigated by thermal X-ray diffraction (TXRD), analyzing the crystallinity index (%Ic) of cellulosic samples, and by simultaneous thermogravimetric and differential thermal analysis coupled with Fourier-transformed infrared spectrometry (TG/DTA-FTIR), which allowed to examine the evolution of the main volatile compounds evolved during the degradation under inert and oxidizing atmospheres. The work demonstrates the potential of this technique to elucidate different steps during the thermal decomposition of sisal, providing extensible results to other lignocellulosic fibers, through the analysis of the evolution of CO 2 , CO, H 2 O, CH 4 , acetic acid, formic acid, methanol, formaldehyde and 2-butanone, and comparing it with the volatile products from pyrolysis of the biomass components. The hydroxyacetaldehyde detected during pyrolysis of sisal is indicative of an alternative route to that of levoglucosan, generated during cellulose pyrolysis.Hot-washing at 75 ºC mostly extracts non-cellulosic components of low decomposition temperature, and reduces the range of temperature in which sisal decomposition occurs, causing a retard in the pyrolysis stage and increasing Tb NCP and Tb CEL , temperatures at the maximum mass loss rate of non-cellulosic polysaccharides and cellulose decompositions, respectively. However, enriching sisal fibers in cellulose produces a decrease of Tb CEL under an oxidizing atmosphere, and furthermore, a delay of the combustion process, displacing Tb COM to higher temperatures.The results and findings of the paper would help further understanding of thermal processes where agave fibers are involved, as the decomposition of their composites.

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Section: Analysis Of the Gases Emitted By Hot-washed Sisal Fibermentioning

confidence: 65%

Section: Ftir Analysis Of Gases Evolvedmentioning

confidence: 88%

Section: Ii) Cellulosementioning

confidence: 99%

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Comparison of thermal behavior of natural and hot-washed sisal fibers based on their main components: Cellulose, xylan and lignin. TG-FTIR analysis of volatile products

et al. 2014

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“…At approximately 400 °C, the ion current intensity of O2 reduced rapidly, and its emission was mostly complete at 450 °C. According to previous research (Li et al 2001), the prevalent mechanism of the O2 formation was mainly due to the elimination of O-acetyl groups that originally associated to the xylose units. As for methyl alcohols, it could be generated by the thermal decomposition of methoxyl groups during the pyrolysis (Jensen et al 1998).…”

Section: Fig 6 Ms Ion Intensity Curves During the Pyrolysis Of CC Umentioning

confidence: 89%

Research on the Thermo-Physical Properties of Corncob Residues as Gasification Feedstock and Assessment for Characterization of Corncob Ash from Gasification

Yao

Liang

2016

BioResources

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Harnessing energy from biomass is environmentally friendly because of the essentially zero net CO2 impact. As a common agricultural byproduct, corncobs are abundant in quantity. This study was carried out to examine the thermo-physical properties of corncobs and characterize the properties of corncob ash produced from gasification, in order to provide a basis for transforming it into value-added products. The results showed that the pyrolysis of corncobs followed a three-step, stepwise mechanism. Activation energies calculated by the Coats-Redfern method at heating rates of 5, 10, and 20 °C/min were 79.08, 76.73, and 75.78 kJ·mol -1 , respectively, implying that the corncobs could be decomposed easily at high heating rates. The emissions of CO, CO2, CH4, H2, H2O, and O2 during pyrolysis corresponded well with thermal curves. Corncob ash could be a good fertilizer because of its high contents of K, P, and Ca. The high SiO2 content makes the corncob ash suitable for ceramics and blended cement concrete. Sylvite (KCl) and quartz (SiO2) were the two major crystal phases in the corncob ash. Relatively large particles of unburnt carbon residues in the ash indicated that low-cost adsorbent could be developed from these carbon residues.

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“…Levoglucosan (1,6-anhydro-b-D-glucopyranose) is the primary product of cellulose pyrolysis; however, other anhydroglucoses (1,2-1,4-anhydro-glucose, 1,6-anhydroglucofuranose, and enones), furan, and furan derivatives are also produced [44,45] . Levoglucosan formation from cellulose pyrolysis is produced by the scission of the 1,4 glucosidic linkage in the cellulose, followed by intramolecular rearrangement of the monomer units [46] .…”

Section: Characterization Of Cellulose Acetatesmentioning

confidence: 99%

Thermal decomposition of mercerized linter cellulose and its acetates obtained from a homogeneous reaction

Morgado

Frollini

2011

Polímeros

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Abstract:Cellulose acetates with different degrees of substitution (DS, from 0.6 to 1.9) were prepared from previously mercerized linter cellulose, in a homogeneous medium, using N,N-dimethylacetamide/lithium chloride as a solvent system. The influence of different degrees of substitution on the properties of cellulose acetates was investigated using thermogravimetric analyses (TGA). Quantitative methods were applied to the thermogravimetric curves in order to determine the apparent activation energy (Ea) related to the thermal decomposition of untreated and mercerized celluloses and cellulose acetates. Ea values were calculated using Broido's method and considering dynamic conditions. Ea values of 158 and 187 kJ mol -1 were obtained for untreated and mercerized cellulose, respectively. A previous study showed that C6OH is the most reactive site for acetylation, probably due to the steric hindrance of C2 and C3. The C6OH takes part in the first step of cellulose decomposition, leading to the formation of levoglucosan and, when it is changed to C6OCOCH 3 , the results indicate that the mechanism of thermal decomposition changes to one with a lower Ea. A linear correlation between Ea and the DS of the acetates prepared in the present work was identified. Keywords: Linter cellulose, cellulose acetates, thermal decomposition. Decomposição Térmica de Celulose de Linter Mercerizado e seus Acetatos Obtidos a partir de Reação HomogêneaResumo: Acetatos de celulose com graus de substituição, GS, variando entre 0,6 e 1,9, foram preparados previamente a partir de celulose de linter mercerizado, em meio homogêneo, usando N,N-dimetilacetamida/cloreto de lítio como sistema de solvente. A influência de diferentes graus de substituição nas propriedades dos acetatos de celulose foi investigada usando a análise termogravimétrica (TGA). Métodos quantitativos foram aplicados nas curvas termogravimétricas obtidas a fim de determinar a energia de ativação aparente (Ea) relacionado à decomposição térmica de celulose não-tratada e mercerizada e acetatos de celulose. Valores de Ea foram calculados usando o método de Broido e considerando condições dinâmicas. Valores de Ea de 158 e 187 kJ mol -1 foram obtidos para a celulose não-tratada e mercerizada, respectivamente. Em trabalho anterior verificou-se que o C6OH é o sítio mais reativo na acetilação, provavelmente devido ao impedimento estérico de C2 e C3. O C6OH participa da primeira etapa de decomposição da celulose, levando à formação de levoglucosana e, quando se tem a substituição para C6OCOCH 3 , o resultado indica que o mecanismo de decomposição térmica muda para um com Ea menor. Uma correlação linear entre Ea e o GS dos acetatos preparados no presente trabalho foi identificada. Palavras-chave: Celulose de linter, acetatos de celulose, decomposição térmica.

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Real-time evolved gas analysis by FTIR method: an experimental study of cellulose pyrolysis

Cited by 208 publications

References 27 publications

Comparison of thermal behavior of natural and hot-washed sisal fibers based on their main components: Cellulose, xylan and lignin. TG-FTIR analysis of volatile products

Comparison of thermal behavior of natural and hot-washed sisal fibers based on their main components: Cellulose, xylan and lignin. TG-FTIR analysis of volatile products

Research on the Thermo-Physical Properties of Corncob Residues as Gasification Feedstock and Assessment for Characterization of Corncob Ash from Gasification

Thermal decomposition of mercerized linter cellulose and its acetates obtained from a homogeneous reaction

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