Comparative study on the pyrolysis of cellulose and its model compounds

Gao, Zixiang; Li, Ning; Chen, Mei; Yi, Weiming

doi:10.1016/j.fuproc.2019.04.038

Cited by 67 publications

(23 citation statements)

References 42 publications

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“…The basic component of insulating paper for oil-immersed transformers is cellulose, it is formed by D-glucose through β-1,4-glycosidic linkage (Gao et al 2019). The degree of polymerization of cellulose molecules is the number of glucose monomers, the degree of polymerization of the newly-running transformer insulation paper is between 1000 and 1200 (Wang et al 2019).…”

Section: Reaxff-md Simulation Detailsmentioning

confidence: 99%

WITHDRAWN: Microscopic Reaction Mechanism of Formic Acid Generated During Pyrolysis of Cellulosic Insulating Paper

Zheng

Yang

et al. 2021

Preprint

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Cellulosic insulating paper is the component part of the insulation in power transformers. Under thermal stress inside the transformer, cellulosic insulating paper degrades to generate formic acid that will dissolve in insulating oil. In addition, the generation of formic acid further accelerates the aging process of insulating paper. This study took cellulose molecule with DP of 2 that was composed of D-glucose as the research object, the ReaxFF reaction force field was used to simulate the high temperature thermal aging process of cellulose. This study obtained the main reaction pathways of cellulose pyrolysis to generate formic acid. During the pyrolysis process, the number of formic acid molecules presented short-term fluctuations, which was the phenomenon of disappearance and regeneration of formic acid molecules. The combined element tracing method obtained three pathways of cellulose pyrolysis to generate formic acid: 1) The ether group oxygen atom O5(O'5) and C1(C'1) form a carbonyl group to generate formic acid. 2) Dehydrogenation of the primary alcohol hydroxyl group and the attached C atom form a carbonyl group to generate formic acid. 3) Dehydrogenation of the secondary alcohol hydroxyl group and the attached C atom form a carbonyl group to generate formic acid. Statistics found that the generation of formic acid molecules mainly come from the first pathway. The pre-exponential factor and activation energy of the calculated pyrolysis model were consistent with the experimental results. This study designed the accelerated thermal aging experiment of oil-paper insulation. The silanization derivatization method was used to detect the formic acid generated by the aging of insulating paper, which further verified the feasibility of formic acid as an index for evaluating the aging of cellulosic insulating paper.

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Section: Reaxff-md Simulation Detailsmentioning

confidence: 99%

WITHDRAWN: Microscopic Reaction Mechanism of Formic Acid Generated During Pyrolysis of Cellulosic Insulating Paper

Zheng

Yang

et al. 2021

Preprint

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“…Cellulose is the main component of the insulation paper. In addition, cellobiose is the repeating unit of cellulose [21], and the DP of new insulation paper is between 1000 and 1200 [22]. However, it is impractical to model molecules with thousands of DPs directly.…”

Section: Model Constructionmentioning

confidence: 99%

A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

Zhang

et al. 2020

Energies

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Cellulosic insulation paper is usually used in oil-immersed transformer insulation systems. In this study, the molecular dynamics method based on reaction force field (ReaxFF) was used to simulate the pyrolysis process of a cellobiose molecular model. Through a series of ReaxFF- Molecular Dynamics (MD) simulations, the generation path of ethanol at the atomic level was studied. Because the molecular system has hydrogen bonding, force-bias Monte Carlo (fbMC) is mixed into ReaxFF to reduce the cost of calculation by reducing the sampled data. In order to ensure the reliability of the simulation, a model composed of 20 cellobioses and a model composed of 40 cellobioses were respectively established for repeated simulation in the range of 500–3000 K. The results show that insulating paper produced ethanol at extreme thermal fault, and the intermediate product of vinyl alcohol is the key to the aging process. It is also basically consistent with others’ previous experiment results. So it can provide an effective reference for the use of ethanol as an indicator to evaluate the aging condition of transformers.

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“…The initial pyrolysis temperature of CE was 305 C, while that of PS was 180 C. This indicated that the thermal stability of cellulose was higher than soluble polysaccharides. The stability of cellulose was ascribed to its stable crystalline structure and large molecular weight, [35][36][37] while the poor stability of soluble polysaccharides was due to its amorphous structure. The next stage ranging from 380 C to 1000 C was the carbonization stage of cellulose.…”

Section: Thermogravimetric Analysis Of Samplesmentioning

confidence: 99%

Co‐pyrolysis characteristics of polysaccharides‐cellulose and the co‐pyrolyzed compound distributions over two kinds of zeolite catalysts

et al. 2020

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Summary Co‐pyrolysis characteristics of soluble polysaccharides‐cellulose were investigated through thermogravimetric analysis (TGA), kinetic analysis, analytical pyrolyser coupled with gas chromatograph‐mass spectrometer (Py‐GC/MS) and subsequent density functional theory (DFT). Results from TGA and differential thermogravimetric analysis (DTG) analyses indicated that there were synergistic effects in the polysaccharides‐cellulose (PS‐CE) blends pyrolysis process. Surprisingly in co‐pyrolysis process from Py‐GC/MS analysis, the furans were suppressed, while the anhydrosugars were increased. The DFT calculation showed that free radicals pyrolyzed from soluble polysaccharides could suppress the ring‐opening reaction of D‐glucopyranose. The co‐pyrolyzed chemical compound distribution over the catalysts (MCM‐41, ZSM‐5 and their mixtures) was also detected through Py‐GC/MS analysis. Both the zeolites showed high selectivity for 5‐methyl‐2‐furaldehyde and 2‐furaldehyde. The two kinds of zeolites could induce the generation of furans but suppress the production of anhydrosugars, which was the opposite effect of the co‐pyrolysis of PS‐CE.

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Comparative study on the pyrolysis of cellulose and its model compounds

Cited by 67 publications

References 42 publications

WITHDRAWN: Microscopic Reaction Mechanism of Formic Acid Generated During Pyrolysis of Cellulosic Insulating Paper

WITHDRAWN: Microscopic Reaction Mechanism of Formic Acid Generated During Pyrolysis of Cellulosic Insulating Paper

A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

Co‐pyrolysis characteristics of polysaccharides‐cellulose and the co‐pyrolyzed compound distributions over two kinds of zeolite catalysts

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