Analytical Pyrolysis

Wampler, Thomas P.

doi:10.1201/9781420017496.ch1

Cited by 26 publications

(33 citation statements)

References 49 publications

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“…The second step involves side group saturation leaving free radicals in the middle carbons of the polymer. The final step is chain termination by adding an R group as seen below ( Figure 4) [32]: The advantage of DC thermal plasma is the ease of operation, expected thermal efficiency of 90% and a possible disadvantage of small jet volume [31]. The thermal plasma used in this research work releases thermal energy as arc discharge [24].…”

Section: Ldpe Degradation Mechanismmentioning

confidence: 99%

DC Thermal Plasma Design and Utilization for the Low Density Polyethylene to Diesel Oil Pyrolysis Reaction

Aboughaly

Stoute

2017

Energies

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Abstract:The exponential increase of plastic production produces 100 million tonnes of waste plastics annually which could be converted into hydrocarbon fuels in a thermal cracking process called pyrolysis. In this research work, a direct current (DC) thermal plasma circuit is designed and used for conversion of low density polyethylene (LDPE) into diesel oil in a laboratory scale pyrolysis reactor. The experimental setup uses a 270 W DC thermal plasma at operating temperatures in the range of 625 • C to 860 • C for a low density polyethylene (LDPE) pyrolysis reaction at pressure = −0.95, temperature = 550 • C with τ = 30 min at a constant heating rate of 7.8 • C/min. The experimental setup consists of a vacuum pump, closed system vessel, direct current (DC) plasma circuit, and a k-type thermocouple placed a few millimeters from the reactant sample. The hydrocarbon products are condensed to diesel oil and analyzed using flame ionization detector (FID) gas chromatography. The analysis shows 87.5% diesel oil, 1,4-dichlorobenzene (Surr), benzene, ethylbenzene and traces of toluene and xylene. The direct current (DC) thermal plasma achieves 56.9 wt. % of diesel range oil (DRO), 37.8 wt. % gaseous products and minimal tar production. The direct current (DC) thermal plasma shows reliability, better temperature control, and high thermal performance as well as the ability to work for long operation periods.

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Section: Ldpe Degradation Mechanismmentioning

confidence: 99%

DC Thermal Plasma Design and Utilization for the Low Density Polyethylene to Diesel Oil Pyrolysis Reaction

Aboughaly

Stoute

2017

Energies

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“…Pyrolysis transforms a nonvolatile compound into a volatile degradation mixture by heat in the absence of oxygen and by the breaking of chemical bonds using thermal energy [54,55]. The ground biomass sample (particle sizes from mm to μm) is heated at temperatures from 400 to 1000°C, in the absence of oxygen, for 300 s to less than 0.5 s, producing charcoal (solid), bio-oil (liquid) and fuel gas products [56,57].…”

Section: Analytical Pyrolysismentioning

confidence: 99%

Compositional Variability of Lignin in Biomass

Lourenço¹,

Pereira²

2018

Lignin - Trends and Applications

100

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The objective of this chapter is to provide a concise overview of lignin composition and structure in different species and materials (wood, barks and nonwood plants). It includes a brief review on the lignin precursors and their polymerization as well as of the analytical tools used for lignin characterization from wet chemical to spectroscopic methods. Wood of gymnosperms is characterized by high lignin content (25-35%) and a HG-type of lignin with more guaiacyl (G) units and a small portion of p-hydroxyphenyl (H) units. Wood of angiosperms has a lignin content of 15-28%, with a GS-lignin having different proportions of syringyl (S) units. Nonwoody monocotyledon species have different lignin content (9-20%) and a HGS type of lignin, characterized by a high proportion of H units. Bark lignin content ranges from 13 to 43% and is of HGS-type with species-specific composition and different in the bark components, phloem and cork. Lignin composition and macromolecular structure are key issues to understand the properties of lignocellulosic materials and to design a lignin-based pathway within biomass biorefineries. The available information on lignin composition is still limited to a few species and plant components. This is certainly an area where more research is needed.

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“…During pyrolysis, the molecules are degraded by the breaking of chemical bonds through homolitic scissions with formation of free radicals that further react by recombination, rearrangements, or elimination of radicals and hydrogen [2]. Any radical is instable and will react as soon as possible with other radicals or molecules.…”

Section: Broad Features Of Pyrolysis Reactionsmentioning

confidence: 99%

“…Pyrolysis can be used to study complex molecular structures, covering wide and diversified fields: fibers and textiles, forensic materials, wood and paper, art materials, synthetic polymers [2]. Analytical pyrolysis presents some advantages over other chemical techniques to characterize lignocellulosic materials:…”

Section: Advantages and Disadvantages Of Analytical Pyrolysismentioning

confidence: 99%

“…Pyrolysis may be defined based on the occurring chemical reactions, e.g., "the transformation of a nonvolatile compound into a volatile degradation mixture by heat, in the absence of oxygen" [1] or "the breaking of chemical bonds using thermal energy" [2], as well as on its potential applications, e.g., "the basic thermochemical process for converting biomass to a more useful fuel" [3].…”

Section: Introductionmentioning

confidence: 99%

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Chemical Characterization of Lignocellulosic Materials by Analytical Pyrolysis

Lourenço¹,

Gominho²,

Pereira³

2019

Analytical Pyrolysis

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Analytical pyrolysis is used to chemically study complex molecular materials and is applied in a wide range of fields. Pyrolysis is a thermochemical process associated to the breaking of chemical bonds using thermal energy, transforming a nonvolatile compound into a volatile degradation mixture. This chapter refers to analytical pyrolysis of lignocellulosic materials, i.e., when pyrolysis is used for chemical characterization, applied to samples with small particle sizes, at 500-650°C, and with short residence times. The reactions that occur during pyrolysis of the structural components are discussed regarding the mechanisms and the pyrolysis products obtained from cellulose, hemicelluloses, and lignin. A compilation of data is made on the characterization of lignocellulosic materials using Py-GC/FID(MS) or Py-GC/MS as analytical tools including woods and barks of several species. The pyrogram profiles and important parameters on lignin chemical composition such as the H:G:S relation and the S/G ratio are summarized. Analytical pyrolysis is a versatile methodology that may be applied to characterize the lignin directly on the lignocellulosic material or after isolation from the cell wall matrix (e.g., as MWL or dioxane lignin) or from pulps or spent liquors. It is therefore an excellent tool to study lignin compositional variability in different materials and along various processing pathways.

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Analytical Pyrolysis

Cited by 26 publications

References 49 publications

DC Thermal Plasma Design and Utilization for the Low Density Polyethylene to Diesel Oil Pyrolysis Reaction

DC Thermal Plasma Design and Utilization for the Low Density Polyethylene to Diesel Oil Pyrolysis Reaction

Compositional Variability of Lignin in Biomass

Chemical Characterization of Lignocellulosic Materials by Analytical Pyrolysis

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