Catalytic thermal decomposition of polyamides and polyurethanes mixed with acidic zeolites

Bozi, János; Blazsó, Marianne

doi:10.1016/j.jaap.2012.06.002

Cited by 19 publications

(8 citation statements)

References 24 publications

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“…With these TG data, kinetics analysis can be performed for inert and oxidative thermal degradation processes and will be discussed later. Similarly, Pannase et al [11] recently reported that for fresh nylon ropes, major degradation occurred in the temperature range of 673 to 793 K, and such observations can be also found in the other studies [9,10].…”

Section: Thermal Degradation Characteristics Of Nylon String Wastessupporting

confidence: 64%

“…It is well-known that pyrolysis and combustion are two effective methods to chemically converse plastic wastes into valuable substances for sustainable energy development [1,2]. To date, a number of attempts have been made to study pyrolysis and oxidative thermal degradations of nylon-6 and its wastes [3][4][5][6][7][8][9][10][11][12]. Principally, nylon-6 has been reported to thermally degrade into ε-caprolactam monomer through a chain end backbiting process or a ring transition state formed within polymer chains [3][4][5] and a yield as high as 83-85 wt.% of ε-caprolactam could be obtained [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Likewise, Kim et al [9] performed a pyrolysis study of teabag waste at 400 and 700 • C and reported that the highest caprolactam yield has turned to be 59.2 wt.%. In contrast, the pyrolysis product composition may become diverse when changing pyrolysis conditions [10,11]. Bozi and Blazsó [10] studied the effect of acidic Y zeolite catalyst on nylon-6 pyrolysis and reported that the pyrolysis product may become mainly dihydro-azepine isomers instead of ε-caprolactam via cis-elimination or intramolecular rearrangement of amide groups and more aromatics and light unsaturated hydrocarbons will be yielded when using greater amounts of zeolite.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, the pyrolysis product composition may become diverse when changing pyrolysis conditions [10,11]. Bozi and Blazsó [10] studied the effect of acidic Y zeolite catalyst on nylon-6 pyrolysis and reported that the pyrolysis product may become mainly dihydro-azepine isomers instead of ε-caprolactam via cis-elimination or intramolecular rearrangement of amide groups and more aromatics and light unsaturated hydrocarbons will be yielded when using greater amounts of zeolite. Interestingly, Pannase et al [11] reported that the condensed pyrolytic oil of fresh nylon-6 ropes, obtained at 823 K under 5 K/min and 873 K under 10 K/min and analyzed via Fourier transform infrared spectroscopy (FTIR), shows a high resemblance with conventional fuel such as diesel.…”

Section: Introductionmentioning

confidence: 99%

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Kinetic Analysis of Pyrolysis and Thermo-Oxidative Decomposition of Tennis String Nylon Wastes

Wan

Huang

2021

Materials

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Thermal degradation of nylon-6 tennis string nylon wastes in inert nitrogen and air atmospheres was investigated by means of multiple heating-rate thermogravimetric analyses. The results obtained under the heating rates of 5–20 K/min are compared in terms of degradation feature and specific temperature for two atmospheres. Using nonisothermal data, kinetic analysis was thoroughly conducted using various isoconversional model-free methods, including Starink, Madhusudanan–Krishnan–Ninan, Tang, Coats–Redfern, and Flynn–Wall–Ozawa methods. With these kinetic analysis methods, the activation energy over the entire degradation process was successfully calculated. By means of the model-fitting master-plots method, the first-order chemical reaction model was determined to be the most appropriate mechanism function for describing pyrolysis and oxidative thermal degradation of nylon-6 waste. Using kinetic parameters, satisfactory matching against experimental data resulted using the Coats–Redfern method for both cases. Furthermore, thermodynamic parameters such as changes in entropy, enthalpy, and Gibbs free energy during thermal degradation processes were evaluated.

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Section: Thermal Degradation Characteristics Of Nylon String Wastessupporting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Kinetic Analysis of Pyrolysis and Thermo-Oxidative Decomposition of Tennis String Nylon Wastes

Wan

Huang

2021

Materials

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“…Aliphatic hydrocarbons (both saturated and unsaturated) are the main products using lower pyrolysis temperatures (<600°C) [4][5][6][7][8][9]. The product yields and composition are affected also by the application of catalysts, which could increase the yield of volatiles (both gases and pyrolysis oils) [10][11][12][13][14]. It was demonstrated, that the structure of zeolites had a key role in relation to the product properties.…”

Section: Introductionmentioning

confidence: 99%

Fuels by Waste Plastics Using Activated Carbon, MCM-41, HZSM-5 and Their Mixture

Miskolczi

Williams

2016

MATEC Web of Conferences

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Abstract. Waste material was pyrolyzed in a horizontal tubular reactor at 530-540°C using different catalysts, such as activated carbon, MCM-41, HZSM-5 and their mixtures. Products were investigated by gas-chromatography, EDXRFS and standardized methods. Catalysts significantly affected the yields of volatiles; e.g. HZSM-5 catalyst increased especially the yield of gaseous hydrocarbons, while MCM-41 catalyst was responsible for increasing the pyrolysis oil yield. Synergistic effects were found using mixtures of different catalysts. Furthermore the catalysts modified the main carbon frame of the products. Pyrolysis oil obtained over HZSM-5 catalyst contained large amounts of aromatics, while MCM-41 catalyst mainly isomerized the carbon frame. Regarding contaminants it was concluded, that the sulphur content could be significantly decreased by activated carbon, however it had only a slight effect to the other properties of the products.

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Red Mud as a Potential Catalyst for Petrochemicals Production From Oxygenated Aromatic Plastic Wastes via Fast Pyrolysis

Pal,

Prabhudesai,

Mohanty

et al. 2024

ChemCatChem

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The increased rate of post‐use accumulation of the heteroatom‐containing plastic wastes like polyethylene terephthalate (PET), polycarbonate (PC) and polyurethane (PU) in the environment propels the research for effective and sustainable valorization. In this study, PET from bottle waste, PC from compact discs and PU from waste wind turbine blade were characterized and employed for fast pyrolysis experiments. Importantly, red mud (RM), a mixed oxide, rich in Fe, Al, Si, Na and Ca, was used as a catalyst for fast pyrolysis. The effects of temperature and feed‐to‐catalyst ratio on product yields were studied to elucidate the product formation mechanism. Benzoic acid and its derivatives, bisphenol‐A and oxygenated aromatics, and 4,4’‐methylenebisbenzamine were the major products obtained from the non‐catalytic fast pyrolysis of PET, PC and PU, respectively. The use of RM improved the yield of aromatic hydrocarbons from PET to 27.8 wt.% at 550°C, phenolics from PC to 46.6 wt.% at 550°C, and 4,4’‐methylenebisbenzamine to 34.9 wt.% at 650oC. The catalytic activity of RM is ascribed to the presence of active basic sites. The present study paves the path for the catalytic upcycling of challenging plastic wastes using industrial waste like RM as a sustainable catalyst from a circular economy viewpoint.

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Catalytic thermal decomposition of polyamides and polyurethanes mixed with acidic zeolites

Cited by 19 publications

References 24 publications

Kinetic Analysis of Pyrolysis and Thermo-Oxidative Decomposition of Tennis String Nylon Wastes

Kinetic Analysis of Pyrolysis and Thermo-Oxidative Decomposition of Tennis String Nylon Wastes

Fuels by Waste Plastics Using Activated Carbon, MCM-41, HZSM-5 and Their Mixture

Red Mud as a Potential Catalyst for Petrochemicals Production From Oxygenated Aromatic Plastic Wastes via Fast Pyrolysis

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