scholarly journals Pyrolysis of Mixed Plastic Waste: I. Kinetic Study

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4912
Author(s):  
Ibrahim Dubdub ◽  
Mohammed Al-Yaari
Keyword(s):  
Polymer Blends ◽  
Model Fitting ◽  
Polymer Mixtures ◽  
Pure Polymer ◽  
Master Plot ◽  
Thermogravimetric Analyzer ◽  
Global Environmental ◽  
Plastic Wastes ◽  
Temperature Ranges ◽  
Recycling Techniques

Plastic wastes have become one of the biggest global environmental issues and thus recycling such massive quantities is targeted. Low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) are considered among the main types of plastic wastes. Since pyrolysis is one of the most promising recycling techniques, this work aims to build knowledge on the co-pyrolysis of mixed polymers using two model-fitting (Criado and Coats–Redfern) methods. Seventeen co-pyrolysis tests using a thermogravimetric analyzer (TGA) at 60 K/min for different mixed compositions of LDPE, HDPE, PP, and PS were conducted. It was observed that the pyrolysis of the pure polymer samples occurs at different temperature ranges in the following order: PS < PP < LDPE < HDPE. However, compared to pure polymer samples, the co-pyrolysis of all-polymer mixtures was delayed. In addition, the synergistic effect on the co-pyrolysis of polymer blends was reported. The Master plot of the Criado model was used to determine the most suitable reaction mechanism. Then, the Coats–Redfern model was used to efficiently obtain the kinetic parameters (R2 ≥ 97.83%) and the obtained values of the activation energy of different polymer blends were ranging from 104 to 260 kJ/mol. Furthermore, the most controlling reaction mechanisms were in the following orders: First order reaction (F1), Contracting sphere (R3), and then Contracting cylinder (R2).

Fractionated Pyrolysis of Biomass and its Components

2014 ◽  
Vol 535 ◽  
pp. 734-737 ◽  
Author(s):  
Qian Liu ◽  
De Kui Shen
Keyword(s):  
Weight Loss ◽  
Rice Straw ◽  
Total Weight Loss ◽  
Wood Biomass ◽  
Thermogravimetric Analyzer ◽  
Dominant Component ◽  
Temperature Ranges ◽  
Biomass Components ◽  
Main Components ◽  
Pyrolysis Of Biomass

Fractionated pyrolysis of biomass and its three main components (viz. hemicellulose, cellulose and lignin) was carried out on a thermogravimetric analyzer, which effectively separated the pyrolysis progress of different compositions. Three temperature ranges of 40-300 °C, 300-400 °C and 400-700 °C were presented with hemicellulose, cellulose and lignin as the dominant component, respectively. Fir contains much more cellulose and lignin than rice straw, and thus the weight loss in 300-400 °C is much higher, as 66.4% of the total weight loss. Rice straw contains more extractives and hemicellulose, resulting in higher mass loss in the early pyrolysis stage of 40-300 °C. The pyrolysis of biomass was predicted by hemicellulose, cellulose and lignin according to the additivity law, and the fractionated pyrolysis showed good performance in the prediction of volatile and residue yields of wood biomass. The interactions of biomass components were revealed to be unneglectable.

Life Cycle Assessment on the Effects of Parameter Setting in Direct Recycling Hot Press Forging of Aluminum

2018 ◽  
Vol 923 ◽  
pp. 143-148 ◽  
Author(s):  
Mohd Amri Lajis ◽  
Nur Kamilah Yusuf ◽  
Azlan Ahmad
Keyword(s):  
Solid State ◽  
Environmental Concern ◽  
Parameter Setting ◽  
Hot Press ◽  
Metallic Material ◽  
Forging Process ◽  
Global Environmental ◽  
The Subject ◽  
Metal Shaping ◽  
Recycling Techniques

Metallic material processing plays a significant role in terms of global environmental impact which contributes to the climate change phenomena that is a serious international environmental concern and the subject of much research and debate. Thus, energy-and resource-efficient strategies in the metal shaping technology domain need to be identified urgently. A frequent theme in the debates that surround waste and resources management is the extent to which the recycling of metallic materials offers genuine benefits to the environment. Solid state recycling techniques allow the manufacture of high density aluminum alloy parts directly from production scrap. In this paper the environmental impacts associated with ‘meltless’ scrap processing routes through hot press forging process with varying parameter has been studied. A comparative analysis has been performed, with different operating temperature and holding time of direct recycling hot press forging process AA6061 aluminum chip. The importance of an environmental performance analysis that included both parameter setting was discussed and highlighted throughout the paper. Finally, the application of the proposed parameter setup has resulted in the setting up of an eco-process. Indeed, LCA study on recycling (solid-state) are recommended as well it gives a noteworthy benefit to the environment and to fill the knowledge gap.

scholarly journals Statistical ecology comes of age

2014 ◽  
Vol 10 (12) ◽  
pp. 20140698 ◽  
Author(s):  
Olivier Gimenez ◽  
Stephen T. Buckland ◽  
Byron J. T. Morgan ◽  
Nicolas Bez ◽  
Sophie Bertrand ◽  
...  
Keyword(s):  
Global Environmental Change ◽  
Model Fitting ◽  
Process Models ◽  
Science Data ◽  
Ecological Processes ◽  
Research Perspectives ◽  
Current Trends ◽  
Global Environmental ◽  
Rigorous Framework ◽  
Statistical Ecology

The desire to predict the consequences of global environmental change has been the driver towards more realistic models embracing the variability and uncertainties inherent in ecology. Statistical ecology has gelled over the past decade as a discipline that moves away from describing patterns towards modelling the ecological processes that generate these patterns. Following the fourth International Statistical Ecology Conference (1–4 July 2014) in Montpellier, France, we analyse current trends in statistical ecology. Important advances in the analysis of individual movement, and in the modelling of population dynamics and species distributions, are made possible by the increasing use of hierarchical and hidden process models. Exciting research perspectives include the development of methods to interpret citizen science data and of efficient, flexible computational algorithms for model fitting. Statistical ecology has come of age: it now provides a general and mathematically rigorous framework linking ecological theory and empirical data.

Definition of terms related to polymer blends, composites, and multiphase polymeric materials (IUPAC Recommendations 2004)

2004 ◽  
Vol 76 (11) ◽  
pp. 1985-2007 ◽  
Author(s):  
W. J. Work ◽  
K. Horie ◽  
M. Hess ◽  
R. F. T. Stepto
Keyword(s):  
Chemical Composition ◽  
Polymer Blends ◽  
Molar Mass ◽  
Polymeric Materials ◽  
Continuous Phase ◽  
Multicomponent Mixtures ◽  
Polymer Mixtures ◽  
The Third ◽  
Phase Domain ◽  
Definition Of

The document defines the terms most commonly encountered in the field of polymer blends and composites. The scope has been limited to mixtures in which the components differ in chemical composition or molar mass and in which the continuous phase is polymeric. Incidental thermodynamic descriptions are mainly limited to binary mixtures although, in principle, they could be generalized to multicomponent mixtures.The document is organized into three sections. The first defines terms basic to the description of polymer mixtures. The second defines terms commonly encountered in descriptions of phase domain behavior of polymer mixtures. The third defines terms commonly encountered in the descriptions of the morphologies of phase-separated polymer mixtures.

Synthesis and Properties of Side Chain Azobenzene Liquid Crystalline Polymers

2013 ◽  
Vol 781-784 ◽  
pp. 436-439
Author(s):  
Dan Shu Yao ◽  
Jun He ◽  
Hai Yan Wang ◽  
Mei Tian ◽  
Xiao Zhi He ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Graft Polymerization ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Scanning Calorimetry ◽  
Crystalline Polymers ◽  
Chemical Structures ◽  
Thermogravimetric Analyzer ◽  
Temperature Ranges ◽  
Mesomorphic Properties

A series of new azobenzene side chain liquid crystalline polymers were synthesized by two different azo mesogen monomers, 4-((4-(ethoxycarbonyl) phenyl) diazenyl) phenyl 4-(allyloxy) benzoate (M1) and (4-((4-(ethoxycarbonyl) phenyl) diazenyl) phenoxy) methyl acetyl 4-(allyloxy) benzoate (M2). All polymers (P1~P8) were synthesized by graft polymerization using polymethyl hydrosiloxane as backbone. Their chemical structures were confirmed by FTIR and 1HNMR spectra. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and thermogravimetric analyzer (TG) measurements. The results showed that P1~P8 exhibited thermotropic liquid crystalline properties and revealed nematic thread texture with wide mesophase temperature ranges. The temperatures when 5% weight loss occurred were higher than 305°C, which declared that the synthesized azobenzene liquid crystalline polymers had a high thermal stability.

scholarly journals Recycling techniques of polyolefins from plastic wastes

2013 ◽  
Vol 10 (1) ◽  
pp. 114-122 ◽  
Keyword(s):  
Liquid Fraction ◽  
Fixed Bed ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Major Type ◽  
Mechanical Recycling ◽  
Experimental Conditions ◽  
Waste Products ◽  
Plastic Wastes ◽  
Recycling Techniques

Disposing of plastic wastes to landfill is becoming undesirable due to legislation pressures, rising costs and the poor biodegradability of commonly used polymers. In addition, incineration meets with strong societal opposition. Therefore, recycling either mechanical or chemical, seems to be the only route of plastic wastes management towards sustainability. Polyolefins, mainly polyethylene (LDPE or HDPE) and polypropylene (PP) are a major type of thermoplastic used throughout the world in a wide variety of applications. In Western Europe alone approximately 22 million tones of these polymers are consumed each year, representing an amount of 56% of the total thermoplastics. In the present investigation the recycling of LDPE, HDPE and PP was examined using two different methods: the dissolution/reprecipitation and pyrolysis. The first belongs to the mechanical recycling techniques while the second to the chemical/feedstock recycling. During the first technique the polymer can be separated and recycled using a solvent/non-solvent system. For this purpose different solvents/non-solvents were examined at different weight percent amounts and temperatures using either model polymers as raw material or commercial waste products (packaging film, bags, pipes and food retail products). At all different experimental conditions and for all samples examined the polymer recovery was always greater than 90%. The quality of the recycled polymer was examined using FTIR and DSC. Furthermore, pyrolysis of LDPE, HDPE and PP was investigated with or without the use of an acid FCC catalyst. Experiments were carried out in a laboratory fixed bed reactor. The gaseous product was analyzed using GC, while the liquid with GC-MS. A small gaseous and a large liquid fraction were obtained from all polymers. Analysis of the derived gases and oils showed that pyrolysis products were hydrocarbons consisting of a series of alkanes and alkenes, with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels.

Intramolecular Screening Effects in Polymer Mixtures. 1. Hydrogen-Bonded Polymer Blends

1997 ◽  
Vol 30 (4) ◽  
pp. 932-942 ◽  
Author(s):  
P. C. Painter ◽  
B. Veytsman ◽  
S. Kumar ◽  
S. Shenoy ◽  
J. F. Graf ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Polymer Mixtures ◽  
Hydrogen Bonded

Thermo-catalytic degradation of different consumer plastic wastes by zeolite a catalyst: A kinetic approach

2020 ◽  
pp. 147776062097240
Author(s):  
Sthitapragyan Patnaik ◽  
Aruna Kumar Barick ◽  
Achyut K Panda
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Research Work ◽  
Model Fitting ◽  
Catalytic Decomposition ◽  
Kinetic Approach ◽  
Zeolite A ◽  
Thermal Degradation Behavior ◽  
Plastic Wastes ◽  
One Step

This research work includes the effect of Zeolite-A catalyst on the thermal degradation behavior of six different consumer plastic wastes like high density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET), polymethylene methacralate (PMMA), polystyrene (PS) and polytetrafluoro ethylene (PTFE) through kinetic approach by using thermogravimetric analysis (TGA) data. Kinetic parameters such as reaction order, activation energy, and Arrhenius constant for the degradation of different waste plastics is determined using model fitting Coats–Redfern method. All the plastics show one-step degradation in the temperature range of 300–600°C. There is a significant decrease in activation energy (Ea) for the thermo-catalytic decomposition of the plastics in presence of Zeolite A catalyst. The extent of catalytic effect is found different for different plastics in the order of HDPE < PP < PS < PET < PMMA < PTFE. The order of the thermal degradation reaction is also found different for different types of plastics. The order of the reaction is altered in case of PET, PS and PTFE in presence of the catalyst but it is unaffected in case of remaining plastics. This treatment would reduce the energy consumption of pyrolysis process and also make the process economical viable.

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