Chemical recycling of plastics

AccessScience ◽  
2019 ◽  
Keyword(s):  
Chemical Recycling

PENGGUNAAN AIR SUPER KRITIS PADA DEPOLIMERISASI NYLON-12 (BATCH PROCESS)

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Mohamad Yusman
Keyword(s):  
Supercritical Water ◽  
Scale Up ◽  
Experimental Studies ◽  
Reaction System ◽  
Batch Process ◽  
Chemical Recycling ◽  
Water Decomposition ◽  
Product Distributions ◽  
New Process ◽  
Nylon 12

Water at the supercritical state is a new process for the chemical recycling. At this thermodynamic state i.e. Pc = 218 atmospheres and Tc = 374oC , water behaves very differently from its everyday temperament and it is a very good solvent for organic components. Experimental studies show that supercritical water can decompose hydrocarbons/polymers and produce useful products like 2-Azacyclotridecanone /lactam-1 from Nylon-12 (batch process). The decomposition process itself was carried out in batch reaction system in order to get more information about product distributions, time dependence, and scale-up possibilities.Keywords: supercritical water, decomposition, batch, polymer, hydrocarbon

scholarly journals Organocatalyzed closed-loop chemical recycling of thermo-compressed films of poly(ethylene furanoate)

2021 ◽  
Author(s):  
Elena Gabirondo ◽  
Beatriz Melendez-Rodriguez ◽  
Carmen Arnal ◽  
Jose M. Lagaron ◽  
Antxon Martínez de Ilarduya ◽  
...  
Keyword(s):  
Closed Loop ◽  
Chemical Recycling ◽  
Thermally Stable ◽  
Poly Ethylene

Poly(ethylene furanoate) (PEF) films were first produced using thermo-compression. Thereafter, the chemical recyclability was demonstrated in the presence of a thermally stable organocatalyst followed by its repolymerization.

scholarly journals Chemical Recycling of WEEE Plastics—Production of High Purity Monocyclic Aromatic Chemicals

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 530
Author(s):  
Tobias Rieger ◽  
Jessen C. Oey ◽  
Volodymyr Palchyk ◽  
Alexander Hofmann ◽  
Matthias Franke ◽  
...  
Keyword(s):  
High Purity ◽  
Fractional Distillation ◽  
Gas Chromatography Mass Spectrometry ◽  
Thermochemical Conversion ◽  
Chemical Recycling ◽  
Pyrolysis Oil ◽  
X Ray ◽  
Benzene Toluene ◽  
Halogen Content ◽  
Methyl Styrene

More than 200 kg real waste electrical and electronic equipment (WEEE) shredder residues from a German dismantling plant were treated at 650 °C in a demonstration scale thermochemical conversion plant. The focus within this work was the generation, purification, and analysis of pyrolysis oil. Subsequent filtration and fractional distillation were combined to yield basic chemicals in high purity. By means of fractional distillation, pure monocyclic aromatic fractions containing benzene, toluene, ethylbenzene, and xylene (BTEX aromatics) as well as styrene and α-methyl styrene were isolated for chemical recycling. Mass balances were determined, and gas chromatography–mass spectrometry (GC-MS) as well as energy dispersive X-ray fluorescence (EDXRF) measurements provided data on the purity and halogen content of each fraction. This work shows that thermochemical conversion and the subsequent refining by fractional distillation is capable of recycling WEEE shredder residues, producing pure BTEX and other monocyclic aromatic fractions. A significant decrease of halogen content (up to 99%) was achieved with the applied methods.

scholarly journals Framework for the Life Cycle Assessment of non-permanent process units in volatile chemical recycling process chains

Procedia CIRP ◽  
2021 ◽  
Vol 98 ◽  
pp. 55-60
Author(s):  
Johanna Hagen ◽  
Selin Erkisi-Arici ◽  
Patrick de Wit ◽  
Felipe Cerdas ◽  
Christoph Herrmann
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Chemical Recycling ◽  
Recycling Process ◽  
Process Chains

scholarly journals Kinetical Study, Thermo-Mechanical Characteristics and Recyclability of Epoxidized Camelina Oil Cured with Antagonist Structure (Aliphatic/Aromatic) or Functionality (Acid/Amine) Hardeners

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2503
Author(s):  
Chiara Di Mauro ◽  
Aratz Genua ◽  
Alice Mija
Keyword(s):  
Disulfide Bonds ◽  
Mechanical Characteristics ◽  
Dicarboxylic Acids ◽  
Thermomechanical Properties ◽  
Chemical Recycling ◽  
Camelina Oil ◽  
Ft Ir ◽  
Tan Δ ◽  
The Individual ◽  
First Time

In an attempt to prepare sustainable epoxy thermosets, this study introduces for the first time the idea to use antagonist structures (aromatic/aliphatic) or functionalities (acid/amine) as hardeners to produce reprocessable resins based on epoxidized camelina oil (ECMO). Two kinds of mixtures were tested: one combines aromatic/aliphatic dicarboxylic acids: 2,2′-dithiodibenzoic acid (DTBA) and 3,3′-dithiodipropionic acid (DTDA); another is the combination of two aromatic structures with acid/amine functionality: DTBA and 4-aminophenyl disulfide (4-AFD). DSC and FT-IR analyses were used as methods to analyze the curing reaction of ECMO with the hardeners. It was found that the thermosets obtained with the dual crosslinked mechanism needed reduced curing temperatures and reprocessing protocols compared to the individual crosslinked thermosets. Thanks to the contribution of disulfide bonds in the network topology, the obtained thermosets showed recycling ability. The final thermomechanical properties of the virgin and mechanical reprocessed materials were analyzed by DMA and TGA. The obtained thermosets range from elastomeric to rigid materials. As an example, the ECMO/DTBA704-AFD30 virgin or reprocessed thermosets have tan δ values reaching 82–83 °C. The study also investigates the chemical recycling and the solvent resistance of these vitrimer-like materials.

scholarly journals Investigation into the color stripping of the pigment printed cotton fabric using the ozone assisted process: A study on the decolorization and characterization

2021 ◽  
Vol 16 ◽  
pp. 155892502199275
Author(s):  
Ajinkya Powar ◽  
Anne Perwuelz ◽  
Nemeshwaree Behary ◽  
Le vinh Hoang ◽  
Thierry Aussenac ◽  
...  
Keyword(s):  
Cotton Fabric ◽  
Photoelectron Spectroscopy ◽  
Treatment Time ◽  
Pilot Scale ◽  
Chemical Recycling ◽  
X Ray ◽  
Cellulosic Fibers ◽  
Dyeing Process ◽  
Cellulosic Textiles ◽  
Ozonation Process

Color stripping is one of the most convenient ways to rectify the various shade faults occurred during printing or dyeing process of textiles. But, the conventional chemical assisted process poses serious risk of the environmental pollution. Secondly, the chemical recycling of the cellulosic fibers may be disrupted due to the presence of the impurities like colorants, finishes, and the additives in the discarded textiles. So, there is a need to study ways to remove such impurities from the discarded cellulosic textiles in a sustainable manner. This work examines the decolorization of the pigment prints on cellulosic fabrics at pilot scale using an ozone-assisted process. The effect of varying pH, ozone concentration and the treatment time on the decolorization of the pigment prints was optimized using the response surface methodology technique. The effects of ozonation process parameters on the mechanical properties of cellulosic cotton fabric were measured. Decolorization of pigment printed samples was studied with respect to the surface effects by a scanning electron microscopy (SEM), and the chemical removal effects of ozonation treatment were studied using X-ray photoelectron spectroscopy. The possible mechanism regarding the action of ozone for the decolorization is discussed.

Wet-mechanical processing of a plastic-rich two-dimensional-fraction from mixed wastes for chemical recycling

2021 ◽  
pp. 0734242X2199643
Author(s):  
Möllnitz Selina ◽  
Bauer Markus ◽  
Schwabl Daniel ◽  
Sarc Renato
Keyword(s):  
Large Scale ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Process Water ◽  
Chemical Recycling ◽  
Mechanical Processing ◽  
Municipal Solid Wastes ◽  
Core Element ◽  
Metal Levels ◽  
Mixed Wastes

The recycling of source separated polyolefins (POs) (e.g., light weight packaging waste) is already state of the art. Therefore, further plastic materials contained in mixed wastes have become more important due to increasing legal pressure. Mixed commercial and municipal solid wastes contain large quantities of POs. These mixed wastes would usually be treated in waste incinerators or processed to refuse-derived fuel for cement plants. Large-scale experiments were conducted to assess the potential of such POs from these waste streams for recycling processes. The potential and applicability of a dry-mechanical and subsequently wet-mechanical (Wet-mechanical) processing with the aim of generating a PO concentrate for chemical recycling purposes was assessed. These investigations’ focus was put on the centrifugal force separator technology as the core element of Wet-mechanical processing. In addition to the input material, all output materials and process water streams were chemically and physically characterized to estimate potential treatment or recycling paths. Results demonstrate that a two-stage purification is necessary to produce POs with sufficient purity out of both wastes. Chlorine and heavy metal levels are simultaneously reduced. The increased quantity of impurities only slightly changes the density of the process waters. Process water analyses show that wastewater treatment is necessary before discharge into a receiving water or sewage treatment plant. The sediment does not fulfil any hazard-relevant properties, and different thermal treatment options are possible.

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