Consumer Grade Polyethylene Recycling via Hydrogenolysis on Ultrafine Supported Ruthenium Nanoparticles DOI Creative Commons
Shibashish D. Jaydev, Antonio J. Martín, Marc‐Eduard Usteri

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 136(11)

Published: Dec. 18, 2023

Abstract Catalytic hydrogenolysis has the potential to convert high‐density polyethylene (HDPE), which comprises about 30 % of plastic waste, into valuable alkanes. Most investigations have focused on increasing activity for lab grade HDPEs displaying low molecular weight, with limited mechanistic understanding product distribution. No efficient catalyst is available consumer grades due their lower reactivity. This study targets HDPE used in bottle caps, a waste form generated globally at rate approximately one million units per hour. Ultrafine ruthenium particles (1 nm) supported titania (anatase) achieved up 80 conversion light alkanes (C 1 −C 45 ) under mild conditions (498 K, 20 bar H 2 , 4 h) and were reused three cycles. Small nanoparticles critical achieving relevant conversions, as sharply decreased particle size. Selectivity commonalities peculiarities across disclosed by reaction modelling approach applied products. Isomerization cedes backbone scission progresses. Within this trend, weight favor isomerization whilst high cleavage. Commercial caps obeyed trend activity, anticipating influence additives realistic processing. demonstrates effective provides selectivity patterns control.

Language: Английский

Green and efficient conversion of polypropylene wastes into Ni@CNTs hybrids and their application for fire resistant polycarbonate composites DOI

Junlin Zhu,

Zhaotian Ba,

Yuanmeng Lou

et al.

Journal of environmental chemical engineering, Journal Year: 2025, Volume and Issue: unknown, P. 116432 - 116432

Published: March 1, 2025

Language: Английский

Citations

0
Cross-Linked Polyolefins: Opportunities for Fostering Circularity Throughout the Materials Lifecycle DOI Creative Commons
Alison J. Shapiro, Paul J. Brigandi,

Maria Moubarak

et al.

ACS Applied Polymer Materials, Journal Year: 2024, Volume and Issue: 6(19), P. 11859 - 11876

Published: Sept. 20, 2024

Cross-linked polyolefins (XLPOs) constitute a significant portion of the plastics commercial market, with market size similar order magnitude to those polystyrene and polyethylene terephthalate. However, few aspects XLPO materials circularity have been examined relative thermoplastic polyolefins. The cross-linking imparts superior performance properties, such as impact strength, chemical electrical resistance, thermal stability vs analogues, but it also makes reprocessing XLPOs valuable products more challenging, cannot be molten. Thus, most are incinerated or landfilled at end first lifecycle, even though commonly collected relatively clean waste stream-providing unique opportunity for valorization. In this review, we discuss approaches improve throughout entire lifecycle by examining biobased feedstocks alternative olefinic monomer sources assessing both traditional mechanical advanced recycling methods based on industrial feasibility potential product value. We consider how advancing longevity can reduce environmental impacts costs recyclable-by-design strategies enable better end-of-life opportunities future generations materials. Throughout highlight routes that balance performance, circularity, scalability necessary impart economic viability an scale.

Language: Английский

Citations

2
Tandem Methanolysis and Catalytic Transfer Hydrogenolysis of Polyethylene Terephthalate to p‐Xylene over Cu/ZnZrOx Catalysts DOI Creative Commons
Ryan Helmer, Siddhesh S. Borkar,

Aojie Li

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 7, 2024

Abstract We demonstrate a novel approach of utilizing methanol (CH 3 OH) in dual role for (1) the methanolysis polyethylene terephthalate (PET) to form dimethyl (DMT) at near‐quantitative yields (~97 %) and (2) serving as an situ H 2 source catalytic transfer hydrogenolysis (CTH) DMT p‐xylene (PX, ~63 % 240 °C 16 h) on reducible ZnZrO x supported Cu catalyst (i.e., Cu/ZnZrO ). Pre‐ post‐reaction surface bulk characterization, along with density functional theory (DFT) computations, explicate metal‐support interface activating both CH OH facilitating lower free‐energy pathway dehydrogenation hydrogenolysis, compared redox‐neutral SiO support. Loading studies thermodynamic calculations showed that, under reaction conditions, gas phase, rather than liquid is critical CTH DMT. Interestingly, was also effective C−C bonds (compared C−O PET) waste polycarbonate (PC), largely forming xylenol (~38 methyl isopropyl anisole (~42 demonstrating versatility this toward valorizing wide range condensation polymers.

Language: Английский

Citations

2
Hydrogen-free upcycling of polyethylene waste to methylated aromatics over Ni/ZSM-5 under mild conditions DOI
Bingyan Sun, Haifeng Xu, Tan Li

et al.

Journal of Hazardous Materials, Journal Year: 2024, Volume and Issue: 482, P. 136564 - 136564

Published: Nov. 19, 2024

Language: Английский

Citations

2
Recent Progress in Polyolefin Plastic: Polyethylene and Polypropylene Transformation and Depolymerization Techniques DOI Creative Commons
Acácio S. de Souza, Patrícia Garcia Ferreira, Iva S. de Jesus

et al.

Molecules, Journal Year: 2024, Volume and Issue: 30(1), P. 87 - 87

Published: Dec. 29, 2024

This paper highlights the complexity and urgency of addressing plastic pollution, drawing attention to environmental challenges posed by improperly discarded plastics. Petroleum-based polymers, with their remarkable range physical properties, have revolutionized industries worldwide. Their versatility—from flexible rigid hydrophilic hydrophobic—has fueled an ever-growing demand. However, versatility has also contributed a massive global waste problem as plastics pervade virtually every ecosystem, from depths oceans most remote terrestrial landscapes. Plastic pollution manifests not just visible waste—such fishing nets, bottles, garbage bags—but microplastics, infiltrating food chains freshwater sources. crisis is exacerbated unsustainable linear model production consumption, which prioritizes convenience over long-term health. The mismanagement only pollutes ecosystems but releases greenhouse gases like carbon dioxide during degradation incineration, thereby complicating efforts achieve climate sustainability goals. Given that mechanical recycling addresses fraction macroplastics, innovative approaches are needed improve this process. Methods pyrolysis hydrogenolysis offer promising solutions enabling chemical transformation depolymerization into reusable materials or valuable feedstocks. These advanced methods can support circular economy reducing creating high-value products. In article, focus on underscores need move beyond traditional recycling. exemplify potential for science technology mitigate while aligning objectives. Recent advances in polyolefins recycling, breaking down at molecular level create feedstocks new products fuels. Pyrolysis produces oil syngas, applications renewable energy chemicals. some process include scalability, feedstock variety, standardization, well concerns about emissions. Companies Shell ExxonMobil investing heavily overcome these barriers efficiencies. By leveraging transformative strategies, we reimagine lifecycle address one pressing our time. review updates knowledge fields derived based recent works available literature, highlighting techniques used, types obtained, highest yields.

Language: Английский

Citations

2
Quantifying synergy for mixed end-scission and random-scission catalysts in polymer upcycling DOI
Ziqiu Chen,

Emmanuel Ejiogu,

Baron Peters

et al.

Reaction Chemistry & Engineering, Journal Year: 2023, Volume and Issue: 9(1), P. 139 - 147

Published: Sept. 26, 2023

Given sufficient end-scission catalyst, random scission causes a proliferation of new chain ends and thereby accelerates the overall depolymerization progress.

Language: Английский

Citations

6
Converting Waste Plastic to Liquid Organic Hydrogen Carriers DOI
Mahdokht Soltani, Julie E. Rorrer

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(51)

Published: Nov. 20, 2023

Abstract The accumulation of waste plastics in landfills and the environment, as well contribution manufacturing to global warming, call for development new technologies that would enable circularity synthetic polymers. Thus far, emerging approaches chemical recycling have largely focused on producing fuels, lubricants, and/or monomers. In a recent study, Junde Wei colleagues demonstrated catalytic system capable converting oxygen‐containing aromatic plastic into liquid organic hydrogen carriers (LOHCs), which can be used storage. authors utilized Ru−ReO x /SiO 2 materials with zeolite HZSM‐5 co‐catalyst direct hydrodeoxygenation (HDO) wastes yield cycloalkanes LOHCs theoretical capacity ≈5.74 wt % under mild reaction conditions. Subsequent efficiency stability tests cycloalkane dehydrogenation over Pt/Al O 3 validated HDO products serve generate H gas. Overall, their approach not only opens doors alleviating severe burden globally, but also offers way clean energy ease challenges associated storage transportation.

Language: Английский

Citations

4
Tandem methanolysis and catalytic transfer hydrogenolysis of polyethylene terephthalate to p-xylene over Cu/ZnZrOx catalysts DOI Creative Commons
Ryan Helmer, Siddhesh S. Borkar,

Aojie Li

et al.

Published: Aug. 28, 2024

We demonstrate a novel approach of utilizing methanol (CH3OH) for both the methanolysis polyethylene terephthalate (PET) to form dimethyl (DMT) at near-quantitative yields (~97%) and catalytic transfer hydrogenolysis (CTH) DMT p-xylene (PX, ~63% 240 °C 16 h) on reducible ZnZrOx supported Cu catalyst (i.e., Cu/ZnZrOx). Pre- post-reaction surface bulk characterization, along with density functional theory (DFT) computations, explicate role metal-support interface Cu/ZnZrOx in providing active sites activation CH3OH facilitating lower free-energy pathway dehydrogenation hydrogenolysis, compared redox-neutral SiO2 support. DFT calculations further reveal that rate-determining step CTH is cleavage C-O linkages –(C=O)-OR) DMT. Loading studies thermodynamic showed that, under reaction conditions, gas phase, rather than liquid critical Interestingly, was also effective C-C bonds (compared PET) waste polycarbonate (PC), largely forming xylenol (~38%) methyl isopropyl anisole (~42%) demonstrating versatility this toward valorizing wide range condensation polymers.

Language: Английский

Citations

1
Kinetic Models for Polymer Upcycling by Tag-and-Cut Strategies DOI

Emmanuel Ejiogu,

Baron Peters

Industrial & Engineering Chemistry Research, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 6, 2024

Population balances are natural frameworks for modeling chemical recycling processes plastics. In this paper, we develop coupled species and population balance equations to model a process that randomly cleaves polymers in two steps. A "tagging" reaction installs functional groups (e.g., double bonds) at random locations along the chains. The tagged segments become susceptible subsequent chain cutting reaction. We provide analytical solutions systems where tag cut steps occur concurrently they stages. apply dehydrogenation/olefin-metathesis system using gel permeation chromatography data [Arroyave et al. J. Am. Chem. Soc. 144, 23280–85 (2022)]. then compare depolymerization rates of concurrent those sequential/two-stage system. Assuming identical rate parameters regardless design, theoretically outperforms all two-stage tag-and-cut processes. However, avoids potential complications with catalyst compatibility allows residence times conditions (which influence parameters) be separately optimized

Language: Английский

Citations

1
Layered self-pillared zeolites convert polyethylene to gasoline DOI
Chris Torres, Julie E. Rorrer

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(6), P. 841 - 842

Published: May 28, 2024

Language: Английский

Citations

1