Microwave-intensified catalytic upcycling of plastic waste into hydrogen and carbon nanotubes over self-dispersing bimetallic catalysts

Chemical Engineering Journal, Год журнала: 2024, Номер 483, С. 149270 - 149270

Опубликована: Фев. 3, 2024

Язык: Английский

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Highly selective upcycling of plastic mixture waste by microwave-assisted catalysis over Zn/b-ZnO

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Фев. 18, 2025

7 billion of 9.2 tons plastic produced becomes waste while conventional catalytic recycling methods are vulnerable with degraded performance and intensive energy input. Here, a hybrid Zn/b-ZnO catalyst, together the specially-designed microwave reaction system, has achieved fast upgrading under atmospheric pressure without using H2. Bifunctional ZnO acts as absorber substrate in-situ formed Zn clusters promote C-C bond cleavage nearly 100% upcycle landfilled mixtures into lubricant base oil precursors monomers. Unprecedented turnover number (250 gplastic g−1catalyst) depolymerisation long-time stability over 50 successive cycles have been demonstrated, 8-time higher efficiency compared catalysis, indicating this strategy is an economical approach to efficient upcycling plastics towards valuable products. Moreover, catalyst can tolerate high contaminates, even still be converted precursors, which never reported before. Traditional for often suffer from reduced demands. authors demonstrate highly rapid process depolymerizing monomers microwave-assisted catalysis mild conditions.

Язык: Английский

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Electrochemical Deconstruction of Waste Polyvinylidene Chloride (PVDC) to Value‐Added Products in Batch and Flow

Chemistry - A European Journal, Год журнала: 2025, Номер unknown

Опубликована: Янв. 22, 2025

Abstract Chlorinated polymers have made enormous contributions to materials science and are commercially produced on a large scale. These chlorinated could be recycled as chlorine sources efficiently produce valuable compounds owing their facile release of HCl. Although the thermal stability PVDC is low compared PVC, this can advantageous in terms easy fast dehydrochlorination. Herein, we report an efficient electrochemical chlorination using poly(vinylidene chloride) (PVDC) source that works undivided cell applies good number examples. This method commodity such waste PVDC‐PVC pharma blister film, PVDC‐PO multilayer food packaging, compression molded sheets Ixan (with heat stabilizer) with similar efficiency. Furthermore, also provides dechlorination up 98 %, leading unsaturated dechlorinated material. Converting into more stable compounds, harmful chlorine‐containing gases during incineration minimized. Additionally, not only restricted batch processes but electroflow process for electrosynthesis has been demonstrated.

Язык: Английский

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High-efficiency Ce-modified ZSM-5 nanosheets for waste plastic upgrading

Nano Research, Год журнала: 2024, Номер 17(6), С. 5645 - 5650

Опубликована: Март 7, 2024

Язык: Английский

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Metabolic and enzymatic engineering strategies for polyethylene terephthalate degradation and valorization

Reviews in Environmental Science and Bio/Technology, Год журнала: 2024, Номер 23(2), С. 351 - 383

Опубликована: Май 14, 2024

Abstract Polyethylene terephthalate (PET) is one of the most marketed aromatic polyesters in world with an annual demand 2022 approximately 29 million metric tons, expected to increase by 40% 2030. The escalating volume PET waste and current inadequacy recycling methods have led accumulation terrestrial ecosystem, thereby posing significant global health risks. pressing energy environmental issues associated underscore urgent need for “upcycling” technologies. These technologies aim transform reclaimed into higher-value products, addressing both concerns sustainability. Enzyme-mediated biocatalytic depolymerization has emerged as a potentially bio-sustainable method treating plastics. Numerous plastic-degrading enzymes been identified from microbial origins, advancements protein engineering employed modify enhance these enzymes. Microbial metabolic allows development modified chassis capable degrading substrates converting their derived monomers industrial relevant products. In this review, we describe several approaches aiming at enhancing performances PET-degrading present strategies adopted bio-upcycle high-value molecules.

Язык: Английский

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Sequential hydrothermal dechlorination and liquefaction of PVC

Energy Conversion and Management, Год журнала: 2024, Номер 304, С. 118228 - 118228

Опубликована: Фев. 23, 2024

Poly(vinyl chloride) (PVC) is globally the third most produced plastic, but recycling PVC waste through mechanical means difficult. Due to high presence of chlorine in PVC, it unsuitable for both pyrolysis and combustion. Consequently, there a need explore innovative methods harnessing its energy potential. Hydrothermal liquefaction (HTL) topic growing interest literature chemical plastic or conversion into liquid carriers. In this work an sequential hydrothermal processing strategy was tested oil production from PVC. at loadings (20 wt.%) first processed under subcritical conditions produce chlorine-free solid, which then liquefied supercritical conditions. Different temperatures were dechlorination stage, 300 °C 99% removed, while 94% carbon remained solid residue. The mechanism behind solid's formation investigated by assessing activation energies, with addition KOH as neutralizing agent (120 kJ/mol) without (186 kJ/mol). screened HTL stage (420–480 °C), maximum dechlorinated 47%, mass yield 10%. Overall, phase demonstrated potential technology producing material density. subsequent step partially valorized aromatic-rich phase.

Язык: Английский

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Understanding ceiling temperature as a predictive design parameter for circular polymers

Cell Reports Physical Science, Год журнала: 2024, Номер 5(4), С. 101910 - 101910

Опубликована: Апрель 1, 2024

The rise of polymeric materials marks a notable achievement the past century, yet challenges in recycling have led to their accumulation various environments. Efforts address this include advancements mechanical recycling, degradation processes, and chemical techniques, particularly monomer, which offers path toward circular economy for plastics. In perspective, we discuss how ceiling temperature (Tc) can be used as design parameter (closed-loop recyclable) polymers provide an overview typical experimental approaches deriving Tc, focusing on ΔHp ΔSp key parameters prediction. concept Tc is heavily embedded polymer literature provides simple but still useful way quickly ranking different terms relative thermodynamic stability versus monomer states. While bulk state intrinsic value desirable quantity, it infeasible many cases measure equilibrium states bulk; thus, researchers focused investigating solution, where there may dependencies solvent, concentration, or other factors, resulting family apparent values at each set conditions. We thus explore computational studies complement measurements Tc. To end, focus here advantages, obstacles, outlook establishment predictive calculate related circularity, namely ΔHp, ΔSp, ΔGp, values.

Язык: Английский

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In Situ Enhancive and Closed-Loop Chemical Recyclable High-Performance Aromatic Polyamides from Lignin-Derived Ferulic Acid

ACS Sustainable Chemistry & Engineering, Год журнала: 2025, Номер unknown

Опубликована: Янв. 4, 2025

The resource and environmental issues caused by discarded plastics make plastic recycling research increasingly urgent. Polyamide, one of the top five general engineering polymers, has yet to be thoroughly explored for its performance or mechanism, particularly aromatic polyamides. In this study, ferulic acid, a lignin derivative generated from bio sources, was used synthesize diacids photoresponsive polyamides that could recycled via dual processes had outstanding thermal mechanical properties. On hand, UV-induced cycloaddition reactions occurred in groups, allowing achieve enhancement materials UV enhancement. hydrolysis amide bonds under alkaline circumstances, on other conferred degradability acid-based addition, simple acidification filtration approach extracting beginning monomers degradation solutions developed, resulting closed-loop chemical This work enriches raw material library preparation high-performance biobased provides new ideas development recyclable

Язык: Английский

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Thermally Robust yet Deconstructable and Chemically Recyclable High‐Density Polyethylene (HDPE)‐Like Materials Based on Si−O Bonds

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(51)

Опубликована: Окт. 30, 2023

Polyethylene (PE) is the most widely produced synthetic polymer. By installing chemically cleavable bonds into backbone of PE, it possible to produce deconstructable PE derivatives; date, however, such designs have primarily relied on carbonyl- and olefin-related functional groups. Bifunctional silyl ethers (BSEs; SiR2 (OR'2 )) could expand scope mimics as they possess strong Si-O facile chemical tunability. Here, we report BSE-containing high-density polyethylene (HDPE)-like materials synthesized through a one-pot catalytic ring-opening metathesis polymerization (ROMP) hydrogenation sequence. The crystallinity these can be adjusted by varying BSE concentration or steric bulk Si-substituents, providing handles control thermomechanical properties. Two methods for recycling HDPE are introduced, including circular approach that leverages acid-catalyzed bond exchange with 1-propanol. Additionally, despite fact starting were chain-growth (ROMP), show recover molar mass dispersity recycled products using step-growth formation exchange, generating high molecular weight mechanical properties similar commercial HDPE.

Язык: Английский

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Characterization of PP and PE Waste Pyrolysis Oils by Ultrahigh-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Energy & Fuels, Год журнала: 2024, Номер 38(12), С. 11148 - 11160

Опубликована: Май 31, 2024

Increasing recycling rates of plastic waste is necessary to achieve a sustainable and climate-neutral chemical industry. For polyolefin waste, corresponding 60% via thermal pyrolysis the most promising process. However, hydrocarbon composition these oils differs from conventional fossil-based feedstocks as they are heavier more unsaturated. GC × GC-FID prevalent characterization method for analysis complex mixtures but fails discern heavy unsaturated, aromatic compounds. An up-and-coming technique fully characterize those analytically challenging fractions ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled with soft ionization techniques, such atmospheric pressure photoionization ionization. In this work, FT-ICR MS has been employed analyze both real PE PP postconsumer oils, which allowed provide additional insights into reaction pathways types. identifies hydrocarbons, up C85, discerns wide range polycyclic hydrocarbons seven rings. These hepta-aromatics were not found in PP, only revealed penta-aromatics; complies mechanism proposed literature. Moreover, polypropylene (PP) oil displayed clear signs depolymerization reactions occurring during pyrolysis, formation olefins diolefins. Here, identified heavier, highly whereas quantified saturated less unsaturated components. observations highlight added benefit combining data completely understand pathways.

Язык: Английский

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