Designing a circular carbon and plastics economy for a sustainable future

Nature, Год журнала: 2024, Номер 626(7997), С. 45 - 57

Опубликована: Янв. 31, 2024

Язык: Английский

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Net-zero emissions chemical industry in a world of limited resources

One Earth, Год журнала: 2023, Номер 6(6), С. 682 - 704

Опубликована: Май 29, 2023

The chemical industry is responsible for about 5% of global CO2 emissions and key to achieving net-zero targets. Decarbonizing this industry, nevertheless, faces particular challenges given the widespread use carbon-rich raw materials, need high-temperature heat, complex value chains. Multiple technology routes are now available producing chemicals with based on biomass, recycling, carbon capture, utilization, storage. However, extent which these viable respect local availability energy natural resources remains unclear. In review, we compare by quantifying their energy, land, water requirements corresponding induced resource scarcity at country level further discuss technical environmental viability a industry. We find that will require location-specific integrated solutions combine circular approaches demand-side measures might result in reshaping trade.

Язык: Английский

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Life-cycle assessment to guide solutions for the triple planetary crisis

Nature Reviews Earth & Environment, Год журнала: 2023, Номер 4(7), С. 471 - 486

Опубликована: Июль 4, 2023

Язык: Английский

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Depolymerization within a Circular Plastics System

Chemical Reviews, Год журнала: 2024, Номер 124(5), С. 2617 - 2650

Опубликована: Фев. 22, 2024

The societal importance of plastics contrasts with the carelessness which they are disposed. Their superlative properties lead to economic and environmental efficiency, but linearity puts climate, human health, global ecosystems at risk. Recycling is fundamental transitioning this linear model into a more sustainable, circular economy. Among recycling technologies, chemical depolymerization offers route virgin quality recycled plastics, especially when valorizing complex waste streams poorly served by mechanical methods. However, exists in interlinked system end-of-life fates, complementarity each approach key environmental, economic, sustainability. This review explores recent progress made five commercial polymers: poly(ethylene terephthalate), polycarbonates, polyamides, aliphatic polyesters, polyurethanes. Attention paid not only catalytic technologies used enhance efficiencies also interrelationship other systemic constraints imposed Novel polymers, designed for depolymerization, concisely reviewed terms their underlying chemistry potential integration current plastic systems.

Язык: Английский

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Chemical Recycling of Commercial Poly(l-lactic acid) to l-Lactide Using a High-Performance Sn(II)/Alcohol Catalyst System

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(36), С. 19840 - 19848

Опубликована: Сен. 1, 2023

Poly(l-lactic acid) (PLLA) is a leading commercial polymer produced from biomass, showing useful properties for plastics and fiber applications; after use, it compostable. One area improvement postconsumer waste PLLA chemical recycling to monomer (CRM), i.e., the formation of l-lactide (l-LA) plastic. This process currently feasible at high reaction temperatures shows low catalytic activity accompanied, in some cases, by side reactions, including epimerization. Here, Sn(II) catalyst, applied with nonvolatile alcohol, enables highly efficient CRM yield l-LA excellent purity (92% yield, >99% theoretical max.). The depolymerization performed using neat films (160 °C) under nitrogen flow or vacuum. operates outstanding activity, achieving turnover frequencies which are up 3000× higher than previously catalysts loadings 6000× lower catalysts. catalyst system achieves TOF = 3000 h–1 0.01 mol % 1:10,000 catalyst:PLLA loading. plastic packaging (coffee cup lids) produces pure selectivity. new (Sn + alcohol) can itself be recycled four times different "batch degradations" maintains its productivity,

Язык: Английский

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Ending fossil-based growth: Confronting the political economy of petrochemical plastics

One Earth, Год журнала: 2023, Номер 6(6), С. 607 - 619

Опубликована: Июнь 1, 2023

The expanding petrochemical industry depends on fossil fuels both as feedstock and a source of energy is at the heart intertwined global crises relating to plastics, climate, toxic emissions. Addressing these requires uprooting deep-seated lock-ins that sustain plastics. This perspective identifies stand in way ambitious emission reductions ending plastic pollution. We emphasize addressing growing production consumption confronting political economy petrochemicals. put forward key elements needed address dual challenges moving away from unsustainable plastics drastically reducing emissions sector argue for attention links between which turn involves challenging entrenched power structures vested interests linked fossil-based economy. A critical step would be ensuring petrochemicals related upstream issues upcoming treaty.

Язык: Английский

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Synthesis and Deconstruction of Polyethylene-type Materials

Chemical Reviews, Год журнала: 2024, Номер 124(5), С. 2327 - 2351

Опубликована: Фев. 26, 2024

Polyethylene deconstruction to reusable smaller molecules is hindered by the chemical inertness of its hydrocarbon chains. Pyrolysis and related approaches commonly require high temperatures, are energy-intensive, yield mixtures multiple classes compounds. Selective cleavage reactions under mild conditions (

Язык: Английский

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Replacing Plastics with Alternatives Is Worse for Greenhouse Gas Emissions in Most Cases

Environmental Science & Technology, Год журнала: 2024, Номер 58(6), С. 2716 - 2727

Опубликована: Янв. 31, 2024

Plastics are controversial due to their production from fossil fuels, emissions during and disposal, potential toxicity, leakage the environment. In light of these concerns, calls use less plastic products move toward nonplastic alternatives common. However, often overlook environmental impacts alternative materials. This article examines greenhouse gas (GHG) emission impact versus alternatives. We assess 16 applications where plastics used across five key sectors: packaging, building construction, automotive, textiles, consumer durables. These sectors account for about 90% global volume. Our results show that in 15 a product incurs fewer GHG than applications, release 10% life cycle. Furthermore, some such as food no suitable exist. demonstrate care must be taken when formulating policies or interventions reduce so we do not inadvertently drive shift with higher emissions. For most products, increasing efficiency use, extending lifetime, boosting recycling rates, improving waste collection would more effective reducing

Язык: Английский

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High Molar Mass Polycarbonates as Closed-Loop Recyclable Thermoplastics

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(12), С. 8381 - 8393

Опубликована: Март 14, 2024

Using carbon dioxide (CO2) to make recyclable thermoplastics could reduce greenhouse gas emissions associated with polymer manufacturing. CO2/cyclic epoxide ring-opening copolymerization (ROCOP) allows for >30 wt % of the polycarbonate derive from CO2; so far, field has largely focused on oligocarbonates. In contrast, efficient catalysts high molar mass polycarbonates are underinvestigated, and resulting thermoplastic structure–property relationships, processing, recycling need be elucidated. This work describes a new organometallic Mg(II)Co(II) catalyst that combines productivity, low loading tolerance, highest polymerization control yield number average molecular weight (Mn) values 4 130 kg mol–1, narrow, monomodal distributions. It is used in ROCOP CO2 bicyclic epoxides produce series samples, each Mn > 100 poly(cyclohexene carbonate) (PCHC), poly(vinyl-cyclohexene (PvCHC), poly(ethyl-cyclohexene (PeCHC, by hydrogenation PvCHC), poly(cyclopentene (PCPC). All these materials amorphous thermoplastics, glass transition temperatures (85 < Tg 126 °C, differential scanning calorimetry) thermal stability (Td 260 °C). The cyclic ring substituents mediate materials' chain entanglements, viscosity, temperatures. Specifically, PCPC was found have 10× lower entanglement (Me)n 100× zero-shear viscosity compared those PCHC, showing potential as future thermoplastic. polymers fully recyclable, either reprocessing or using highly selective depolymerizations CO2. shows fastest depolymerization rates, achieving an activity 2500 h–1 >99% selectivity cyclopentene oxide

Язык: Английский

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Unlocking naphtha from polyolefins using Ni-based hydrocracking catalysts

Chemical Engineering Journal, Год журнала: 2024, Номер 487, С. 150468 - 150468

Опубликована: Март 15, 2024

Язык: Английский

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