Challenges and opportunities of light olefin production via thermal and catalytic pyrolysis of end-of-life polyolefins: Towards full recyclability

Progress in Energy and Combustion Science, Journal Year: 2023, Volume and Issue: 96, P. 101046 - 101046

Published: Feb. 14, 2023

Is full recyclability of polyolefins via chemical recycling a dream, or can it become reality? The main problem in plastic waste is that its composition highly heterogeneous while sorting and purifying solutions to obtain mono-streams are complex require large investments, thereby hampering the economy scale. Ideally, novel processes designed have mixed wastes as input higher value products produced such C2–C4 olefins aromatics instead low oil. In this review we show directions how realize these objectives. Classical thermal pyrolysis offers some possibilities but requires very high temperatures exceeding 800 °C transform back into desired temperatures. Nevertheless, because robustness, polyolefinic currently intensively studied first industrial applications operated at medium temperature range maximize oil product. Catalytic still under development, ideal lab-scale conditions around 85 wt.% be when pure polyolefin feeds used. With improved catalyst design should possible get number further up without affecting stability. As yield light impacted by both process (reactor type, efficiency prior conversion, flexibility towards feed composition) experimental parameters (temperature, catalyst/feed ratio, contact mode, residence time, addition inert reactants) also improvements respect. To industrialize waste, short times (<1 s) crucial avoid secondary reactions by-products methane, coke, aromatics. Pyrolysis reactors according principles, downers, spouted fluidized bed, vortex reactors, envisaged result optimal yields olefins. However, coke formation seems inevitable reactor designs need sufficiently robust allow for in-situ removal. For future research will viability improve purification stream, optimize catalysts selectivity stability, suitable reactor. It innovations three areas eventually reaching 90 target.

Language: Английский

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Hydroformylation of pyrolysis oils to aldehydes and alcohols from polyolefin waste

Science, Journal Year: 2023, Volume and Issue: 381(6658), P. 660 - 666

Published: Aug. 10, 2023

Waste plastics are an abundant feedstock for the production of renewable chemicals. Pyrolysis waste produces pyrolysis oils with high concentrations olefins (>50 weight %). The traditional petrochemical industry uses several energy-intensive steps to produce from fossil feedstocks such as naphtha, natural gas, and crude oil. In this work, we demonstrate that oil can be used aldehydes through hydroformylation, taking advantage olefin functionality. These then reduced mono- dialcohols, oxidized dicarboxylic acids, or aminated diamines by using homogeneous heterogeneous catalysis. This route high-value oxygenated chemicals low-value postconsumer recycled polyethylene. We project produced could lower greenhouse gas emissions ~60% compared their petroleum feedstocks.

Language: Английский

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Depolymerization within a Circular Plastics System

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(5), P. 2617 - 2650

Published: Feb. 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.

Language: Английский

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Towards high-quality petrochemical feedstocks from mixed plastic packaging waste via advanced recycling: The past, present and future

Fuel Processing Technology, Journal Year: 2022, Volume and Issue: 238, P. 107474 - 107474

Published: Sept. 6, 2022

Language: Английский

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How much can chemical recycling contribute to plastic waste recycling in Europe? An assessment using material flow analysis modeling

Resources Conservation and Recycling, Journal Year: 2023, Volume and Issue: 192, P. 106916 - 106916

Published: Feb. 26, 2023

Plastic recycling rate in Europe is low, urging developments technology and strategies to increase circularity.Mechanical (MR) has been the reference for years, but near future chemical (CR) options are expected contribute improve plastic circularity.This study uses a material flow analysis (MFA) at European level provide quantitative estimates of contribution CR technologies recycling.Ten most used polymer types from five sectors selected.A status quo 2018 scenario modelled compared potential scenarios (in 2030) waste treatment, including one that only looks improved collection, sorting, MR four exploring options.The so-called 'missing plastics', i.e., generated currently not accounted statistics, considered scenarios.The MFA results by calculating circularity indicators namely end-of-life (EoL-RR), plastic-to-plastic rate, plasticto-chemicals plastic-to-fuels rate.The indicate optimistic EoL-RR 2030 73-80% (sum plastic-to-chemical rates, excluding plastic-to-fuel rate), which 41-46% MR, 15-38% 19-35% plastic-to-chemicals.The highest achievable estimated be 61% (46% 15% CR).In all scenarios, 3-6%.The also estimate recycled content availability 2030, suggest closed-loop processing plastics' will necessary achieve targets.

Language: Английский

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Techno-economic analysis and life cycle assessment for catalytic fast pyrolysis of mixed plastic waste

Energy & Environmental Science, Journal Year: 2023, Volume and Issue: 16(9), P. 3638 - 3653

Published: Jan. 1, 2023

This study analyzes catalytic fast pyrolysis as a conversion technology for mixed plastic waste, highlighting key economic and environmental drivers potential opportunities process improvements.

Language: Английский

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Chemical recycling of plastic waste to monomers: Effect of catalyst contact time, acidity and pore size on olefin recovery in ex-situ catalytic pyrolysis of polyolefin waste

Journal of Analytical and Applied Pyrolysis, Journal Year: 2023, Volume and Issue: 172, P. 106036 - 106036

Published: June 1, 2023

Language: Английский

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Thermal pyrolysis of waste versus virgin polyolefin feedstocks: The role of pressure, temperature and waste composition

Waste Management, Journal Year: 2023, Volume and Issue: 165, P. 108 - 118

Published: April 27, 2023

Language: Английский

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Chemical recycling of plastic waste for sustainable polymer manufacturing – A critical review

Journal of environmental chemical engineering, Journal Year: 2024, Volume and Issue: 12(2), P. 112323 - 112323

Published: Feb. 25, 2024

Language: Английский

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Technical and market substitutability of recycled materials: Calculating the environmental benefits of mechanical and chemical recycling of plastic packaging waste

Waste Management, Journal Year: 2022, Volume and Issue: 152, P. 69 - 79

Published: Aug. 19, 2022

Language: Английский

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