Enzymes’ Power for Plastics Degradation

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(9), P. 5612 - 5701

Published: March 14, 2023

Plastics are everywhere in our modern way of living, and their production keeps increasing every year, causing major environmental concerns. Nowadays, the end-of-life management involves accumulation landfills, incineration, recycling to a lower extent. This ecological threat environment is inspiring alternative bio-based solutions for plastic waste treatment toward circular economy. Over past decade, considerable efforts have been made degrade commodity plastics using biocatalytic approaches. Here, we provide comprehensive review on recent advances enzyme-based biocatalysis design related processes recycle or upcycle plastics, including polyesters, polyamides, polyurethanes, polyolefins. We also discuss scope limitations, challenges, opportunities this field research. An important message from that polymer-assimilating enzymes very likely part solution reaching

Language: Английский

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Chemical upcycling of polyethylene, polypropylene, and mixtures to high-value surfactants

Science, Journal Year: 2023, Volume and Issue: 381(6658), P. 666 - 671

Published: Aug. 10, 2023

Conversion of plastic wastes to fatty acids is an attractive means supplement the sourcing these high-value, high-volume chemicals. We report a method for transforming polyethylene (PE) and polypropylene (PP) at ~80% conversion with number-average molar masses up ~700 670 daltons, respectively. The process applicable municipal PE PP their mixtures. Temperature-gradient thermolysis key controllably degrading into waxes inhibiting production small molecules. are upcycled by oxidation over manganese stearate subsequent processing. ꞵ-scission produces more olefin wax yields higher acid-number than does ꞵ-scission. further convert large-market-volume surfactants. Industrial-scale technoeconomic analysis suggests economic viability without need subsidies.

Language: Английский

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Dynamic crosslinking compatibilizes immiscible mixed plastics

Nature, Journal Year: 2023, Volume and Issue: 616(7958), P. 731 - 739

Published: April 26, 2023

Language: Английский

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Recyclable and (Bio)degradable Polyesters in a Circular Plastics Economy

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(7), P. 4393 - 4478

Published: March 22, 2024

Polyesters carrying polar main-chain ester linkages exhibit distinct material properties for diverse applications and thus play an important role in today's plastics economy. It is anticipated that they will even greater tomorrow's circular economy focuses on sustainability, thanks to the abundant availability of their biosourced building blocks presence bonds can be chemically or biologically cleaved demand by multiple methods bring about more desired end-of-life plastic waste management options. Because this potential promise, there have been intense research activities directed at addressing recycling, upcycling biodegradation existing legacy polyesters, designing biorenewable alternatives, redesigning future polyesters with intrinsic chemical recyclability tailored performance rival commodity are either petroleum based and/or hard recycle. This review captures these exciting recent developments outlines challenges opportunities. Case studies poly(lactic acid), poly(3-hydroxyalkanoate)s, poly(ethylene terephthalate), poly(butylene succinate), poly(butylene-adipate presented, emerging recyclable comprehensively reviewed.

Language: Английский

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Chemically circular, mechanically tough, and melt-processable polyhydroxyalkanoates

Science, Journal Year: 2023, Volume and Issue: 380(6640), P. 64 - 69

Published: April 6, 2023

Polyhydroxyalkanoates (PHAs) have attracted increasing interest as sustainable plastics because of their biorenewability and biodegradability in the ambient environment. However, current semicrystalline PHAs face three long-standing challenges to broad commercial implementation application: lack melt processability, mechanical brittleness, unrealized recyclability, last which is essential for achieving a circular economy. Here we report synthetic PHA platform that addresses origin thermal instability by eliminating α-hydrogens repeat units thus precluding facile cis-elimination during degradation. This simple α,α-disubstitution enhances stability so substantially become melt-processable. Synergistically, this structural modification also endows with toughness, intrinsic crystallinity, closed-loop chemical recyclability.

Language: Английский

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Highly Efficient Biomass Upgrading by a Ni−Cu Electrocatalyst Featuring Passivation of Water Oxidation Activity

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(37)

Published: July 24, 2023

Abstract Electricity‐driven organo‐oxidations have shown an increasing potential recently. However, oxygen evolution reaction (OER) is the primary competitive reaction, especially under high current densities, which leads to low Faradaic efficiency (FE) of product and catalyst detachment from electrode. Here, we report a bimetallic Ni−Cu electrocatalyst supported on Ni foam (Ni−Cu/NF) passivate OER process while oxidation 5‐hydroxymethylfurfural (HMF) significantly enhanced. A density 1000 mA cm −2 can be achieved at 1.50 V vs . reversible hydrogen electrode, both FE yield keep close 100 % over wide range potentials. Both experimental results theoretical calculations reveal that Cu doping impedes OH* deprotonation O* hereby greatly passivated. Those instructive provide new approach realizing highly efficient biomass upgrading by regulating activity.

Language: Английский

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Construction of microbial consortia for microbial degradation of complex compounds

Frontiers in Bioengineering and Biotechnology, Journal Year: 2022, Volume and Issue: 10

Published: Dec. 6, 2022

Increasingly complex synthetic environmental pollutants are prompting further research into bioremediation, which is one of the most economical and safest means restoration. From current research, using microbial consortia to degrade compounds more advantageous compared isolated bacteria, as former adaptable stable within growth environment can provide a suitable catalytic for each enzyme required by biodegradation pathway. With development biology gene-editing tools, artificial systems be designed efficient, stable, robust, they used produce high-value-added products with their strong degradation ability. Furthermore, shown promising in compounds. In this review, strategies constructing robust discussed. The advances also classified detailed, including plastics, petroleum, antibiotics, azo dyes, some present sewage. Thus, paper aims support helps those who focus on consortia.

Language: Английский

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Polystyrene Waste Thermochemical Hydrogenation to Ethylbenzene by a N-Bridged Co, Ni Dual-Atom Catalyst

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(29), P. 16218 - 16227

Published: July 12, 2023

Recycling waste plastics requires the degradation of into small molecules. However, various products are widely distributed using traditional methods depolymerizing polystyrene (PS) such as catalytic pyrolysis and hydrogenolysis. Here, we creatively report a N-bridged Co, Ni dual-atom (Co-N-Ni) catalyst for targeted conversion PS to ethylbenzene via pressurized tandem fixed-bed reactor where hydropyrolysis is coupled with downstream vapor-phase hydrotreatment. The Co-N-Ni achieves 95 wt % 92 yield, significantly superior corresponding single-atom catalysts, enables real plastics. Theoretical calculations experimental results demonstrate that d-band center metal atoms well regulated in catalyst. Co site activates C═C bond more easily, while spatially optimizes adsorption configuration styrene molecule due electronic interaction. This also shows excellent durability provides new direction plastic degradation.

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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Photoredox-Catalyzed Plastic Waste Conversion: Nonselective Degradation versus Selective Synthesis

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(6), P. 3575 - 3590

Published: Feb. 27, 2023

Plastic waste pollution is becoming one of the most pressing environmental crises due to large-scale production without satisfactory recycling schemes, especially with outbreak COVID-19 pandemic in recent years. Upcycling plastic into valuable chemicals powered by solar energy presents a substantially untapped opportunity turn treasure. In this review, fundamental principles from nonselective degradation selective synthesis are first clarified. Then, we aim outline representative advances photoredox-based catalytic conversion. Particular emphasis placed on valorization regarding versus synthesis. Finally, present challenges and individual insights for further exploration conversion domain. It anticipated that timely critical review would provide an instructive direction foresight plastics value-added chemical feedstocks, thus stimulating development circular sustainable economy coming decades.

Language: Английский

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