1
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Anh Nguyen TK, Trần-Phú T, Daiyan R, Minh Chau Ta X, Amal R, Tricoli A. From Plastic Waste to Green Hydrogen and Valuable Chemicals Using Sunlight and Water. Angew Chem Int Ed Engl 2024; 63:e202401746. [PMID: 38757221 DOI: 10.1002/anie.202401746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/15/2024] [Accepted: 05/15/2024] [Indexed: 05/18/2024]
Abstract
Over 79 % of 6.3 billion tonnes of plastics produced from 1950 to 2015 have been disposed in landfills or found their way to the oceans, where they will reside for up to hundreds of years before being decomposed bringing upon significant dangers to our health and ecosystems. Plastic photoreforming offers an appealing alternative by using solar energy and water to transform plastic waste into value-added chemical commodities, while simultaneously producing green hydrogen via the hydrogen evolution reaction. This review aims to provide an overview of the underlying principles of emerging plastic photoreforming technologies, highlight the challenges associated with experimental protocols and performance assessments, discuss recent global breakthroughs on the photoreforming of plastics, and propose perspectives for future research. A critical assessment of current plastic photoreforming studies shows a lack of standardised conditions, hindering comparison amongst photocatalyst performance. Guidelines to establish a more accurate evaluation of materials and systems are proposed, with the aim to facilitate the translation of promising fundamental discovery in photocatalysts design.
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Affiliation(s)
- Thi Kim Anh Nguyen
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW 2006, Australia
| | - Thành Trần-Phú
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW 2006, Australia
- Present address: Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Rahman Daiyan
- Particles and Catalysis Research Laboratory, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Xuan Minh Chau Ta
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW 2006, Australia
| | - Rose Amal
- Particles and Catalysis Research Laboratory, School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Antonio Tricoli
- Nanotechnology Research Laboratory, Faculty of Engineering, University of Sydney, Sydney, NSW 2006, Australia
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2
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Li A, Wu L, Cui H, Song Y, Zhang X, Li X. Unlocking a Sustainable Future for Plastics: A Chemical-Enzymatic Pathway for Efficient Conversion of Mixed Waste to MHET and Energy-Saving PET Recycling. CHEMSUSCHEM 2024; 17:e202301612. [PMID: 38385577 DOI: 10.1002/cssc.202301612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 02/23/2024]
Abstract
The heterogeneous monomers obtained from plastic waste degradation are unfavorable for PET recondensation and high-value derivative synthesis. Herein, we developed an efficient chemical-enzymatic approach to convert mixed plastic wastes into homogeneous mono-2-hydroxyethyl terephthalate (MHET) without downstream purification, benefiting from three discovered BHETases (KbEst, KbHyd, and BrevEst) in nature. Towards the mixed plastic waste, integrating the chemical K2CO3-driven glycolysis process with the BHETase depolymerization technique resulted in an MHET yield of up to 98.26 % in 40 h. Remarkably, BrevEst accomplished the highest BHET hydrolysis (~87 % efficiency in 12 h) for yielding analytical-grade MHET compared to seven state-of-the-art PET hydrolases (18 %-40 %). In an investigation combining quantum theoretical computations and experimental validations, we established a MHET-initiated PET repolymerization pathway. This shortcut approach with MHET promises to strengthen the valorization of mixed plastics, offering a substantially more efficient and energy-saving route for PET recycling.
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Affiliation(s)
- Anni Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210009, People's Republic of China
| | - Luxuan Wu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210009, People's Republic of China
| | - Haiyang Cui
- School of Life Sciences, Nanjing Normal University, Nanjing, People's Republic of China
| | - Yibo Song
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210009, People's Republic of China
| | - Xing Zhang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210009, People's Republic of China
| | - Xiujuan Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210009, People's Republic of China
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3
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Ji L, Meng J, Li C, Wang M, Jiang X. From Polyester Plastics to Diverse Monomers via Low-Energy Upcycling. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2403002. [PMID: 38626364 PMCID: PMC11220695 DOI: 10.1002/advs.202403002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 03/31/2024] [Indexed: 04/18/2024]
Abstract
Polyester plastics, constituting over 10% of the total plastic production, are widely used in packaging, fiber, single-use beverage bottles, etc. However, their current depolymerization processes face challenges such as non-broad spectrum recyclability, lack of diversified high-value-added depolymerization products, and crucially high energy consumption. Herein, an efficient strategy is developed for dismantling the compact structure of polyester plastics to achieve diverse monomer recovery. Polyester plastics undergo swelling and decrystallization with a low depolymerization energy barrier via synergistic effects of polyfluorine/hydrogen bonding, which is further demonstrated via density functional theory calculations. The swelling process is elucidated through scanning electron microscopy analysis. Obvious destruction of the crystalline region is demonstrated through X-ray crystal diffractometry curves. PET undergoes different aminolysis efficiently, yielding nine corresponding high-value-added monomers via low-energy upcycling. Furthermore, four types of polyester plastics and five types of blended polyester plastics are closed-loop recycled, affording diverse monomers with exceeding 90% yields. Kilogram-scale depolymerization of real polyethylene terephthalate (PET) waste plastics is successfully achieved with a 96% yield.
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Affiliation(s)
- Lei Ji
- State Key Laboratory of Molecular & Process EngineeringSchool of Chemistry and Molecular EngineeringEast China Normal UniversityNorth Zhongshan Road 3663Shanghai200062China
| | - Jiaolong Meng
- State Key Laboratory of Molecular & Process EngineeringSchool of Chemistry and Molecular EngineeringEast China Normal UniversityNorth Zhongshan Road 3663Shanghai200062China
| | - Chengliang Li
- State Key Laboratory of Molecular & Process EngineeringSchool of Chemistry and Molecular EngineeringEast China Normal UniversityNorth Zhongshan Road 3663Shanghai200062China
| | - Ming Wang
- State Key Laboratory of Molecular & Process EngineeringSchool of Chemistry and Molecular EngineeringEast China Normal UniversityNorth Zhongshan Road 3663Shanghai200062China
| | - Xuefeng Jiang
- State Key Laboratory of Molecular & Process EngineeringSchool of Chemistry and Molecular EngineeringEast China Normal UniversityNorth Zhongshan Road 3663Shanghai200062China
- School of Chemistry and Chemical EngineeringHenan Normal UniversityXinxiangHenan453007China
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4
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Nordahl SL, Scown CD. Recommendations for life-cycle assessment of recyclable plastics in a circular economy. Chem Sci 2024; 15:9397-9407. [PMID: 38939149 PMCID: PMC11206198 DOI: 10.1039/d4sc01340a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/21/2024] [Indexed: 06/29/2024] Open
Abstract
Technologies that enable plastic circularity offer a path to reducing waste generation, improving environmental quality, and reducing reliance on fossil feedstocks. However, life-cycle assessment (LCA) methods commonly applied to these systems fall far short of capturing the full suite of advantages and tradeoffs. This perspective highlights inconsistencies in both the research questions and methodological choices across the growing body of LCA literature for plastics recycling. We assert that conducting LCAs on the basis of tonnes of waste managed vs. tonnes of recycled plastics yields results with fundamentally different conclusions; in most cases, analyses of recyclable plastics should focus on the unit of recycled product yielded. We also offer straightforward paths to better approach LCAs for recycling processes and plastics in a circular economy by rethinking study design (metrics, functional unit, system boundaries, counterfactual scenarios), upstream assumptions (waste feedstock variability, pre-processing requirements), and downstream assumptions (closed-loop vs. open-loop systems, material substitution). Specifically, we recommend expanding to metrics beyond greenhouse gases by including fossil carbon balances, net diversion of waste from landfill, and quantity of avoided plastic waste leakage to the environment. Furthermore, we highlight the role that plastic waste plays as a problematic contaminant in preventing greater diversion of all wastes to recycling, energy recovery, and composting, suggesting that plastics may hold a shared responsibility for the system-wide greenhouse gas emissions that occur when mixed wastes are landfilled.
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Affiliation(s)
- Sarah L Nordahl
- Energy Technologies Area, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
| | - Corinne D Scown
- Energy Technologies Area, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
- Joint BioEnergy Institute 5885 Hollis Street Emeryville CA 94608 USA
- Biosciences Area, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
- Energy & Biosciences Institute, University of California Berkeley CA 94720 USA
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5
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Qu M, Guo Y, Cai Y, Nie Z, Zhang C. Upgrading Polyolefin Plastic Waste into Multifunctional Porous Graphene using Silicone-Assisted Direct Laser Writing. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2310273. [PMID: 38794868 DOI: 10.1002/smll.202310273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 05/07/2024] [Indexed: 05/26/2024]
Abstract
The widespread use of plastics, especially polyolefin including polyethylene and polypropylene, has led to severe environmental crises. Chemical recycling, a promising solution for extracting value from plastic waste, however, is underutilized due to its complexity. Here, a simple approach, silicone-assisted direct laser writing (SA-DLW) is developed, to upgrade polyolefin plastic waste into multifunctional porous graphene, called laser-induced graphene (LIG). This method involves infiltrating polyolefins with silicone, which retards ablation during the DLW process and supplies additional carbon atoms, as confirmed by experimental and molecular dynamic results. A remarkable conversion yield of 38.3% is achieved. The upgraded LIG exhibited a porous structure and high conductivity, which is utilized for the fabrication of diverse energy and electronic devices with commendable performance. Furthermore, the SA-DLW technique is versatile for upgrading plastic waste in various types and forms. Upgrading plastic waste in the form of fabric has significantly simplified pre-treatment. Finally, a wearable flex sensor is fabricated on the non-woven fabric of a discarded medical mask, which is applied for gesture monitoring. This work offers a simple but effective solution to upgrade plastic waste into valuable products, contributing to the mitigation of environmental challenges posed by plastic pollution.
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Affiliation(s)
- Menglong Qu
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, China
| | - Yani Guo
- School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, 211816, China
- Sinopec Nanjing Engineering & Construction Incorporation, Nanjing, 210049, China
| | - Yahan Cai
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, China
| | - Zhengwei Nie
- School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Cheng Zhang
- College of Engineering, Nanjing Agricultural University, Nanjing, 210031, China
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6
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Zeng F, He L, Ma J, Fang D, Zeng Z, Bai T, Ding R, Liu B, Zhao H, Wang Y. Microcage flame retardants with complete recyclability and durability via reversible interfacial locking engineering. MATERIALS HORIZONS 2024; 11:1867-1876. [PMID: 38454889 DOI: 10.1039/d4mh00116h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Flame retardants are effective in protecting materials from fire but pose environmental challenges due to limited recyclability. Urgently needed for circular material economy are new flame retardants that are chemically recyclable and durable. Here, we report a new facile and scalable strategy for engineering reversible microcages with infinite chemical recyclability to starting monomers, exceptional durability, and versatile flame retardancy. This is achieved through a highly synergistic hierarchical assembly of easily obtainable phosphoric acid and Cu2+ monomers. By leveraging dynamic reversible assembly networks, microcages can be circularly and infinitely dissociated into starting monomers via eco-friendly pH adjustment. Remarkable recovery rates of 92% for phosphoric acid and 96.2% for Cu2+ monomers are achieved, while the separated virgin matrix undergoes conventional chemical recycling, facilitating reformulation and seamless reintroduction into new supply chains as needed. Notably, when integrated with matrix-like surfaces, microcage clasp matrices tightly engage through in situ formed interfacial locking structures, showcasing outstanding flame-retardant efficiency, prolonged durability in hydrothermal aging, and extensive applicability across diverse polymeric materials such as polyurethane, epoxy resin, and polycarbonate. This study emphasizes a novel, straightforward, and scalable chemical platform, utilizing reversible interfacial locking engineering, for the development of flame retardants that are not only infinitely recyclable but also durable and broadly applicable.
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Affiliation(s)
- Furong Zeng
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Lei He
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Jianwen Ma
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Danxuan Fang
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Zhiwei Zeng
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Tongyu Bai
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Rong Ding
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Bowen Liu
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Haibo Zhao
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
| | - Yuzhong Wang
- School of Chemical Engineering, The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Polymer Materials Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu, Sichuan 610064, China.
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7
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Shi C, Quinn EC, Diment WT, Chen EYX. Recyclable and (Bio)degradable Polyesters in a Circular Plastics Economy. Chem Rev 2024; 124:4393-4478. [PMID: 38518259 DOI: 10.1021/acs.chemrev.3c00848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2024]
Abstract
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 play an even greater role in tomorrow's circular plastics economy that focuses on sustainability, thanks to the abundant availability of their biosourced building blocks and the presence of the main-chain ester bonds that can be chemically or biologically cleaved on demand by multiple methods and thus bring about more desired end-of-life plastic waste management options. Because of this potential and promise, there have been intense research activities directed at addressing recycling, upcycling or biodegradation of existing legacy polyesters, designing their biorenewable alternatives, and redesigning future polyesters with intrinsic chemical recyclability and tailored performance that can rival today's commodity plastics that are either petroleum based and/or hard to recycle. This review captures these exciting recent developments and outlines future challenges and opportunities. Case studies on the legacy polyesters, poly(lactic acid), poly(3-hydroxyalkanoate)s, poly(ethylene terephthalate), poly(butylene succinate), and poly(butylene-adipate terephthalate), are presented, and emerging chemically recyclable polyesters are comprehensively reviewed.
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Affiliation(s)
- Changxia Shi
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Ethan C Quinn
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Wilfred T Diment
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
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8
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Akram Cheema H, Ilyas S, Kang H, Kim H. Comprehensive review of the global trends and future perspectives for recycling of decommissioned photovoltaic panels. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 174:187-202. [PMID: 38056367 DOI: 10.1016/j.wasman.2023.11.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 11/13/2023] [Accepted: 11/22/2023] [Indexed: 12/08/2023]
Abstract
With the rapid deployment of renewable energy using photovoltaic (PV) panels, the sustainable management of decommissioned PV modules has become challenging. Decommissioned modules contain heavy metals, such as copper, cadmium, and lead, and hazardous polymer substances, such as ethylene vinyl acetate, polyethylene terephthalate, and polyvinylidene fluoride, which can pose a serious threat to the environment if disposed in a landfill. In addition, the low concentration value of critical metals, such as silver, indium, and tellurium, can also be lost. In this context, recycling decommissioned PV panels can be useful to resource recovery of valuable metals while lowering environmental stress. However, the lower share of PV modules and the prolonged life of 25-30 years compared to other waste volumes (e.g., electronic waste) hinder the progress in this direction. In contrast, reaching the end-of-life of the deployed first-generation PV panels is creating attraction toward the recycling of decommissioned modules. Henceforth, exploring the commercial viability of PV recycling necessitates a review of the methodologies that have been investigated on a laboratory scale and have the potential to be up-scaled. In this review, the recent trends in various PV-recycling steps, including frame disassembly, delamination, metal extraction, and recovery, are underlined while the associated problems are determined to suggest the required improvements in future technology. Furthermore, the environmental and economic feasibility of a few techniques are discussed to establish the viability of the recycling process. This review contributes to formulating PV waste management strategies and providing future research directions.
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Affiliation(s)
- Humma Akram Cheema
- Department of Earth Resources & Environmental Engineering, Hanyang University, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Sadia Ilyas
- Department of Earth Resources & Environmental Engineering, Hanyang University, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Heewon Kang
- Department of Earth Resources & Environmental Engineering, Hanyang University, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Hyunjung Kim
- Department of Earth Resources & Environmental Engineering, Hanyang University, Seongdong-gu, Seoul 04763, Republic of Korea.
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9
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Wei SY, Wang CY, Guo C, Zhu YN, Cao XW, Kuang QL, He GJ. Oxidization and Chain-Branching Reaction for Recycling HDPE and Mixed HDPE/PP with In-situ Compatibilization by Ozone-Induced Reactive Extrusion. CHEMSUSCHEM 2024; 17:e202301035. [PMID: 37724860 DOI: 10.1002/cssc.202301035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/14/2023] [Accepted: 09/14/2023] [Indexed: 09/21/2023]
Abstract
High-density polyethylene (HDPE) and isotactic polypropylene (iPP) are widely used in industrial and residential applications due to their low cost and chemical stability, thus their recycling process can contribute to a circular economy. However, both polymers are non-polar materials, and the incompatibility with most other materials leads to substantially inferior properties of blends. In this work, we propose a flexible compatibilization strategy to improve the compatibility of HDPE/iPP blends. Ozone is adopted to induce reactive extrusion for rapid oxidation of HDPE and chain-branching reactions for both HDPE and HDPE/iPP blends. During extrusion process, ozone oxidizes HDPE effectively in a short time and introduces oxygen-containing groups such as carbonyl and ester groups, which improves the hydrophilicity. The addition of trimethylolpropane triacrylate (TMPTA) could promote branching reaction and facilitate the formation of HDPE-g-iPP copolymers, which improved the compatibility for HDPE/iPP. As a result, the impact strength of ozone-modified HDPE and HDPE/iPP blends increased by 22 % and 82 %, respectively, and the tensile strength also increased. This strategy would have potential applications in the field of sorting-free and solvent-free recycling of waste polyolefin plastics.
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Affiliation(s)
- Shi-Yi Wei
- National Engineering Research Center of Novel Equipment for Polymer Processing, The Key Laboratory of Polymer Processing Engineering of Ministry of Education, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Chun-Yan Wang
- National Engineering Research Center of Novel Equipment for Polymer Processing, The Key Laboratory of Polymer Processing Engineering of Ministry of Education, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Chao Guo
- National Engineering Research Center of Novel Equipment for Polymer Processing, The Key Laboratory of Polymer Processing Engineering of Ministry of Education, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Ya-Nan Zhu
- National Engineering Research Center of Novel Equipment for Polymer Processing, The Key Laboratory of Polymer Processing Engineering of Ministry of Education, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Xian-Wu Cao
- National Engineering Research Center of Novel Equipment for Polymer Processing, The Key Laboratory of Polymer Processing Engineering of Ministry of Education, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
| | | | - Guang-Jian He
- National Engineering Research Center of Novel Equipment for Polymer Processing, The Key Laboratory of Polymer Processing Engineering of Ministry of Education, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
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10
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Fu Z, Zhang YS, Ji G, Li A. Experimental analysis on products distribution, characterization and mechanism of waste polypropylene (PP) and polyethylene terephthalate (PET) degradation in sub-/supercritical water. CHEMOSPHERE 2024; 350:141045. [PMID: 38154671 DOI: 10.1016/j.chemosphere.2023.141045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/08/2023] [Accepted: 12/25/2023] [Indexed: 12/30/2023]
Abstract
Supercritical water (SCW) treatment of plastics is a clean technology in the 'waste-to-energy' path. In this work, PP and PET plastics were processed by sub-/supercritical water. The results showed that temperature was the most important factor of the PP and PET degradation. The influence of factors on the degradation of plastics follows the following order: temperature > residence time > plastic/water ratio. These factors influenced the yield of gas products by promoting or inhibiting various reactions (such as reverse water gas shift reaction, methylation reaction, and Fischer-Tropsch synthesis reaction). Besides, the composition of liquid oil was also analyzed. The main composition of the liquid oil produced by PET was benzoic acid and acetaldehyde, which were generated from the decarboxylation of terephthalic acid (TPA) and dehydration reaction of ethylene glycol (EG). The liquid oil from PP was mainly long-chain olefins, long-chain alkanes, cycloalkanes, etc., which were formed by the interaction of various methyl, alkyl, hydroxyl, and other free radicals. This study could build fundamental theories of plastic mixture treatment.
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Affiliation(s)
- Zegang Fu
- School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Ye Shui Zhang
- School of Engineering, University of Aberdeen, Aberdeen AB24 3UE, UK
| | - Guozhao Ji
- School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, Liaoning, China.
| | - Aimin Li
- School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, Liaoning, China.
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11
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Ibrahim IA, Rawindran H, Alam MM, Leong WH, Sahrin NT, Ng HS, Chan YJ, Abdelfattah EA, Lim JW, Aliyu US, Khoo KS. Mitigating persistent organic pollutants from marine plastics through enhanced recycling: A review. ENVIRONMENTAL RESEARCH 2024; 240:117533. [DOI: 10.1016/j.envres.2023.117533] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
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12
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Klotz M, Oberschelp C, Salah C, Subal L, Hellweg S. The role of chemical and solvent-based recycling within a sustainable circular economy for plastics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167586. [PMID: 37804985 DOI: 10.1016/j.scitotenv.2023.167586] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/02/2023] [Accepted: 10/02/2023] [Indexed: 10/09/2023]
Abstract
Chemical and solvent-based recycling of plastic waste may help overcome some of the challenges faced by predominantly applied mechanical recycling techniques. This study quantifies the environmental impacts of chemical and solvent-based recycling as a function of varying process parameters and product composition using life cycle assessment. Furthermore, potential benefits and impacts on a system level are determined. To that end, a high-resolution material flow analysis is conducted for the reference system of Switzerland, covering all main plastic types and applications. In a scenario for the year 2040, we employ environmentally beneficial mechanical recycling where possible and convey suitable remaining waste streams to chemical or solvent-based recycling processes. Applying chemical or solvent-based recycling as a complement to maximum mechanical recycling, instead of thermal treatment with energy recovery, may achieve a reduction in the climate change impact of the system ranging from less than 10 % to almost 40 %. For achieving high environmental benefits, proper process choice and configuration are crucial. Dissolution or depolymerization provide higher benefits relative to other chemical recycling processes, but can only treat certain waste streams and require prior sorting into plastic types. Pyrolysis and gasification appeared to only have the ability to achieve substantial benefits over incineration if their output products can substitute high-impact chemicals and provided that efficient heat transfer and recovery is warranted when implemented on a large scale. As industrial-scale plants for chemical or solvent-based plastic recycling are still lacking, the upscaling potential and the environmental benefits achievable in practice are highly uncertain today.
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Affiliation(s)
- Magdalena Klotz
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland.
| | - Christopher Oberschelp
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland; National Centre of Competence in Research (NCCR) Catalysis, ETH Zurich, Leopold-Ružička-Weg 4, 8093 Zurich, Switzerland
| | - Cecilia Salah
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland; National Centre of Competence in Research (NCCR) Catalysis, ETH Zurich, Leopold-Ružička-Weg 4, 8093 Zurich, Switzerland
| | - Luc Subal
- Realcycle GmbH, Hagenholzstrasse 85A, 8050 Zürich, Switzerland
| | - Stefanie Hellweg
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland
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13
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de Sousa Junior RR, Cezario FEM, Antonino LD, dos Santos DJ, Lackner M. Characterization of Poly(3-hydroxybutyrate) (P3HB) from Alternative, Scalable (Waste) Feedstocks. Bioengineering (Basel) 2023; 10:1382. [PMID: 38135973 PMCID: PMC10740857 DOI: 10.3390/bioengineering10121382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
Bioplastics hold significant promise in replacing conventional plastic materials, linked to various serious issues such as fossil resource consumption, microplastic formation, non-degradability, and limited end-of-life options. Among bioplastics, polyhydroxyalkanoates (PHA) emerge as an intriguing class, with poly(3-hydroxybutyrate) (P3HB) being the most utilized. The extensive application of P3HB encounters a challenge due to its high production costs, prompting the investigation of sustainable alternatives, including the utilization of waste and new production routes involving CO2 and CH4. This study provides a valuable comparison of two P3HBs synthesized through distinct routes: one via cyanobacteria (Synechocystis sp. PCC 6714) for photoautotrophic production and the other via methanotrophic bacteria (Methylocystis sp. GB 25) for chemoautotrophic growth. This research evaluates the thermal and mechanical properties, including the aging effect over 21 days, demonstrating that both P3HBs are comparable, exhibiting physical properties similar to standard P3HBs. The results highlight the promising potential of P3HBs obtained through alternative routes as biomaterials, thereby contributing to the transition toward more sustainable alternatives to fossil polymers.
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Affiliation(s)
- Rogerio Ramos de Sousa Junior
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC, Santo André 09210-580, Brazil; (R.R.d.S.J.); (F.E.M.C.); (L.D.A.)
| | - Fabiano Eduardo Marques Cezario
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC, Santo André 09210-580, Brazil; (R.R.d.S.J.); (F.E.M.C.); (L.D.A.)
| | - Leonardo Dalseno Antonino
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC, Santo André 09210-580, Brazil; (R.R.d.S.J.); (F.E.M.C.); (L.D.A.)
| | - Demetrio Jackson dos Santos
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC, Santo André 09210-580, Brazil; (R.R.d.S.J.); (F.E.M.C.); (L.D.A.)
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14
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Mudersbach M, Jürgens M, Pohler M, Spierling S, Venkatachalam V, Endres HJ, Barner L. Life Cycle Assessment in a Nutshell-Best Practices and Status Quo for the Plastic Sector. Macromol Rapid Commun 2023:e2300466. [PMID: 38009772 DOI: 10.1002/marc.202300466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 11/02/2023] [Indexed: 11/29/2023]
Abstract
Life cycle assessment (LCA) is an internationally standardized methodology to evaluate the potential environmental impacts of products and technologies and assists in lowering their negative environmental consequences. So far, extensive knowledge of LCA-their application and interpretation-is restricted to experts. However, the importance of LCA is increasing due to its application in business, environmental, and policy decision-making processes. Therefore, general knowledge of LCA is critically important. The current work provides an introduction to LCA for non-experts discussing important steps and aspects and therefore can be used as a starting point for LCA. In addition, a comprehensive checklist for non-experts with important content and formal aspects of LCA is provided. Specific aspects of LCA for the plastics sector along the value chain are also discussed, including their limitations.
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Affiliation(s)
- Marina Mudersbach
- Institute of Plastics and Circular Economy, Leibniz Universität Hannover, An der Universität 2, 30823, Garbsen, Germany
| | - Meret Jürgens
- Institute of Plastics and Circular Economy, Leibniz Universität Hannover, An der Universität 2, 30823, Garbsen, Germany
| | - Merlin Pohler
- Institute of Plastics and Circular Economy, Leibniz Universität Hannover, An der Universität 2, 30823, Garbsen, Germany
| | - Sebastian Spierling
- Institute of Plastics and Circular Economy, Leibniz Universität Hannover, An der Universität 2, 30823, Garbsen, Germany
| | - Venkateshwaran Venkatachalam
- Institute of Plastics and Circular Economy, Leibniz Universität Hannover, An der Universität 2, 30823, Garbsen, Germany
| | - Hans-Josef Endres
- Institute of Plastics and Circular Economy, Leibniz Universität Hannover, An der Universität 2, 30823, Garbsen, Germany
| | - Leonie Barner
- Centre for a Waste-Free World, Faculty of Science, School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, Queensland, 4000, Australia
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15
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Nordahl SL, Baral NR, Helms BA, Scown CD. Complementary roles for mechanical and solvent-based recycling in low-carbon, circular polypropylene. Proc Natl Acad Sci U S A 2023; 120:e2306902120. [PMID: 37934823 PMCID: PMC10655212 DOI: 10.1073/pnas.2306902120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/05/2023] [Indexed: 11/09/2023] Open
Abstract
Plastic recycling presents a vexing challenge. Mechanical recycling offers substantial greenhouse gas emissions savings relative to virgin plastic production but suffers from degraded aesthetic and mechanical properties. Polypropylene, one of the most widely used and lowest-cost plastics, features methyl pendants along the polymer backbone, rendering it particularly susceptible to declining properties, performance, and aesthetics across a succession of mechanical recycles. Advanced processes, such as solvent-assisted recycling, promise near-virgin quality outputs at a greater energy and emissions footprint. Mechanical and advanced recycling are often presented as competing options, but real-world plastic waste streams are likely to require preprocessing regardless of whether they are routed to an advanced process. This study quantifies the life-cycle greenhouse gas implications of multiple recycling strategies and proposes a system in which mechanical and solvent-assisted recycling can be leveraged together to boost recycling rates and satisfy demand for a wider range of product applications. Polypropylene can be recovered from mixed-plastic bales produced at material recovery facilities and processed through mechanical recycling, with a varying fraction sent for further upgrading via solvent-assisted recycling to produce material approved for food packaging and other higher-quality applications. The resulting mechanically recycled rigid polypropylene reduces life-cycle greenhouse gas emissions by 80% relative to the same quantity of virgin material, while the upgraded higher-quality material achieves GHG savings of 30%.
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Affiliation(s)
- Sarah L. Nordahl
- Energy Analysis and Environmental Impacts Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA94720
| | - Nawa R. Baral
- Joint BioEnergy Institute, Emeryville, CA94608
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Brett A. Helms
- Joint BioEnergy Institute, Emeryville, CA94608
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Corinne D. Scown
- Energy Analysis and Environmental Impacts Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Joint BioEnergy Institute, Emeryville, CA94608
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Energy and Biosciences Institute, University of California, Berkeley, CA94720
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16
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Shi JX, Ciccia NR, Pal S, Kim DD, Brunn JN, Lizandara-Pueyo C, Ernst M, Haydl AM, Messersmith PB, Helms BA, Hartwig JF. Chemical Modification of Oxidized Polyethylene Enables Access to Functional Polyethylenes with Greater Reuse. J Am Chem Soc 2023; 145:21527-21537. [PMID: 37733607 DOI: 10.1021/jacs.3c07186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Polyethylene is a commodity material that is widely used because of its low cost and valuable properties. However, the lack of functional groups in polyethylene limits its use in applications that include adhesives, gas barriers, and plastic blends. The inertness of polyethylene makes it difficult to install groups that would enhance its properties and enable programmed chemical decomposition. To overcome these deficiencies, the installation of pendent functional groups that imbue polyethylene with enhanced properties is an attractive strategy to overcome its inherent limitations. Here, we describe strategies to derivatize oxidized polyethylene that contains both ketones and alcohols to monofunctional variants with bulk properties superior to those of unmodified polyethylene. Iridium-catalyzed transfer dehydrogenation with acetone furnished polyethylenes with only ketones, and ruthenium-catalyzed hydrogenation with hydrogen furnished polyethylenes with only alcohols. We demonstrate that the ratio of these functional groups can be controlled by reduction with stoichiometric hydride-containing reagents. The ketones and alcohols serve as sites to introduce esters and oximes onto the polymer, thereby improving surface and bulk properties over those of polyethylene. These esters and oximes were removed by hydrolysis to regenerate the original oxygenated polyethylenes, showing how functionalization can lead to materials with circularity. Waste polyethylenes were equally amenable to oxidative functionalization and derivatization of the oxidized material, showing that this low- or negative-value feedstock can be used to prepare materials of higher value. Finally, the derivatized polymers with distinct solubilities were separated from mechanically mixed plastic blends by selective dissolution, demonstrating that functionalization can lead to novel approaches for distinguishing and separating polymers from a mixture.
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Affiliation(s)
- Jake X Shi
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nicodemo R Ciccia
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Subhajit Pal
- Department of Materials Science and Bioengineering, University of California, Berkeley, California 94720, United States
| | - Diane D Kim
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John N Brunn
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | | | | | | | - Phillip B Messersmith
- Department of Materials Science and Bioengineering, University of California, Berkeley, California 94720, United States
| | - Brett A Helms
- The Molecular Foundry and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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17
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Xayachak T, Haque N, Lau D, Emami N, Hood L, Tait H, Foley A, Pramanik BK. White spill: Life cycle assessment approach to managing marine EPS litter from flood-released pontoons. CHEMOSPHERE 2023; 337:139400. [PMID: 37406937 DOI: 10.1016/j.chemosphere.2023.139400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/22/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023]
Abstract
Expanded polystyrene (EPS) pollution in the marine environment is a pressing issue in Queensland, Australia due to a recent flood that scattered hundreds of EPS-containing pontoons along the coastline, causing severe ecological damage. To assist in the clean-up effort and provide crucial data for developing management guidelines, this study investigates the environmental performance of different end-of-life (EoL) disposal/recycling methods, including (i) landfill; (ii) on-site mechanical re-processing using a thermal densifier (MR); and (iii) on-site dissolution/precipitation using d-limonene (DP). Applying the life cycle assessment framework, the results showed that DP was the most environmentally favourable option. Its impacts in climate change (GWP), acidification (TAP), and fossil fuel depletion (FFD) were 612 kg CO2 eq, 4.3 kg SO2 eq, and 184.7 kg oil eq, respectively. For comparison, the impacts of landfilling EPS in these categories were found to be 700 kg CO2 eq, 3.5 kg SO2 eq, and 282 kg oil eq, respectively. Landfill also contributed considerably to eutrophication potential (MEP), at 3.77 kg N eq. Impacts from MR were most significant due to the need to transport the densifier unit to the site. The analysis also revealed that the transportation of personnel and heavy machinery to the site, was the biggest contributor to impacts in the EoL stage. Its impacts in GWP, TAP, MEP, and FFD were 1369.8 kg CO2 eq, 6.5 kg SO2 eq, 0.2189 kg N eq, and 497.7 kg oil eq, respectively. Monte Carlo analysis showed that the conclusions made from these results were stable and reliable. Limitations of this model and recommendations for future investigations were also discussed in this work.
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Affiliation(s)
- Tu Xayachak
- School of Engineering, RMIT University, VIC, 3001, Australia
| | - Nawshad Haque
- CSIRO Mineral Resources, Clayton South, Melbourne, VIC, 3169, Australia
| | - Deborah Lau
- CSIRO Manufacturing, Private Bag 10, Clayton South, VIC, 3169, Australia
| | - Nargessadat Emami
- CSIRO Land & Water, Black Mountain Science & Innovation Park, Acton, ACT, 2601, Australia
| | - Lincoln Hood
- Tangaroa Blue Foundation, Dunsborough, WA, 6281, Australia
| | - Heidi Tait
- Tangaroa Blue Foundation, Dunsborough, WA, 6281, Australia
| | - Alison Foley
- Ten Little Pieces, Sunshine Coast, QLD, Australia
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18
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Li X, Kong Y, Juhasz AL, Zhou P, Zhang Q, Cui X. Effect of Microplastic Types on the In Vivo Bioavailability of Polychlorinated Biphenyls. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:12838-12846. [PMID: 37587565 DOI: 10.1021/acs.est.3c04068] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
As MPs are released into the soil, various equilibrium statuses are expected. MPs could play roles as a "source," a "cleaner," or a "sink" of HOCs. Three types of MPs (LDPE, PLA, and PS) were selected to study their effect on polychlorinated biphenyl (PCBs) relative bioavailability (RBA) measured by a mouse model. As a "source" of HOCs, exposure to MP-sorbed PCBs resulted in their accumulation in adipose tissue with PCB RBA as 101 ± 6.73% for LDPE, 76.2 ± 19.2% for PLA, and 9.22 ± 2.02% for PS. The addition of 10% MPs in PCB-contaminated soil led to a significant (p < 0.05) reduction in PCB RBA (52.2 ± 16.7%, 49.3 ± 4.85%, and 47.1 ± 5.99% for LDPE, PLA, and PS) compared to control (75.0 ± 4.26%), implying MPs acted as "cleaner" by adsorbing PCBs from the digestive system and reducing PCB accumulation. MPs acted as a "sink" for PCBs in contaminated soil after aging, but the sink effect varied among MP types with more pronounced effect for LDPE than PLA and PS. Therefore, the role played by MPs in bioavailability of HOCs closely depended on the MP types as well as the equilibrium status among MPs, soil, and HOCs.
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Affiliation(s)
- Xinyu Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Yi Kong
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Albert L Juhasz
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Pengfei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Qian Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Xinyi Cui
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
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19
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Saleem J, Moghal ZKB, McKay G. Designing super-fast trimodal sponges using recycled polypropylene for organics cleanup. Sci Rep 2023; 13:14163. [PMID: 37644209 PMCID: PMC10465528 DOI: 10.1038/s41598-023-41506-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023] Open
Abstract
Sorbent pads and films have been commonly used for environmental remediation purposes, but designing their internal structure to optimize access to the entire volume while ensuring cost-effectiveness, ease of fabrication, sufficient strength, and reusability remains challenging. Herein, we report a trimodal sorbent film from recycled polypropylene (PP) with micropores, macro-voids, and sponge-like 3D cavities, developed through selective dissolution, thermally induced phase separation, and annealing. The sorbent has hundreds of cavities per cm2 that are capable of swelling up to twenty-five times its thickness, allowing for super-fast saturation kinetics (within 30 s) and maximum oil sorption (97 g/g). The sorption mechanism follows a pseudo-second-order kinetic model. Moreover, the sorbent is easily compressible, and its structure is retained during oil sorption, desorption, and resorption, resulting in 96.5% reuse efficiency. The oil recovery process involves manually squeezing the film, making the cleanup process efficient with no chemical treatment required. The sorbent film possesses high porosity for effective sorption with sufficient tensile strength for practical applications. Our integrated technique results in a strengthened porous polymeric structure that can be tailored according to end-use applications. This study provides a sustainable solution for waste management that offers versatility in its functionality.
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Affiliation(s)
- Junaid Saleem
- Division of Sustainable Development, College of Science and Engineering, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
| | | | - Gordon McKay
- Division of Sustainable Development, College of Science and Engineering, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
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20
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Yan T, Balzer AH, Herbert KM, Epps TH, Korley LTJ. Circularity in polymers: addressing performance and sustainability challenges using dynamic covalent chemistries. Chem Sci 2023; 14:5243-5265. [PMID: 37234906 PMCID: PMC10208058 DOI: 10.1039/d3sc00551h] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/14/2023] [Indexed: 05/28/2023] Open
Abstract
The circularity of current and future polymeric materials is a major focus of fundamental and applied research, as undesirable end-of-life outcomes and waste accumulation are global problems that impact our society. The recycling or repurposing of thermoplastics and thermosets is an attractive solution to these issues, yet both options are encumbered by poor property retention upon reuse, along with heterogeneities in common waste streams that limit property optimization. Dynamic covalent chemistry, when applied to polymeric materials, enables the targeted design of reversible bonds that can be tailored to specific reprocessing conditions to help address conventional recycling challenges. In this review, we highlight the key features of several dynamic covalent chemistries that can promote closed-loop recyclability and we discuss recent synthetic progress towards incorporating these chemistries into new polymers and existing commodity plastics. Next, we outline how dynamic covalent bonds and polymer network structure influence thermomechanical properties related to application and recyclability, with a focus on predictive physical models that describe network rearrangement. Finally, we examine the potential economic and environmental impacts of dynamic covalent polymeric materials in closed-loop processing using elements derived from techno-economic analysis and life-cycle assessment, including minimum selling prices and greenhouse gas emissions. Throughout each section, we discuss interdisciplinary obstacles that hinder the widespread adoption of dynamic polymers and present opportunities and new directions toward the realization of circularity in polymeric materials.
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Affiliation(s)
- Tianwei Yan
- Department of Chemical & Biomolecular Engineering, University of Delaware Newark 19716 Delaware USA
- Center for Plastics Innovation (CPI), University of Delaware Newark 19716 Delaware USA
| | - Alex H Balzer
- Department of Chemical & Biomolecular Engineering, University of Delaware Newark 19716 Delaware USA
- Center for Plastics Innovation (CPI), University of Delaware Newark 19716 Delaware USA
| | - Katie M Herbert
- Center for Plastics Innovation (CPI), University of Delaware Newark 19716 Delaware USA
| | - Thomas H Epps
- Department of Chemical & Biomolecular Engineering, University of Delaware Newark 19716 Delaware USA
- Center for Plastics Innovation (CPI), University of Delaware Newark 19716 Delaware USA
- Department of Materials Science and Engineering, University of Delaware Newark 19716 Delaware USA
- Center for Research in Soft matter and Polymers (CRiSP), University of Delaware Newark 19716 Delaware USA
| | - LaShanda T J Korley
- Department of Chemical & Biomolecular Engineering, University of Delaware Newark 19716 Delaware USA
- Center for Plastics Innovation (CPI), University of Delaware Newark 19716 Delaware USA
- Department of Materials Science and Engineering, University of Delaware Newark 19716 Delaware USA
- Center for Research in Soft matter and Polymers (CRiSP), University of Delaware Newark 19716 Delaware USA
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21
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Lu L, Li W, Cheng Y, Liu M. Chemical recycling technologies for PVC waste and PVC-containing plastic waste: A review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 166:245-258. [PMID: 37196390 DOI: 10.1016/j.wasman.2023.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/29/2023] [Accepted: 05/07/2023] [Indexed: 05/19/2023]
Abstract
The extensive production and consumption of plastics has resulted in significant plastic waste and plastic pollution. Polyvinyl chloride (PVC) waste has a high chlorine content and is the primary source of chlorine in the plastic waste stream, potentially generating hazardous chlorinated organic pollutants if treated improperly. This review discusses PVC synthesis, applications, and the current types and challenges of PVC waste management. Dechlorination is vital for the chemical recycling of PVC waste and PVC-containing plastic waste. We review dehydrochlorination and dechlorination mechanisms of PVC using thermal degradation and wet treatments, and summarize the recent progress in chemical treatments and dechlorination principles. This review provides readers with a comprehensive analysis of chemical recycling technologies for PVC waste and PVC-containing plastic waste to transform them into chemicals, fuels, feedstock, and value-added polymers.
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Affiliation(s)
- Lihui Lu
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Weiming Li
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Ying Cheng
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Meng Liu
- School of Environmental Science and Technology, Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian University of Technology, Dalian 116024, Liaoning, China.
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22
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Rumetshofer T, Fischer J. Information-Based Plastic Material Tracking for Circular Economy-A Review. Polymers (Basel) 2023; 15:polym15071623. [PMID: 37050237 PMCID: PMC10097355 DOI: 10.3390/polym15071623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/14/2023] [Accepted: 03/22/2023] [Indexed: 04/14/2023] Open
Abstract
At the moment, it looks like the plastics recycling industry is skimming only low-hanging fruits of its business. To reach intended targets, a greater effort and disruptive innovations are necessary. Physical- or digital-information-based solutions for tracking plastic material can support the circular economy and help to overcome hurdles along the value chain. In this paper, the scientific literature and initiatives in four different technology areas for information-based tracking solutions are reviewed and analyzed. Physical markers can improve sorting efficiencies on short notice but adhere some technical difficulties. Blockchain as a new concept promises high transparency and security, with the drawbacks of energy-intense verification and technical uncertainties. As a third group, the digital product passport claims a combination of physical and digital solutions with open questions on data ownership. The fourth and last group includes standards and certification systems that aim for maximum consensus with slow market implementation. To enable an integrated circular economy of plastics, plastic material tracking solutions must experience broad acceptance by all players along the value chain in the plastics industry and they should additionally be supported by society.
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Affiliation(s)
- Thomas Rumetshofer
- Institute of Polymeric Materials and Testing, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Jörg Fischer
- Institute of Polymeric Materials and Testing, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
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23
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Huang YZ, Liu XX, Huang ZX, Li YJ, He HZ. From Waste to Wealth: Upcycling Waste Polypropylene/Polyethylene for Thermal Management via Pressure-Induced, Flow-Enhanced Segregated Structurizing with Hexagonal Boron Nitride. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.2c04069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Yun-Zhi Huang
- National Engineering Research Center of Novel Equipment for Polymer Processing; Key Laboratory of Polymer Processing Engineering, Ministry of Education; Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing; School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, China
| | - Xiao-Xiao Liu
- School of Advanced Manufacturing Technology, Guangdong Mechanical & Electrical Polytechnic, Guangzhou 510550, China
| | - Zhao-Xia Huang
- National Engineering Research Center of Novel Equipment for Polymer Processing; Key Laboratory of Polymer Processing Engineering, Ministry of Education; Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing; School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, China
| | - Yi-Jun Li
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, Sichuan, China
| | - He-Zhi He
- National Engineering Research Center of Novel Equipment for Polymer Processing; Key Laboratory of Polymer Processing Engineering, Ministry of Education; Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing; School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, China
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24
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Padmanabhan S, Kumar TV, Giridharan K, Stalin B, Nagaprasad N, Jule LT, Ramaswamy K. An analysis of environment effect on ethanol blends with plastic fuel and blend optimization using a full factorial design. Sci Rep 2022; 12:21719. [PMID: 36522376 PMCID: PMC9755122 DOI: 10.1038/s41598-022-26046-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
There is a growing amount of plastic waste that needs to be properly disposed of in order to protect the environment from the negative effects of increasing reliance on plastic products. Recent interest has focused on chemical recycling as a means of reducing plastic's negative environmental effects. Converting waste plastics into basic petrochemicals allows them to serve as hydrocarbon feedstock or fuel oil through pyrolysis operations. Scientists have taken a keen interest in the production of bioethanol from renewable feedstocks due to its potential as a source of energy and alternative fuel. Due to its beneficial effects on the environment, ethanol has emerged as a promising biofuel. In this paper, energy recovered from low-density polyethylene and high-density polyethylene waste was converted into an alternative plastic fuel and evaluated for its environmental impact with the blending of ethanol in a diesel engine. Ternary fuel blends with 20%, 30%, and 40% waste plastic fuel and 10%, 15%, and 20% ethanol with standard diesel were tested. The study found that blending 10% ethanol with 20% plastic fuel decreased fuel consumption by around 7.9% compared to base diesel. Carbon monoxide emissions are reduced by about 10.2%, and hydrocarbon emissions are reduced by about 13.43% when using the same ternary blend. The optimum values of fuel consumption and emissions were obtained by full factorial design for a ternary fuel blend of 10% ethanol and 20% plastic fuel at the full load condition.
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Affiliation(s)
- S. Padmanabhan
- grid.464713.30000 0004 1777 5670School of Mechanical and Construction, Vel Tech Rangarajan Dr.Sagunthala R&D Institute of Science and Technology, Chennai, India
| | - T. Vinod Kumar
- grid.412815.b0000 0004 1760 6324Department of Mechanical Engineering, Vels Institute of Science, Technology and Advanced Studies (VISTAS), Chennai, India
| | - K. Giridharan
- grid.252262.30000 0001 0613 6919Department of Mechanical Engineering, Easwari Engineering College, Chennai, India
| | - B. Stalin
- grid.252262.30000 0001 0613 6919Department of Mechanical Engineering, Anna University, Regional Campus Madurai, Madurai, Tamilnadu 625019 India
| | - N. Nagaprasad
- Department of Mechanical Engineering, ULTRA College of Engineering and Technology, Madurai, Tamilnadu 625104 India
| | - Leta Tesfaye Jule
- Centre for Excellence-Indigenous Knowledge, Innovative Technology Transfer and Entrepreneurship, Dambi Dollo University, Dambi Dollo, Ethiopia ,Department of Physics, College of Natural and Computational Science, Dambi Dollo University, Dambi Dollo, Ethiopia
| | - Krishnaraj Ramaswamy
- Centre for Excellence-Indigenous Knowledge, Innovative Technology Transfer and Entrepreneurship, Dambi Dollo University, Dambi Dollo, Ethiopia ,Department of Mechanical Engineering, Dambi Dollo University, Dambi Dollo, Ethiopia
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25
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Cook E, Velis CA, Cottom JW. Scaling up resource recovery of plastics in the emergent circular economy to prevent plastic pollution: Assessment of risks to health and safety in the Global South. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2022; 40:1680-1707. [PMID: 35875954 PMCID: PMC9606178 DOI: 10.1177/0734242x221105415] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Over the coming decades, a large additional mass of plastic waste will become available for recycling, as efforts increase to reduce plastic pollution and facilitate a circular economy. New infrastructure will need to be developed, yet the processes and systems chosen should not result in adverse effects on human health and the environment. Here, we present a rapid review and critical semi-quantitative assessment of the potential risks posed by eight approaches to recovering value during the resource recovery phase from post-consumer plastic packaging waste collected and separated with the purported intention of recycling. The focus is on the Global South, where there are more chances that high risk processes could be run below standards of safe operation. Results indicate that under non-idealised operational conditions, mechanical reprocessing is the least impactful on the environment and therefore most appropriate for implementation in developing countries. Processes known as 'chemical recycling' are hard to assess due to lack of real-world process data. Given their lack of maturity and potential for risk to human health and the environment (handling of potentially hazardous substances under pressure and heat), it is unlikely they will make a useful addition to the circular economy in the Global South in the near future. Inevitably, increasing circular economy activity will require expansion towards targeting flexible, multi-material and multilayer products, for which mechanical recycling has well-established limitations. Our comparative risk overview indicates major barriers to changing resource recovery mode from the already dominant mechanical recycling mode towards other nascent or energetic recovery approaches.
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Affiliation(s)
| | - Costas A Velis
- Costas A Velis, Room 304, School of Civil Engineering, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
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26
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Martinez Sanz V, Morales Serrano A, Schlummer M. A mini-review of the physical recycling methods for plastic parts in end-of-life vehicles. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2022; 40:1757-1765. [PMID: 35708148 DOI: 10.1177/0734242x221094917] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although the use of plastic components is increasing in the automotive industry, yet the recovery rates of these materials in end-of-life vehicle (ELV) is lower compared to metals. One of the main problems of ELV plastic waste is poor separation and sorting. Large car plastic parts consist of fibre-reinforced plastics, whereas other components end up in the automotive shredder residue (ASR), featuring a very heterogeneous mix of light materials that contains mostly non-metallic materials such as textiles, plastics, cartridges and wood. Generally, ASR was disposed in landfill or diverted to thermal treatments, such as pyrolysis or gasification, for energy recovery. Currently, the recovery of raw materials from various waste streams plays a key role in new European strategy for plastics in a circular economy. The approach of physical recycling methods described in this mini-review helps to maintain the value of polymer materials in the value chain allowing the reuse in the original or similar application.
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Affiliation(s)
| | | | - Martin Schlummer
- FRAUNHOFER IVV, Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany
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27
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Modelling and Simulation of Dissolution/Reprecipitation Technique for Low-Density Polyethene Using Solvent/Non-Solvent System. Processes (Basel) 2022. [DOI: 10.3390/pr10112387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The global production and consumption of plastics have continued to increase. Plastics degrade slowly, causing persistent environmental pollution Developed waste plastic recycling methods are discussed in this report, with a focus on the dissolution/reprecipitation technique to restore low-density polyethene (LDPE) wastes. Aspen HYSYS is used to simulate the recycling of waste LDPE. Turpentine/petroleum ether (TURP/PetE) is chosen as solvent/non-solvent with fractions proved efficient through laboratory experiments. PetE is selected to be the non-solvent used for the precipitation of pure LDPE. The feedstock is assumed to be LDPE products containing additives such as dye. The simulation model developed estimated a pure LDPE precipitate recovery with a composition of 99% LDPE with a flowrate of 1024 tonnes per year. In addition, Aspen HYSYS could approximate a rough cost estimate that includes utility cost, installation cost and other factors. Technical challenges were eliminated, and several assumptions were taken into consideration to be able to simulate the process.
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28
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Karim SS, Farrukh S, Matsuura T, Ahsan M, Hussain A, Shakir S, Chuah LF, Hasan M, Bokhari A. Model analysis on effect of temperature on the solubility of recycling of Polyethylene Terephthalate (PET) plastic. CHEMOSPHERE 2022; 307:136050. [PMID: 35977561 DOI: 10.1016/j.chemosphere.2022.136050] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 07/11/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
The massive increase in the use of PET plastic bottles has raised the challenge of accumulated waste plastics disposal and its related environmental concerns. Reusing this plastic waste through a solvent-based recycling process seems to be an eco-friendly solution for eliminating waste plastic and converting them into high quality products. The selection of solvent with its temperature requirement for the dissolution of polymeric materials is crucial in the solvent-based recycling process. Therefore, an innovative MATLAB program named HSPs-TPT was designed and constructed in this work to evaluate the dissolving power of solvents. Through this program, the solubility of the waste PET polymer was examined in thirteen (13) different solvents at different temperatures. As a results, the degree of waste PET polymer dissolution in the solvents was presented as the polymer-solvent solubility diagram, which provided the information about the relative energy difference (RED) change with the temperature rise. The program also provided the temperature range effective for the dissolution of PET by indicating the minimum and maximum solubility point for each solvent, which was further validated by the experimental data found in the literature. The proposed MATLAB program can numerically analyse the solubility of a polymer in different solvents in a short time for the recycling process and fabrication of different value-added plastic products such as polymer monoliths and membrane filters.
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Affiliation(s)
- Syed Shujaat Karim
- School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan.
| | - Sarah Farrukh
- School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan.
| | - Takeshi Matsuura
- Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Street, Ottawa, Ontario, K1N 6N5, Canada.
| | - Muhammad Ahsan
- School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan.
| | - Arshad Hussain
- Department of Chemical, Mechanical, Materials, and Mining Engineering, Pak-Austria Fachhochschule, Institute of Applied Sciences and Technology, Haripur, KPK, Pakistan.
| | - Sehar Shakir
- U.S.- Pakistan Center for Advance Studies in Energy (USPCAS-E), National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan
| | - Lai Fatt Chuah
- Faculty of Maritime Studies, Universiti Malaysia Terengganu, Terengganu, Malaysia.
| | - Mudassir Hasan
- College of Engineering, Department of Chemical Engineering, King Khalid University, Abha, 61411, Saudi Arabia
| | - Awais Bokhari
- Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, 54000, Pakistan; Sustainable Process Integration Laboratory, SPIL, NETME Centre, Faculty of Mechanical Engineering, Brno University of Technology, VUT Brno, Technická 2896/2, 616 00, Brno, Czech Republic.
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29
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Gazzotti S, De Felice B, Ortenzi MA, Parolini M. Approaches for Management and Valorization of Non-Homogeneous, Non-Recyclable Plastic Waste. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:10088. [PMID: 36011719 PMCID: PMC9408078 DOI: 10.3390/ijerph191610088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/07/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
The environmental accumulation of plastic wastes has become one of the most discussed topics in the scientific community. The development of new strategies to tackle this issue is of crucial importance, and different approaches are being investigated to effectively reduce plastic waste generated by improper or inefficient disposal. In addition to the efforts addressing the development of biodegradable plastics, the research is currently focused on the development of innovative recycling approaches. Indeed, although most plastic materials are potentially recyclable, only 15% of the worldwide plastic waste is currently recycled, while the remaining 85% is usually incinerated to recover thermal energy or landfilled. The hurdles to efficient recycling come from improper management of end-of-life plastic goods. Moreover, the highly heterogeneous nature and versatility of plastic and polymeric materials have led to the development of multilayered materials, composites, blends and many other different species, whose management and/or reprocessing to yield high-value products is extremely challenging. Thus, although these materials are extremely valuable from an industrial point of view, they add a high degree of complexity to the recycling process because each one of them is different from the other, but they cannot be separated efficiently. The aim of the present review is to return a comprehensive overview of environmental and management issues related to the complex and heterogeneous mixture of plastic waste that is generated at the end of the sorting procedures in Italian plastic recycling plants, the so-called 'Plasmix'. This review lists the difficulties and limitations related to the management of non-recyclable Plasmix and highlights the strategies for the proper, sustainable and valuable use of this plastic waste.
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Affiliation(s)
- Stefano Gazzotti
- Department of Environmental Science and Policy, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Beatrice De Felice
- Department of Environmental Science and Policy, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Marco Aldo Ortenzi
- Department of Chemistry, University of Milan, Via Golgi 19, 20133 Milan, Italy
| | - Marco Parolini
- Department of Environmental Science and Policy, University of Milan, Via Celoria 26, 20133 Milan, Italy
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30
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Guo X, Peng S, Jiang L, Mo X, Zhu Y, Liu Y, Cai K, Song Q. Removal of polybrominated diphenyl ethers in high impact polystyrene (HIPS) from waste TV sets. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:59317-59327. [PMID: 35384541 DOI: 10.1007/s11356-022-20046-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Most studies have shown that improper disposal of e-waste can accelerate the release of high concentrations of polybrominated diphenyl ethers (PBDEs), and this situation causes environmental pollution and human health risks. The recycling technology of waste electronic plastics based on solvent processes can reduce environmental pollution and health risks from PBDEs. In this study, high impact polystyrene (HIPS) from waste TV sets was taken as the research object, and d-limonene and n-propanol were used as solvent and precipitant, respectively. We studied the relationship between the precipitation conditions and the size of precipitate particles, and the effect laws of precipitation conditions on the removal percentage of PBDEs were discussed. Transferring behavior of PBDEs during precipitation was investigated, and the parameters suitable for removing PBDEs from HIPS solution were confirmed. Results showed that lower HIPS concentration in d-limonene, lower precipitation temperature, higher mass ratio of n-propanol to HIPS solution, and greater stirring speed were conducive to form smaller and more uniform precipitate particles. All conditions (concentration, temperature, mass ratio, and stirring rate) that could increase the solubility of PBDEs in the mixed solvent of limonene and n-propanol or decrease the swelling degree of HIPS precipitate particles, or reduce the size of particles could improve the removal percentage of PBDEs. The investigated results indicated that insoluble PBDEs (e.g., decabromodiphenyl ether) transferred into the HIPS precipitate mainly through the generated crystals and then precipitated together with the HIPS particles, and soluble PBDEs (e.g., octabromodiphenyl ether) migrated into the precipitate by the solution entrained. The precipitate particles, which measured approximately 1.0 mm (on average), were obtained when the solution containing 10% of HIPS from waste TV shell was precipitated by adding n-propanol equivalent to twice the mass of the solution at 40 °C and 3000 r/min stirring speed. The total concentration of PBDEs in the precipitate particles (dried) was reduced to 2369 mg/kg, and 88.06% of the PBDEs in the original plastic solution was successfully removed by this process.
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Affiliation(s)
- Xinran Guo
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Maoming, 525000, Guangdong, China
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 52500, China
| | - Shaohong Peng
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Maoming, 525000, Guangdong, China.
- School of Material Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, Guangdong, China.
| | - Liwang Jiang
- School of Material Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, Guangdong, China
| | - Xiaoning Mo
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 52500, China
| | - Yunhong Zhu
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 52500, China
| | - Yang Liu
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, 52500, China
| | - Kaihan Cai
- Macao Environmental Research Institute, Macau University of Science and Technology, Macao, 999078, China
| | - Qingbin Song
- Macao Environmental Research Institute, Macau University of Science and Technology, Macao, 999078, China
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31
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Current Prospects for Plastic Waste Treatment. Polymers (Basel) 2022; 14:polym14153133. [PMID: 35956648 PMCID: PMC9370925 DOI: 10.3390/polym14153133] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 07/17/2022] [Accepted: 07/28/2022] [Indexed: 12/04/2022] Open
Abstract
The excessive amount of global plastic produced over the past century, together with poor waste management, has raised concerns about environmental sustainability. Plastic recycling has become a practical approach for diminishing plastic waste and maintaining sustainability among plastic waste management methods. Chemical and mechanical recycling are the typical approaches to recycling plastic waste, with a simple process, low cost, environmentally friendly process, and potential profitability. Several plastic materials, such as polypropylene, polystyrene, polyvinyl chloride, high-density polyethylene, low-density polyethylene, and polyurethanes, can be recycled with chemical and mechanical recycling approaches. Nevertheless, due to plastic waste’s varying physical and chemical properties, plastic waste separation becomes a challenge. Hence, a reliable and effective plastic waste separation technology is critical for increasing plastic waste’s value and recycling rate. Integrating recycling and plastic waste separation technologies would be an efficient method for reducing the accumulation of environmental contaminants produced by plastic waste, especially in industrial uses. This review addresses recent advances in plastic waste recycling technology, mainly with chemical recycling. The article also discusses the current recycling technology for various plastic materials.
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32
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Gilbert EA, Polo ML, Maffi JM, Guastavino JF, Vaillard SE, Estenoz DA. The organic chemistry behind the recycling of poly(bisphenol‐A carbonate) for the preparation of chemical precursors: A review. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20220119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Elangeni Ana Gilbert
- Instituto de Desarrollo Tecnológico para la Industria Química, INTEC (Universidad Nacional del Litoral ‐ CONICET) Santa Fe Argentina
| | - Mara Lis Polo
- Instituto de Desarrollo Tecnológico para la Industria Química, INTEC (Universidad Nacional del Litoral ‐ CONICET) Santa Fe Argentina
| | | | - Javier Fernando Guastavino
- Instituto de Desarrollo Tecnológico para la Industria Química, INTEC (Universidad Nacional del Litoral ‐ CONICET) Santa Fe Argentina
| | - Santiago Eduardo Vaillard
- Instituto de Desarrollo Tecnológico para la Industria Química, INTEC (Universidad Nacional del Litoral ‐ CONICET) Santa Fe Argentina
| | - Diana Alejandra Estenoz
- Instituto de Desarrollo Tecnológico para la Industria Química, INTEC (Universidad Nacional del Litoral ‐ CONICET) Santa Fe Argentina
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33
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Schirmeister CG, Mülhaupt R. Closing the Carbon Loop in the Circular Plastics Economy. Macromol Rapid Commun 2022; 43:e2200247. [PMID: 35635841 DOI: 10.1002/marc.202200247] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/07/2022] [Indexed: 11/06/2022]
Abstract
Today, plastics are ubiquitous in everyday life, problem solvers of modern technologies, and crucial for sustainable development. Yet the surge in global demand for plastics of the growing world population has triggered a tidal wave of plastic debris in the environment. Moving from a linear to a zero-waste and carbon-neutral circular plastic economy is vital for the future of the planet. Taming the plastic waste flood requires closing the carbon loop through plastic reuse, mechanical and molecular recycling, carbon capture, and use of the greenhouse gas carbon dioxide. In the quest for eco-friendly products, plastics do not need to be reinvented but tuned for reuse and recycling. Their full potential must be exploited regarding energy, resource, and eco efficiency, waste prevention, circular economy, climate change mitigation, and lowering environmental pollution. Biodegradation holds promise for composting and bio-feedstock recovery, but it is neither the Holy Grail of circular plastics economy nor a panacea for plastic littering. As an alternative to mechanical downcycling, molecular recycling enables both closed-loop recovery of virgin plastics and open-loop valorization, producing hydrogen, fuels, refinery feeds, lubricants, chemicals, and carbonaceous materials. Closing the carbon loop does not create a Perpetuum Mobile and requires renewable energy to achieve sustainability. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Carl G Schirmeister
- Freiburg Materials Research Center and Institute for Macromolecular Chemistry, University of Freiburg, Stefan-Meier-Str. 31, D-79104, Freiburg, Germany
| | - Rolf Mülhaupt
- Sustainability Center, University of Freiburg, Ecker-Str. 4, D-79104, Freiburg, Germany
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34
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Roosen M, Harinck L, Ügdüler S, De Somer T, Hucks AG, Belé TGA, Buettner A, Ragaert K, Van Geem KM, Dumoulin A, De Meester S. Deodorization of post-consumer plastic waste fractions: A comparison of different washing media. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 812:152467. [PMID: 34952061 DOI: 10.1016/j.scitotenv.2021.152467] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/17/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
An important impediment to the acceptance of recyclates into a broader market is their unwanted odor after reprocessing. Different types of washing procedures are already in place, but fundamental insights into the deodorization efficiencies of different washing media are still relatively scarce. Therefore, in this study, the deodorization efficiencies of different types of plastics after washing with different media were determined via gas chromatography and mass spectrometry analysis. A total of 169 compounds subdivided into various chemical classes, such as alkanes, terpenes, and oxygenated compounds, were detected across all packaging types. Around 60 compounds were detected on plastic bottles, and around 40 were detected on trays and films. Owing to the differences in physicochemical properties of odor compounds, different deodorization efficiencies were obtained with different washing media. Water and caustic soda were significantly more efficient for poly(ethylene terephthalate) bottles with deodorization efficiencies up to 80%, whereas for polyethylene (PE) and polypropylene bottles, the washing media were relatively inefficient (around 30-40%). Adding a detergent or an organic solvent could increase deodorization efficiencies by up to 70-90% for these packaging types. A similar trend was observed for PE films having deodorization efficiencies in the range of 40-50% when washing with water or caustic soda and around 70-80% when a detergent was added. Polystyrene trays were most effectively deodorized with a detergent, achieving efficiencies up to 67%. Hence, this study shows that optimal washing processes should be tailored to specific packaging types to further improve deodorization and to eventually be able to meet ambitious European recycling targets.
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Affiliation(s)
- Martijn Roosen
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium
| | - Lies Harinck
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium
| | - Sibel Ügdüler
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium; Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering & Architecture, Ghent University, Technologiepark 125, B-9052 Zwijnaarde, Belgium
| | - Tobias De Somer
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium; Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering & Architecture, Ghent University, Technologiepark 125, B-9052 Zwijnaarde, Belgium
| | - Amaury-Gauvain Hucks
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium
| | - Tiago G A Belé
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Chair of Aroma and Smell Research, Department of Chemistry and Pharmacy, Henkestraße 9, 91054 Erlangen, Germany
| | - Andrea Buettner
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Chair of Aroma and Smell Research, Department of Chemistry and Pharmacy, Henkestraße 9, 91054 Erlangen, Germany; Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Straße 35, 85354 Freising, Germany
| | - Kim Ragaert
- Center for Polymer and Material Technologies (CPMT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 130, B-9052 Zwijnaarde, Belgium
| | - Kevin M Van Geem
- Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering & Architecture, Ghent University, Technologiepark 125, B-9052 Zwijnaarde, Belgium
| | - Ann Dumoulin
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium
| | - Steven De Meester
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium.
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35
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Muñoz Meneses RA, Cabrera-Papamija G, Machuca-Martínez F, Rodríguez LA, Diosa JE, Mosquera-Vargas E. Plastic recycling and their use as raw material for the synthesis of carbonaceous materials. Heliyon 2022; 8:e09028. [PMID: 35342833 PMCID: PMC8941171 DOI: 10.1016/j.heliyon.2022.e09028] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/04/2021] [Accepted: 02/24/2022] [Indexed: 11/24/2022] Open
Abstract
Pollution by polymeric materials - in particular plastics - has a negative effect on the health of our planet. Approximately 4.9 billion tons of plastic are estimated to have been improperly disposed of, with the environment as their final destination. This scenario comes from a linear economic system, extraction-production-consumption and finally disposal. The alarming panorama has created the need to find technological solutions that generate new uses for discarded polymeric materials or turn them into part of the production process to produce new and novel materials, such as carbon nanotubes, graphene, or other carbonaceous materials of high added value, modifying the economy for a circular and sustainable production model. This review highlights the negative impact that the disposal of plastic materials has on the environment and the research needs that allow solving the pollution problems generated in the environment by these wastes. Also, the review highlights the current and future directions of recovery plastic waste research-based to promote innovations in the plastic production sector that could allow obtaining breakpoints in other industrial sectors with the technology-based companies.
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Affiliation(s)
- Rodrigo A Muñoz Meneses
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Cali, Colombia.,Faculty Gama, University of Brasilia, Gama DF, 72.444-240, Brazil
| | | | - Fiderman Machuca-Martínez
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Cali, Colombia.,Grupo de Investigación en Procesos Avanzados para Tratamientos Biológicos y Químicos (GAOX), Escuela de Ingeniería Química, Universidad del Valle, Cali, Colombia
| | - Luis A Rodríguez
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Cali, Colombia.,Grupo de Transiciones de Fase y Materiales Funcionales (GTFMF), Departamento de Física, Universidad del Valle, Cali, Colombia
| | - Jesús E Diosa
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Cali, Colombia.,Grupo de Transiciones de Fase y Materiales Funcionales (GTFMF), Departamento de Física, Universidad del Valle, Cali, Colombia
| | - Edgar Mosquera-Vargas
- Centro de Excelencia en Nuevos Materiales (CENM), Universidad del Valle, Cali, Colombia.,Grupo de Transiciones de Fase y Materiales Funcionales (GTFMF), Departamento de Física, Universidad del Valle, Cali, Colombia
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36
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Lee J, Kwon KH. Why is Generation MZ Passionate About Good Consumption of K-Cosmetics Amid the COVID-19 Pandemic? J Cosmet Dermatol 2022; 21:3208-3218. [PMID: 35176199 PMCID: PMC9115150 DOI: 10.1111/jocd.14859] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 04/02/2022] [Accepted: 02/14/2022] [Indexed: 11/25/2022]
Abstract
Background The ongoing pandemic of coronavirus disease 2019 (COVID‐19) is putting millions at risk in more and more countries, making it a serious public health threat worldwide. Under such circumstances, “Untact” and “Streaming Life” are emerging as major trends in the recent service industry, and the beauty lives commerce market is expanding centering on mobile shopping in Republic of Korea. Objectives This study descriptively investigated changes in the needs of beauty and cosmetics industry consumers for good consumption of the MZ generation after COVID‐19 pandemic. Methods This review paper is a literature review, and a narrative review approach has been used for this study. A total of 300 to 400 references were selected using representative journal search websites such as PubMed, Google Scholar, Scopus, ResearchGate, and RISS, of which a total of 39 papers were selected in the final stage based on 2009 to 2021. Results An E‐commerce packaging production and use have grown steadily in recent years as online purchases increase. As a result, the impact on the environment has also increased. Humanity faces climate change, pollution, environmental degradation, and/or destruction of air, soil, water, and ecosystems. The climate and environmental crisis will be one of the greatest challenges in human history. This review paper conducted a comprehensive study on the good consumption of MZ generation for K‐Cosmetics in COVID‐19 pandemic. Conclusion This review clearly identifies the needs of consumers in the beauty and cosmetics industry for good consumption of the MZ generation for K‐beauty in COVID‐19 pandemic. In addition, it is expected to be used as an important marketing material in the global cosmetics market by confirming new changes in the Korean cosmetic market, which is the center of K‐Beauty and K‐Cosmetics.
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Affiliation(s)
- Jinkyung Lee
- Division of Beauty Arts Care, Department of Practical Arts, Graduate School of Culture and Arts, Dongguk University, Seoul, 04620, South Korea.,Daily Beauty Unit, Amorepacific Co., Seoul, 04386, South Korea
| | - Ki Han Kwon
- College of General Education, Kookmin University, Seoul, 02707, Republic of Korea
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37
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Sheydaei M, Pouraman V, Alinia-Ahandani E, Shahbazi-Ganjgah S. PVCS/GO nanocomposites: investigation of thermophysical, mechanical and antimicrobial properties. J Sulphur Chem 2022. [DOI: 10.1080/17415993.2022.2036151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Milad Sheydaei
- Faculty of Polymer Engineering, Sahand University of Technology, Tabriz, Iran
| | - Vahid Pouraman
- Faculty of Polymer Engineering, Sahand University of Technology, Tabriz, Iran
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38
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Epps TH, Korley LTJ, Yan T, Beers KL, Burt TM. Sustainability of Synthetic Plastics: Considerations in Materials Life-Cycle Management. JACS AU 2022; 2:3-11. [PMID: 35098218 PMCID: PMC8790729 DOI: 10.1021/jacsau.1c00191] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Indexed: 06/01/2023]
Abstract
The sustainability of current and future plastic materials is a major focus of basic research, industry, government, and society at large. There is a general recognition of the positive impacts of plastics, especially packaging; however, the negative consequences around end-of-life outcomes and overall materials circularity are issues that must be addressed. In this perspective, we highlight some of the challenges associated with the many uses of plastic components and the diversity of materials needed to satisfy consumer demand, with several examples focused on plastics packaging. We also discuss the opportunities provided by conventional and advanced recycling/upgrading routes to petrochemical and bio-based materials and feedstocks, along with overviews of chemistry-related (experimental, computational, data science, and materials traceability) approaches to the valorization of polymers toward a closed-loop environment.
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Affiliation(s)
- Thomas H. Epps
- Department
of Chemical & Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States of America
- Department
of Materials Science and Engineering, University
of Delaware, Newark, Delaware 19716, United
States of America
- Center
for Research in Soft matter & Polymers (CRiSP), University of Delaware, Newark, Delaware 19716, United States of America
| | - LaShanda T. J. Korley
- Department
of Chemical & Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States of America
- Department
of Materials Science and Engineering, University
of Delaware, Newark, Delaware 19716, United
States of America
- Center
for Research in Soft matter & Polymers (CRiSP), University of Delaware, Newark, Delaware 19716, United States of America
| | - Tianwei Yan
- Department
of Chemical & Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States of America
- Center
for Plastics Innovation (CPI), University
of Delaware, Newark, Delaware 19716, United
States of America
| | - Kathryn L. Beers
- Materials
Measurement Laboratory, National Institute
of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States of America
| | - Tiffani M. Burt
- Innovation
& Sustainability, Sealed Air Corporation, Charlotte, North Carolina 28208, United States of America
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39
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Pretreatment of Plastic Waste: Removal of Colorants from HDPE Using Biosolvents. MOLECULES (BASEL, SWITZERLAND) 2021; 27:molecules27010098. [PMID: 35011334 PMCID: PMC8746977 DOI: 10.3390/molecules27010098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 11/17/2022]
Abstract
Plastics recycling remains a challenge due to the relatively low quality of the recycled material, since most of the developed recycling processes cannot deal with the additives present in the plastic matrix, so the recycled products end up in lower-grade applications. The application of volatile organic solvents for additives removal is the preferred choice. In this study, pretreatment of plastic packaging waste to remove additives using biosolvents was investigated. The plastic waste used was high-density polyethylene (HDPE) with blue and orange colorants (pigment and/or dye). The first step was to identify the type of colorants present in the HDPE, and we found that both plastics presented only one colorant that was actually a pigment. Then, limonene, a renewable solvent, was used to solubilize HDPE. After HDPE dissolution, a wide range of alcohols (mono-, di-, and tri-alcohols) was evaluated as antisolvents in order to selectively precipitate the polymer and maximize its purity. The use of limonene as solvent for plastic dissolution, in combination with poly-alcohols with an intermediate alkyl chain length and a large number of hydroxyl (OH) groups, was found to work best as an antisolvent (1,2,3-propanetriol and 1,2,4-butanetriol), leading to a removal of up to 94% and 100% of the blue and orange pigments, respectively. Finally, three cycles of extraction were carried out, proving the capability of the solvent and antisolvent to be recovered and reused, ensuring the economic viability and sustainability of the process. This pretreatment provides a secondary source of raw materials and revenue for the recycling process, which may lead to an increase in the quality of recycled polymers, contributing to the development of an economical and sustainable recycling process.
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40
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Toroslu AG. An Experimental Study on the Properties of Recycled High-Density Polyethylene. INT POLYM PROC 2021. [DOI: 10.1515/ipp-2020-4071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Recycling of plastic materials has become more environmentally important than recycling of other materials. The most important problem during recycling is the presence of oil, dirt, dust and metal particles that are mixed with plastic materials. These mixtures can change their its mechanical and physical properties and it is quite costly to remove them completely. Removing iron alloy particles from plastic is possible by using the magnetic method. However, removing non-metallic materials requires extra processing. In this study, the use of recycled High-Density Polyethylene (rHDPE) without an expensive cleaning processes has been investigated. Different amounts of aluminium oxide (Al2O3) were added to High Density Polyethylene (HDPE) to simulate the effect of non-metallic material involved. The effect of these contamination rates on the mechanical and physical properties of HDPE was examined in detail. For this purpose, recyclable materials were produced by mixing rHDPE with 1%, to 7% Al2O3
. The results show that up to 7% of the mixture has acceptable effects on the properties of HDPE. When the results of the experiments are examined, it is observed that there is a 3.74% change in the elastic modulus of the material. This means, that up to 7% non-metal contaminated rHDPE material can be used without any costly recycling process.
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41
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Sánchez-Rivera KL, Zhou P, Kim MS, González Chávez LD, Grey S, Nelson K, Wang SC, Hermans I, Zavala VM, Van Lehn RC, Huber GW. Reducing Antisolvent Use in the STRAP Process by Enabling a Temperature-Controlled Polymer Dissolution and Precipitation for the Recycling of Multilayer Plastic Films. CHEMSUSCHEM 2021; 14:4317-4329. [PMID: 34378340 DOI: 10.1002/cssc.202101128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/06/2021] [Indexed: 05/11/2023]
Abstract
The recently reported processing strategy called solvent-targeted recovery and precipitation (STRAP) enables deconstruction of multilayer plastic packaging films into their constituent resins by selective dissolution. It uses a series of solvent washes that are guided by thermodynamic calculations of polymer solubility. In this work, the use of antisolvents in the STRAP process was reduced and solvent mixtures were considered to enable the temperature-controlled dissolution and precipitation of the target polymers in multilayer films. This was considered as a means to further improve the STRAP process and its estimated costs. Two STRAP approaches were compared based on different polymer precipitation techniques: precipitation by the addition of an antisolvent (STRAP-A) and precipitation by decreasing the solvent temperature (STRAP-B). Both approaches were able to separate the constituent polymers in a post-industrial film composed primarily of polyethylene (PE), ethylene vinyl alcohol (EVOH), and polyethylene terephthalate (PET) with near 100 % material efficiency. Technoeconomic analysis indicates that the minimum selling price (MSP) of the recycled resins with STRAP-B is 21.0 % lower than that achieved with STRAP-A. This provides evidence that thermally driven polymer precipitation is an option to reduce the use of antisolvents, making the STRAP process more economically and environmentally attractive. A third process, STRAP-C, was demonstrated with another post-industrial multilayer film of a different composition. The results demonstrate that this process can also recover polymers at similar costs to those of virgin resins, indicating that the STRAP technology is flexible and can remain economically competitive as the plastic feed complexity is increased.
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Affiliation(s)
- Kevin L Sánchez-Rivera
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Panzheng Zhou
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Min Soo Kim
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Leonardo D González Chávez
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Steve Grey
- Amcor, Neenah Innovation Center, Neenah, WI, 54956, USA
| | - Kevin Nelson
- Amcor, Neenah Innovation Center, Neenah, WI, 54956, USA
| | - Shao-Chun Wang
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ive Hermans
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Victor M Zavala
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Reid C Van Lehn
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - G W Huber
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
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42
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Zhou P, Sánchez-Rivera KL, Huber GW, Van Lehn RC. Computational Approach for Rapidly Predicting Temperature-Dependent Polymer Solubilities Using Molecular-Scale Models. CHEMSUSCHEM 2021; 14:4307-4316. [PMID: 34240559 DOI: 10.1002/cssc.202101137] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/03/2021] [Indexed: 06/13/2023]
Abstract
One promising approach to recycle multicomponent plastic waste (e. g., multilayer plastic films) is selective dissolution. Selective dissolution is a solvent-mediated process in which differences in polymer solubility in a carefully chosen solvent system are exploited to recover a target polymer. Here, a computational approach was developed that rapidly predicts temperature-dependent polymer solubilities to guide the design of solvent systems for solvent-mediated polymer recycling. Polymer conformations were obtained from molecular dynamics simulations by modeling the polymer as a short oligomer and then used as input to the conductor-like screening model for real solvents (COSMO-RS) for solubility predictions. Using polyethylene (PE) and ethylene vinyl alcohol (EVOH) as representative polymers, the effect of simulation parameters was systematically studied, and predicted solubilities were found to be in good agreement with experimental measurements. The applicability of the approach was demonstrated by identifying selective solvents for PE and EVOH dissolution from a library of 524 solvents.
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Affiliation(s)
- Panzheng Zhou
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Kevin L Sánchez-Rivera
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - George W Huber
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Reid C Van Lehn
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53706, USA
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43
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Hackler RA, Vyavhare K, Kennedy RM, Celik G, Kanbur U, Griffin PJ, Sadow AD, Zang G, Elgowainy A, Sun P, Poeppelmeier KR, Erdemir A, Delferro M. Synthetic Lubricants Derived from Plastic Waste and their Tribological Performance. CHEMSUSCHEM 2021; 14:4181-4189. [PMID: 34038620 DOI: 10.1002/cssc.202100912] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/22/2021] [Indexed: 06/12/2023]
Abstract
The energy efficiency, mechanical durability, and environmental compatibility of all moving machine components rely heavily on advanced lubricants for smooth and safe operation. Herein an alternative family of high-quality liquid (HQL) lubricants was derived by the catalytic conversion of pre- and post-consumer polyolefin waste. The plastic-derived lubricants performed comparably to synthetic base oils such as polyalphaolefins (PAOs), both with a wear scar volume (WSV) of 7.5×10-5 mm-3 . HQLs also performed superior to petroleum-based lubricants such as Group III mineral oil with a WSV of 1.7×10-4 mm-3 , showcasing a 44 % reduction in wear. Furthermore, a synergistic reduction in friction and wear was observed when combining the upcycled plastic lubricant with synthetic oils. Life cycle and techno-economic analyses also showed this process to be energetically efficient and economically feasible. This novel technology offers a cost-effective opportunity to reduce the harmful environmental impact of plastic waste on our planet and to save energy through reduction of friction and wear-related degradations in transportation applications akin to synthetic oils.
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Affiliation(s)
- Ryan A Hackler
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Kimaya Vyavhare
- Applied Materials Division, Argonne National Laboratory, Lemont, IL 60439, USA
- Materials Science and Engineering Department, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Robert M Kennedy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Gokhan Celik
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
- Department of Chemical Engineering, Middle East Technical University, Ankara, 06800, Turkey
| | - Uddhav Kanbur
- Department of Chemistry, Iowa State University and Ames Laboratory, Ames, IA 50011, USA
| | - Philip J Griffin
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Aaron D Sadow
- Department of Chemistry, Iowa State University and Ames Laboratory, Ames, IA 50011, USA
| | - Guiyan Zang
- Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Amgad Elgowainy
- Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Pingping Sun
- Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | | | - Ali Erdemir
- J. Mike Walker'66 Department of Mechanical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Massimiliano Delferro
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
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Muhyuddin M, Mustarelli P, Santoro C. Recent Advances in Waste Plastic Transformation into Valuable Platinum-Group Metal-Free Electrocatalysts for Oxygen Reduction Reaction. CHEMSUSCHEM 2021; 14:3785-3800. [PMID: 34288512 PMCID: PMC8519148 DOI: 10.1002/cssc.202101252] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/20/2021] [Indexed: 05/22/2023]
Abstract
Plastic waste causes severe environmental hazards, owing to inadequate disposal and limited recycling. Under the framework of circular economy, there are urgent demands to valorize plastic waste more safely and sustainably. Therefore, much scientific interest has been witnessed recently in plastic waste-derived electrocatalysts for the oxygen reduction reaction (ORR), where the plastic waste acts as a cost-effective and easily available precursor for the carbon backbone. The ORR is not only a key efficiency indicator for fuel cells and metal-air batteries but also a major obstacle for their commercial realization. The applicability of the aforementioned electrochemical devices is limited, owing to sluggish ORR activity and expensive platinum-group metal electrocatalysts. However, waste-derived ORR electrocatalysts are emerging as a potential substitute that could be inexpensively fabricated upon the conversion of plastic waste into active materials containing earth-abundant transition metals. In this Minireview, very recent research developments regarding plastic waste-derived ORR electrocatalysts are critically summarized with a prime focus on the followed synthesis routes, physicochemical properties of the derived electrocatalysts, and their ultimate electrochemical performance. Finally, the prospects for the future development of plastic waste-derived electrocatalysts are discussed.
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Affiliation(s)
- Mohsin Muhyuddin
- Department of Material ScienceUniversity of Milano-BicoccaU5 Via Cozzi 5520125MilanItaly
| | - Piercarlo Mustarelli
- Department of Material ScienceUniversity of Milano-BicoccaU5 Via Cozzi 5520125MilanItaly
| | - Carlo Santoro
- Department of Material ScienceUniversity of Milano-BicoccaU5 Via Cozzi 5520125MilanItaly
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45
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Lowe CN, Phillips KA, Favela KA, Yau AY, Wambaugh JF, Sobus JR, Williams AJ, Pfirrman AJ, Isaacs KK. Chemical Characterization of Recycled Consumer Products Using Suspect Screening Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:11375-11387. [PMID: 34347456 PMCID: PMC8475772 DOI: 10.1021/acs.est.1c01907] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Recycled materials are found in many consumer products as part of a circular economy; however, the chemical content of recycled products is generally uncharacterized. A suspect screening analysis using two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) was applied to 210 products (154 recycled, 56 virgin) across seven categories. Chemicals in products were tentatively identified using a standard spectral library or confirmed using chemical standards. A total of 918 probable chemical structures identified (112 of which were confirmed) in recycled materials versus 587 (110 confirmed) in virgin materials. Identified chemicals were characterized in terms of their functional use and structural class. Recycled paper products and construction materials contained greater numbers of chemicals than virgin products; 733 identified chemicals had greater occurrence in recycled compared to virgin materials. Products made from recycled materials contained greater numbers of fragrances, flame retardants, solvents, biocides, and dyes. The results were clustered to identify groups of chemicals potentially associated with unique chemical sources, and identified chemicals were prioritized for further study using high-throughput hazard and exposure information. While occurrence is not necessarily indicative of risk, these results can be used to inform the expansion of existing models or identify exposure pathways currently neglected in exposure assessments.
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Affiliation(s)
- Charles N. Lowe
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, 37831, United States
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
| | - Katherine A. Phillips
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
| | - Kristin A. Favela
- Southwest Research Institute, San Antonio, Texas, 78759, United States
| | - Alice Y. Yau
- Southwest Research Institute, San Antonio, Texas, 78759, United States
| | - John F. Wambaugh
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
| | - Jon R. Sobus
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
| | - Antony J. Williams
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
| | - Ashley J. Pfirrman
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
- Oak Ridge Associated Universities, Oak Ridge, Tennessee, 37831, United States
| | - Kristin K. Isaacs
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, North Carolina, 27709, United States
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46
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Ellis LD, Rorrer NA, Sullivan KP, Otto M, McGeehan JE, Román-Leshkov Y, Wierckx N, Beckham GT. Chemical and biological catalysis for plastics recycling and upcycling. Nat Catal 2021. [DOI: 10.1038/s41929-021-00648-4] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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47
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Chen X, Luo Y, Bai X. Upcycling polyamide containing post-consumer Tetra Pak carton packaging to valuable chemicals and recyclable polymer. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 131:423-432. [PMID: 34252692 DOI: 10.1016/j.wasman.2021.06.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
Billion tons of post-consumer Tetra Pak cartons are discarded annually as land and ocean wastes, creating significant environmental problems and resource losses. Recycling of the carton wastes is hindered by its multi-material compositions and low values of the recycled products. In this study, a novel upcycling of the cartons was investigated. A post-consumer carton consisting of paper, polyolefin, and polyamide was directly converted in 210-230 °C tetrahydrofuran containing 10-20 mM acid to produce up to 19.2% of levoglucosenone and 8.6% of furfural by selectively decomposing paper fraction. The remaining solids containing mostly intact polyethylene and polyamide but also a smaller fraction of paper-derived char were separated using a solvent-dissolution method. The xylene-soluble fraction was a recycled polymer similar to the original polyethylene, which was verified by its functional groups, the composition of the pyrolysis products, and the melt rheology results. The xylene-insoluble fraction was a mixture of polyamide and paper-derived char. Upon pyrolysis, caprolactam was produced as the only major vapor product. The remaining, thermally stable paper-derived char could be used as a high-quality solid fuel. Overall, the demonstrated recycling method could potentially maximize the values of the products recovered from carton wastes.
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Affiliation(s)
- Xiaolin Chen
- Department of Mechanical Engineering, Iowa State University, Ames, IA, USA
| | - Yixin Luo
- Department of Mechanical Engineering, Iowa State University, Ames, IA, USA
| | - Xianglan Bai
- Department of Mechanical Engineering, Iowa State University, Ames, IA, USA.
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48
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Korley LTJ, Epps TH, Helms BA, Ryan AJ. Toward polymer upcycling-adding value and tackling circularity. Science 2021; 373:66-69. [PMID: 34210879 DOI: 10.1126/science.abg4503] [Citation(s) in RCA: 171] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Plastics have revolutionized modern life, but have created a global waste crisis driven by our reliance and demand for low-cost, disposable materials. New approaches are vital to address challenges related to plastics waste heterogeneity, along with the property reductions induced by mechanical recycling. Chemical recycling and upcycling of polymers may enable circularity through separation strategies, chemistries that promote closed-loop recycling inherent to macromolecular design, and transformative processes that shift the life-cycle landscape. Polymer upcycling schemes may enable lower-energy pathways and minimal environmental impacts compared with traditional mechanical and chemical recycling. The emergence of industrial adoption of recycling and upcycling approaches is encouraging, solidifying the critical role for these strategies in addressing the fate of plastics and driving advances in next-generation materials design.
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Affiliation(s)
- LaShanda T J Korley
- Center for Plastics Innovation, University of Delaware, Newark, DE 19716, USA. .,Center for Research in Soft matter and Polymers, and Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA.,Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
| | - Thomas H Epps
- Center for Plastics Innovation, University of Delaware, Newark, DE 19716, USA. .,Center for Research in Soft matter and Polymers, and Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA.,Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
| | - Brett A Helms
- The Molecular Foundry, Materials Sciences Division, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Anthony J Ryan
- Grantham Centre for Sustainable Futures and the Department of Chemistry, The University of Sheffield, Brookhill, Sheffield S3 7HF, UK
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Das P, Gabriel JCP, Tay CY, Lee JM. Value-added products from thermochemical treatments of contaminated e-waste plastics. CHEMOSPHERE 2021; 269:129409. [PMID: 33388566 DOI: 10.1016/j.chemosphere.2020.129409] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 12/14/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
The rise of electronic waste (e-waste) generation around the globe has become a major concern in recent times and its recycling is mostly focused on the recovery of valuable metals, such as gold, silver, and copper, etc. However, e-waste consists of a significant weight fraction of plastics (25-30%) which are either discarded or incinerated. There is a growing need for recycling of these e-waste plastics. The majority of them are made from high-quality polymers (composites), such as acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), polycarbonate (PC), polyamide (PA), polypropylene (PP) and epoxies. These plastics are often contaminated with hazardous materials, such as brominated flame retardants (BFRs) and heavy metals (such as Pb and Hg). Under any thermal stress (thermal degradation), the Br present in the e-waste plastics produces environmentally hazardous pollutants, such as hydrogen bromide or polybrominated diphenyl ethers/furans (PBDE/Fs). The discarded plastics can lead to the leaching of toxins into the environment. It is important to remove the toxins from the e-waste plastics before recycling. This review article gives a detailed account of e-waste plastics recycling and recovery using thermochemical processes, such as extraction (at elevated temperature), incineration (combustion), hydrolysis, and pyrolysis (catalytic/non catalytic). A basic framework of the existing processes has been established by reviewing the most interesting findings in recent times and the prospects that they open in the field recycling of e-waste plastics.
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Affiliation(s)
- Pallab Das
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
| | | | - Chor Yong Tay
- School of Materials Science and Engineering, Nanyang Technological University, N4.1, 50 Nanyang Avenue, Singapore, 639798, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Jong-Min Lee
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
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Kosloski-Oh SC, Wood ZA, Manjarrez Y, de Los Rios JP, Fieser ME. Catalytic methods for chemical recycling or upcycling of commercial polymers. MATERIALS HORIZONS 2021; 8:1084-1129. [PMID: 34821907 DOI: 10.1039/d0mh01286f] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Polymers (plastics) have transformed our lives by providing access to inexpensive and versatile materials with a variety of useful properties. While polymers have improved our lives in many ways, their longevity has created some unintended consequences. The extreme stability and durability of most commercial polymers, combined with the lack of equivalent degradable alternatives and ineffective collection and recycling policies, have led to an accumulation of polymers in landfills and oceans. This problem is reaching a critical threat to the environment, creating a demand for immediate action. Chemical recycling and upcycling involve the conversion of polymer materials into their original monomers, fuels or chemical precursors for value-added products. These approaches are the most promising for value-recovery of post-consumer polymer products; however, they are often cost-prohibitive in comparison to current recycling and disposal methods. Catalysts can be used to accelerate and improve product selectivity for chemical recycling and upcycling of polymers. This review aims to not only highlight and describe the tremendous efforts towards the development of improved catalysts for well-known chemical recycling processes, but also identify new promising methods for catalytic recycling or upcycling of the most abundant commercial polymers.
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Affiliation(s)
- Sophia C Kosloski-Oh
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
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