ArticlePublisher preview available

Life Cycle Assessment of Polyethylene Terephthalate Packaging: An Overview

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Life cycle assessment (LCA) is a common technique to evaluate the environmental impact of poly(ethylene terephthalate) (PET) packaging. A review is needed to gain a clear view of the accumulated knowledge, scientific trends and what remains to be done. The main purpose of this paper is to present an overview of LCA of PET, mainly for packaging. LCA studies of PET consist largely of two segments: final destination of post-consumer PET, comparing recycling with other options (incineration, landfilling); and alternative materials, comparing PET with other polymers or materials such as glass and aluminum cans. In the first case, the scenarios most often compared have been landfill disposal and mechanical recycling. There has also been considerable research on the use of post-consumer PET for energy conversion and chemical recycling. In the second case, the main polymer compared with PET is poly(lactic acid), whose mechanical properties make it unsuitable for carbonated beverage bottles. Numerous articles have focused only on energy consumption or global warming potential. Few studies have discussed mechanical recycling technologies in LCA and there is a lack of data on the processes used in developing countries. This review highlights the need to conduct LCA studies of PET, since many aspects are still not fully understood.
Vol.:(0123456789)
1 3
Journal of Polymers and the Environment (2019) 27:533–548
https://doi.org/10.1007/s10924-019-01375-5
REVIEW
Life Cycle Assessment ofPolyethylene Terephthalate Packaging:
AnOverview
ThiagoS.Gomes1 · LeilaL.Y.Visconte1,2· ElenB.A.V.Pacheco1,2
Published online: 17 January 2019
© Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract
Life cycle assessment (LCA) is a common technique to evaluate the environmental impact of poly(ethylene terephthalate)
(PET) packaging. A review is needed to gain a clear view of the accumulated knowledge, scientific trends and what remains to
be done. The main purpose of this paper is to present an overview of LCA of PET, mainly for packaging. LCA studies of PET
consist largely of two segments: final destination of post-consumer PET, comparing recycling with other options (incineration,
landfilling); and alternative materials, comparing PET with other polymers or materials such as glass and aluminum cans. In
the first case, the scenarios most often compared have been landfill disposal and mechanical recycling. There has also been
considerable research on the use of post-consumer PET for energy conversion and chemical recycling. In the second case,
the main polymer compared with PET is poly(lactic acid), whose mechanical properties make it unsuitable for carbonated
beverage bottles. Numerous articles have focused only on energy consumption or global warming potential. Few studies
have discussed mechanical recycling technologies in LCA and there is a lack of data on the processes used in developing
countries. This review highlights the need to conduct LCA studies of PET, since many aspects are still not fully understood.
Keywords Poly(ethylene terephthalate)· PET· Life cycle assessment· Recycling· Environmental impact
Introduction
Poly(ethylene terephthalate) (PET) is one of the main plas-
tics in urban waste, with global production of 30.3 × 106
tons in 2017 [1]. It is primarily used for packaging and tex-
tile production [2, 3]. This overview paper concentrates on
LCA of PET for packaging. PET has become popular in
the production of disposable carbonated beverage bottles
due to its durability, strength and transparency. However,
because of PET packaging short useful life and large produc-
tion volume, new challenges in determining the most appro-
priate final destination [4, 5] or replacement by renewable
materials [69] have emerged. The growing environmental
concern underscores the need for scientific research into
ways of reducing the environmental impact and managing
waste, in light of the complex interaction between produc-
tion, consumption and disposal or recycling [10]. Among
the available tools, life cycle assessment (LCA) has shown
promising results in sustainability studies [11, 12]. The most
common aspects considered in applying LCA to analyze the
final destination of PET packaging after consumption or its
replacement by renewable materials are the impact analysis
methods within geographical boundaries or scope of appli-
cations of recycled PET [4, 8, 13, 14].
This paper aims to clarify knowledge on LCA of PET,
and identify patterns between past research [15], in addition
to describing current LCA studies applied to PET and the
recycling possibilities or alternative materials used. It con-
sists of three sections: the first provides a brief definition of
the LCA method, the second involves alternative PET mate-
rials and the third alternative destinations for post-consumer
PET.
* Thiago S. Gomes
thiagosg@ima.ufrj.br
1 Instituto de Macromoléculas Professora Eloisa Mano,
Universidade Federal doRio de Janeiro, Avenida Horácio
Macedo 2.030, Centro de Tecnologia, Bloco J, Ilha do
Fundão, RiodeJaneiro, RJCEP21941-598, Brazil
2 Escola Politécnica/Programa de Engenharia Ambiental,
Universidade Federal doRio de Janeiro, RiodeJaneiro, RJ,
Brazil
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... The environmental performance of biobased products (e.g., biobased chemicals) has been evaluated using life cycle assessment (LCA) tools ( Gomes et al., 2019 ;Liptow et al., 2015 ;Volanti et al., 2019 ). However, the design of biomass supply chains has mostly focused on producing biofuels and electricity from renewable resources (e.g., agricultural products and waste) ( Ba et al., 2016 ;Malladi and Sowlati, 2020 ). ...
... Therefore, the accounting of GHG emissions (from transportation and process) is not a strong criterion (alone) to play a key role in the design of biobased supply chains. The production of biobased PET also contributes to other impact categories (e.g., acidification, land use, eutrophication) ( Chen et al., 2016 ;Garcia-Velasquez and van der Meer, 2021 ;Gomes et al., 2019 ). These 'externalities' should also be accounted for in economic terms in the optimization model to provide a full picture of environmental costs. ...
Article
Full-text available
Bioplastics are considered a sustainable alternative to (partly) substitute fossil-based plastics. Nevertheless, it is still uncertain if the use of biomass for the production of bioplastics can mitigate the environmental impact of fossil-based plastics and simultaneously provide economic benefits. An optimization model is proposed to design biobased supply chain networks that account for economic (total costs) and environmental (greenhouse gas emissions) criteria. Life cycle costing and life cycle assessment were used to evaluate the economic and environmental costs of the biobased polyethylene terephthalate (PET) production using sugar beet and wheat as feedstock. The 100% biobased PET production evidenced higher economic and environmental costs than the 30% biobased PET production. The feedstock selection played a key role, whereas the use of wheat for both 30% and 100% biobased PET had the highest costs and greenhouse gas emissions. It is highlighted that the economic performance of the biobased terephthalic acid (PTA) production, the feedstock selection (sugar beet), and the carbon tax scenario (>100 €/t CO2) are key parameters for designing a sustainable biobased PET supply chain.
... Meanwhile, the non-packaging sector involves trash bags, labels, films for agriculture, construction, etc. Low-density polyethylene (LDPE) [5][6][7] and high-density polyethylene (HDPE) [8,9] are the most common polymers used in the consumer packaging sector, followed by polyethylene terephthalate (PET) [10][11][12] and polypropylene (PP) [13,14]. In the case of agricultural applications and another non-consumer packaging, LDPE and linear low-density polyethylene (LLDPE) [15,16] are the most used materials [17]. ...
Article
Full-text available
In a circular economy context with the dual problems of depletion of natural resources and the environmental impact of a growing volume of wastes, it is of great importance to focus on the recycling process of multilayered plastic films. This review is dedicated first to the general concepts and summary of plastic waste management in general, making emphasis on the multilayer films recycling process. Then, in the second part, the focus is dealing with multilayer films manufacturing process, including the most common materials used for agricultural applications, their processing, and the challenges of their recycling, recyclability, and reuse. Hitherto, some prospects are discussed from eco-design to mechanical or chemical recycling approaches.
... Life cycle assessments (LCA) are commonly conducted by industry and scientists as a comprehensive tool for assessing the environmental impacts of different packaging products (Batlle-Bayer et al., 2019;Ferrara and De Feo, 2018;Gomes et al., 2019;Molina-Besch et al., 2019). A specific challenge in monitoring the circularity of packaging relates to the application of appropriate circularity metrics. ...
Article
This paper introduces a new methodology for the analysis of the time of recycling to compare different life cycle assessments (LCA). We apply the three variables that define the value creation principles in the Ellen MacArthur Foundation’s definition of circularity: material, energy and time. Including time in the LCA methodology improves understanding of the system under study, especially for products that have a relatively short usage time compared to their recycling time. We developed a formula that includes the time necessary for obtaining the secondary material needed for "n+1" product. The paper shows that we need to consider the production of additional packaging products, quantity of which depends on the time needed for recycling, to develop comparative LCAs between systems that serve same function. The proposed approach to packaging LCA contributes to the scientific debate over the allocation of credits and burdens between several consecutive life cycles of a material.
... However, in a circular economy, introduction of any environmental pressure reducing technique requires social performance criteria where the feasibility of proposed environmental scenario can be cross-checked and implemented. Moreover, many researchers have highlighted the lack of inventory data for EOL scenarios in polymeric wastes oriented LCA studies (Gomes et al., 2019;Saleh, 2016;Sazdovski et al., 2021), which significantly alters the overall environmental performance of a product. Thus, the LCA with EOL studies are more lucid and viable for designing materials which aims at the conservation of environment with practical disposal scenarios. ...
Article
Carbon black (CB) and silica (Sil) as rubber reinforcement have raised environmental concerns for being high resources consumptive and less susceptible towards biodegradability. Cellulose nanocrystal (CNC) has demonstrated great potentials for use as biodegradable nanofillers in rubber nanocomposites while evaluation of its environmental impacts with optimal end-of-life (EOL) choices is not carried out. To simulate realistic EOL, thermo-oxidative aging and soil burial aging behaviors of rubber nanocomposites with 33.3% filler were performed. The environmental weathering performance modeled with the help of life cycle assessment (LCA) illustrates increased biodegradation susceptibility with partial replacement of CB or Sil with CNC in the nanocomposites, hence promoting the environmental solutions for waste minimalization by enhancing the biodegradability potentials. In terms of LCA, the CNC incorporation contributes more to the environmental impacts in manufacturing but greatly lowers the EOL choices, by reducing the global warming potential values.
... They found that the global GHG emissions of traditional plastics are projected to grow to 650 million tonnes of CO 2 e by 2050. Gomes et al. (2019) carried out a systematic review on the LCA studies of PET packaging materials. Brizga et al. (2020) analyzed the potential environmental consequences of replacing petrochemical packaging plastics with bioplastics (in terms of GHG emissions, land and water footprints) based on a review of LCA studies and calculations to assess the footprint of such alternatives. ...
Article
The plastic industry is a high carbon emission industry in China. Previous studies mainly focused on the flows and stocks of polystyrene (PS), polyvinyl chloride (PVC), and acrylonitrile-butadiene-styrene (ABS) plastics. However, there is limited detailed information on the GHG emissions of PS, PVC, and ABS in China and the key paths of carbon peak in 2030. Therefore, we established the GHG accounting model of PS, PVC, and ABS based on dynamic material flow analysis and life cycle assessment, and further analyzed the carbon peak path and strategy in 2030. The results show that the main source of GHG is the production and manufacturing stages. Notably, the key paths of GHG emissions are the manufacturing process of PS STP&C and foam plastics, PVC film and STP&C, and ABS STP&C. Moreover, the cumulative GHG emissions of these plastics reached 230.34, 677.43, 143.12 Tg CO2e in 2007-2017, respectively. From 2007 to 2017, the trends of GHG emissions from the PS, PVC, and ABS had their characteristics. PVC had the largest GHG emissions. Different from PVC and ABS, GHG emissions from PS showed a trend of slow rise and then slow decline in this period. According to the current trend, the life-cycle GHG emissions of PS, PVC, and ABS would not reach the carbon peak in 2030. Under some mitigation strategies, the carbon peak would be achieved before 2030. This study clarifies the main sources of life-cycle GHG emissions of these plastics, and reveals the path and strategy of carbon peak in 2030.
... According to international standards of life cycle assessment, closed-loop and open-loop methods are the two different recycling processes (Gomes et al. 2019). The former occurs if the same product is produced using the same process of reintroducing the material. ...
Article
Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries. Polyethylene terephthalate has beneficial properties such as light weight, high tensile strength, transparency and gas barrier. Nonetheless, there is actually increasing concern about plastic pollution and toxicity. Here we review the properties, occurrence, toxicity, remediation and analysis of polyethylene terephthalate as macroplastic, mesoplastic, microplastic and nanoplastic. Polyethylene terephthalate occurs in groundwater, drinking water, soils and sediments. Plastic uptake by humans induces diseases such as reducing migration and proliferation of human mesenchymal stem cells of bone marrow and endothelial progenitor cells. Polyethylene terephthalate can be degraded by physical, chemical and biological methods.
Article
Full-text available
The plastic economy, despite offering unique properties in fulfilling the functions of products in different industrial sectors over decades, has so far been mainly linear, that is, “take‐make and dispose” with only a small fraction of plastics being recycled worldwide. With ever‐increasing circular economy initiatives and the urge to conserve resources and prevent plastic pollution from affecting ecosystems, more emphasis on the resource recovery of plastic products after its use has been made over the last few years. It is necessary for manufacturers to understand the value chain as early as the design phase while manufacturing and distributing plastic products across the world. The current study provides an overview of the status quo of plastic waste management and analyzes the Life Cycle Assessment (LCA) studies of different End‐of‐Life (EoL) options for plastics. Based on the LCA studies, a preliminary, country‐specific Circular Footprint (CF) is calculated and Design for Recycling (DfR) strategies are identified. Results show that the environmental impacts of different EoL options differ significantly for different plastics. The CF highlights the lack of data regarding the composition and recovery of plastics in different countries thus showing the necessity to consider the whole lifecycle when quantifying the environmental impacts of plastics. To understand the environmental impacts of treating plastic wastes, a review on the Life Cycle Assessment (LCA) studies of End‐of‐Life (EoL) options of different plastic types is conducted. A preliminary Circular Footprint (CF) for treating plastic wastes in different countries is calculated from the environmental impacts. Based on these results, Design for Recycling (DfR) strategies are identified in this study.
Article
Full-text available
A series of aryl sulfonic acids were tested as catalysts for acid hydrolysis occurring at the surface of poly(ethylene) terephthalate (PET) particles. Specifically, p-toluenesulfonic acid monohydrate (PTSA), 2-naphthalenesulfonic acid (2-NSA), and 1,5-naphthalenedisulfonic acid tetrahydrate (1,5-NDSA) were chosen to provide sulfonic acid active groups and varying hydrophobic func-tionality. The effect of catalyst concentration and reaction temperature on PET hydrolysis rate was studied. The aryl sulfonic acid catalysts exhibited much higher rates of PET hydrolysis than the mineral acid, H 2 SO 4. At 150 C and 4 M catalyst, the time required to achieve more than 90% TPA yield was 3, 3, and 8 h, and 18 h for (PTSA), (2-NSA), (1,5-NDSA), and H 2 SO 4 , respectively. Ethyl acetate hydrolysis was performed as a model reaction to probe the activity of the catalysts in homogenous reactions to compare with the heterogenous hydrolysis reaction occurring at the PET surface. The higher catalytic activities for PET hydrolysis of the PTSA, 2-NSA, and 1,5-NDSA than H 2 SO 4 was attributed to improved wetting by the reaction media and affinity of the aryl sulfonic acid catalysts for the PET surface.
Article
Production, consumption, and disposal of plastics are associated with the generation of a large amount of greenhouse gas (GHG). Polyethylene terephthalate (PET) is one of the most widely used plastics, which is mainly produced and consumed by China and causing increasing concerns. The Previous studies mainly focused on material flows and stocks of PET. Detailed information on GHG emissions for the entire life cycle of PET in China is limited. Particularly, the key paths of emission reduction for life-cycle PET considering carbon neutrality are unknown. In this research, a network analysis system and model of GHG emissions were developed for PET in China and helping explore characteristics of GHG emissions over the three development periods of the PET industry. The results showed that the most potential stage of carbon neutrality for PET was from the exploitation of raw materials to the end of PET chips production, accounting for approximately 74.9% over 2000 to 2018. The manufacturing process of PET fibers and bottles would have a major contribution to GHG emissions. At the same time, GHG emissions from the mechanical recovery process should not be ignored. The plastic restriction order for PET and the waste treatment ways of low-carbon would have a significant contribution to emission reduction. According to the results, this study identified the most potential key process of carbon neutrality in the PET life cycle and proposed policies to reduce GHG emissions, which would provide scientific support for the PET industry to achieve the goal of carbon neutrality in China.
Article
Full-text available
Industrial ecology and life cycle sustainability assessment (LCSA) are increasingly important in research, regulation, and corporate practice. However, the assessment of the social pillar is still at a developmental stage, because social life cycle assessment (SLCA) is fragmented and lacks a foundation on empirical experience. A critical reason is the absence of general standardized indicators that clearly reflect and measure businesses’ social impact along product life cycles and supply chains. Therefore, we systematically review trends, coherences, inconsistencies, and gaps in research on SLCA indicators across industry sectors. Overall, we find that researchers address a broad variety of sectors, but only few sectors receive sufficient empirical attention to draw reasonable conclusions while the field is additionally still largely a-theoretical. Furthermore, researchers overlook important social core issues as they concentrate heavily on worker- and health-related indicators. Therefore, we synthetize the most important indicators used in research as a step toward standardization (including critical challenges in applying these indicators and recommendations for their future development), highlight important trends and gaps (e.g., the focus on worker- and health-related indicators and the a-theoretical nature of the SLCA literature), and emphasize critical shortcomings in the SLCA field organized along the key phases of design, implementation, and evolution through which performance measurement approaches such as SLCA typically progress in their development and maturation. With this, we contribute to the maturation and establishment of the social pillar of LCSA and industrial ecology.
Article
Full-text available
PurposeIn agricultural life cycle assessment (LCA), the allocation method chosen to divide impacts among co-products is an important issue, since it may change conclusions about a product’s impacts. We developed a biophysical allocation method to assign upstream environmental burdens and the use of raw materials at farm gate to the livestock co-products at the slaughterhouse based on their metabolic energy requirements. Methods Biophysical allocation is designed to build a relationship between co-products of a meat-production system and their associated net metabolic energy requirements. A metabolic growth model (Gompertz function) was combined with an energy calculation model to estimate metabolic energy requirements for the growth of an animal from birth to slaughter age. Allocation factors were calculated based on the energy required to maintain and produce body tissues (excluding waste), as a function of their chemical (protein and lipid) and physiological properties. This method was applied for an average beef cow and then compared to other allocation methods (e.g., mass, dry matter, protein, and economic). Results and discussionAt slaughter age, carcass tissues required the most energy (44 %) due to their high quantity of protein; the gastrointestinal tract and liver required about 28 and 5 %, respectively, of total metabolic energy requirements due to their roles in body metabolism. Biophysical allocation considers the energy cost of building and maintaining the tissues, regardless of their final uses. It reflects physical relationships among co-products as well as other allocation methods do. It also reveals the cause-effect relationship between tissues according to the energy required to maintain physiological functions. Once the growing time until slaughter is set, biophysical allocation factors are not influenced over time, unlike those of economic allocation, which is highly influenced by price variability. Conclusions This study provides a generic and robust biophysical allocation method for estimating environmental burdens of co-products, in accordance with ISO allocation rules. The method can be considered an original contribution to international debates on allocation methods applied to livestock products in LCA. In this paper, it is applied to cattle-related product, but it is generic and the principles can be adapted to any kind of livestock species. It should be considered and discussed by stakeholders in livestock production industries.
Article
Full-text available
PurposeIn response to a need for interoperable LCA databases of adequate quality, a review of 40 datasets from emerging economies has been conducted with UNEP support by independent LCA experts, with the purpose to encourage improvements, either prior to publication or as part of a continuous improvement cycle. We discuss the lessons learned during this reviewing process. Methods The review effort had to be delivered in a set and limited timeline of 9 months and covered 20 datasets from Malaysia, ten from Brazil, and ten from Thailand. The developed review process consisted in, among others, (i) developing a set of review criteria for this specific effort, (ii) pairing a local sector reviewer with an international LCA expert to enhance capacity development, (iii) establishing a legal relationship via a non-disclosure agreement (NDA) between the data provider and the data reviewers, and (iv) providing a review report for each dataset that assesses the presence and magnitude of gaps or deficiencies relative to the criteria, as well as their implications for qualifying usage. Results and discussionThe reviews provided solid recommendations for improvement to the majority of the datasets submitted by the three countries. This review exercise has been conducted in the given timeframe for the majority of the datasets. Many challenges have been faced along the way; among them agreeing on an NDA, the need for sufficient information, and the question of the confidentiality of the data. The developed set of criteria for this exercise have not been presented or discussed outside of the narrow review exercise and therefore can be seen as a starting point for further debates and improvements that should involve the broad LCA community. Conclusions This hands-on exercise provided some valuable insights into the road towards global consensus and guidance on data review. Beyond this time-constrained effort, a broader discussion and consensus at international level on the review of datasets and a continuous effort in reviewing datasets is desirable. Four key aspects were identified as necessary to consider: review criteria, review process, reviewers’ selection criteria, and development of a legal basis which protects the confidentiality of the data, as well as the position of the reviewers. This last aspect is sensitive as, in LCA datasets reviews, companies and/or countries might disclose some information with high stakes regarding competition and trade.
Chapter
This chapter lists and answers key questions relating to the packaging, storage and distribution of soft drinks and fruit juices. It covers packaging selection, defects, problems during filling and packaging operations, post filling defects, storage conditions and distribution problems.
Chapter
Biodegradable polymers have undergone extensive investigation since the 1970s. They can be either natural or synthetic and can be derived from either renewable or nonrenewable resources. A series of truly biodegradable petroleum-based synthetic polymers has been developed. However, owing to concerns over environmental pollution and the depletion of fossil oils, intensive research is being conducted for developing biodegradable polymers and plastic materials from renewable natural resources such as starch, cellulose, and soy protein. Polylactic acid and polyhydroxyalkanoates are the two most important biodegradable polymers derived from renewable resources. They are thermoplastics and show mechanical properties and processability similar to some petroleum-based polymers. There have been many research achievements in biodegradable and biobased polymers, including naturally occurring biodegradable polymers, biodegradable polymers derived from renewable resources, and biodegradable polymers based on petroleum, although several biobased polymers may not be biodegradable.
Chapter
In short, LCA or Life Cycle Assessment is a method for capturing environmental impacts of a product or service from raw material extraction (or "cradle") through to disposal (the "gravea"). As we strive to understand what is sustainable from an environmental perspective, we need credible, comprehensive scientific tools to understand the system that we are trying to change. LCA is a powerful tool that allows us to study the system, measure impacts, and understand tradeoffs. As we can see in Fig. 1, LCA studies the entire supply chain for product manufacturing as well as impacts occurring during use and end of life. This allows us to understand how changing impacts in one part of the life cycle affects other parts of the life cycle. Because LCA attempts to assess all environmentally relevant impacts, it also allows us to understand tradeoffs between different impacts, such as climate change and ozone depletion.
Article
This paper presents an attributional life cycle assessment of biopolymers and traditional plastics using real world disposal methods based on collected data and existing inventories. The focus of this LCA is to investigate actual disposal methods for the end of life phase of biopolymers and traditional fossil-based plastics relative to their corresponding production impacts. This paper connects commonly available methods of disposal for traditional fossil-based plastics and the compostability of polylactic acid and thermoplastic starch to compare these materials not just based on production impacts but also on various scenarios for recycling, composting, and landfilling. Additionally, three traditional resins were evaluated (PET, HDPE, and LDPE) using fossil and bio-based production pathways to assess the performance of bio-based products in the recycling stream. The results demonstrate real environmental tradeoffs associated with agricultural production of plastics and the consequential changes resulting from shifting from recyclable to compostable products. The potential for methane production in landfills is a significant factor for global warming impacts associated with biopolymers while recycling provides major benefits in the global warming and fossil fuel depletion categories. A sensitivity analysis was conducted to investigate the relative importance of locale-specific factors such as travel distances and sorting technologies to the end of life treatment methods of recycling, composting, and landfilling. The results show that composting has some advantages, especially when compared to impacts associated with landfilling, but that recycling provides the greatest benefits at end of life.
Article
The aim of this study was to evaluate the environmental burden of non-alcoholic single serving size polyethylene terephthalate beverage bottle systems in the state of California through a life cycle assessment model. A mass flow of polyethylene terephthalate beverage bottle in the U.S., and the state of California is drawn as a Sankey diagram. The life cycle assessment model is designed with five main sections; material production, polyethylene terephthalate bottle production, waste management, environmental benefit, and transportation. The scope is cradle-to-grave with a representative functional unit as the amount of polyethylene terephthalate necessary to deliver 1000 L of beverage, specifically in carbonated soda, water and tea. To identify the strategy to reduce the environmental burden of the overall system, several scenarios are established as the management intervention by reducing two different polyethylene terephthalate waste sources; post-consumer polyethylene terephthalate bottle collection waste, scenario ‘c’, and yield loss of the reclamation process, scenario ‘r’. The contribution analysis indicates that the polyethylene terephthalate bottle production is the highest environmental burden source in most of the impact indicator. Scenario ‘r’ is translated in higher environmental benefit than the pursuit of scenario ‘c’ in every impact indicator. The results show that increasing efficiency of the reclamation process provides a larger environmental benefit than improving the post-consumer bottle collection system for polyethylene terephthalate beverage bottle in the state of California. The results can be used to comprehend the main environmental burden of polyethylene terephthalate bottles and to optimize their recovery in the other 49 U.S. states and around the world.
Article
To attend the growing consumer demand for novel ready-to-eat fresh cut fruits packaging polylactic acid (PLA)-based active packaging was realized. The aim of these packaging is to provide an improved protection and even to extend their shelf-life. PLA-based active packaging was prepared by adding nanoclays and surfactants in its formulation. The evaluation of PLA-nanocomposite packaging was done in comparison to pristine PLA and conventional plastic (polyethylene terephthalate, PET) using fresh-cut melons. Physicochemical properties were investigated by the means of weight loss, visual appearance, pH, colour, and firmness. In addition, microbial profile was tested via microbiological assays. In order to evaluate the environmental impact of PLA-based active packaging compared to commonly used PET, life cycle assessment (LCA) was conducted. In terms of physicochemical and antimicrobial properties, the results clearly showed that the presence of nanoclays and surfactants in the PLA formulations improved their performance, thus contributing to bring the characteristic and behaviour of PLA packages close to those of PET. Furthermore, assessment of life cycle environmental impacts indicated that PLA packaging with nanoclays had the highest environmental performance.