No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Mechanical recycling scenarios in India through the lens of plastic circular economy
Abstract
Mechanical recycling is an essential tool in an environmentally and economically sustainable circular economy of plastic (CEoP). The existing mechanical recycling scenario in India is depicted. The semi-structured interviews with the mechanical recyclers were conducted in five clusters to obtain primary data. Results indicated that the plastics waste (PW) is productively recycled into various recycled products. There is a dominance of conventional sorting methods and recycling machineries. Post-consumer (PC) PW requires larger operating expenses and consumes more utilities compared to post-industrial (PI) PW. Recycled products are manufactured according to the demands of customers and technicalities such as recyclability and quality are often neglected. The actions such as the promotion of PI recycling, industrial symbiosis, and incentivization of operating expenses can positively affect the mechanical recycling process. India is having huge potential for the creation of CEoP, nevertheless, substantial investments in research, infrastructure development and a regulatory framework are required for mechanical recycling technologies.
... As a follow-up, assessing different PW handling collection treatment and disposal scenarios is warranted. For instance, Ref. [112] explored how a country like India can deal with PW management by focusing on mechanical recycling and covering stakeholder, technical, and economic aspects, providing comprehensive information for policy-making and essential data for future LCA studies. Moreover, an LCA was conducted to clarify the current and future environmental impacts of implementing Australia's PW management strategies [113]. ...
Low-income coastal nations such as Mozambique grapple with providing sustainable and effective management of plastic waste (PW), which influences the increase in disease prevalence and of diverse adverse environmental impacts, primarly terrestrial and marine pollution. About 490,000 tons, from domestic generation and imports, make up the total PW in the system. In this study, a life cycle assessment (LCA) was employed to clarify the associated environmental impacts of 1 kg of PW within the waste management system in Mozambique. It was explained that over 95% of PW ended up in open dumpsites, with about 60% open burned, significantly impacting the ecotoxicity and global warming categories—5.49 kg of 1,4-dichlorobenzene (1,4-DCB) for terrestrial ecotoxicity, 4.99 kg of 1,4-DCB for human non-carcinogenic ecotoxicity, and 1.57 kg of carbon dioxide equivalent (CO 2 eq) for global warming potential. The findings provide a quantitative baseline understanding of PW management impacts in the country, thus identifying junctures and opportunities that can help inform and enable the development of policies and strategies for a sustainable PW management system.
Graphical abstract
... The yearly generation of plastic waste in India is nearly 3.4 metric tons (MT) [12], yet only 30 percent of it is recycled, and of which, more than 90% undergo mechanical recycling, a process which gradually reduces the quality of recyclate in the subsequent recycling process [13]. Even though India is the world's second-largest producer of plastic resins, its per capita plastic consumption rate (12 kg/capita/ year) is lower than that of the US and China. ...
Amidst the challenges faced by economically developing countries in managing their plastic waste, the decentralized solid waste management practices followed in Kerala emerge as a unique example of a people-centric waste management program. Considering the importance of people’s cooperation in the success of such initiatives, we conducted an online survey among Keralites to understand their behaviors, opinions, and knowledge regarding plastic waste and its management. Further, the influence of sociodemographic attributes in shaping individual characteristics was also investigated. The Plastic Waste Literacy Rate (PWLR) of the state was 62%, with women and older people being increasingly pro-environmental in managing plastic waste. However, despite this positive trend, a majority of women still resort to improper methods for disposing of sanitary pads. Illicit dumping of plastic waste was more prevalent in urban areas compared to rural ones. Even though the plastic waste collection service provided by Haritha Karma Sena (HKS) received positive feedback, most of the public (40.7%) opined against levying user fees for the same. In essence, the present work offers insights to enhance the efficiency of the existing waste management program, which will ultimately broaden the scope of adoption of the model by other regions in the developing world.
Plastic manufacturing accounts for 6% of global oil consumption and is one of the world's fastest-growing waste streams. As the global supply of fossil fuels becomes critical, it is important to quantify how virgin plastic made from fossil fuel sources is recovered, reused, and remanufactured. In this study, the authors undertook the first systematic literature review of Australia's plastic waste (PW) management system to assess challenges and opportunities in moving towards a circular economy. Sources included government reports, industry survey reports, academic research articles, and national household and waste data. Results of the study showed that despite the sharp exponential growth in consumption of plastics (3.5 million tonnes (Mt) in 2018–19), Australia's national recovery rate is only 11.5%, which leaves substantial room for improvement. From 2007 to 2019, average PW generation was just over 2.6 Mt and in 2019, the generation was close to 2.55 Mt. In terms of polymer types, high-density polyethylene (HDPE) generated the most, followed by polyethylene terephthalate (PET) and low-density polyethylene (LDPE). Close to half (47%) the volume of plastic waste is generated by households (specifically, PET and HDPE). Market growth was of biodegradable plastics is much slower than expected. Most recycling facilities use mechanical recycling as the main processing technology, and more facilities are required to process PET (especially in NSW and Victoria). The construction (built environment) sector consumes the largest quantity of recycled plastics; however, local recycled material use was only 10% in all the Australian sectors. Plastic waste is also used for energy recovery, with polyethylene (PE), polypropylene (PP) and polystyrene (PS). This study also discusses the benefits of implementing state-of-the-art processing facilities using diversified recycling technology; vertical integration of plastic manufacturers and pre-processors; regulatory and structural reform; and development of local manufacturing industries using recycled plastics. It is incompetent to efficiently resolve the Australian plastic waste problem with simply bans, it is a global cross-sectoral issue that calls for cross-departmental cooperation. The future of plastic waste management not only relies on the effectiveness of local government and recyclers, but also on community involvement, and initiatives on national, regional, and global level. Numerous stakeholders including industry insiders, governments, customs agencies, regulators, intergovernmental organizations, non-governmental organizations, and civil society need to be involved.
Scientific analysis and media coverage of rampant plastic pollution has taken a toll on the material's reputation in recent years, fueling talk of a “plastic crisis”. Brand owners have made ambitious pledges to overcome this crisis—but can voluntary commitments turn the tide? In this paper, we analyze the current flow of polyethylene terephthalate (PET) from production to recycling in the European Union (EU). We show that the pledged volume for recycled PET (rPET) to be used in the EU in 2025 amounts to 2.066 m tons, requiring the annual recycling growth rate to double in the next years compared to 2014–2018. Our results indicate that even widespread adoption of deposit return systems for bottles will not suffice, especially when increasing demand from other industries drives the price above the packaging producers’ willingness to pay. To realize the pledges, substantial investments and a regulatory framework for the targeted and sensible use of PET recyclate are necessary.
Over the years, the petrochemical industry has developed a plethora of polymers that are contributing to the well-being of humanity. Irresponsible disposal of used plastics has, however, led to the buildup of litter, which is fouling the environment, harming wildlife, and wasting valuable resources. This paper critically reviews the challenge and opportunities in converting plastic waste into a feedstock for the industry. It discusses (a) the amount, quality, and sorting of plastic waste; (b) mechanical recycling and extraction or dissolution/precipitation; (c) chemical recycling to monomers and to feedstock and other chemicals; and (d) waste disposal by incineration, biodegradation, landfill, and microplastics. It will, finally, broaden the circularity discussion with life-cycle analyses (LCA), design for recycling, and the future role of renewable carbon as a feedstock.
Greenhouse gas (GHG) emissions need to be reduced to limit global warming. Plastic production requires carbon raw materials and energy that are associated today with predominantly fossil raw materials and fossil GHG emissions. Worldwide, the plastic demand is increasing annually by 4%. Recycling technologies can help save or reduce GHG emissions, but they require comparative assessment. Thus, we assess mechanical recycling, chemical recycling by means of pyrolysis and a consecutive, complementary combination of both concerning Global Warming Potential (GWP) [CO 2 e], Cumulative Energy Demand (CED) [MJ/kg], carbon efficiency [%], and product costs [€] in a process-oriented approach and within defined system boundaries. The developed techno-economic and environmental assessment approach is demonstrated in a case study on recycling of separately collected mixed lightweight packaging (LWP) waste in Germany. In the recycling paths, the bulk materials polypropylene (PP), polyethy-lene (PE), polyvinylchloride (PVC), and polystyrene (PS) are assessed. The combined mechanical and chemical recycling (pyrolysis) of LWP waste shows considerable saving potentials in GWP (0.48 kg CO2e/kg input), CED (13.32 MJ/kg input), and cost (0.14 €/kg input) and a 16% higher carbon efficiency compared to the baseline scenario with state-of-the-art mechanical recycling in Germany. This leads to a combined recycling potential between 2.5 and 2.8 million metric tons/year that could keep between 0.8 and 2 million metric tons/year additionally in the (circular) economy instead of inciner-ating them. This would be sufficient to reach both EU and German recycling rate targets (EC 2018). This article met the requirements for a gold-silver JIE data openness badge described at http://jie.click/badges.
In 2018, European Union adopted a European strategy for plastics in a circular economy as a part of their action plan for a circular economy. Sustainability is the underlying motivation behind the plastics strategy with a goal of addressing how plastics are designed, used and recycled in the EU. One of the strategies outlined is that by 2030, all plastic packaging placed on the EU market is either reusable or can be recycled in a cost-effective manner. A large portion of food packaging is multi-layer plastic that is not recyclable in a cost-effective manner. Given the difficulties associated with recycling today’s complex food packaging, what impacts will the European Union’s strategies for plastics in a circular economy have on food safety? This article explores what is being done and what can be done to mitigate the risks to food safety while adhering to the EU’s plastic strategy. It has been observed that the plastic plays a vital role in maintaining food safety, extending shelf-life and minimising food waste. However, it is currently not possible to recycle multi-layer plastic packaging which is widely used throughout the food industry, and there are currently no viable alternatives offering the same level of protection. Unless possible substitutes to multi-layer plastics offering the same level of food protection can be developed then there will be detrimental effects on food quality, safety and shelf-life, which will lead to increased food waste, additional food costs and a reduction in the variety and availability of certain foods.
The current global plastics economy is highly linear, with the exceptional performance and low carbon footprint of polymeric materials at odds with dramatic increases in plastic waste. Transitioning to a circular economy that retains plastic in its highest value condition is essential to reduce environmental impacts, promoting reduction, reuse, and recycling. Mechanical recycling is an essential tool in an environmentally and economically sustainable economy of plastics, but current mechanical recycling processes are limited by cost, degradation of mechanical properties, and inconsistent quality products. This review covers the current methods and challenges for the mechanical recycling of the five main packaging plastics: poly(ethylene terephthalate), polyethylene, polypropylene, polystyrene, and poly(vinyl chloride) through the lens of a circular economy. Their reprocessing induced degradation mechanisms are introduced and strategies to improve their recycling are discussed. Additionally, this review briefly examines approaches to improve polymer blending in mixed plastic waste streams and applications of lower quality recyclate.
The use of plastics, and even the existence of this versatile material, has been increasingly demonised in the UK. Public campaigns exist to expand use of recyclable cups and to eliminate plastic straws. Retailers supplying 80% of the market are now members of the UK Plastics Pact, with goals to ensure that products are designed to be recycled, that recycling takes place, and that more recyclate is used in new products.
Public awareness has not translated into action, as domestic collection rates for discarded plastics remain pitifully low. We started with a systems-wide vision that these rates can only be increased if all household plastic recycling is made easy and consistent christened ‘One Bin to Rule Them All’ - and used this premise as a starting point to examine the implications of a fully mixed plastics waste stream entering the supply chain. An agenda for future research was developed through 25 interviews with senior industrial and commercial management and a cross-sector workshop.
We determined that if improved household collection rates are to translate into significantly improved recycling rates, rapid progress is required in four areas: standardisation (materials, kerbside collections, waste sorting), infrastructure investment, development of cross-supply chain business models and creation of higher value recyclate. Creating a harmonised national solution to plastic waste sorting is critically dependent on maintaining value in discarded plastics. This in turn reduces plastic leakage into the environment. Enabling this value-based scenario in the UK would form a best-practice model for other regions.
Polymer extrusion is an important but an energy intensive method of processing polymeric materials. The rapid increase in demand of polymeric products has forced manufactures to rethink their processing efficiencies to manufacture good quality products with low‐unit‐cost. Here, analyzing the operational conditions has become a key strategy to achieve both energy and thermal efficiencies simultaneously. This study aims to explore the effects of polymers' rheology on the energy consumption and melt thermal quality (ie, a thermally homogeneous melt flow in both radial and axil directions) of extruders. Six commodity grades of polymers (LDPE, LLDPE, PP, PET, PS, and PMMA) were processed at different conditions in two types of continuous screw extruders. Total power, motor power, and melt temperature profiles were analyzed in an industrial scale single‐screw extruder. Moreover, the active power (AP), mass throughput, torque, and power factor were measured in a laboratory scale twin‐screw extruder. The results confirmed that the specific energy consumption for both single and twin screw extruders tends to decrease with the processing speed. However, this action deteriorates the thermal stability of the melt regardless the nature of the polymer. Rheological characterization results showed that the viscosity of LDPE and PS exhibited a normal shear thinning behavior. However, PMMA presented a shear thickening behavior at moderate‐to‐high shear rates, indicating the possible formation of entanglements. Overall, the findings of this work confirm that the materials' rheology has an appreciable correlation with the energy consumption in polymer extrusion and also most of the findings are in agreement with the previously reported investigations. Therefore, further research should be useful for identifying possible correlations between key process parameters and hence to further understand the processing behavior for wide range of machines, polymers, and operating conditions.
The circular economy rationale is increasingly promoted as a means to move from a global plastic waste dilemma to a plastics economy that is aligned with the principles of sustainable development. However, any such effort will have to account for the socioeconomic settings in low-income and middle-income countries of the global south which are the main entry points of mismanaged plastic wastes into the environment. Since waste management and recycling in these economies are characterized by a great degree of informality, there is an urgent need to find models for partnering with the informal recycling sector in an effective, scalable, and sustainable manner. In this work, we present the case of a for-profit company located in Nairobi, Kenya, that operates on the interface between formal and informal by processing post-consumer plastics sourced from local waste pickers through a fair-trade-like business model. Economic incentives, trust building measures, and a general willingness to learn and adapt were identified as prerequisites for establishing accountable supplier-buyer relationships. The combination of informed material pre-sorting by the individual waste picker and subsequent industrial scale sorting and washing resulted in re-cyclates that were comparable to commercially available benchmark recyclates from the sophisticated formal recycling system of a high-income country in terms of both composition and selected engineering properties. High-quality mechanical recycling of plastic wastes under informal conditions seems feasible and may even come along with socioeconomic benefits for marginalized waste pickers when suitable modes of cooperation are put in place.
Microplastic pollution represents a side-effect stemming from a global
plastic waste mismanagement problem and includes degraded particles or mass produced plastic particles less than 5 mm in largest dimension. The small nature of microplastics gives this area of pollution different environmental concerns than general plastic waste in the environment. The biological toxicity of particles, their internal components, and their surface level changes all present opportunities for these particles to adversely affect the environment around them. Thus, it is necessary to review the current literature surrounding this topic and identify areas where the study of microplastic can be pushed forward. Here we present current methods in studying microplastics, some of the ways by which microplastics affect the environment and attempt to shed light on how this research can continue. In addition, we review current recycling methods developing for the processing of
mixed-plastic waste. These methods, including hydrothermal processing and solvent extraction, provide a unique opportunity to separate plastic waste and improve the viability of the plastics recycling industry.
This review presents a comprehensive description of the current pathways for recycling of polymers, via both mechanical and chemical recycling. The principles of these recycling pathways are framed against current-day industrial reality, by discussing predominant industrial technologies, design strategies and recycling examples of specific waste streams. Starting with an overview on types of solid plastic waste (SPW) and their origins, the manuscript continues with a discussion on the different valorisation options for SPW. The section on mechanical recycling contains an overview of current sorting technologies, specific challenges for mechanical recycling such as thermo-mechanical or lifetime degradation and the immiscibility of polymer blends. It also includes some industrial examples such as polyethylene terephthalate (PET) recycling, and SPW from post-consumer packaging, end-of-life vehicles or electr(on)ic devices. A separate section is dedicated to the relationship between design and recycling, emphasizing the role of concepts such as Design from Recycling. The section on chemical recycling collects a state-of-the-art on techniques such as chemolysis, pyrolysis, fluid catalytic cracking, hydrogen techniques and gasification. Additionally, this review discusses the main challenges (and some potential remedies) to these recycling strategies and ground them in the relevant polymer science, thus providing an academic angle as well as an applied one.
Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050.
Over the last few years, waste management strategies are shifting from waste disposal to recycling and recovery and are considering waste as a potential new resource. To monitor the progress in these waste management strategies, governmental policies have developed a wide range of indicators. In this study, we analyzed the concept of the recyclability benefit rate indicator, which expresses the potential environmental savings that can be achieved from recycling the product over the environmental burdens of virgin production followed by disposal. This indicator is therefore, based on estimated environmental impact values obtained through Life Cycle Assessment (LCA) practices. We quantify the environmental impact in terms of resource consumption using the Cumulative Exergy Extraction from the Natural Environment method. This research applied this indicator to two cases of plastic waste recycling in Flanders: closed-loop recycling (case A) and open-loop recycling (case B). Each case is compared to an incineration scenario and a landfilling scenario. The considered plastic waste originates from small domestic appliances and household waste other than plastic bottles. However, the existing recyclability benefit rate indicator does not consider the potential substitution of different materials occurring in open-loop recycling. To address this issue, we further developed the indicator for open-loop recycling and cascaded use. Overall, the results show that both closed-loop and open-loop recycling are more resource efficient than landfilling and incineration with energy recovery.
Plastics are inexpensive, easy to mold, and lightweight. These and many other advantages make them very promising candidates for commercial applications. In many areas, they have substantially suppressed traditional materials. However, the problem of recycling still is a major challenge. There are both technological and economic issues that restrain the progress in this field. Herein, a state-of-art overview of recycling is provided together with an outlook for the future by using popular polymers such as polyolefins, poly(vinyl chloride), polyurethane, and poly(ethylene terephthalate) as examples. Different types of recycling, primary, secondary, tertiary, quaternary, and biological recycling, are discussed together with related issues, such as compatibilization and cross-linking. There are various projects in the European Union on research and application of these recycling approaches; selected examples are provided in this article. Their progress is mirrored by granted patents, most of which have a very limited scope and narrowly cover certain technologies. Global introduction of waste utilization techniques to the polymer market is currently not fully developed, but has an enormous potential.
Polypropylene (PP) degradation during multiple extrusion at different temperatures was studied by following changes in rheological properties. Dynamic and transient experiments were carried out in a rheometer with parallel plate geometry. In addition, a statistical experimental design (22, with replicates) was employed using die zone temperature (X1) and number of extrusion cycles (X2) varying at two levels. The system degradation was modeled using melt flow index (MFI) as a control variable. A rapid increase of chain scissions of the PP macromolecules and, consequently, a molecular weight reduction, was observed through abrupt increase of MFI and reduction of properties such as complex viscosity (η*) and elasticity of the molten polymer.
This review article aims to suggest recycling technological options in India and illustrates plastic recycling clusters and reprocessing infrastructure for plastic waste (PW) recycling in India. The study shows that a majority of states in India are engaged in recycling, road construction, and co-processing in cement kilns while reprocessing capabilities among the reprocessors are highest for polypropylene (PP) and polyethylene (PE) polymer materials. This review suggests that there are key opportunities for mechanical recycling, chemical recycling, waste-to-energy approaches, and bio-based polymers as an alternative to deliver impact to India's PW problem. On the other hand, overall, polyurethane, nylon, and polyethylene terephthalate appear most competitive for chemical recycling. Compared to conventional fossil fuel energy sources, polyethylene (PE), polypropylene (PP), and polystyrene are the three main polymers with higher calorific values suitable for energy production. Also, multi-sensor-based artificial intelligence and blockchain technology and digitization for PW recycling can prove to be the future for India in the waste flow chain and its management. Overall, for a circular plastic economy in India, there is a necessity for a technology-enabled accountable quality-assured collaborative supply chain of virgin and recycled material.
Supplementary information:
The online version contains supplementary material available at 10.1007/s13762-022-04079-x.
Plastic pollution has become one of the most pressing environmental issues. Recycling is a potential means of reducing plastic pollution in the environment. However, plastic fragments are still likely released to the aquatic environment during mechanical recycling processes. Here, we examined the plastic inputs and effluent outputs of three mechanical recycling facilities in Vietnam dealing with electronic, bottle, and household plastic waste, and we found that large quantities of microplastics (plastics <5 mm in length) are generated and released to the aquatic environment during mechanical recycling without proper treatment. Comparisons with literature data for microplastics in wastewater treatment plant effluents and surface water indicated that mechanical recycling of plastic waste is likely a major point source of microplastics pollution. Although there is a mismatch between the size of the microplastics examined in the present study and the predicted no-effect concentration reported, it is still possible that microplastics generated at facilities pose risks to the aquatic environment because there might be many plastic particulates smaller than 315 μm, as suggested by our obtained size distributions. With mechanical recycling likely to increase as we move to a circular plastics economy, greater microplastics emissions can be expected. It is therefore an urgent need to fully understand not only the scale of microplastic generation and release from plastic mechanical recycling but also the environmental risk posed by microplastics in the aquatic environment.
Petro-derived commodity thermoplastics are relatively inexpensive, lightweight, and non-biodegradable materials, which can be readily molded at high temperatures into a range of products. The manufacturing of such thermoplastic resins and products has increased dramatically over the last 70 years. The plastics based on polyolefins, polystyrenes, and polyesters occupy the largest share (80%) of the world's plastic markets. However, the disposal of waste plastics has created considerable environmental concerns. Therefore, environment protection agencies and plastic manufacturers are constantly seeking appropriate techniques for recycling or upcycling waste plastics into new products. In recent years, the recycling rates are approximately 9 to 15% out of total plastics produced annually in the United States and Europe, which are predominantly limited to individual plastic fractions such as HDPE and PET. The recycling process is associated with various expensive and time-consuming sorting techniques, which are not economically attractive to the recycling industries. A significant issue is when multiple plastics are blended, they often are not chemically compatible, resulting in phase separation and inferior-quality materials. Therefore, it is important to apply certain performance modifiers during the re-extrusion of waste thermoplastics, which include compatibilizers, coupling agents, impact modifiers, and many others. There are different additives and techniques available, suitable to improve the mechanical and other associated properties of polymer blends and composites, and these can also be used for improving the performance of recycled thermoplastics. This review article summarizes various chemical additives and approaches, which can be used in thermomechanical upcycling of waste thermoplastics to new materials with superior mechanical performance via improving interfacial adhesion or phase homogeneity of polymer blends.
Developing countries like India and Indonesia struggle with proper management of plastic waste, causing rampant plastic pollution that adversely impacts the ecosystem and potentially human health. In this study, life cycle assessment (LCA) was adopted to compare the environmental impact of end-of-life (EOL) treatment of 1 kg plastic waste in India and Indonesia based on the EOL mix, which includes mechanical recycling, co-processing in cement kilns, incineration, sanitary landfill, open dumping and open burning. Nine environmental impacts were considered, namely climate change, cumulative energy demand, water depletion and marine eco-toxicity, human toxicity, terrestrial acidification, fossil depletion, particulate matter formation and urban land occupation. Waste plastics EOL treatment in India was found to have a lower environmental impact than Indonesia among all nine categories, which was attributed to higher mechanical recycling rates in India. Hotspot analysis revealed that open burning is a major contributor to climate change, while landfills are the major contributor to marine eco-toxicity. A sensitivity analysis found that the percentage of plastic waste collection, percentage of uncollected plastic waste openly burnt, percentage of plastic rejects from recycling and percentage replacement of virgin plastic from recycled plastic granules were key sensitive parameters. The results of a future scenario analysis showed that further investments in mechanical recycling by 2030 can not only reduce mismanaged plastic waste, but also contribute towards the Paris Agreement carbon reduction pledges for both India and Indonesia. The results from this study can be used to support future waste management investment decisions in both countries.
The increasing demand for plastic products continues to result in a growing tonnage of plastic packaging waste with significant environmental consequences. Circular economy models are established to overcome the resource and environmental challenges caused by this increase. In the literature, the evaluation of how the plastic packaging value chain can be enhanced by circular economy practices remains underexplored. This paper aims to explore the impact of three circular economy models on the European plastic packaging value chain, covering circular economy strategies:, (i) promoting cross-sectoral valorization of plastic wastes through IS, (ii) improvement in recycling efficiency of wastes within the plastics sector, and (iii) introduction of a new bio-based biodegradable plastic product. Three linear single-objective optimization models were developed for maximization of environmental benefits and circularity, to assess how European plastics wastes supply chains could be made more circular by 2025. The results show that if better upcycling options including industrial symbiosis can be identified and established in the future, in addition to the composting as a viable End of Life option, plastic packaging value chain can create higher environmental benefits. Also, all circular economy strategies contribute to the improvement of circularity.
Increasing plastic recycling rates is crucial to tackle plastic pollution and reduce consumption of fossil resources. Recycling routes for post-consumer plastic fractions that are technologically and economically feasible remain a challenge. Profitable value chains for recycling mixed film and tray-like plastics have hardly been implemented today, in sharp contrast to recycling of relatively pure fractions such as polyethylene terephthalate and high-density polyethylene bottles.
This study examines the economic feasibility of implementing mechanical recycling for plastic waste such as polypropylene, polystyrene, polyethylene films and mixed polyolefins. In most European countries these plastic fractions are usually incinerated or landfilled whilst in fact technologies exist to mechanically recycle them into regranulates or regrinds.
Results show that the economic incentives for the recycling of plastic packaging depend predominantly on the product price and product yield. At current price levels, the most profitable plastic fraction to be recycled is PS rigids, with an internal rate of return of 14%, whereas the least profitable feed is a mixed polyolefin fraction with a negative internal rate of return in a scenario with steadily rising oil prices. Moreover, these values would be substantially reduced if oil prices, and therefore plastic product prices decrease. Considering a discount rate of 15% for a 15-year period, mechanical recycling is not profitable if no policy changes would be imposed by governments. Clearly low oil prices may jeopardize the mechanical recycling industry, inducing the need for policies that would increase the demand of recycled products such as imposing minimal recycled content targets.
Given increasing concerns for the marine environment and human health, as well as trade restrictions from Asian countries, plastics have become a great challenge for the United States. This study addresses the seven commonly used plastics: low-density polyethylene/linear low-density polyethylene, high-density polyethylene, polyethylene terephthalate (PET), polypropylene, polystyrene, polyvinyl chloride, and other plastics. Material flows of the seven polymers were tracked from production into fabrication, manufacturing, flow into use, waste management, and recycling in the United States in 2015. Low- and high-density polyethylene and polypropylene were found to be the largest in both production and product manufacture. More than 88% of the plastics went into three end-use sectors: Packaging, Consumer and Institutional Products, and Building and Construction. In-use lifetimes across the plastics are generally short. Virgin plastics were mainly exported, while intermediate plastic products were largely imported. The actual end-of-life recycling rate of the plastics as a group was no more than 6.2%, with PET and the polyethylene family the most recycled. The high yearly plastic throughput and low recycling rate pose a serious challenge to the sustainability goals of the United States and is in stark contrast to the vision of a circular economy of plastics.
Use of recycled fibres in apparel is being seen as one of the major ways to achieve sustainability and circular economy in textile industry. Waste poly-ethylene terephthalate (PET) bottles create serious disposal problem as they are not biodegradable. In recent years, many companies have started to collect the waste PET bottles and upcycle them, by melting and extruding, into textile grade polyester fibre. This paper presents an exhaustive study on the properties of mechanically recycled polyester fibres and fabrics. The recycled polyester fibre has lower level of crystallinity and tensile strength than its virgin counterpart. The transmission properties like air permeability and moisture vapour permeability of fabric do not change significantly with the increase in proportion of recycled polyester. However, the shear and bending rigidities of woven fabric tend to increase (24-44% and 9-26%, respectively) with the incorporation of recycled polyester. This implies that the fabric becomes stiffer and less pliable when recycled polyester fibre is used and thus the virgin and recycled polyester fibres cannot be considered as functionally equivalent for life cycle or other analysis.
Environmentally sound management of plastic packaging waste is an issue of concern around the world because it causes potential threats to oceans and the environment upon disposal and mismanagement. This study examines the current efforts on recycling of the waste by extended producer responsibility (EPR) in South Korea as well as other countries. Material flow analysis (MFA) was performed on plastic packaging by life cycle. Based on the results in this study, material footprint of common single use plastics (i.e., PET water bottles, plastic cups, plastic bags, and plastic containers and cutlery by food delivery) by consumption was estimated to be on average 11.8 kg or 638 disposable plastics per capita a year, resulting in 32.6 billion disposable plastics and 603,000 ton of waste for disposal in South Korea. Approximately, 3 million ton of plastic packaging waste from household waste streams in 2017 in South Korea was generated and treated by energy recovery with solid refuse fuels and heat recovery, incineration without energy recovery, material recycling, and landfilling. Material recycling and recovery rates of plastic packaging waste from households were relatively low at 13.5% and 50.5%, respectively. It was estimated that as much as 3.6 million ton of CO2eq was generated from 2.7 million ton of plastic waste by incineration in 2017. Approximately 6.6 million ton CO2eq could be avoided by material recycling. Challenges and efforts have been discussed to improve current recycling system of plastic packaging waste towards a circular economy.
China used to receive more than 50% of the global post-consumer plastics export, the largest share of which was PET bottles. However, China recently banned the import of foreign wastes including waste plastics. The original intention of this ban was to protect China’s ecosystem quality and human health, while its environmental implications have yet to be examined. This study analyzes the life-cycle environmental impacts of this ban on post-consumer PET under a number of post-ban scenarios. Our analysis shows that the ban may substantially exacerbate environmental impacts both in China and globally, if China, in the absence of imported recyclates, increases its virgin PET fiber production using carbon-intensive coal as the feedstock. Recycling waste PET bottles within the countries that generate them to replace China’s virgin PET fiber production, however, is shown to significantly reduce life-cycle environmental impacts both in China and globally. Our study highlights the potential unintended environmental consequences of the ban and the need to consider marginal technologies and their consequences in policy decisions. Our results call for cost-effective recycling infrastructure among the waste-producing countries and the mechanism to coordinate plastics recycling on a global scale.
In this study, Life Cycle Assessment technique has been used to assess possible environmental impacts of the
existing and proposed plastic waste management scenarios on various impact categories for the study area
Dhanbad city, India. This study considered two major plastic wastes, Polyethylene Terephthalate (PET) and
Polyethylene (PE). The scenarios considered in the present study are Landfilling without bio-gas recovery
(denoted by S1); Incineration without energy recovery (denoted by S2); Recycling (denoted by S3) and Incineration
with energy recovery (denoted by S4). The environmental impacts of all the four scenarios (S1 to S4)
were evaluated and compared. The method used was CML 2 baseline 2000 method, and the results showed
that the scenario S3 had the least environmental impacts on most of the impact categories due to use of recycled
PET and PE flakes as substitution for virgin PET and PE flakes and also due to less emissions during
recycling process of these two plastic wastes. Scenario S2 had the highest environmental impacts on most
of the impact categories. S4 had lower environmental impacts than scenario S3 on abiotic depletion, abiotic
depletion (fossil fuel), and acidification (only PE recycling) impact categories. This study will help the policy
makers to implement better plastic waste management plan.
Low density polyethylene (LDPE) was exposed to one hundred (100) consecutive extensive extrusion
cycles to simulate mechanical recycling. Collected samples were characterized by means of small
amplitude oscillatory measurements to investigate rheological properties, by gel permeation chromatography
(GPC) to measure molecular weight, and with differential scanning calorimetry (DSC) to study
thermal properties. Finally, solid time-dependent mechanical properties were characterized by
measuring creep compliance. The results show that simulated recycling did not significantly change the
melting and crystallization temperatures of LDPE. However, results from rheological measurement,
crystallinity, creep measurements and GPC suggest that thermal degradation and gelation of LDPE occur
after extensive extrusion which leads to simultaneous chain scission and crosslinking of the polymer
chains. It can be concluded that processability, measured by rheological parameters at high frequency
and durability of LDPE measured by creep compliance, are only affected after the 40th extrusion cycle.
These observations correspond to the molecular changes of LDPE measured through GPC, MFI and
crystallinity calculations obtained from DSC measurements.
Polypropylene (PP) was injection moulded several times to mimic the effect of recycling procedures. The influence of the recycling was studied by following changes in chemical structure, melt viscosity, crystallisation behaviour, and tensile and fracture properties. The main effect of recycling is the lowering of the melt viscosity, which is attributed to molecular weight decrease. Recycled PP exhibits greater crystallisation rate, higher crystallinity and equilibrium melting temperature than those measured for virgin PP. Elastic modulus and yield stress increase with the number of recycling steps. However, elongation at break and fracture toughness decrease.
Plastic solid waste (PSW) presents challenges and opportunities to societies regardless of their sustainability awareness and technological advances. In this paper, recent progress in the recycling and recovery of PSW is reviewed. A special emphasis is paid on waste generated from polyolefinic sources, which makes up a great percentage of our daily single-life cycle plastic products. The four routes of PSW treatment are detailed and discussed covering primary (re-extrusion), secondary (mechanical), tertiary (chemical) and quaternary (energy recovery) schemes and technologies. Primary recycling, which involves the re-introduction of clean scrap of single polymer to the extrusion cycle in order to produce products of the similar material, is commonly applied in the processing line itself but rarely applied among recyclers, as recycling materials rarely possess the required quality. The various waste products, consisting of either end-of-life or production (scrap) waste, are the feedstock of secondary techniques, thereby generally reduced in size to a more desirable shape and form, such as pellets, flakes or powders, depending on the source, shape and usability. Tertiary treatment schemes have contributed greatly to the recycling status of PSW in recent years. Advanced thermo-chemical treatment methods cover a wide range of technologies and produce either fuels or petrochemical feedstock. Nowadays, non-catalytic thermal cracking (thermolysis) is receiving renewed attention, due to the fact of added value on a crude oil barrel and its very valuable yielded products. But a fact remains that advanced thermo-chemical recycling of PSW (namely polyolefins) still lacks the proper design and kinetic background to target certain desired products and/or chemicals. Energy recovery was found to be an attainable solution to PSW in general and municipal solid waste (MSW) in particular. The amount of energy produced in kilns and reactors applied in this route is sufficiently investigated up to the point of operation, but not in terms of integration with either petrochemical or converting plants. Although primary and secondary recycling schemes are well established and widely applied, it is concluded that many of the PSW tertiary and quaternary treatment schemes appear to be robust and worthy of additional investigation.
A material flow analysis of polymers and plastics in India
- T M Baynes
- S Kapur-Bakshi
- N Emami
- S Bhattacharja
- S Tapsuwan
- S Joseph
- K Locock
- M Kaur
- R Sinha
- N Bajpai
- S Talwar
Baynes TM, Kapur-Bakshi S, Emami N, Bhattacharja S, Tapsuwan S, Joseph S, Locock K, Kaur M, Sinha R, Bajpai N, and
Talwar S (2021) A material flow analysis of polymers and plastics
in India. Report Number 2021-1. CSIRO, Australia. https:// resea
rch. csiro. au/ rpwi/ publi catio ns/, Accessed 28 September 2022
Government notifies the Plastic Waste Management Amendment Rules, 2021, prohibiting identified single use plastic items by 2022
- Ministry
- Forest Environment
- Climate Change
Ministry of Environment, Forest and Climate Change (2021)
Government notifies the Plastic Waste Management Amendment Rules, 2021, prohibiting identified single use plastic items
by 2022. https:// pib. gov. in/ Press Relea sePage. aspx Accessed 20
October 2022