Tandem Integration of Biological and Electrochemical Catalysis for Efficient Polyester Upcycling under Ambient Conditions.

Excessive production of waste polyethylene terephthalate (PET) poses an ecological challenge, which necessitates developing technologies to extract the values from end-of-life PET. Upcycling has proven effective in addressing the low profitability of current recycling strategies, yet existing upcycling technologies operate under energy-intensive conditions. Here we report a cascade strategy to steer the transformation of PET waste into glycolate in an overall yield of 92.6% under ambient conditions. The cascade approach involves setting up a robust hydrolase with 95.6% PET depolymerization into ethylene glycol (EG) monomer within 12 h, followed by an electrochemical process initiated by a CO-tolerant Pd/Ni(OH)2 catalyst to convert the EG intermediate into glycolate with high Faradaic efficiency of 97.5%. Techno-economic analysis and life cycle assessment indicate that, compared with the widely adopted electrochemical technology that heavily relies on alkaline pretreatment for PET depolymerization, our designed enzymatic-electrochemical approach offers a cost-effective and low-carbon pathway to upgrade PET.

Upgrading Polyolefin Plastic Waste into Multifunctional Porous Graphene using Silicone-Assisted Direct Laser Writing.

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.

Recent Advancements in Pyrolysis of Halogen-Containing Plastics for Resource Recovery and Halogen Upcycling: A State-of-the-Art Review.

Plastic waste has emerged as a serious issue due to its impact on environmental degradation and resource scarcity. Plastic recycling, especially of halogen-containing plastics, presents challenges due to potential secondary pollution and lower-value implementations. Chemical recycling via pyrolysis is the most versatile and robust approach for combating plastic waste. In this Review, we present recent advancements in halogen-plastic pyrolysis for resource utilization and the potential pathways from "reducing to recycling to upcycling" halogens. We emphasize the advanced management of halogen-plastics through copyrolysis with solid wastes (waste polymers, biomass, coal, etc.), which is an efficient method for dealing with mixed wastes to obtain high-value products while reducing undesirable substances. Innovations in catalyst design and reaction configurations for catalytic pyrolysis are comprehensively evaluated. In particular, a tandem catalysis system is a promising route for halogen removal and selective conversion of targeted products. Furthermore, we propose novel insights regarding the utilization and upcycling of halogens from halogen-plastics. This includes the preparation of halogen-based sorbents for elemental mercury removal, the halogenation-vaporization process for metal recovery, and the development of halogen-doped functional materials for new materials and energy applications. The reutilization of halogens facilitates the upcycling of halogen-plastics, but many efforts are needed for mutually beneficial outcomes. Overall, future investigations in the development of copyrolysis and catalyst-driven technologies for upcycling halogen-plastics are highlighted.

Traded Plastic, Traded Impacts? Designing Counterfactual Scenarios to Assess Environmental Impacts of Global Plastic Waste Trade.

The global trade of plastic waste has raised environmental concerns, especially regarding pollution in waste-importing countries. However, the overall environmental contribution remains unclear due to uncertain treatment shares between handling plastic waste abroad and domestically. Here, we conduct a life cycle assessment of global plastic waste trade in 2022 across 18 countries and six plastic waste types, alongside three "nontrade" counterfactual scenarios. By considering the required cycling rate, which balances importers' costs and recycling revenues, we find that the trade resulted in lower environmental impacts than treating domestically with the average treatment mix. The trade scenario alone reduced climate change impact by 2.85 million tonnes of CO2 equivalent and mitigated damages to ecosystem quality, human health, and resource availability by 12 species-years, 6200 disability-adjusted life years (DALYs), and 1.4 billion United States dollars (USD in 2013), respectively. These results underscore the significance of recognizing plastic waste trade as a pivotal factor in regulating global secondary plastic production when formulating a global plastics treaty.

Disposable Plastic Waste and Associated Antioxidants and Plasticizers Generated by Online Food Delivery Services in China: National Mass Inventories and Environmental Release.

China's online food delivery (OFD) services consume enormous amounts of disposable plastics. Here, we investigated and modeled the national mass inventories and environmental release of plastics and chemical additives in the plastic. The extra-tree regression identified six key descriptors in determining OFD sales in Chinese cities. Approximately 847 kt of OFD plastic waste was generated in 2021 (per capita 1.10 kg/yr in the megacities and 0.39 kg/yr in other cities). Various additives were extensively detected, with geomean concentrations of 140.96, 4.76, and 0.25 µg/g for ∑8antioxidants, ∑21phthalates, and bisphenol A (BPA), respectively. The estimated mass inventory of these additives in the OFD plastics was 164.7 t, of which 51.1 t was released into the atmosphere via incineration plants and 51.0 t was landfilled. The incineration also released 8.07 t of polycyclic aromatic hydrocarbons and 39.1 kt of particulate matter into the atmosphere. Takeout food may increase the dietary intake of phthalates and BPA by 30% to 50% and raise concerns about considerable exposure to antioxidant transformation products. This study provides profound environmental implications for plastic waste in the Chinese OFD industry. We call for a sustainable circular economy action plan for waste disposal, but mitigating the hazardous substance content and their emissions is urgent.

Make my haemodynamic monitor GREEN: sustainable monitoring solutions.

Anaesthesiologists overwhelmingly favour pulse wave analysis techniques as their primary method to monitor cardiac output during high-risk noncardiac surgery. In patients with a radial arterial catheter in place, pulse wave analysis techniques have the advantage of instantly providing non-operator-dependent and continuous haemodynamic monitoring information. Green pulse wave analysis techniques working with any standard pressure transducer are as reliable as techniques requiring dedicated pressure transducers. They have the advantage of minimising plastic waste and related carbon dioxide emissions, and also significantly reducing hospital costs. The future integration of pulse wave analysis algorithms into multivariable bedside monitors, obviating the need for standalone haemodynamic monitors, could lead to wider use of haemodynamic monitoring solutions by further reducing their cost and carbon footprint.

Environmental and economic impact of sustainable anaesthesia interventions: a single-centre retrospective observational study.

BACKGROUND: Anaesthesia contributes substantially to the environmental impact of healthcare. To reduce the ecological footprint of anaesthesia, a set of sustainability interventions was implemented in the University Hospital Zurich, Switzerland. This study evaluates the environmental and economic implications of these interventions. METHODS: This was a single-centre retrospective observational study. We analysed the environmental impact and financial implications of changes in sevoflurane, desflurane, propofol, and plastic consumption over 2 yr (April 2021 to March 2023). The study included pre-implementation, implementation, and post-implementation phases. RESULTS: After implementation of sustainability measures, desflurane use was eliminated, there was a decrease in the consumption of sevoflurane from a median (inter-quartile range) of 25 (14-39) ml per case to 11 (6-22) ml per case (P<0.0001). Propofol consumption increased from 250 (150-721) mg per case to 743 (370-1284) mg per case (P<0.0001). Use of plastics changed: in the first quarter analysed, two or more infusion syringes were used in 62% of cases, compared with 74% of cases in the last quarter (P<0.0001). Two or more infusion lines were used in 58% of cases in the first quarter analysed, compared with 68% of cases in the last quarter (P<0.0001). This resulted in an 81% reduction in overall environmental impact from 3 (0-7) to 1 (0-3) CO2 equivalents in kg per case (P<0.0001). The costs during the final study phase were 11% lower compared with those in the initial phase: from 25 (13-41) to 21 (14-31) CHF (Swiss francs) per case (P<0.0001). CONCLUSIONS: Implementing sustainable anaesthesia interventions can significantly reduce the environmental impact and cost of anaesthesia.

Conversion of char from pyrolysis of plastic wastes into alternative activated carbons for heavy metal removal.

The valorization of post-consumer mixed plastics in pyrolysis processes represents an abundant reservoir of carbon that can be effectively converted into useful chars. This process not only holds appeal in terms of improving plastic waste concerns but also contributes to the reduction of greenhouse gas emissions, thus aligning with the principles of a circular economy paradigm. In this study, the char produced from the pyrolysis of post-consumer mixed plastic waste has been activated with Na2CO3, KOH, NaOH, and K2CO3 to improve the textural, structural, and composition characteristics, leading to improved adsorption capability. These characteristics were studied by N2 adsorption-desorption isotherms, scanning electron microscopy, elemental and immediate analysis, and X-ray photoelectron spectroscopy. The developed surface area (SBET) was 573, 939, 704 and 592 m2 g-1 for Na2CO3, KOH, NaOH and K2CO3 activated carbons, respectively. These activated chars (ACs) were tested for the adsorption of heavy metals in both synthetic waters containing Pb, Cd, and Cu and industrial wastewater collected at an agrochemical production plant. Na2CO3-AC was the best performing material. The metal uptake in synthetic waters using a batch set-up was 40, 13 and 12 mg g-1 for Pb, Cd and Cu. Experiments in a column set-up using Na2CO3-AC resulted in a saturation time of 290, 16, and 80 min for Pb, Cd, and Cu synthetic waters, respectively, and metal uptakes of 26.8, 4.1, and 7.9 mg g-1, respectively. The agrochemical effluents, containing mainly Cr, Cu, Mn, and Zn were tested in a plug-flow column. The metal uptake notably decreased compared to synthetic water due to a competition effect for active sites.

A waste-to-wealth conversion of plastic bottles into effective carbon-based adsorbents for removal of tetracycline antibiotic from water.

Currently, plastic waste and antibiotic wastewater are two of the most critical environmental problems, calling for urgent measures to take. A waste-to-wealth strategy for the conversion of polyethylene terephthalate (PET) plastic bottles into value-added materials such as carbon composite is highly recommended to clean wastewater contaminated by antibiotics. Inspired by this idea, we develop a novel PET-AC-ZFO composite by incorporating PET plastic-derived KOH-activated carbon (AC) with ZnFe2O4 (ZFO) particles for adsorptive removal of tetracycline (TTC). PET-derived carbon (PET-C), KOH-activated PET-derived carbon (PET-AC), and PET-AC-ZFO were characterized using physicochemical analyses. Central composite design (CCD) was used to obtain a quadratic model by TTC concentration (K), adsorbent dosage (L), and pH (M). PET-AC-ZFO possessed micropores (d ≈ 2 nm) and exceptionally high surface area of 1110 m2 g-1. Nearly 90% TTC could be removed by PET-AC-ZFO composite. Bangham kinetic and Langmuir isotherm were two most fitted models. Theoretical maximum TTC adsorption capacity was 45.1 mg g-1. This study suggested the role of hydrogen bonds, pore-filling interactions, and π-π interactions as the main interactions of the adsorption process. Thus, a strategy for conversion of PET bottles into PET-AC-ZFO can contribute to both plastic recycling and antibiotic wastewater mitigation.

Review on personal protective equipment: Emerging concerns in micro(nano)plastic pollution and strategies for addressing environmental challenges.

The COVID-19 pandemic was caused by the SARS-CoV-2 virus, marking one of the most catastrophic global health crises of the 21st century. Throughout this period, widespread use and improper disposal of personal protective equipment (PPE) emerged as a pressing environmental issue, significantly impacting various life forms. During the COVID-19 pandemic, there was a high rate of PEP disposal. An alarming 1.6 × 106 tons of plastic waste each day has been generated since the onset of the outbreak, predominantly from the inadequate disposal of PPE. The mismanagement and subsequent degradation of discarded PPE significantly contribute to increased non-biodegradable micro(nano)plastic (MNP) waste. This pollution has had profound adverse effects on terrestrial, marine, and aquatic ecosystems, which have been extensively of concern recently. Accumulated MNPs within aquatic organisms could serve as a potential route for human exposure when consuming seafood. This review presents a novel aspect concerning the pollution caused by MNPs, particularly remarking on their role during the pandemic and their detrimental effects on human health. These microplastic particles, through the process of fragmentation, transform into nanoparticles, persisting in the environment and posing potential hazards. The prevalence of MNP from PPE, notably masks, raises concerns about their plausible health risks, warranting global attention and comprehensive exploration. Conducting a comprehensive evaluation of the long-term effects of these processes and implementing effective management strategies is essential.

Production of light olefins and monocyclic aromatic hydrocarbons from the pyrolysis of waste plastic straws over high-silica zeolite-based catalysts.

Owing to the ever-increasing generation of plastic waste, the need to develop environmentally friendly disposal methods has increased. This study explored the potential of waste plastic straw to generate valuable light olefins and monocyclic aromatic hydrocarbons (MAHs) via catalytic pyrolysis using high-silica zeolite-based catalysts. HZSM-5 (SiO2/Al2O3:200) exhibited superior performance, yielding more light olefins (49.8 wt%) and a higher MAH content than Hbeta (300). This was attributed to the increased acidity and proper shape selectivity. HZSM-5 displayed better coking resistance (0.7 wt%) than Hbeta (4.4 wt%) by impeding secondary reactions, limiting coke precursor formation. The use of HZSM-5 (80) resulted in higher MAHs and lower light olefins than HZSM-5 (200) because of its higher acidity. Incorporation of Co into HZSM-5 (200) marginally lowered light olefin yield (to 44.0 wt%) while notably enhancing MAH production and boosting propene selectivity within the olefin composition. These observations are attributed to the well-balanced coexistence of Lewis and Brønsted acid sites, which stimulated the carbonium ion mechanism and induced H-transfer, cyclization, Diels-alder, and dehydrogenation reactions. The catalytic pyrolysis of plastic straw over high-silica and metal-loaded HZSM-5 catalysts has been suggested as an efficient and sustainable method for transforming plastic waste materials into valuable light olefins and MAHs.

Recent advances in liquid fuel production from plastic waste via pyrolysis: Emphasis on polyolefins and polystyrene.

The management of plastic waste (PW) has become an indispensable worldwide issue because of the enhanced accumulation and environmental impacts of these waste materials. Thermo-catalytic pyrolysis has been proposed as an emerging technology for the valorization of PW into value-added liquid fuels. This review provides a comprehensive investigation of the latest advances in thermo-catalytic pyrolysis of PW for liquid fuel generation, by emphasizing polyethylene, polypropylene, and polystyrene. To this end, the current strategies of PW management are summarized. The various parameters affecting the thermal pyrolysis of PW (e.g., temperature, residence time, heating rate, pyrolysis medium, and plastic type) are discussed, highlighting their significant influence on feed reactivity, product yield, and carbon number distribution of the pyrolysis process. Optimizing these parameters in the pyrolysis process can ensure highly efficient energy recovery from PW. In comparison with non-catalytic PW pyrolysis, catalytic pyrolysis of PW is considered by discussing mechanisms, reaction pathways, and the performance of various catalysts. It is established that the introduction of either acid or base catalysts shifts PW pyrolysis from the conventional free radical mechanism towards the carbonium ion mechanism, altering its kinetics and pathways. This review also provides an overview of PW pyrolysis practicality for scaling up by describing techno-economic challenges and opportunities, environmental considerations, and presenting future outlooks in this field. Overall, via investigation of the recent research findings, this paper offers valuable insights into the potential of thermo-catalytic pyrolysis as an emerging strategy for PW management and the production of liquid fuels, while also highlighting avenues for further exploration and development.

Eco-friendly approaches for mitigating plastic pollution: advancements and implications for a greener future.

Plastic pollution has become a global problem since the extensive use of plastic in industries such as packaging, electronics, manufacturing and construction, healthcare, transportation, and others. This has resulted in an environmental burden that is continually growing, which has inspired many scientists as well as environmentalists to come up with creative solutions to deal with this problem. Numerous studies have been reviewed to determine practical, affordable, and environmentally friendly solutions to regulate plastic waste by leveraging microbes' innate abilities to naturally decompose polymers. Enzymatic breakdown of plastics has been proposed to serve this goal since the discovery of enzymes from microbial sources that truly interact with plastic in its naturalistic environment and because it is a much faster and more effective method than others. The scope of diverse microbes and associated enzymes in polymer breakdown is highlighted in the current review. The use of co-cultures or microbial consortium-based techniques for the improved breakdown of plastic products and the generation of high-value end products that may be utilized as prototypes of bioenergy sources is highlighted. The review also offers a thorough overview of the developments in the microbiological and enzymatic biological degradation of plastics, as well as several elements that impact this process for the survival of our planet.

Plastic waste in major orthopaedic surgical procedures: descriptive and sources of improvement.

PURPOSE: The healthcare industry is a significant contributor to single-use plastic waste, particularly in the operating room (OR). This study aims to assess the volume of plastic waste generated during total hip, knee, and shoulder arthroplasty in the OR and identify areas for improvement. METHOD: A prospective transversal study at a tertiary hospital was conducted. All total knee arthroplasty (TKA), total hip arthroplasty (THA), and reverse shoulder arthroplasty (RSA) from April to July 2021 were included. The weight of plastic used during patient preparation, anaesthesia, and the surgical procedure was recorded. To calculate the environmental impact, a calculator generated by the United States Environmental Protection Agency (U.S. EPA) was used. RESULTS: A total of 68 surgeries were included. The mean weight of plastic used in total was 7.3 kg (SD 0.48), with the highest yielding procedure being TKA. It generated a mean of 7.63 kg (SD 0.28), followed by THA at 7.28 kg (SD 0.43), and RSA at 6.87 kg (SD 0.47). Various scenarios were simulated to evaluate the potential impact of reducing plastic waste. Substituting plastic wrapping with recyclable materials could save 159.6 kg of CO2 emissions per 100 prostheses. Eliminating non-essential equipment and adopting reusable fabric drapes also showed a significant potential. CONCLUSION: The findings highlight the need for environmentally sustainable practices in the OR. In this way, the healthcare sector can contribute to a cleaner and greener world without compromising patient safety.

Closing the loop: A framework for tackling single-use plastic waste in the food and beverage industry through circular economy- a review.

The escalating threat of plastic pollution necessitates urgent and immediate action, particularly within the food and beverage (F&B) industry, a significant contributor to single-use plastic waste (SUP). As the global population surges, so does the consumption of single-use plastics in the F&B sector, perpetuating a linear economy model characterized by a 'take, make, use, dispose' approach. This model significantly exacerbates plastic waste issues, with projections indicating an alarming increase in plastic outputs by 2050 if current practices continue. Against this backdrop, the circular economy presents a viable alternative, with its emphasis on resource retention, recovery, and the extension of product lifecycles. This study delves into the problems posed by single-use plastics, introduces the circular economy as a sustainable model, and explores effective strategies for the recycling and reuse of plastic waste within this framework. By examining the environmental impact of SUP in the F&B sector and advocating for the adoption of circular economy principles, this paper underscores a critical pathway towards sustainable solutions in the battle against plastic pollution. In conclusion, the transition to a circular economy, underpinned by global collaboration and the proactive implementation of supportive policies, is imperative for reducing the environmental footprint of single-use plastics and fostering a sustainable future.

Public acceptance towards plastic waste-to-energy gasification projects: The role of social trust and health consciousness.

Public acceptance plays an essential role in successfully constructing and operating innovative and evolving technologies that promote ecological sustainability and pollution reduction. The present study investigates the factors influencing public acceptance of plastic waste-to-energy gasification projects. The research added social trust and health consciousness to the theory of planned behavior. Using the structural equation modeling, 513 valid survey questionnaire responses from the Beijing-Tianjin-Hebei region, China, were analyzed. The most notable results reveal that attitude, social norms, and perceived behavioral control have a major impact on the public acceptability of the initiative. There was no correlation between social trust and public support for the project. Social trust affects public acceptance of the project through attitude. Health consciousness was shown to be favorably connected with public approval of the project both directly and indirectly through attitude. This study serves policymakers and stakeholders with robust policy recommendations to promote public acceptance of plastic waste-to-energy gasification schemes and other hazardous facilities.

Plastic waste management through liquefaction in hydrogen donating solvents: A review.

Plastic pollution poses a significant environmental threat, particularly to marine ecosystems, as conventional plastics persist without degradation, accumulating plastic waste in landfills and natural environments. A promising alternative to address this issue involves the use of hydrogen donor solvents in plastic liquefaction, offering a dual benefit of waste reduction and the generation of valuable liquid products with diverse industrial applications. This review delves into plastic recycling methods with a specific focus on liquefaction using hydrogen donating solvents as an innovative approach to waste management. Liquefaction, conducted at moderate to high temperatures (280-450 °C) and pressures (7-30 MPa), yields high oil conversion using various solvents. This study examined the performance of hydrogen-donating solvents, including water, alcohols, decalin, and cyclohexane, in enhancing the oil yield while minimising the oxygen content. Supercritical water, recognised for its effective plastic degradation and chemical production capabilities, and alcohols, with their alkylating and hydrogen-donating properties, have emerged as key solvents in plastic liquefaction. The use of hydrogen donor solvents stabilizes the free radicals, enhancing the conversion of plastic waste into valuable products. In addition, this review addresses the economic efficiency of the liquefaction process.

Predictive modeling of plastic pyrolysis process for the evaluation of activation energy: Explainable artificial intelligence based comprehensive insights.

Pyrolysis, a thermochemical conversion approach of transforming plastic waste to energy has tremendous potential to manage the exponentially increasing plastic waste. However, understanding the process kinetics is fundamental to engineering a sustainable process. Conventional analysis techniques do not provide insights into the influence of characteristics of feedstock on the process kinetics. Present study exemplifies the efficacy of using machine learning for predictive modeling of pyrolysis of waste plastics to understand the complexities of the interrelations of predictor variables and their influence on activation energy. The activation energy for pyrolysis of waste plastics was evaluated using machine learning models namely Random Forest, XGBoost, CatBoost, and AdaBoost regression models. Feature selection based on the multicollinearity of data and hyperparameter tuning of the models utilizing RandomizedSearchCV was conducted. Random forest model outperformed the other models with coefficient of determination (R2) value of 0.941, root mean square error (RMSE) value of 14.69 and mean absolute error (MAE) value of 8.66 for the testing dataset. The explainable artificial intelligence-based feature importance plot and the summary plot of the shapely additive explanations projected fixed carbon content, ash content, conversion value, and carbon content as significant parameters of the model in the order; fixed carbon > carbon > ash content > degree of conversion. Present study highlighted the potential of machine learning as a powerful tool to understand the influence of the characteristics of plastic waste and the degree of conversion on the activation energy of a process that is essential for designing the large-scale operations and future scale-up of the process.

Household mixed plastic waste derived adsorbents for CO2 capture: A feasibility study.

The feasibility of producing activated carbon (AC) from real Household Mixed Plastic Waste (HMPW) comprising of LDPE, HDPE, PP, PS, and PET for carbon capture via direct carbonisation followed by microwave-assisted or conventional thermally assisted chemical activation was investigated. A microwave-assisted activation procedure was adopted to assess the impact on the CO2 capture capacity of the resulting AC using both a lower temperature (400 °C vs. 700 °C) and a shorter duration (5 vs. 120 mins) than that required for conventional activation. The results obtained showed that the AC yield was 71 and 78% for the conventional and microwave-assisted samples, respectively. Microwave activation consumed five-fold less energy (0.19 kWh) than the conventional activation (0.98 kWh). Thermal stability results indicated total weight loss of 10.0 and 8.3 wt%, respectively, for conventional and microwave-activated samples over the temperature range of 25-1000 °C, with ACs from both activation routes displaying a type 1 nitrogen isotherm. The dynamic CO2 uptake capacity at 1 bar and 25 °C was 1.53 mmol/g, with maximum equilibrium uptake ranging between 1.32 and 2.39 mmol/g at temperatures (0-50 °C) and 1 bar for the conventionally activated AC. The analogous microwave-activated sample showed a higher dynamic CO2 uptake of 1.62 mmol/g and equilibrium uptake in the range 1.58-2.88 mmol/g under equivalent conditions. The results therefore indicate that microwave activation results in enhanced carbon capture potential. To the best of our knowledge, this is the first-time microwave heating has been employed to convert household mixed plastic wastes directly into ACs for carbon capture applications. This report therefore demonstrates that the management of mixed plastics could lead to the development of a circular economy through the conversion of waste into value-added materials.

Production of hydrogen-rich fuel gas from waste plastics using continuous plasma pyrolysis reactor.

There is a serious concern about the large amount of accumulated plastic waste all around the world. Synthetic polymers such as polyethylene terephthalate (PET), polypropylene (PP), and polyethylene (HDPE, LDPE) are substantially present in the plastic waste generated. There are various methods reported to minimise such plastics waste with certain limitations. To overcome such limitations the present study have been carried out in which thermal decomposition of plastic waste of PET, PP, HDPE, and LDPE studied using a novel plasma pyrolysis reactor. The major objective of this work is to investigate the viability of the continuous plasma pyrolysis process for the treatment of various plastic wastes with respect to waste volume reduction and production of combustible hydrogen-rich fuel gas. The effect of temperature and feed flow rate on product gas yield, product gas efficiency, solid residue yield, and H2/CO ratio has been evaluated. The experiments have been carried out at different temperatures within the range of 700-1000 °C. Plasma pyrolysis system exhibited combustible hydrogen-rich gas as a product and solid residue. Liquid products have not been observed during plasma pyrolysis, unlike conventional pyrolysis. The reaction mechanism of plastic cracking has been discussed based on literature and products obtained in the present work. The effects of feed flow rate and temperature on exergy efficiency were studied using the response surface method. The mass, energy, and exergy analyses have also been carried out for all the experiments, which are in the range of 0.95-0.99, 0.48 to 0.77, and 0.30 to 0.69, respectively.