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Due to the complexity and diversity of polyolefinic plastic waste streams and the inherent non-selective nature of the pyrolysis chemistry, the chemical decomposition of plastic waste is still not fully understood. Accurate data of feedstock and products that also consider impurities is, in this context, quite scarce. Therefore this work focuses on the thermochemical recycling via pyrolysis of different virgin and contaminated waste-derived polyolefin feedstocks (i.e., low-density polyethylene (LDPE), polypropylene (PP) as main components), along with an investigation of the decomposition mechanisms based on the detailed composition of the pyrolysis oils. Crucial in this work is the detailed chemical analysis of the resulting pyrolysis oils by comprehensive two-dimensional gas chromatography (GC × GC) and ICP-OES, among others. Different feedstocks were pyrolyzed at a temperature range of 430–490 °C and at pressures between 0.1 and 2 bar in a continuous pilot-scale pyrolysis unit. At the lowest pressure, the pyrolysis oil yield of the studied polyolefins reached up to 95 wt%. The pyrolysis oil consists of primarily α-olefins (37–42 %) and n-paraffins (32–35 %) for LDPE pyrolysis, while isoolefins (mostly C9 and C15) and diolefins accounted for 84–91 % of the PP-based pyrolysis oils. The post-consumer waste feedstocks led to significantly less pyrolysis oil yields and more char formation compared to their virgin equivalents. It was found that plastic aging, polyvinyl chloride (PVC) (3 wt%), and metal contamination were the main causes of char formation during the pyrolysis of polyolefin waste (4.9 wt%).

This study describes the solvent-assisted organocatalysed depolymerisation of BPA-PC at low temperature for the selective formation of trimethylene carbonate. The key role of 1-methylimidazole as solvent and imidazole as catalyst is investigated.

In Kenya, agriculture is an important economic activity, which implies that a significant amount of bio-waste is generated. This is on one hand a waste management problem, but on the other hand, it is an opportunity for creating a sustainable bioeconomy. Therefore, this study investigates the potential recovery of bioresources from Kenyan bio-waste. The study first quantifies occurrence, current usage and disposal of three selected biomass types, being banana, Irish potato and coconut waste. Next, material flow analysis is used to systematically track the mass flow of these wastes. Finally, the potential of biomolecules, biomaterials and bioenergy from the waste streams is evaluated. The study revealed that about 6007, 426 and 50 kt of banana, Irish potato and coconut biomass is wasted. All these wastes can be biorefined, offering potential towards recovery of; flavonoids (74 kt), starch (377 kt), cellulose (2001 kt) and biogas (1757 GWh), being the total potential of the main bioresources from the three waste streams. The study therefore, concluded that, with proper waste collection, sorting and valorisation, there is a huge potential for bioeconomy in Kenya, at the same time reducing waste management problems. Graphical Abstract

Sustainable solvent mediated recycling of plastic multilayer packaging by splitting of polyurethane adhesive glue.

Textile products are composed of various blends of synthetic or natural polymers. Elastane increases the functionality during use phase, but impedes high quality recycling. This study investigates the selective chemical dissolution of elastane from blended textile. Hansen solubility parameters and COSMO-RS were applied for solvent screening. The most recommended biobased solvents were experimentally validated with polyester, polyamide, cotton, wool and elastane for which solubility limits were determined and hence, their selectivity towards elastane dissolution. A TGA-corrected gravimetric method was developed as quantification tool and showed that tetrahydrofurfuryl alcohol and ɣ-valerolactone have comparable elastane dissolution capabilities to classical solvents (5 mg elastane/g solvent). Polyester/elastane and polyamide/elastane blends were subjected to this process as case studies. The LCA study showed that this selective solvent-based dissolution process saves 60% CO2-eq./kg textile waste compared to incineration. This interdisciplinary work can set the benchmark for further developing and upscaling physical/dissolution recycling processes for blended textiles.

Plastic recycling rate in Europe is low, urging developments in recycling technology and strategies to increase circularity. Mechanical recycling (MR) has been the reference recycling technology for years, but in the near future chemical recycling (CR) options are expected to contribute to improve plastic circularity. This study uses a material flow analysis (MFA) at European level to provide quantitative estimates of the contribution of CR technologies to plastic recycling. Ten most used polymer types from five sectors are selected. A status quo 2018 scenario is modelled and compared to five potential future scenarios (in 2030) of plastic waste treatment, including one that only looks at improved waste collection, sorting, and MR technologies and four exploring developments of CR options. The so-called ‘missing plastics’, i.e., plastic waste generated but currently not accounted for in statistics, is considered in one of the future scenarios. The MFA results are compared by calculating four circularity indicators namely end-of-life recycling rate (EoL-RR), plastic-to-plastic rate, plasticto-chemicals rate, and plastic-to-fuels rate. The results indicate that in the most optimistic scenario the EoL-RR in 2030 is 73–80% (sum of plastic-to-plastic and plastic-to-chemical rates, excluding plastic-to-fuel rate), in which 41–46% is plastic-to-plastic from MR, 15–38% is plastic-to-plastic from CR and 19–35% is plastic-to-chemicals. The highest achievable plastic-to-plastic rate is estimated to be 61% (46% from MR and 15% from CR). In all future scenarios, the plastic-to-fuel rate is estimated to be 3–6%. The MFA results are also used to estimate potential recycled content availability in 2030, which suggest that closed-loop recycling and processing the ‘missing plastics’ will be necessary to achieve the targets.

Advanced plastic waste recycling via pyrolysis and subsequent steam cracking of pyrolysis oils has the potential to partly close the cycle between the petrochemical production of plastics and current end-of-life waste man-agement (i.e., downcycling, incineration, landfilling). However, the greatest obstacle is the complex composition of real plastic waste and their contamination with numerous additives and residues. Consequently, the lower quality of pyrolysis products compared to fossil feedstocks needs to be drastically improved by universally applicable upgrading and decontamination techniques. Techniques range from waste pre-treatment to reduce the halogen and additive contents, via in-situ techniques applied during pyrolysis to post-treatment techniques to purify the obtained pyrolysis oils using hydrotreatment, filtration or adsorption. Incorporated into a petro-chemical cluster, high-quality petrochemical feedstocks can be produced from plastic waste, which, combined with electrification, could lead to a CO2 emission reduction of >90% compared to incineration as the current mostly used disposal method.

Synthetic dyes are by far the most widely applied colourants in industry. However, environmental and sustainability considerations have led to an increasing efforts to substitute them with safer and more sustainable equivalents. One promising class of alternatives is the natural quinones; these are class of cyclic organic compounds characterized by a saturated (C6) ring that contains two oxygen atoms that are bonded to carbonyls and have sufficient conjugation to show color. Therefore, this study looks at the potential of isolating and applying quinone dye molecules from a sustainable source as a possible replacement for synthetic dyes. It presents an in-depth description of the three main classes of quinoid compounds in terms of their structure, occurrence biogenesis and toxicology. Extraction and purification strategies, as well as analytical methods, are then discussed. Finally, current dyeing applications are summarised. The literature review shows that natural quinone dye compounds are ubiquitous, albeit in moderate quantities, but all have a possibility of enhanced production. They also display better dyeability, stability, brightness and fastness compared to other alternative natural dyes, such as anthocyanins and carotenoids. Furthermore, they are safer for the environment than are many synthetic counterparts. Their extraction, purification and analysis are simple and fast, making them potential substitutes for their synthetic equivalents. Graphic Abstract

Recycling multilayer plastic packaging is challenging due to its intrinsic compositional heterogeneity. A promising route to increase recycling rates for these materials is delamination, which allows recycling the polymers separately. Yet, this process is not well understood on a fundamental level. This study aimed to obtain first principles‐based insights of the delamination mechanism of multilayer flexible packaging film (MFPF) with carboxylic acids. Delamination of MFPFs was described through a model based on Fick's first law of diffusion and first‐order dissolution kinetics of polyurethane adhesives. The model was experimentally tested on 5 different MFPFs at different temperatures (50–75 °C), formic acid concentrations (50–100 vol %), and solid/liquid (S/L) ratios (0.005, 0.025, and 0.12 g mL−1). Under the studied conditions the model proved to successfully estimate the delamination time of MFPF with the average Theil's Inequality Coefficient (TIC) value of 0.14. Essential for scaling‐up delamination processes is the possibility to use high S/L ratios as the solubility of the adhesive is rarely limiting., Multilayer plastic packaging: Delamination of multilayer flexible packaging films (MFPFs) is described through a model based on Fick's first law of diffusion and first‐order dissolution kinetics of polyurethane adhesives. The model is validated on typical MFPFs under different experimental conditions. Under the studied conditions the model successfully estimates the delamination time of MFPFs.

Every year, within Europe, 7700 tonnes of acrylic textiles are disposed of by landfill or incineration. Recycling this waste would conserve over 8 times the energy regained from incineration. In addition, acrylic fibres are predominantly solution spun using toxic and carcinogenic solvents such as dimethyl formamide, so mechanically recycling these fibres would avoid the need for re-extrusion using these solvents, thus providing a benefit to health. Despite these benefits, acrylic textiles are not currently recycled. One crucial reason for this lack of recycling is the presence of finishing chemicals on the fibre substrate. These include harmful formaldehyde- and fluorine-containing resins, which complicate the recycling process and remain in the recycled product, thus limiting its application potential and remaining a health risk. These finishes must thus be removed at the start of the recycling process, which is one of the goals of the REACT project.

There is an urgent need to close the loop of plastic waste. One of the main challenges towards plastic packaging waste recycling is the presence of a variety of contaminants. These contaminants include organic residues, additives, labels, inks and also other plastic types that can be present in the waste stream due to missorting or in multimaterial structures (e.g. multilayer films in packaging). In this context, pre-treatment processes are a promising route to tackle the difficulties that are encountered in mechanical and chemical recycling due to these contaminants. This chapter gives better insight on the already existing pre-treatment techniques and on the advances that are being developed and/or optimized in order to achieve closed-loop recycling. Some of these advanced pre-treatments include chemical washing to remove inks (deinking), extraction methods to remove undesired plastic additives and dissolution-based pre-treatments, such as delamination and dissolution-precipitation techniques.

Plastic packaging typically consists of a mixture of polymers and contains a whole range of components, such as paper, organic residue, halogens, and metals, which pose problems during recycling. Nevertheless, until today, limited detailed data are available on the full polymer composition of plastic packaging waste taking into account the separable packaging parts present in a certain waste stream, nor on their quantitative levels of (elemental) impurities. This paper therefore presents an unprecedented indepth analysis of the polymer and elemental composition, including C, H, N, S, O, metals, and halogens, of commonly generated plastic packaging waste streams in European sorting facilities. Various analytical techniques are applied, including Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), polarized optical microscopy, ion chromatography, and inductively coupled plasma optical emission spectrometry (ICP-OES), on more than 100 different plastic packaging products, which are all separated into their different packaging subcomponents (e.g., a bottle into the bottle itself, the cap, and the label). Our results show that certain waste streams consist of mixtures of up to nine different polymers and contain various elements of the periodic table, in particular metals such as Ca, Al, Na, Zn, and Fe and halogens like Cl and F, occurring in concentrations between 1 and 3000 ppm. As discussed in the paper, both polymer and elemental impurities impede in many cases closed-loop recycling and require advanced pretreatment steps, increasing the overall recycling cost.

A major difficulty in operating biorefinery processes is the large feedstock variability. A systematic multivariate analysis (sMVA) strategy for improved process understanding of industrial biorefinery processes is proposed to support identification of effects of feedstock and process variability on product quality. This sMVA strategy comprises nine steps categorized in data set organization, exploratory analysis, and regression. Different MVA techniques are used, such as principal component analysis (PCA) and partial least squares regression (PLS). As a case study, two main operations in fatty acid production are investigated: oil hydrolysis and fatty acid distillation. Key feedstock properties and process parameters affecting the product properties were identified for both operations. For fatty acid production, product quality largely depends on the type of fat or oil used, such as canola or palm oil, due to the large difference in composition and quality between the oil types. However, if a single oil type is used, the variability in product quality does not always critically depend on the variability in feedstock properties. For both operations, flow rate variations, mainly caused by planning issues, were identified as a main cause. In oil hydrolysis, the feed flow rate influences the residence time and thereby directly influences the hydrolysis and side reactions. In fatty acid distillation, a better control is required of the middle reflux ratio in relation to this changing flow rate. The case study showed that applying our proposed sMVA strategy improves the understanding of a biorefinery process by identifying critical sources of variability, which allows more targeted decisions for optimization and control.

Slowing and closing loop strategies have the ultimate goal of avoiding materials’ losses, hibernation, and emissions, therefore all kind of actions that hamper useful applications. Consequently, there is a need to develop indicators that can deal with mass and time. A way to indicate circularity is by measuring the in-use occupation of resources, that is, keeping materials in a useful state, avoiding dissipation, and adverse effects, such as burden transfer. The objective of this work is to advance in-use occupation as an indicator for the circularity of products; therefore, we schematically present a framework and parameters for such indicators.

Expanding the curbside collection system for household plastic packaging could help in accomplishing the ambitious recycling targets set by the European Union. In this study, the effects of such expansion in terms of quality and quantity of sorted plastic waste fractions were investigated. By applying a validated sorting model, the flows of packages in Belgium from their use phase until the output of the sorting plant and the quantity and composition of sorted waste fractions were simulated. These data were subsequently used to calculate existing performance indicators, such as grade and recovery, as well as new indicators, such as the Simpson's Diversity Index (SDI), which is a measure for the compositional diversity of sorted waste fractions. The highest SDI was calculated for the fraction named ‘other films’, namely 82%, showing that this fraction comprised the most diverse polymer mixture. Results indicated that certain sorted fractions achieve high product grade levels, e.g. more than 99% for the PS rigid fraction, whereas others had significantly lower product grades of approximately 80% for the PE films. Material Flow Analysis showed that by expanding the collection portfolio the collection rate of plastic packaging increased from 33.6 to 64.4 m%, of which 77.3% is simulated to be separated in the targeted waste fractions. However, this will be insufficient to meet the recycling target of 50% by 2025 as in total only 49.8% of plastic packaging is sorted correctly. Hence, additional improvements in both recycling technologies and packaging design are needed to further increase plastic recycling rates.

An important impediment to the acceptance of recyclates into a broader market is their unwanted odor after reprocessing. Different types of washing procedures are already in place, but fundamental insights into the deodorization efficiencies of different washing media are still relatively scarce. Therefore, in this study, the deodorization efficiencies of different types of plastics after washing with different media were determined via gas chromatography and mass spectrometry analysis. A total of 169 compounds subdivided into various chemical classes, such as alkanes, terpenes, and oxygenated compounds, were detected across all packaging types. Around 60 compounds were detected on plastic bottles, and around 40 were detected on trays and films. Owing to the differences in physicochemical properties of odor compounds, different deodorization efficiencies were obtained with different washing media. Water and caustic soda were significantly more efficient for poly(ethylene terephthalate) bottles with deodorization efficiencies up to 80%, whereas for polyethylene (PE) and polypropylene bottles, the washing media were relatively inefficient (around 30-40%). Adding a detergent or an organic solvent could increase deodorization efficiencies by up to 70-90% for these packaging types. A similar trend was observed for PE films having deodorization efficiencies in the range of 40-50% when washing with water or caustic soda and around 70-80% when a detergent was added. Polystyrene trays were most effectively deodorized with a detergent, achieving efficiencies up to 67%. Hence, this study shows that optimal washing processes should be tailored to specific packaging types to further improve deodorization and to eventually be able to meet ambitious European recycling targets.

The viscosity of polymer solutions is important for both polymer synthesis and recycling. Polymerization reactions can become hampered by diffusional limitations once a viscosity threshold is reached, and viscous solutions complicate the cleaning steps during the dissolution-precipitation technique. Available experimental data is limited, which is more severe for green solvents, justifying dedicated viscosity data recording and interpretation. In this work, a systematic study is therefore performed on the viscosity of polystyrene solutions, considering different concentrations, temperatures, and conventional and green solvents. The results show that for the shear rate range of 1-1000 s(-1), the solutions with concentrations between 5 and 39 wt % display mainly Newtonian behavior, which is further confirmed by the applicability of the segment-based Eyring-NRTL and Eyring-mNRF models. Moreover, multivariate data analysis successfully predicts the viscosity of polystyrene solutions under different conditions. This approach will facilitate future data recording for other polymer-solvent combinations while minimizing experimental effort.

Industrial-scale application of end-of-life plastic pyrolysis still faces significant problems, such as a lack of detailed knowledge on degradation mechanisms, parameters affecting the degradation, and formation pathways of the primary pyrolysis products. Today, the degradation mechanisms based on radical chain scission are insufficiently understood to explain the pyrolysis chemistry from feedstock-to-product comprehensively. In this study, the impact of operating conditions on the degradation mechanism is evaluated by pyrolyzing end-of-life and virgin high-density polyethylene (HDPE) in a continuous pilot-scale unit at temperature and pressure ranges of 450–504 ºC and 0.1–2 bara. The pyrolysis products were analyzed based on the detailed product composition obtained using comprehensive two-dimensional gas chromatography (GC×GC). A simplified kinetic mechanism was proposed to describe the main production pathways of the various components by considering the weakest points along the polymer chain. The results showed that the chain-end scission mechanism is the main mechanism in the HDPE pyrolysis process, even at low temperatures and pressures in the studied ranges. The pyrolysis of virgin HDPE under sub-atmospheric pressure, 0.1 bara, at 464 ºC reactor temperature, yields the highest concentration of linear hydrocarbons in the pyrolysis oil (93.2 wt%). At higher pressure and temperature, the cyclic and branched hydrocarbons had a higher share of up to 17.4 wt% compared to 6.8 wt% at vacuum pressure and lower temperature. Interestingly, the pyrolysis of end-of-life HDPE at atmospheric pressure and 450 ºC led to more cyclic and branched hydrocarbons (sum: 22.1 wt%), as opposed to that of virgin HDPE which is more prone to the production of linear hydrocarbons at the studied conditions. Regarding the additives and contaminants, a large amount of different metals and halogen atoms in the ppm range were detected in end-of-life HDPE, of which a small amount was still found in the pyrolysis oil.

Increasing the recycling rates for post-consumer flexible plastics (PCFP) waste is imperative as PCFP is considered a difficult-to-recycle waste with only 17 % of PCFP effectively recycled in Europe. To tackle this pressing issue, improved mechanical recycling processes are being explored to increase the recycling rates of PCFP. One interesting option is the so-called quality recycling process (QRP) proposed by CEFLEX, which supplements more conventional mechanical recycling of PCFP with additional sorting, hot washing, improved extrusion, and deodorization. Material flow analysis (MFA) model is applied to assess the performance of QRP. Four performance indicators related to quantity (process yield and net recovery) and quality (polymer grade and transparency grade) are applied to measure the performance of three PCFP mechanical recycling scenarios. The results are compared against the conventional recycling of PCFP, showing that QRP has a similar process yield (64 % - 66 %) as conventional recycling (66 %). The net recovery indicator shows that in QRP higher recovery rates are achieved for transparent-monolayer PCFP (>90 %) compared to colored-multilayer PCFP (51 % - 91 %). The quality indicators (polymer and transparency grades) demonstrate that the regranulates from QRP have better quality compared to the conventional recycling. To validate the modeling approach, the modeled compositional data is compared with experimental compositional analyses of flakes and regranulates produced by pilot recycling lines. Main conclusions are: (i) although yields do not increase significantly, extra sorting and recycling produces better regranulates' quality (ii) performing a modular MFA gives insights into future recycling scenarios and helps in decision making.

The increasing focus on circular economy at the level of governments and policy requires the development of appropriate indicators to effectively monitor the progress towards the circular economy. Currently two very different types of indicator areas are under development: (i) monitoring frameworks based on macro indicators that summarize the progress at (supra)national level, and (ii) micro indicators tailored towards assessing circularity at the level of products. It is not possible to obtain sufficiently direct feedback about the impact of policy interventions by either macro or micro indicators alone. In this paper, a conceptual approach is developed that aims to bridge the gap between the micro and macro level with meso level indicators, and thus ultimately deliver more direct feedback for policymakers, via the insertion of an extra level of meso indicators in between the macro and the micro level. These indicators have been extracted from a dedicated workshop that involved policy, sector and societal stakeholders. The aim of these indicators is to report on progress towards circular economy objectives based on the fulfillment of societal needs. In this way the consumption perspective is given a central position, and the role of circular business models is acknowledged. Following the development of the concept, the next steps towards tailored, flexible and agile monitoring frameworks for circular economy at (supra)national and regional level are outlined. The paper concludes with an illustrative example of the framework applied to the mobility system.

Most biopharmaceuticals are produced as sterile parenteral preparations, requiring very strict production conditions. In addition, liquid formulations face stability challenges which is why currently around half of all biologics are freeze dried for preservation. The environmental impact of the fill and finish processes to produce a freeze dried biopharmaceutical (infliximab) was evaluated from two perspectives: (i) considering only process-specific needs and (ii) calculating the overall site needs. An Exergetic Life Cycle Assessment was conducted using both a bottom-up and top-down approach. The process-specific and overall site needs are 6.5 and 39.6 MJex/vial, respectively. These results reveal that 84% of the cumulative exergy entering the manufacturing plant is non-process-specific. Electricity consumption is the highest footprint driver (86%), dominated by the Heating, Ventilation and Air Conditioning (HVAC) system running during non-production hours and/or supporting non-production related areas. If resource efficiency is pursued, the focal target might need to shift towards non-process-specific needs which are not essential for the product functionality/quality (e.g. full HVAC regime during non-production hours). It should be kept in mind that Good Manufacturing Practices conditions always have to be maintained. Currently performed energy saving measures addressing HVAC systems could potentially reduce the overall site needs calculated in this study by up to 16.5 MJex/vial.

Shifting from a linear to a circular economy has consequences on how the sustainability of products is assessed. This is the case for products recovered from resources such as sewage sludge. The “zero-burden” assumption is commonly used in Life Cycle Assessment and considers that waste streams are burden-free, which becomes debatable when comparing waste-based with virgin material-based products in the context of the growing circular economy. If waste streams are considered as resources rather than waste, upstream burdens should be partly allocated to all products to allow a fair comparison with their virgin material-based equivalents. In this paper, five allocation approaches are applied to allocate the resource use of upstream processes (consumer goods production) to products recovered from the processing of sewage sludge in the Netherlands, which produces biogas, (phosphorus-based) chemicals and building materials. Except for the approach which allocates 100% of the impact from resource recovery processes to the preceding consumer goods, the allocation approaches show a resource use 27 to 80% higher than with the “zero-burden” assumption. In this particular case, using these allocation approaches is likely to find little support from recyclers. The producers of household products, recyclers and policy makers should find a consensus to consider the shift from a linear to a circular economy in sustainability assessment studies while avoiding discouraging the implementation of recovery technologies. This paper suggests starting the discussion with the approach which allocates the impacts from upstream processes degressively to the downstream products as it best translates the industrial ecology principles.

Highlights • Indicators are useful to support circular economy progress. • Circular economy has different definitions entailing challenges for indicators. • A classification framework to understand what indicators measure is proposed. • Most of the analysed indicators focus on the preservation of materials. • None of the analysed indicators focuses on the preservation of functions., Circular Economy (CE) is a growing topic, especially in the European Union, that promotes the responsible and cyclical use of resources possibly contributing to sustainable development. CE is an umbrella concept incorporating different meanings. Despite the unclear concept, CE is turned into defined action plans supported by specific indicators. To understand what indicators used in CE measure specifically, we propose a classification framework to categorise indicators according to reasoning on what (CE strategies) and how (measurement scope). Despite different types, CE strategies can be grouped according to their attempt to preserve functions, products, components, materials, or embodied energy; additionally, indicators can measure the linear economy as a reference scenario. The measurement scope shows how indicators account for technological cycles with or without a Life Cycle Thinking (LCT) approach; or their effects on environmental, social, or economic dimensions. To illustrate the classification framework, we selected quantitative micro scale indicators from literature and macro scale indicators from the European Union ‘CE monitoring framework’. The framework illustration shows that most of the indicators focus on the preservation of materials, with strategies such as recycling. However, micro scale indicators can also focus on other CE strategies considering LCT approach, while the European indicators mostly account for materials often without taking LCT into account. Furthermore, none of the available indicators can assess the preservation of functions instead of products, with strategies such as sharing platforms, schemes for product redundancy, or multifunctionality. Finally, the framework illustration suggests that a set of indicators should be used to assess CE instead of a single indicator.

BACKGROUND: Although the biopharmaceutical market grows rapidly, the environmental impacts of biopharmaceutical manufacturing have been hardly evaluated. The aim of the study is to comprehensively assess the environmental sustainability of a biologically‐produced active pharmaceutical ingredient (API) manufacturing process. For this purpose, an exergy analysis and an (exergetic) life cycle assessment were performed using primary (foreground system) and modeled data (background system). Infliximab, a monoclonal antibody, was considered. RESULTS: The fermentation and its raw materials' supply chain was determined to have the highest environmental impact, since the culture media requires chemicals and complex compounds such as animal‐derived materials (ADMs). The total impact per 100 mg of API produced ranged between 18.6 and 101.8 MJₑₓ and 2.0–3.1 kg CO₂‐eq, mainly as a function of the ADMs' source. A comparison of infliximab and ustekinumab, a biopharmaceutical produced without ADMs, showed that eliminating these materials can reduce the cumulative resource consumption of monoclonal antibody manufacturing by up to 7.5 times. The fermentation is the process taking the longest and the heating, ventilation and air conditioning system which support fermentation areas consumes approximately 75% of all plant electricity use. CONCLUSIONS: Culture media nutrients and cleanroom requirements are driving factors in the environmental impact of biological API manufacturing. Obtaining more precise data of the bioprocesses behind these nutrients' supply chain is crucial to corroborating this study's results. © 2019 Society of Chemical Industry

Waste Electrical and Electronic Equipment (WEEE) is a key resource in the circular economy given its high concentration of valuable materials such as metals. The complexity of recycling this resource, however, is high due to different collection, separation and reprocessing steps. A combined Material Flow Analysis (MFA) and Life Cycle Assessment (LCA) can be used to optimise the environmental performance of this recycling chain. Whereas usually these methodologies are used post-factum, i.e. when data is available, this paper presents how MFA and LCA can be used to predict material flows and the potential environmental benefit of the recycling chain, guiding policy makers and industries towards effective decision making. Based on a case study in Flanders, Belgium, firstly, it is shown that currently only 32% of WEEE materials are recycled towards high-end applications whereas 68% is lost in low-end applications, landfill or incineration. Ferrous and non-ferrous metals such as aluminium and copper achieve the highest high-end material recoveries (54, 46 and 44% respectively), whereas precious metals and plastic achieve lower high-end material recoveries (21–38% and 20% respectively). Secondly, it is shown that the most promising factors to improve material recovery and environmental benefit are consumer behaviour and technological progress (mainly in separation technologies), both potentially doubling the current environmental benefit.

Whilst freeze drying is known for its high energy requirements, few studies have been conducted assessing the efficiency of freeze dryers, especially related to pharmaceuticals. A quantitative anal...

Plastic waste is steadily polluting oceans and environments. Even if collected, most waste is still predominantly incinerated for energy recovery at the cost of CO

The complexity of lipid feedstocks and the lack of data on physical properties hinder the simulation of oleochemical processing units. In this work, an iterative lumping approach is proposed to define an adequate number of key compounds such that diversification between lipid feedstocks becomes possible, while keeping the determination of physical properties as required for process modeling manageable. As a case study, the iterative lumping approach is used for simulation and optimization of a fatty acid distillation plant. For predicting vapor–liquid equilibria of fatty acids, the best results were acquired using the property method universal quasichemical-Hayden–O'Conell. Using the iterative lumping approach, 11 key compounds wereselected to represent the feedstock. The process model properly predicts the product composition, yield, purity and heat duty. The most important process parameters are found to be side-reflux-ratio, reboiler-outlet-temperature, and heat-duty of the pitch-distiller. For optimization, an increase of the side-reflux-ratio and reboiler-outlet-temperature is recommended.

Household packaging waste sorting facilities consist of complex networks of processes to separate diverse waste streams. These facilities are a key first step to re-enter materials into the recycling chain. However, so far there are no general methods to predict the performance of such sorting facilities, i.e. how efficiently the heterogeneous packaging waste is sorted into fractions with value for further recycling. In this paper, a model of the material flow in a sorting facility is presented, which allows changing the incoming waste composition, split factors on the sorting units as well as the setup of the sorting facility. The performance of the sorting facility is judged based on the purity of the output material (grade) and the recovery of the input material. A validation of the model was performed via a case study on Belgian post-consumer packaging waste with a selection of typical waste items that can be found in this stream. Moreover, the model was used to predict the possible sorting qualities of future Belgian post-consumer packaging waste after an extension of the allowed waste packaging items in the waste stream. Finally, a sensitivity analysis was performed on the split factors, which are a key data source in the model. Overall, the developed model is flexible and able to predict the performance of packaging waste sorting facilities as well as support waste management and design for recycling decisions, including future design of packaging, to ensure proper sorting and separation. (C) 2020 Elsevier Ltd. All rights reserved.

This manuscript provides an overview of the legislative requirements for the use of mechanical recycled plastics in articles placed on the EU market, as seen from the perspective of a plastics recycler. The first part reviews the main principles included in the overarching legislation on Registration, Evaluation, Authorisation and Restrictions of Chemicals (REACH) and to what extent these are applicable for mechanical recyclers of plastics. The interactions between REACH and the Waste Framework Directive (WFD) is discussed, as well as the difficulties for recyclers to comply with certain REACH requirements. In a second part, the focus is moved to the use of recycled plastics as Food Contact Material (FCM). The scope of the different applicable EU FCM regulations is inventorised as well as the key legislative principles involved. A final section is dedicated to the discussion on the authorisation of recycling processes under the FCM regulation and the practical challenges involved for the effective introduction of FCMs containing recycled plastics. Altogether it could be concluded that the complexity of the different legal perspectives, a lack of communication and transparency within the plastic value chain together with technical challenges related to recycling processes have been hindering the effective uptake of recycled plastic FCM (with the exception for bottle PET). The development of targeted solutions across the entire value-chain, taking into account different perspectives in terms of legislation and health protection, economic growth and technical innovations, will be crucial in achieving a circular economy for plastics, including recycled plastics for FCM.

A comprehensive model for simulation and optimization of industrial-scale splitting towers that is able to predict the yield for the hydrolysis of bio-based triglyceride feedstocks is presented in this work. This model includes a variable glycerol equilibrium ratio, which is a function of the composition and temperature and is calculated using the polar version of the perturbed chain statistical association fluid theory (PC-SAFT), the autocatalytic effect of fatty acids in hydrolysis, and isomerization of poly-unsaturated fatty acids. Model validation is performed using process data from three real-life splitting towers covering four feedstock types, i.e., tallow, rapeseed oil, palm oil, and palm fatty acid distillate. Due to the composition gradients of the organic phase throughout the tower, it is crucial to properly account for the changes in the glycerol equilibrium ratio. The importance of feedstock flow rate, water/oil ratio, and temperature profile throughout the tower is analyzed and confirmed by sensitivity analysis. Our results show that modifying the temperature profile may shift the reaction equilibrium toward the fatty acid product. This knowledge is crucial for improving the energy and resource efficiency of fatty acid production, thereby improving its economic and environmental sustainability.

Plastics are highly versatile materials, which can substantially vary in their properties, within a single polymer type, to cope with the range of different applications. Sorted bales of end-of-life plastics typically still contain a mixture of various plastic types and grades, which significantly affects the technical properties of the recycled material made from these bales. The evaluation of the technical recycling quality is crucial to determine which applications can be targeted with the produced recyclates, and if actual substitution of virgin plastics is possible. This is relevant from a technical perspective, but also for sustainability assessments such as life cycle assessment. The functionality of a plastic material is determined by a range of mechanical characteristics and by its ease of processing. These aspects cannot be generalized, as they are dependant on the intended application. This work, therefore, proposes a concept for calculating the effective technical substitutability, in which application specific functions generate a score for processability and mechanical recycling quality. To illustrate this concept, the substitutability of three commercially available recycled plastics is determined for four different application categories. The results show the strong application dependency of the changes in technical quality for a given recycled plastic stream. The approach is a step forward in the correct determination of the substitutability and consequently the proper assessment of the potential of end-of-life plastics as secondary resource.

Among the different thermo-chemical recycling routes for plastic waste valorization, gasification is one of the most promising, converting plastic waste into syngas (H2+CO) and energy in the presence of an oxygen-rich gas. Plastic waste gasification is associated with many different complexities due to the multi-scale nature of the process, the feedstock complexity (mixed polyolefins with different contaminations), intricate reaction mechanisms, plastic properties (melting behavior and molecular weight distribution), and complex transport phenomena in a multi-phase flow system. Hence, creating a reliable model calls for an extensive understanding of the phenomena at all scales, and more advanced modeling approaches than those applied today are required. Indeed, modeling of plastic waste gasification (PWG) is still in its infancy today. Our review paper shows that the thermophysical properties are rarely properly defined. Challenges in this regard together with possible methodologies to decently define these properties have been elaborated. The complexities regarding the kinetic modeling of gasification are numerous, compared to, e.g., plastic waste pyrolysis, or coal and biomass gasification, which are elaborated in this work along with the possible solutions to overcome them. Moreover, transport limitations and phase transformations, which affect the apparent kinetics of the process, are not usually considered, while it is demonstrated in this review that they are crucial in the robust prediction of the outcome. Hence, possible approaches in implementing available models to consider these limitations are suggested. Finally, the reactor-scale phenomena of PWG, which are more intricate than the similar processes—due to the presence of molten plastic—are usually simplified to the gas-solid systems, which can result in unreliable modeling frameworks. In this regard, an opportunity lies in the increased computational power that helps improve the model’s precision and allows us to include those complexities within the multi-scale PWG modeling. Using the more accurate modeling methodologies in combination with multi-scale modeling approaches will, in a decade, allow us to perform a rigorous optimization of the PWG process, improve existing and develop new gasifiers, and avoid fouling issues caused by tar.

Anthocyanins and pyranoanthocyanins are flavonoids that are present in various food products (e.g., fruit, vegetables, wine, etc.). The large chemical diversity amongst these molecules leads to compound-specific properties such as color and stability towards external conditions. These properties are also attractive for food and non-food applications. The photophysical experimental characterization is not easy as this generally demands advanced analytical techniques along with optimized separation procedures. Molecular modeling can provide insights into the fundamental understanding of the photophysical properties of these compounds in a uniform way for a broad set of compounds. However, the current literature is quite fragmented on this topic. Herein, a large set of 140 naturally derived anthocyanins was evaluated in a systematic way with three functionals (B3LYP, PBE0, and CAM-B3LYP). The accuracy of these functionals was determined with experimental literature lambda(max,vis) values. In addition to lambda(max,vis) values, time-dependent (TD)-DFT calculations also provided oscillator strengths, molar absorption coefficients, and orbital energies, which define whether specific natural anthocyanin-based compounds can be deployed in food and non-food applications such as food additives/colorants, textile dyeing, analytical standards, and dye-sensitized solar cells (DSSCs).

Mechanical recycling is to date the most commonly applied recycling technology. However, mechanical recycling of post-consumer plastics still faces many challenges, such as the presence of odorous constituents. Accordingly, recycling industry is looking for cost-effective solutions to improve the current washing efficiencies. However, scientific literature and basic understanding of deodorization processes are still scarce, which impedes efficient industrial optimization. Therefore, this study aims to obtain more fundamental insights in the deodorization mechanisms of plastic films in different washing media such as water, detergent, caustic soda, and ethyl acetate as organic solvent. The removal efficiencies of 19 odor components with a wide range of physicochemical properties were quantified via GC-MS analysis. The results revealed that deodorization depends on various factors such as temperature and physicochemical properties as polarity, volatility, and molecular weight of the odor components and the washing media. It was shown that polar washing media are less efficient compared to apolar media or media containing a detergent, achieving efficiencies of around 50% and 90%, respectively. The desorption processes can be accurately modeled by the isotherm model of Fritz-Schlunder in combination with a reversible first order kinetic model for the deodorization kinetics. Aspen Plus® process simulations of a water-based washing process reveal that at least 60% fresh water is needed to avoid saturation of the medium and undesired (re-)adsorption of odor components onto the plastics, which results in a substantial ecological footprint.

Microplastics are ubiquitous pollutants within the marine environment, predominantly (>90%) accumulating in sediments worldwide. Despite the increasing global concern regarding these anthropogenic pollutants, research into the remediation of microplastics is lacking. Here, we examine those characteristics of microplastics that are essential to adequately evaluate potential remediation techniques such as sedimentation and (air) flotation techniques. We analyzed the sinking behavior of typical microplastics originating from real plastic waste samples and identified the best-available drag model to quantitatively describe their sinking behavior. Particle shape is confirmed to be an important parameter strongly affecting the sinking behavior of microplastics. Various common shape descriptors were experimentally evaluated on their ability to appropriately characterize frequently occurring particle shapes of typical microplastics such as spheres, films, and fibers. This study is the first in this field to include film particles in its experimental design, which were found to make up a considerable fraction of marine pollution and are shown to significantly affect the evaluation of shape-dependent drag models. Circularity χ and sphericity Φ are found to be appropriate shape descriptors in this context. We also investigated the effect of biofouling on the polarity of marine plastics and estimated its potential contribution to the settling motion of initially floating microplastics based on density-modification. It is found that biofouling alters the polarity of plastics significantly; this is from (near) hydrophobic (i.e., water contact angles from 70 to 100°) to strong hydrophilic (i.e., water contact angles from 30 to 40°) surfaces, rendering them more difficult to separate from sediment based on polarity as a primary separation factor. Thus, besides providing a better understanding of the fate and behavior of typical marine microplastics, these findings serve as a fundamental stepping-stone to the development of the first large-scale sediment remediation technique for microplastics to address the global microplastic accumulation issue.

The mixing of polymers, even structurally similar polyolefins, inevitably leads to blend systems with a phase-separated morphology. Fundamentally understanding the changes in mechanical properties and occurring deformation mechanisms of these immiscible polymer blends, is important with respect to potential mechanical recycling. This work focuses on the behavior of binary blends of linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP) under tensile deformation and their related changes in crystallinity and morphology. All of these polymers plastically deform by shear yielding. When unmixed, the high crystalline polyolefins HDPE and PP both exhibit a progressive necking phenomenon. LDPE initiates a local neck before material failure, while LLDPE is characterized by a uniform deformation as well as clear strain hardening. LLDPE/LDPE and LLDPE/PP combinations both exhibit a clear-cut matrix switchover. Polymer blends LLDPE/LDPE, LDPE/HDPE, and LDPE/PP show transition forms with features of composing materials. Combining PP in an HDPE matrix causes a radical switch to brittle behavior.

The vast majority of commodity plastics do not degrade and therefore they permanently pollute the environment. At present, less than 20% of post-consumer plastic waste in developed countries is recycled, predominately for energy recovery or repurposing as lower-value materials by mechanical recycling. Chemical recycling offers an opportunity to revert plastics back to monomers for repolymerization to virgin materials without altering the properties of the material or the economic value of the polymer. For plastic waste that is either cost prohibitive or infeasible to mechanically or chemically recycle, the nascent field of chemical upcycling promises to use chemical or engineering approaches to place plastic waste at the beginning of a new value chain. Here state-of-the-art methods are highlighted for upcycling plastic waste into value-added performance materials, fine chemicals and specialty polymers. By identifying common conceptual approaches, we critically discuss how the advantages and challenges of each approach contribute to the goal of realizing a sustainable plastics economy.

The vast increase in the generation of post-consumer PET plastic waste, as well as fast increasing pledges of brand owners around the world to include recycled content have resulted in a pressing need for efficient recycling processes, such as chemical depolymerization. Although recycling rates of PET bottles are high, those of PET trays and films are still significantly lower due to the broad range of colours and multilayer structures, as well as due to a much poorer collection. In this study, a two-step aqueous alkaline hydrolysis was carried out on different types of real PET plastic waste under mild conditions (≤80 °C under atmospheric pressure). Reaction conditions such as temperature (50–80 °C), ethanol to water ratio (20–100 vol%), NaOH amount (5–15 wt%) and stirring rate (250–500 rpm) have been optimized by using pure PET pellets in order to maximize the product yield. At optimal conditions (60 : 40 vol% EtOH : H2O, 5 wt% NaOH and at 80 °C) product yields on a mass basis of approximately 95% have been achieved in less than 20 minutes. The purity of the obtained monomers, ethylene glycol (EG) and terephthalic acid (TPA), was characterized by NMR, UV-VIS and FTIR measurements. The experimental kinetic data are represented adequately using the diffusion model. Experiments performed at optimal conditions with different types of post-consumer plastic waste, revealed that the degradation rate increases inversely proportional to the particle size. Furthermore, the increased thickness of the samples and the presence of multilayers reduce the decomposition yield with a factor two as observed for monolayer (80%) versus multilayer PET trays (45%). In addition to transparent multilayer PET samples, by using the optimized alkaline hydrolysis with further cleaning processes different types of colours, including carbon black are removed from the hydrolysate successfully. A life cycle assessment (LCA) shows that the key to lower the carbon emissions is keeping the energy consumption low by increasing the solid/liquid (S/L) ratio and avoiding excess water addition during monomer purification.

Europe is strongly committed to the recycling of plastics, especially packaging. In the development of closed loop recycling processes, recyclates must have appropriate properties, including lack of odour. The main objective of this study was to develop a technique to qualitatively and semi-quantitatively analyse the volatile contaminants in these complex plastic waste matrices before and after washing procedures. Three sampling methods were explored, SPME and purge and trap methods (activated carbon with solvent desorption and Tenax-TA with thermal desorption). All analyses were then carried out using gas chromatography – mass spectrometry. SPME was not repeatable due to the heterogeneity of the waste samples and the static character of the method. Solvent desorption with CS2 (RSD 14,5 %) and thermal desorption (RSD 13,4 %), were capable of measuring the removal efficiency of pollutants in a semi-quantitative way. A broad spectrum of chemically different, but mostly apolar volatiles can be detected. In addition, it became clear that also the analysis of the less volatile components is essential, as these are strongly adhered to the hydrophobic polymer matrix. A post-consumer film waste stream was analysed, before and after washing and pelletizing. A general decrease of 97 % and 44 %, was measured with respectively thermal and solvent desorption for the screened components. However, after reprocessing potentially odour-causing compounds are again released or formed, showing the complexity of odour removal processes in plastic recycling.

Highlights • This study empirically assesses the determinants of organizations’ intentions and organizations’ behaviors towards a circular economy for plastics. • Attitudes and perceived behavioral control of corporate decision makers are the strongest predictors of organizations’ intentions and organizations’ behaviors respectively. • Most organizations are willing to contribute to a circular economy for plastics, but they are failing to do so due to some critical barriers. • This study suggests some measures to overcome this intention-behavior gap. • Government or relevant institutions should provide incentives, disseminate knowledge, and establish networking platforms., The production and consumption of plastics, although inevitable in our modern life, are predominantly unsustainable and inefficient. Hence, the concept of a circular economy for plastics has been proposed as a sustainable approach to thrive both economy and our modern life. To implement a circular economy for plastics, an understanding of both individuals’ and organizations’ behaviors is needed since psychological effects often undermine technical solutions. We particularly focus on organizations’ behaviors since commercial plastic waste has not been thoroughly investigated compared to household plastic waste. Using the Theory of Planned Behavior (TPB) and Partial Least Squares Structural Equation Modeling (PLS-SEM), we assess the determinants of intentions and behaviors of 637 organizations in Belgium towards a circular economy for plastics. Our PLS-SEM analysis support that attitudes, subjective norms, and perceived behavioral control of decision makers positively influence organizations’ intentions to implement best practices of plastic recycling. Furthermore, organizations’ intentions, perceived behavioral control, pressures, and enablers positively, whereas barriers negatively, influence organizations’ behaviors. Our study shows that most organizations have positive intentions, yet they seem to be failing in implementing best practices of plastic recycling due to some critical barriers. To overcome this intention-behavior gap and to attain a circular economy for plastics, our study suggests some measures.