Methodology to quantify single-use plastic products in municipal solid waste Part 2: Quantification of tobacco products with filters in Germany.

Discharge from unrestricted tobacco products with filters (TPF) causes environmental damage. To reduce TPF litter quantities, Directive (EU) 2019/904 requires TPF producers to proportionally contribute to the costs of discarding their products in public waste collection systems, including litter waste ones. An appropriate output-based cost model requires assessing TPF quantities in relevant waste streams. Currently, there is no comprehensive data available on TPF quantities in municipal solid waste (MSW). Therefore, a case study was conducted to quantify TPF in MSW. This study aimed to determine TPF quantities (1) in residual waste from four German district types and (2) in waste from public collection systems for three settlement structures within Trier City. Relevant waste streams from public collection systems, namely waste from public waste receptacles, street-cleaning waste and sinkhole residues, were identified. For both sampling campaigns, consideration was given to extrapolating the results to a larger scale. The results showed that the average specific TPF quantities in residual waste were 277.7, 271.8, 193.3 and 204.5 gi- 1a- 1 in the selected city district, urban district, densely populated rural district and sparsely populated rural district, respectively. Extrapolation of these results to Germany yielded a specific TPF quantity in residual waste of 250.3 gi-1a-1. The average specific TPF quantities in waste from public waste receptacles, street-cleaning waste and sinkhole residues were 12.2, 47.4 and 9.9 gi-1a- 1, respectively. The results could contribute to cost model development based on Directive (EU) 2019/904.

Methodology to quantify single-use plastic products in municipal solid waste Part 1: Development of a sampling methodology.

In recent years, the consumption of plastic products intended for single use has increased. Directive (EU) 2019/904 aims to reduce the use and the resulting generated waste quantity of single-use plastic (SUP) products. Therefore, manufacturers of SUP products are required to contribute proportionately to the costs of disposing of their products in public collection systems, including litter waste. One possibility to develop a cost model is to determine SUP-product quantities in relevant municipal solid waste (MSW) streams. The partly low quantities and small size of specific SUP products and the focus on waste from public collection systems, including litter waste, impede special requirements for the sampling and analytical procedures. This article provides an approach for sampling and analysing MSW to determine SUP-product quantities. The developed sampling method examines the selection of a suitable sampling area, considering the possibility of extrapolation to a national scale. The adapted sampling procedure aims to achieve statistically representative results. The presented sample preparation is especially suitable for low quantities and small SUP-product sizes. The developed sampling and analytical method aims to achieve representative and reproducible results regarding SUP-product quantities in MSW. The results can contribute to the development of a cost model based on Directive (EU) 2019/904.

Influences of bioplastic polylactic acid on near-infrared-based sorting of conventional plastic.

Bioplastics are developed to replace oil-derived plastics due to the high consumption of oil and related environmental impacts of oil-derived plastics. It was predicted that bioplastics can potentially replace 94% of conventional plastic production. With their increasing market share, more bioplastics will end in conventional post-consumer plastic waste streams. Although part of bioplastics is biodegradable and could be biologically decomposed, mechanical recycling achieves higher ecological benefits mainly because of its low pollution risk and the reduction in requirement for virgin feedstock. In this study, the classification of lightweight packaging waste with inflow of bioplastics, more specifically polylactic acid (PLA), was analysed with near-infrared spectroscopy to evaluate the influence of bioplastics on sorting processes of conventional plastics. Besides which, the sortability of PLA was determined through investigating the physical and the spectroscopic characteristics of both non-degraded and degraded PLA. The results show that the classification of all the materials was possible with a pixel-based accuracy of higher than 97.4% and PLA does not influence the sorting process of conventional plastics regarding detection and classification. Furthermore, the sorting of PLA from post-consumer waste is possible, which makes further recycling theoretically achievable.

Characterization of pyrolysis products of high-ash excavated-waste and its char gasification reactivity and kinetics under a steam atmosphere.

The focus of this study is the pyrolysis and gasification of Refuse Derived Fuel (RDF) and fine fractions recovered from the excavation of landfill waste, with an emphasize on the characterization of the reactivity and kinetics of the char-steam gasification. The results from the pyrolysis tests demonstrated that CO and CO2 are the main produced gases during the pyrolysis of the finer fraction of landfill waste. This might be caused by the accumulation of degraded organic materials. The oil products from the pyrolysis of landfill waste were dominated by the derivative products of plastics such as styrene, toluene, and ethylbenzene. The chars obtained from the pyrolysis process were gasified under steam and steam/air atmospheres at temperatures between 800 and 900 °C by using thermogravimetry. The results from the gasification tests demonstrated that the char reactivity was mainly affected by the amount ratio between catalytic elements (K, Ca, Na, Mg, and Fe) over the inhibitor elements (Si, Al, and Cl), as well as the ash amount in the char. The results showed that char from the fine fraction of landfill waste has a higher reactivity than the RDF fraction, due to the high content of catalytic metal elements. These results suggest the use of a smaller sieve opening size for landfill waste separation processes may produce waste fuels with a high reactivity during gasification. Further, based on the thermogravimetric data, the kinetic parameters of landfill waste char gasification were calculated to have activation energies ranging from 54 to 128 kJ/mol.

Improvement of the recycling of plastics in lightweight packaging treatment plants by a process control concept.

In Germany, only approximately 30% by mass of plastics from lightweight packaging waste is recycled; 65% by mass is transferred to inferior residual fractions (sorting residue and mixed plastics), which are currently only utilized thermally. An increase in the recycling of valuable resources in the sense of material recycling would both contribute to the saving of resources and improve the economic situation of plant operators. It is generally known from operating and planning experience that fluctuation in the amount of material loaded into the sorting process is one of the main reasons for suboptimal recycling quotas. In particular, overfilling in the input stream leads to a deterioration of the separation result of the entire process. A novel process control concept envisages equalizing the material flow in such a way that all separation steps are operated in the intended design range. For the example of a lightweight packaging treatment process, the requirements and technological solutions for a sensor-based process control concept will be presented.

A methodical approach for the assessment of waste sorting plants.

A techno-economical evaluation of the processing result of waste sorting plants should at least provide a realistic assessment of the recovery yields of valuable materials and of the qualities of the obtained products. This practical data is generated by weighing all the output products and sampling these products. Due to the technological complexity of sorting plants, for example, lightweight packaging waste treatments plants and the high expenditures concerning time and costs of sampling with subsequent manual sorting for quality determination, usually only final products undergo such an investigation. Thereby, the transferability of the results depends decisively on the boundary conditions (extent, throughput of the plant, process parameterization). Given that the process is too complex, not all relevant information of the process steps can be determined by sampling. By model calculations and/or adjustment of reasonable assumptions, information concerning weak points in the process can be identified, which can be used for further plant optimization. For the example of the recovery of beverage cartons from co-collected and mechanically recovered mixtures of lightweight packaging waste, a methodical approach for the assessment of processing results will be presented.

Separate collection of plastic waste, better than technical sorting from municipal solid waste?

The politically preferred solution to fulfil legal recycling demands is often implementing separate collection systems. However, experience shows their limitations, particularly in urban centres with a high population density. In response to the European Union landfill directive, mechanical biological waste treatment plants have been installed all over Europe. This technology makes it possible to retrieve plastic waste from municipal solid waste. Operators of mechanical biological waste treatment plants, both in Germany and the Netherlands, have started to change their mechanical separation processes to additionally produce plastic pre-concentrates. Results from mechanical biological waste treatment and separate collection of post-consumer packaging waste will be presented and compared. They prove that both the yield and the quality of plastic waste provided as feedstock for the production of secondary plastic raw material are largely comparable. An economic assessment shows which conditions for a technical sorting plant are economically attractive in comparison to separate collection systems. It is, however, unlikely that plastic recycling will ever reach cost neutrality.

Central sorting and recovery of MSW recyclable materials: A review of technological state-of-the-art, cases, practice and implications for materials recycling.

Today's waste regulation in the EU comprises stringent material recovery targets and calls for comprehensive programs in order to achieve them. A similar movement is seen in the US where more and more states and communities commit to high diversion rates from landfills. The present paper reviews scientific literature, case studies and results from pilot projects, on the topic of central sorting of recyclable materials commonly found in waste from households. The study contributes, inter alia, with background understanding on the development of materials recovery, both in a historical and geographical perspective. Physical processing and sorting technology has reached a high level of maturity, and many quality issues linked to cross-contamination by commingling have been successfully addressed to date. New sorting plants tend to benefit from economies of scale, and innovations in automation and process control, which are targeted at curtailing process inefficiencies shown by operational practice. Technology developed for the sorting of commingled recyclables from separate collection is also being successfully used to upgrade residual MSW processing plants. The strongest motivation for central sorting of residual MSW is found for areas where source separation and separate collection is difficult, such as urban agglomerations, and can in such areas contribute to increasing recycling rates, either complementary to- or as a substitute for source separation of certain materials, such as plastics and metals.