Recovery Of Raw Materials Research Articles

Environmental assessment of the recycling process for polyamides - Polyethylene multilayer packaging films

The plastic packaging, and in particular the multilayer flexible packaging, has several characteristics that make it essential in everyday life. However, the sustainability of used materials is undermined by the difficulties encountered for their recycling. The purpose of this study is to assess both the technical feasibility, and above all the environmental sustainability of an effective process enabling the recycling of polyamides-polyethylene multilayers packaging films. The technique used for the separation of the polymers is based on a selective dissolution, carried out using monoethylene glycol. The experimental tests made possible to identify the best conditions for treating the films and for maximizing yields and final products quality. The Life Cycle Assessment of the recycling process modelled at an industrial level, firstly allowed to determine the main process hotspots (i.e. the energy consumption). The LCA analysis was then extended, examining the life cycle of polyamides-polyethylene films with different end-of-life treatments, i.e. incineration, energy recovery and recycling. The results showed that the recycling process, carried out through the selective dissolution of the films, allows to reduce the overall environmental impacts of these materials along their life cycle. Therefore the recycling process analysed here can be considered an effective approach to increase environmental sustainability and recovery of raw materials.

Specification and Classification of Pelletised Dried Sewage Sludge: Identifying Its Key Properties as a Renewable Material for Enabling Environmentally Non-Harmful Energy Utilisation

Renewable active sludge is a smart material for wastewater treatment and the protection of surface water bodies. The generated pellets (dried and pelletised dehydrated anaerobically stabilised excess sludge) are produced in a quantity of 31.4 ± 5.6 g dry matter (DM) per one Population equivalent (PE) calculated to COD (PECOD) in one day. As pellets are combustible material, their energy utilisation must reach the sustainable development goals (SDGs)—a bridge must be created between “treated sewage sludge as the tool to remove pollutants and nutrients from wastewater” and “preparation of the valuable material as a solid recovered fuel (SRF) that meets customer-specific requirements”. Technical Report CEN/TR 15508 and Technical Standard EN ISO 21640 set up methods for specifying and classifying pellets as an SRF. In the last eleven years (2010–2021), pellets’ net calorific value (NCV) is 13.0 ± 0.7 MJ kg−1 as received (ar). In 2021, the 80th percentile of the Hg/NCV ratio was 0.079 mg Hg MJ−1. In 2010–2021, the annual amount of Hg transferred to stakeholders reduced by 64.3% m/m—from 10.1 kg to 3.67 kg. The halogen contents of the pellets do not threaten corrosion to the incineration facility. Stable pellets’ energy potential and perspective ash composition for critical raw materials recovery qualify pellets as a specific waste stream and a renewable material for SRF production.

Lithium recovery through WS2 nanofillers-promoted solar photothermal membrane crystallization of LiCl

The recovery of raw materials represents one of the greatest challenges for a circular economy. Especially, the increased demand for lithium in the last years for its critical role in Li-ion batteries implies the need for green technology for Li recovery able to address market requests. Here, we devise and implement a new technology exploiting excitons-based light-to-heat conversion promoted by WS2 nanofillers in nanocomposite polymeric membranes for sunlight-driven photothermal membrane crystallization, applied for the efficient extraction of lithium from Li-rich brines. The activation of photothermal effects of excitonic nanofillers in the PVDF-WS2 nanocomposite enhances the evaporative flux of water under solar irradiation by 364 %, triggering the heterogeneous nucleation and the crystallization of LiCl salt, once achieved supersaturation. This new facile, economical, and green nanotechnology-enabled platform renews the interest in functional inks based on nanosheets of van der Waals semiconductors for the fabrication of functional nanocomposites, here exploited for the first time in the field of crystallization and the recovery of economically strategic minerals in a circular-economy paradigm. Moreover, these findings open up new opportunities for large-scale, efficient, and sustainable recovery of lithium (as well as other critical raw materials) for next-generation devices for the clean energy transition.

The Role of Mycorrhizal-Assisted Phytomining in the Recovery of Raw Materials from Mine Wastes

In recent years, critical and secondary raw materials (CRMs and SRMs, respectively) have received great interest within the circular economy model. In this work, the mycorrhizal-assisted phytomining (MAP) system, composed of Helianthus annuus–arbuscular mycorrhizal fungus Rhizophagus intraradices–Zn-volcanic ashes, was applied in bioreactors for the recovery of CRMs (Sr, P) and SRMs (Cr, Zn, Cu, Mn, Rb, Ni) from mining wastes of the Los Cóndores mine (Argentina). Our results showed high bioaccumulation of Sr, P, Mn, and Zn in the aerial tissues, and a high root-to-shoot translocation for Mn (4.02) > Sr > P > Rb > Zn (0.84). Mycorrhization treatment increased the root-to-leaf translocation for Cr and P and prevented translocation towards flower tissues in most elements. The estimated bioextracting potential of the MAP system (290 plants) in a vegetable depuration module (VDM) ranged from 158 mg/m3 P > Zn > Mn > 15.1 mg/m3 Sr. We demonstrated a promising and cost-effective biotechnology applicable in agronomical practices, given the exclusion of toxic elements in flower parts, as well as for the recovery of CRMs and SRMs by hydrometallurgy from plant biomass.

CURRENT STATE OF SOLAR PHOTOVOLTAIC PANELS WASTE MANAGEMENT OPERATIONS IN UKRAINE

The paper analyzes the steady trend of solar energy development, which is accompanied by the formation and accumulation of solar panel waste. This process requires the application of accomplished waste management and the development of waste disposal technologies. It was determined that the problem of waste solar photovoltaic panels becomes more urgent due to the military actions taking place on the territory of Ukraine. The general characteristics of waste for different types of panels are given. The heterogeneity of the materials of photovoltaic panels leads to an ambiguous classification and involves a combination of safe and dangerous components. It has been determined that photovoltaic panel waste can be divided into two hazard classes: hazardous waste and non-hazardous waste. The key points of solar panel waste management operations are characterized in accordance with the Law of Ukraine “On Waste Management” and EU Legislation. The main points of disposal of unusable photovoltaic panels with recovery of valuable raw materials are described. It is noted that there are significant differences in the material composition of crystalline silicon panels and thin film modules. It is noted that two processing types of PV modules are currently distinguished – coarse and fine, and the most effective steps in the preparatory stage of disposal are also determined. In general, PV panel waste disposal operations combine mechanical and chemical material extraction processes. The imperfection of the legislative and regulatory framework in the field of waste management, the increase in the ecological danger of the generation and accumulation of waste, the imperfection of the information base and waste monitoring, the insufficient development of the processes of organizing the processes of collection, accumulation and transfer of waste for disposal, the insufficiency of proposals for methods of processing and disposal of solar panels waste as a valuable resource of secondary raw materials are notable as the main problems in the field of waste management of photovoltaic panels in Ukraine. One of the main tasks for development is to increase the share of waste materials that are currently not disposed of, but can be used as secondary raw materials.

Applied Tests to Select the Most Suitable Fungal Strain for the Recovery of Critical Raw Materials from Electronic Waste Powder

Electrical and electronic wastes (WEEEs) are a potential source of raw materials. The main challenge for scientists is to set up a reliable and eco-friendly process to recycle raw materials and precious elements from WEEEs. Today, we know that fungi could play an active role in green technologies aimed at recycling valuable elements. The bioaccumulation mechanism and bioleaching activity of filamentous fungal species have already been exploited fruitfully in extraction processes. However, not all fungal strains possess the same characteristics, and it is crucial to choose the right strains to use. In this work, we show a method to assess the precious elements’ recovery efficiency from WEEE using fungal strains. A CAS agar screening test for siderophore detection was carried out with three strains. The following plate accumulation test performed on a medium added with 120 ppm of electronic waste powder highlighted the differences in accumulation capability, growth rate, and biomass production. Among the elements in tested waste, yttrium, copper, and palladium show the highest bioconcentration factor. The results confirm the biotechnological potential of fungi to recover valuable elements at the bench scale, highlighting the importance of effective screening tests to assess the most efficient strain for each kind of waste.

Material recovery in Li-ion battery recycling: Case study

As the global demand for Lithium-ion batteries is on the rise and is expected to grow multifold in the next decade, the limited source and reserves of the raw materials like Lithium, Cobalt, Nickel, Manganese, etc. are also well known. These elements are crucial for the high energy density of batteries and are continuously in demand in the global supply chain of raw materials for battery. Hence, to optimize the utilization of these elements, battery recycling can contribute considerably. In this work, a model is developed to estimate the recovery of raw materials after recycling the battery pack of an electric bus. The cells in this battery pack had NMC (Nickel Manganese Cobalt) chemistry and the rated energy of pack was 89kWh. The elements Li, Ni, Mn and Co constitute the cathode of an NMC cell. The mass of each element in the cathode of cell is calculated and then the total mass of each element in the battery pack is estimated. Then the possible recovery of these raw materials from recycling is estimated using European Unions estimated targets of recycling. The cost of recovered material and the cost of recycling process is also calculated to estimate the efficiency of recycling. The results give an idea of the recycling efficiency and the value that can be recovered from the battery by recycling.

The significance of resource recycling for coking wastewater treatment: based on environmental and economic life cycle assessment

The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements. The traditional measures substantially increased the related costs for enterprises to reach standards. This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems. Typical three coking wastewater treatment processes in China were evaluated. Results showed that eutrophication dominantly contributed to the overall environmental effect. Improving effluent quality could significantly reduce the total environmental impact. In terms of an economic perspective, the price of raw materials was the main factor that affected the operating cost of comprehensive treatment. Based on subsystem analysis, the pretreatment stage accounted for the majority of environmental and cost burdens, respectively reaching 64%–78% and 64%–86%. Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8% and 57%, respectively, which was an effective way to improve the potential performance of coking wastewater treatment plants (WWTPs).

Hydrothermally-assisted recovery of Yttria- stabilized zirconia (YSZ) from end-of-life solid oxide cells

Effective and scalable recycling strategies for the recovery of critical raw materials are yet to be validated for solid oxide cells (SOCs) technologies. The current study aimed at filling this gap by developing optimized recycling processes for the recovery of Yttria-stabilized Zirconia (YSZ) from End-of-Life (EoL) SOC components, in view of using the recovered ceramic phase in cell re-manufacturing. A multi-step procedure, including milling, hydrothermal treatment (HT), and acidic-assisted leaching of nickel from composite Ni-YSZ materials, has been implemented to obtain recovered YSZ powders with defined specifications, in terms of particle size distribution, specific surface area, and chemical purity. The overall optimized procedure includes a pre-milling step (6 h) of the EoL composite materials, and a hydrothermal (HT) treatment at 200 °C for 4 h to further disaggregate the sintered composite, followed by selective oxidative leaching of Ni2+ by HNO3 solution at 80 °C for 2 h. In particular, the intermediate HT step was assessed to play an essential role in promoting the disaggregation of the sintered powders, with a related increase of specific surface area (up to 13 m2 g−1) and the overall reduction of the primary particle aggregates. The acid-assisted leaching allowed to fully extract Nickel from the composite Ni-YSZ powders, with retention of YSZ crystallinity and negligible loss of Zr and Y, as revealed by ICP analysis on the recovered supernatants.The developed multi-step pathway offers a promising strategy to recover valuable YSZ materials for the re-manufacturing of SOCs components, with the aim to boost a circular economy approach in the field of fuel-cell and hydrogen (FCH) technologies.

A mini-review of the physical recycling methods for plastic parts in end-of-life vehicles.

Although the use of plastic components is increasing in the automotive industry, yet the recovery rates of these materials in end-of-life vehicle (ELV) is lower compared to metals. One of the main problems of ELV plastic waste is poor separation and sorting. Large car plastic parts consist of fibre-reinforced plastics, whereas other components end up in the automotive shredder residue (ASR), featuring a very heterogeneous mix of light materials that contains mostly non-metallic materials such as textiles, plastics, cartridges and wood. Generally, ASR was disposed in landfill or diverted to thermal treatments, such as pyrolysis or gasification, for energy recovery. Currently, the recovery of raw materials from various waste streams plays a key role in new European strategy for plastics in a circular economy. The approach of physical recycling methods described in this mini-review helps to maintain the value of polymer materials in the value chain allowing the reuse in the original or similar application.

The Importance of Recovery of PGMS from Catalysts – A Case Study of Recycling Network in Poland

Abstract Combustion engines are the main driving force of passenger cars, trucks or buses. Engines burn fuels, and as a side effect, release many pollutions to the atmosphere. Car manufacturers had been aware of a need of lowering the amount of exhaust fumes. This brought on the market the first catalytic converters. Nowadays automobile catalyst manufacturing is the largest sector of demand of PGMs (mainly platinum, palladium and rhodium), and unfortunately consumption and future demand of there critical metals is getting higher. Over the past two decades, most countries around the world have developed and implement solutions that would minimize the impact of the growing number of cars on the environment. One solution contributing to this is the organisation of an end-of-life car collection and recycling network, which is now an integral part of automotive industry. The main drivers for the development of such network were stricter environmental regulations and economic conditions. The development of recycling is also becoming more popular in Poland. However, catalyst recycling system is still not transparent to all stakeholders. Due to the huge variety of catalysts and their different structure and composition of elements from the PGMs group, the valuation of their price before they are recycled is not obvious. This raises a lot of controversy and does not inspire trust among those who recycle their catalysts. The aim of this work is to show how the management of used catalytic converters looks like in Poland and how developed is network of catalysts recycling in Poland. At the same time this will show how important it is in terms of a circular economy and the recovery of valuable raw materials from a group of PGMs.

Applicability of new sustainable and efficient alginate-based composites for critical raw materials recovery: General composites fabrication optimization and adsorption performance evaluation

Based on the 2020 list of raw materials for the EU, there are 30 critical minerals on the critical raw materials list, among which the rare earth elements group is placed. This study demonstrates a viable approach to the increasing possibility of the critical materials recovery through biosorption. The environmentally friendly biosorbents were prepared modifying calcium alginate with biochar and clinoptilolite. Firstly, the optimization procedure was applied for obtaining new biocomposites. After that the adsorption studies of La(III), Ce(III), Pr(III), and Nd(III) ions as a function of solution pH, biosorbent mass, interaction time, initial metal concentration, temperature, and competing ions presence were carried out using the batch mode. The kinetic studies were analyzed using the pseudo-first order, pseudo-second order, Weber and Morris intraparticle diffusion, Boyd as well as Dumwald-Wagner kinetic models. The experimental equilibrium data were fitted using the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The thermodynamic functions, i.e. ΔG°, ΔH°, and ΔS° were also determined. Importantly, the biocomposite beads were readily regenerated using diluted mineral acids (exemplary 0.1 mol/dm3 HNO3) and moreover, the adsorption effectiveness was very satisfactory even after six adsorption–desorption cycles (97%). New biocomposites as potential sorbents were characterized with ATR/FT-IR and XPS spectroscopy, SEM, EDX, OM and AFM microscopy, nitrogen adsorption, TG/DTG, CHNS, XRD as well as the sieve analysis and pHpzc measurements. After the interactions of the alginate composites with La(III) ions, a possible sorption mechanism was analyzed by ATR/FT-IR, XPS, and EDX spectroscopy.

Electrochemical routes for environmentally friendly recycling of rare-earth-based (Sm–Co) permanent magnets

The consumption of critical raw materials, especially those in permanent magnets of Nd–Fe–B and Sm–Co-type, has significantly grown in the past decade. With predictions on further electrification growing exponentially the demand for these materials will even increase. This implies that efforts in assuring sustainability must involve recycling from secondary resources. In recent years the electrochemical approaches in recycling have been extensively investigated and applied owing to their advantages of high efficiency and selectivity, easy operation, low energy consumption, and environmental friendliness. In this paper, we investigate the Sm2(Co,Fe,Cu,Zr)17 permanent magnet leaching process using the anodic oxidation to be paired with the metal deposition on the cathode. Linear sweep voltammetry was performed from − 0.15 to 1 V versus Pt quasi reference electrode that indicated current peaks that would correspond to some preferential leaching of the crystal phases contained in the magnet. The latter was confirmed using the SEM/EDXS analysis. The continuous leaching of the Sm2(Co,Fe,Cu,Zr)17 magnet was performed at a direct current density of 2, 4 and 8 mA cm−2 at the time period of 0–240, 240–480 and 480–720 min, respectively. The ICP-MS results confirmed the leaching of all the metals from the original Sm2(Co,Fe,Cu,Zr)17 permanent magnet. The concentration of Sm3+, Cu2+, Fe2+ and Zr2+ increases linearly along with the leaching time. Reversely the concentration of Co2+ decreases linearly due to its consumption by electrodeposition of Co, Fe and Cu on the cathode. The presented paired electrochemical process could serve as a starting point for the recycling and recovery of critical raw materials without any acid usage and waste generation.Graphical abstract

Progress on the Recovery of Critical Raw Materials

Progress on the Recovery of Critical Raw Materials

Insights about inductively coupled plasma optical emission spectroscopy interferences of major rare earth elements in complex e-waste feeds

The advent of rare earth elements (REEs) with optoelectronic properties has shifted the technology paradigm from digital to a smart and hybrid world. Their substantial uses also resulted in a large piling up of e-waste. Therefore, e-waste is now a lucrative recycling target for the recovery of such critical raw materials. Their recycling from e-waste is often challenged by dilute metal concentration, complex composition, and difficult chemical characterisation. Generally, the characterisation of e-waste involves elemental determination techniques, such as inductively coupled plasma optical emission spectroscopy (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS). ICP-OES is attractive for a recycling or research sector because it has a higher matrix tolerance and lower cost than ICP-MS. In this work, the intensity at 445 line positions measured by an ICP-OES instrument was compiled in a 2D diagram to map interferences by 27 prominent lines from 9 REEs. The second diagram shows the impact at 230 neighbouring line positions measured in each of, in total, 17 (i.e., 9 REEs and 8 non-REEs) single-standard solutions in terms of the concentration of the element type affected. The spectral interference correction algorithm proposed here had been developed by us for a recycling process to obtain pure Y, Eu, and Tb from fluorescent powder (FP) in spent lamps. The ICP-OES analysis and spectral interference correction approach presented here can be applied to any element and e-waste type. To underline this, the paper gives examples for elements in dissolved FP and surrogate NdFeB magnet samples.

Disassembly Line Balancing of Electronic Waste Considering the Degree of Task Correlation

With growing concerns about the depletion of rare-earth elements, managing End-of-Life products has become a key sustainability initiative in the supply chains of global corporations. Recycling, the process of dismantling, separating, and recovery of components and raw materials from wastes, is technologically challenging and should be planned in such a way as to ensure operational efficiency as well as safety. This study explores the Disassembly Line Balancing Problem with Correlated Tasks (DLBP-CT), which is prevalent in the recycling of the Waste of Electrical and Electronic Equipment (WEEE). For this purpose, an original Integer Nonlinear Programming (INLP) model is proposed to find the optimal configuration for the disassembly lines. Given the NP-hard nature of this problem, the Adaptive Genetic Algorithm (AGA) is developed to solve the problem, minimizing the number of workstations and maximizing the relationship between the disassembly tasks. A case example from electronic waste is provided to test the practicality of the developed optimization approach. Sensitivity analysis is conducted to explore the impact of parameter changes in the optimization outcomes. Results are supportive of the applicability of the developed approach and show that it can serve as a strong decision aid tool when selecting the best disassembly process, workstations, and task assignments.

Prospects of improving technologies for apple raw materials processing

A resource-saving technology for processing apples, including the main production of finished dried products in the form of dried apples, apple chips, apple semi-finished products and additional production based on secondary raw materials recovery from the main production, were proposed in the work. The possibility of using of secondary raw materials from the apples industrial processing to obtain natural products that allows to make the main manufacture of dried apple products as efficient as possible was studied by the authors. The main directions of apples and secondary apple raw materials processing were considered in the work. The technological scheme of the line for apples and their wastes processing based on dehydration and moisture-thermal processing of components, taking into account the specifics of the production of dried fruits, chips and their semi-finished products, was proposed in the course of this study. The main production line for the manufacture of dried apples, apple chips and apple semi-finished products was designed. The resource-saving technological scheme of the dried apple and apple chips production line includes a washing machine, an inspection conveyor, a calibrator, a machine for seeds removing and a device for cutting fruits into chips, a sulfitator, a combined continuous toroidal apparatus for wet-heat treatment, divided into sections for raw materials heating, convective drying , preliminary hydrothermal treatment between sections of microwave drying and dried product cooling and a filling and packaging machine. Taking into account the type of raw materials, a set of equipment from a drum machine with a washing unit and a multifunctional plant with raw materials crushing and seeds separation was provided in the line. The recirculation circuit, the feedstock heating, the steam and condensate used after drying in a closed circuit were used to create an energy-saving technology for the finished product manufacturing. The line consists of modular blocks and is reconfigured depending on the type of dried apples or apple chips obtained based on the developed resource-saving scheme and combined convective microwave drying of raw materials.

Material system analysis: Characterization of flows, stocks, and performance indicators of manganese, nickel, and natural graphite in the EU, 2012–2016

AbstractRaw materials form an industrial base to provide the wide range of products and services demanded by industry and society. In particular, manganese, nickel, and natural graphite are examples of materials having a globally consolidated supply chain with interlinked use in steelmaking and essential role in clean energy systems and e‐mobility. A stable material supply chain is hence a priority for import‐dependent regions like the EU and builds upon quantitative system understanding. To this aim, the EU Material System Analysis is applied to analyze the anthropogenic cycle of manganese, nickel, and natural graphite from 2012 to 2016. We provide a detailed characterization of their material stocks, flows, and changes in selected performance indicators including end‐of‐life recycling rate (51% ± 3%, 49% ± 8%, and 8% ± 0% for manganese, nickel, and natural graphite, respectively), self‐sufficiency potential (40% ± 3%, 32% ± 5%, and 5% ± 1%), old scrap ratio (31% ± 0%, 22% ± 2%, and 90% ± 1%), recycling input rate (25% ± 1%, 38% ± 2%, and 3% ± 0%), recycling process efficiency rate (84% ± 2%, 85% ± 6%, and 48% ± 3%), and pre‐consumer losses rate (83% ± 3%, 5% ± 1%, and 24% ± 2%). The achieved results may inform decision‐makers engaged with raw materials recovery and recycling as well as the strategic securement of a reliable material supply to the EU for resilient industrial ecosystems.

Analysis of the factors limiting the performance of small-to-medium scale sawmills in the copperbelt of Zambia

Small-to-medium scale softwood sawmills in the Copperbelt of Zambia are operating below 50% capacity. The timber supply is uncertain as demand continues to increase in tandem with economic activities and population growth. This study identified the financial, i.e., access to finance and operating costs, and non-financial, i.e., raw material, transport, skilled labor, and sawn timber recovery, as the limiting factors affecting performance. The authors benchmarked various financial ratios, i.e., gross profit margin, net profit margin, return on investment, return on capital employed, and working capital turnover, of the small-scale sawmills compiled from survey data with the average industry ratios. Raw material is the most limiting factor affecting profitability/success of small-scale sawmills. A Cobb-Douglas model demonstrated that sawn timber recovery depends on operator skills, particularly in non-automatic machinery, which are common. Strategies currently employed are value addition, multiple sourcing, equipment acquisition and modernization, and labor cost reduction. Measures proposed to enhance profitability are credit guarantee schemes, collaboration, tax reduction, lesser-used timber utilization, and timber auction floor.

How to Identify Potentials and Barriers of Raw Materials Recovery from Tailings? Part II: A Practical UNFC-Compliant Approach to Assess Project Sustainability with On-Site Exploration Data

A sustainable raw materials (RMs) recovery from waste requires a comprehensive generation and communication of knowledge on project potentials and barriers. However, a standardised procedure to capture sustainability aspects in early project development phases is currently missing. Thus, studies on different RM sources are not directly comparable. In this article, an approach is presented which guides its user through a practical interpretation of on-site exploration data on tailings compliant with the United Nations Framework Classification for Resources (UNFC). The development status of the overall project and the recovery of individual RMs are differentiated. To make the assessment results quickly comparable across different studies, they are summarised in a heat-map-like categorisation matrix. In Part I of this study, it is demonstrated with the case study tailings storage facility Bollrich (Germany) how a tailings mining project can be assessed by means of remote screening. In Part II, it is shown how to develop a project from first on-site exploration to a decision whether to intensify costly on-site exploration. It is concluded that with a UNFC-compliant assessment and classification approach, local sustainability aspects can be identified, and a commonly acceptable solution for different stakeholder perspectives can be derived.