Digital twin of end-of-life process-chains for a circular economy adapted product design - A case study on PET bottles

in Journal of Cleaner Production (2023), 382

The concept of Circular Economy (CE) is gaining increasing attention as an indispensable renewal of linear economy without neglecting sustainable development goals. Closing resource loops and keeping ... [more ▼]

The concept of Circular Economy (CE) is gaining increasing attention as an indispensable renewal of linear economy without neglecting sustainable development goals. Closing resource loops and keeping resources in the system at the highest level of use for as long as possible are cited as the main goals of CE. However, due to missing information exchange, the lack of consistency between the existing end-of-life (EOL) infrastructure and the respective product designs hinders a successful circularity of resources. This research presents a method to collect, process, and apply EOL process data to provide the beginning-of-life (BOL) with important EOL-knowledge through a CE-adapted product design assessment. EOL-data is collected using a Circular Value Stream Mapping (C-VSM), EOL-information is processed using a digital state flow representation, and EOL-knowledge is applied by providing a decision-support tool for product designers in the context of a PET bottle case study in Luxembourg. The goal is to anticipate a circular flow of resources by reflectively aligning product design with the relevant EOL infrastructure. In contrast to the linear economy, the developed method makes it possible to consider not only the requirements of users but also the actual end users, the EOL process chains, when designing products. [less ▲]

Greenhouse gas emission reduction in residential buildings: A lightweight model to be deployed on edge devices

in Journal of cleaner production (2022), 368

Keywords Greenhouse gas emission; Energy efficiency; Photovoltaics; Battery; Edge computing; Linear programming Electricity produced and used in the residential sector is responsible for approximately 30 ... [more ▼]

Keywords Greenhouse gas emission; Energy efficiency; Photovoltaics; Battery; Edge computing; Linear programming Electricity produced and used in the residential sector is responsible for approximately 30% of the greenhouse gas emissions (GHGE). Insulating houses and integrating renewable energy and storage resources are key for reducing such emissions. However, it is not only a matter of installing renewable energy technologies but also of optimizing the charging/discharging of the storage units. A number of optimization models have been proposed lately to address this problem. However, they are often limited in several respects: (i) they often focus only on electricity bill reduction, placing GHGE reduction on the backburner; (ii) they rarely propose hybrid-energy storage optimization strategies considering thermal and storage heater units; (iii) they are often designed using Linear Programming (LP) or metaheuristic techniques that are computational intensive, hampering their deployment on edge devices; and (iv) they rarely evaluate how the model impacts on the battery lifespan. Given this state-of-affairs, the present article compares two approaches, the first one proposing an innovative sliding grid carbon intensity threshold algorithm developed as part of a European project named RED WoLF, the second one proposing an algorithm designed based on LP. The comparison analysis is carried out based on two distinct real-life scenarios in France and UK. Results show that both algorithms contribute to reduce GHGE compared to a solution without optimization logic (between 10 to 25%), with a slight advantage for the LP algorithm. However, RED WoLF makes it possible to reduce significantly the computational time ([almost equal to]25 min for LP against [almost equal to]1 ms for RED WoLF) and to extend the battery lifespan (4 years for LP against 12 years for RED WoLF). Author Affiliation: (a) Université de Lorraine, CNRS, CRAN, F-54000, France (b) Interdisciplinary Centre for Security, Reliability and Trust, University of Luxembourg, L-1359 Esch-sur-Alzette, Luxembourg (c) Department of Industrial and Systems Engineering, Rochester Institute of Technology, 81 Lomb Memorial Drive, Rochester, NY 14623, United States (d) School of Built Environment, Engineering and Computing, Leeds Beckett University, Leeds, LS1 3HE, UK * Corresponding author. Article History: Received 12 March 2022; Revised 3 June 2022; Accepted 8 July 2022 (miscellaneous) Handling Editor: Panos Seferlis Byline: Paul Ortiz [paul.ortiz@univ-lorraine.fr] (a,*), Sylvain Kubler [s.kubler@univ-lorraine.fr] (a,b), Éric Rondeau [eric.rondeau@univ-lorraine.fr] (a), Katie McConky [ktmeie@rit.edu] (c), Alexander Alexandrovich Shukhobodskiy [A.Shukhobodskiy@leedsbeckett.ac.uk] (d), Giuseppe Colantuono [G.Colantuono@leedsbeckett.ac.uk] (d), Jean-Philippe Georges [jean-philippe.georges@univ-lorraine.fr] (a) [less ▲]

Practising circles: Studying institutional change and circular economy practice

in Journal of Cleaner Production (2019), 237

Energy saving in wastewater treatment plants: A plant-generic cooperative decision support system

in Journal of Cleaner Production (2017)

In Europe, the analysis of Waste Water Treatment Plants (WWTPs) shows a significant energy efficiency potential (up to 25%). Optimistically, plant managers assess their plant efficiency once or twice per ... [more ▼]

In Europe, the analysis of Waste Water Treatment Plants (WWTPs) shows a significant energy efficiency potential (up to 25%). Optimistically, plant managers assess their plant efficiency once or twice per year. Consequently, the time gap between an inefficiency and its detection produces avoidable operational costs. Although the installation of multiple on-line sensors can provide detailed energy information, for a human operator it is unrealistic to analyse the produced data in a satisfactory time-scale. This paper proposes a cooperative tool for energy saving that remotely accesses and evaluates WWTP databases to produce daily energy assessment reports. The novelty of this decision support tool lies in the original combination of: key performance indicators, daily benchmarking, expert knowledge, scenario analysis, fuzzy logic and shared knowledge. In this paper, the Shared Knowledge Decision Support System (SK-DSS) concept is presented and the methodology demonstrated and validated on the energy consumption of biological aeration systems. [less ▲]

Using atmospheric plasma to design multilayer film from polylactic acid and thermoplastic starch: a screening Life Cycle Assessment

in Journal of Cleaner Production (2015), 87

The accumulation of plastic waste and the increasing awareness of the environmental implications and technical challenges associated to their treatment and recycling have led to a constant increase of ... [more ▼]

The accumulation of plastic waste and the increasing awareness of the environmental implications and technical challenges associated to their treatment and recycling have led to a constant increase of biopolymers market in the 90's. Polylactic acid (PLA) is one of the most promising biodegradable plastics, showing a wide range of potential applications, e.g. in the packaging industry. However, the high production costs hamper its further development. The use of PLA in multilayer (ML) films is a potential opportunity to reduce the production costs. This study tackled the ecodesign of a clam shell for packaging applications based on a novel ML film made of PLA and thermoplastic starch (TPS), evaluating the environmental performance of different design concepts through Life Cycle Assessment (LCA). In order to assure proper compatibility between PLA and TPS, the use of dielectric barrier discharge (dbd) plasma technology at atmospheric pressure to increase the hydrophilicity of PLA was investigated. The results have highlighted the significant contribution of plasma treatment to the overall environmental impact of the ML film and the need for further optimisation. Despite the contribution of the PLA end-of-life phase to the overall environmental impact of the ML clam shell is low, the methodological approach to end-of-life can have a significant influence on the LCA results. This seems to be due to the low PLA recycling and recovery rate assumed, which is nevertheless realistic. The promotion of high recovery and recycling rates should therefore be a priority in the future. At the current development stage, even the most improved ML clam shell concept obtained using atmospheric plasma technology is not an environmentally sound alternative to pure PLA clam shell, although it is likely to be a cost-effective option. A good compromise between cost and environmental constrains to be further investigated could be to increase further the proportion of PLA in the ML, by improving the water adsorption capability of TPS through, e.g., the addition of a phthalate free plasticiser. [less ▲]

Simulated and experimental results on heat recovery from hot steel beams in a cooling bed applying modified solar absorbers

in Journal of Cleaner Production (2014), (68), 261-271

In recent years, the steel industry has undertaken efforts to increase energy efficiency by reducing energy consumption and recover otherwise lost heat. About 60% of the energy consumed in a steel plant ... [more ▼]

In recent years, the steel industry has undertaken efforts to increase energy efficiency by reducing energy consumption and recover otherwise lost heat. About 60% of the energy consumed in a steel plant is lost in cooling beds where the hot steel beams are cooled down by natural convection and radiation. In this paper, the potential of heat recovery by radiation in a cooling bed was determined. Firstly, numerical simulations of the heat flux were done and validated with experimental measures. Secondly, a pilot test to recover the heat with modified solar absorbers was installed at the side of the cooling bed. The standard solar panels were painted with high absorption paint in the wavelength range of the hot beams. The results showed that up to 1 kW/m2 could be recovered with a temperature of 70°C at the side of the cooling bed, with a thermal efficiency of approximately 40%. As the experimental results were promising, further research is suggested to find an adequate selective coating and glazing. This would maximize the absorption at the wavelength range of the hot beams and minimize the emissivity at operational temperature of the absorber (100°C). Additionally, it would be of interest to find the optimum position for the absorbers in the cooling bed, which maximizes the heat recovery and does not interfere in the production process. [less ▲]