Browsing by Author "Duflou, Joost R."

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Closed loop recycling of plastics containing flame retardants
(2014-03) Peeters, Jef R.; Vanegas, Paul; Tange, Lein; Van Houwelingen, Jan; Duflou, Joost R.
Annually 2.7 million tonnes of plastics containing Flame Retardants (FRs) are globally discarded in Waste Electrical and Electronic Equipment (WEEE). Little is known on the feasibility of closing material loops for FR plastics. Therefore, series of experiments were set up to analyze the feasibility of separating plastics containing FRs from one specific product category, namely End-of-Life (EoL) Liquid Crystal Display (LCD) TVs. The characterization of the housings of this waste stream indicated a concentration of 18 wt% Bromine based (Br) FRs and 31 wt% Phosphor based (P) FRs, the remainder not containing FRs. With practical tests it was demonstrated that, after disassembly and plastic identification, the co-polymer poly-carbonate (PC)/acrylonitrile-butadiene-styrene (ABS) containing PFR can be recycled in a closed loop system. Based on the determined plastic density distributions and separation efficiencies of optical sorters, a purity of 82% was calculated for PFR PC/ABS separated from EoL LCD TVs after size-reduction (shredding). Performed miscibility tests indicated that for this fraction at least a factor 10 dilution with virgin material is required. In addition, higher waste volumes are required for a size-reduction based treatment to become economically viable and technical challenges still need to be faced, whereas closed loop recycling of PFR PC/ABS from the current waste stream of EoL LCD TVs of different brands in a disassembly based treatment is found to be technically feasible and economically viable under European boundary conditions.
Ease of disassembly of products to support circular economy strategies
(2018) Vanegas Peña, Paúl Fernando; Peeters, Jef R.; Cattrysse, Dirk G.; Tecchio, Paolo; Ardente, Fulvio; Mathieux, Fabrice; Dewulf, Wim; Duflou, Joost R.
Abstract Circular economy strategies encourage, among others, concrete actions to extend the product lifetime. Product’s repair and reuse, and component harvesting for reuse, all require the facilitated access to product components. Consequently, a reduction of the disassembly time and the related costs will increase the economic feasibility of product lifetime extension and therefore increase the viability of a circular economy in industrialised regions. Furthermore, disassembly has the potential to significantly increase the recycling yield and purity for precious metals, critical metals and plastics. For this reason, the European Commission and several ecolabels have considered to include design for disassembly requirements in legislation or voluntary environmental instruments. However, up to date, there is no standardised method to evaluate the ease of disassembly in an unambiguous manner with a good trade-off between the efforts required to apply the method and the accuracy of the determined disassembly time. The article proposes a robust method “eDiM” (ease of Disassembly Metric), to calculate the disassembly time based on the Maynard operation sequence technique (MOST). A straightforward calculation sheet is employed in eDiM to calculate the disassembly time given the sequence of actions and basic product information. This makes the results fully verifiable in an unambiguous manner, which makes eDiM suited to be used in policy measures in contrast to the results of prior developed methods One of the innovative aspects of eDiM is the categorization of disassembly tasks in six categories, which provides better insights on which disassembly tasks are the most time consuming and how the product design could be improved. The proposed method is illustrated by means of a case study of an LCD monitor. The presented case study demonstrates how the proposed method can be used in a policy context and how the calculated disassembly times per category can provide insights to manufacturers to improve the disassemblability of their products. The results also demonstrate how the proposed method can produce realistic results with only limited detail of input data.
Synergizing industrialized and developing countries to improve resource recovery for e-waste: case study Belgium - Kenya
(2014) Vanegas, Paul; Peeters, Jef R.; Plessers, Frank; Cattrysse, Dirk; Duflou, Joost R.
Due to high labor costs, e-waste recycling companies in industrialized countries increasingly adopt destructive mechanical pre-processing based treatments. These processes perform poorly for precious metals and plastics due to material incompatibility and increased entropy, resulting in low effective recycling efficiencies for these material categories. In developing countries most e-waste treatments consist of manual dismantling, followed by primitive refining techniques, which is not only inefficient, but also poses a serious threat to the environment. This article assesses, from an economic and environmental perspective, a cooperation scenario between Belgium and Kenya in which manual dismantling and state of the art metal refining techniques for recycling computers are combined. Findings show that international cooperation could offer a more sustainable solution, yet measures must be taken to avoid the “cherry picking” of valuable components and environmentally unsound disposal of the remaining parts.
The energy saving potential of retrofitting a smart heating system: a residence hall pilot study
(2021) Duflou, Joost R.; De Bock, Yannick; Auquilla Sangolquí, Andrés Vinicio; Bracquené, Ellen; Nowé, Ann
Energy conservation is of increasing importance in contemporary society. A large fraction of energy end-use can be attributed to space conditioning. Therefore, intelligent control systems were devised and commercialised in the form of smart thermostats. Hereto, the availability of occupancy information is essential such that heating and/or cooling schedules can be tailored to user needs. This way energy savings can be obtained without jeopardising user satisfaction. However, preceding studies generally rely on simulations to estimate the potential reduction in energy consumption. This work aims at quantifying the potential based on a real life experiment. The development of a smart heating system is presented along with the results of an actual field test of retrofitting this system in 14 single-user student rooms of a university residence hall. An experiment was conducted in which the heating was automatically steered for 1 week (26 March 2018–01 April 2018). Total energy savings range between 26.9% and 59.5% and calculated thermal comfort was not significantly affected by the autonomous control. Furthermore, an environmental impact reduction of 3.2 to 12.9 EcoPoints is estimated for the controlled week, resulting in a reduction of 37.5 to 150.2