A two-phase approach to efficiently support product recovery systems in a circular economy context

PurposeThe execution of product recovery strategies and the definition of an adequate system to manage its performance are crucial to move toward the employment of a successful circular economy (CE) concept. Defining strategies for the efficient management of product recovery requires product data that is difficult to obtain, making it harder to handle. However, efficient product recovery management can play a key role in shifting companies from a linear economy model to a more sustainable CE model, providing economic benefits and increasing customer satisfaction by recovering and adding value to the discarded product. Therefore, this study aims to provide better models to support decision-making and to evaluate product recovery performance.Design/methodology/approachThe present study highlights a comprehensive two-stage decision approach to identify and examine the relevant key performance indicators (KPIs) for performance improvement of an information facilitated product recovery system (IFPRS) in a CE context. In the first phase, a structural equation modeling (SEM) methodology is adopted to categorize the KPIs by employing exploratory factor analysis and measurement of the model fit is obtained using the confirmatory factor analysis. Further, in the second phase, the KPIs are ranked and prioritized on the basis of expert’s recommendations adopting fuzzy-technique for order of preference by similarity to ideal solution (FTOPSIS).FindingsEmpirical investigation is conducted by compiling data from an association of six decision-makers (DMs) and two DMs from a respective prospect. The results highlight that “Technology Capacity” is ranked as the highest and is the most prominent KPI for successful employment of IFPRS practices. The results of the study would benefit policy makers and company directors in the selection of KPIs based on their importance in a context of high competition and greater pressure to adopt sustainable practices in the management of their companies.Originality/valueAs far as the authors know, no study has been performed till date to identify and construct a structural KPIs model for IFPRS performance improvement in the context of CE. The paper, therefore, proposes a two-phase SEM-TOPSIS technique to measure the impact of KPIs which is a new integration in the existing literature. The results of the study would benefit policy makers and company directors in the selection of KPIs based on their importance in a context of high competition and greater pressure to adopt sustainable practices in managing their organizations.

A MODIFIED ANALYTICAL HIERARCHY PROCESS DESIGN EVALUATION METHODS FOR PRODUCT RECOVERY

The absence of existing standards for product recovery planning and the associated difficulty in prioritising the conflicting design requirements are among the main challenges faced during product design. In this paper, a concept for the Design for Multiple Life-Cycles (DFMLC) is proposed to address this situation. The objective of the DFMLC model is to assist designers in evaluating design attributes of Multiple Life-Cycle Products (MLCP) at the early design stage. The methodology adopted for the evaluation of MLCP design strategies has been based on a modified Analytical Hierarchy Process (AHP). Two mapping matrices of the design guidelines and design strategies concerning MLCP design attributes were developed for the modified AHP model. Disassemblability (> 21 %) was found to be the most important design element for MLCP followed by serviceability (> 20 %) and reassembly (> 12 %).

Prospects for selective-and-advanced recovery of rhenium from pregnant solutions of in-situ leaching of uranium ores at Dobrovolnoye deposit

Analysis of exploration materials and market conditions showed that by-product recovery of rhenium, one of the rarest strategic elements of the periodic system, was not always effective in processing the whole volume of pregnant uranium-bearing solutions. The main goal of the research was to develop an effective method for recovery rhenium from pregnant solutions in in-situ uranium leaching. The objectives of the research were as follows: evaluation of the possibility of selective-and-advanced recovery of rhenium from ores by in-situ leaching method and comparison of the technological advantages of the new proposed method with the known ones. The study involved the analysis of historical geological, mineralogical and geochemical information on the Dobrovolnoye deposit and analysis of technological aspects of by-product recovery of rhenium in the world practice. A selective-and-advanced scheme of rhenium recovery from pregnant uranium-bearing sulfate (sulfuric acid) solutions of the Dobrovolnoye deposit ISL (Russia) using mobile installations was proposed. The process has the following features: zoning of production blocks when constructing injection and extraction (pumping) wells; piping of selective extraction wells into a separate collecting pipe; implementation of advanced rhenium sorption. The process implementation makes it possible to obtain rhenium from economically viable areas of the uranium deposit. The mobile installation includes the following main units: a filter for purification (aftertreatment) to remove suspension, a chain of sorption apparatuses (sorption filters or columns), connecting fittings, control and measuring instruments. The sorption apparatuses are filled with rhenium-selective ionite (ion exchanger). As a selective sorbent for the primary concentration of rhenium from sulfate solutions (pH 2), weakly basic nitrogen-bearing ionites containing amine functional groups of various types can be used. If further concentration of rhenium is required, in order to unify the equipment used, materials with a mobile extractant phase (so-called TVEXs (solid extractants or Levextrel resins in English literature) and so-called “impregnated” or “impregnates”), such as TVEX-DIDA containing diisododecyl amine, or TAA-impregnate containing trialkylamine, can be used. Rhenium desorption from these materials is carried out by an ammonia solution, which allows producing rough ammonium perrhenate from the eluate. Economic aspects of the rhenium selective-andadvanced technology were evaluated. Implementation of the recovery selective-and-advanced technology allows obtaining rhenium from economically-viable areas of the uranium deposit.

Design and development of a fuzzy credibility-based reverse logistics network with buyback offers: A case study

The ever-growing stream of waste production has become a critical issue for many metropolitan areas. An effective strategy to address this problem has been the concept of reverse logistics (RL). This paper seeks to develop an appropriate product recovery approach for electronic waste generated in an urban area. Consequently, we have proposed an integrated fuzzy RL model with buyback (BB) offers based on the condition of used-products (UPs) at the time of return. However, this strategy contains a significant challenge, which derives from unpredictability surrounding the return rate of UPs due to its dependency on multiple external factors. Hence, a novel fuzzy probability function is developed to approximate UPs’ chance of return. Besides that, the mathematical RL network’s inherent uncertainty prompted us to employ the fuzzy credibility-based method in the model. Afterward, the model’s objectives are locating and allocating collection centres to customer zones, determining flow between facilities and finding the optimal amount of gathered UPs and BB offers. Finally, we applied the model to a case study concerning product recovery in Mashhad city, Iran, and the results have proven its validity and utility.