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Water superabsorbent composites of dialdehyde cellulose from various cellulosic sources: a comparative study
No full textInternational audienceIn the context of global water shortages, there is an urgent need to implement effective strategies for the management of water resources. The objective of our research is to synthesize superabsorbent polymers to efficiently utilize water resources in agriculture, with a particular focus on the impact of cellulose sources and properties on absorption capacity. A hybrid superabsorbant polymer (SAP) hydrogel was prepared by combining 5% (wt) cellulose pulps or their dialdehyde cellulose (DACs) with a poly (acrylic co-itaconic) copolymer acid through radical chain polymerization. The crosslinker used was N,N-methylene-bis-acrylamide (MBA), while potassium persulfate (KPS) was employed as the polymerization initiator. The bleached pulps, DACs, and superabsorbent composites (SAPs) hydrogels were characterized by FTIR, XRD, SEM, and TGA. The results showed that an increase in the periodate equivalent relative to the glucose residue resulted in an increase in aldehyde content and a decrease in crystallinity, accompanied by a change in the morphological properties of the obtained oxidized fibers. Moreover, SAPs containing dialdehyde cellulose exhibited greater porosity compared to SAPs without DACs. The swelling capacity of the hydrogels was determined using the tea bag method. The SAPs of DAC extracted from banana fibers demonstrated a higher water absorption capacity of 1300 g g-1 compared to other SAPs due to the specific hydrophilic properties of the DAC derived from banana, especially its lower crystalline index
Production of Polyols from Linseed Oil by Reductive Hydroformylation
No full textInternational audienc
Valorization of prickly pear seeds as pasta fortifier
No full textInternational audienceOur study concerns the fortification of pasta with prickly pear seeds (PPS); the addition percentage was 0, 2.5, 5.0, and 7.5% in pasta formulation. With the fortification of pasta with PPS, ash and fat contents increased, and moisture decreased.The total polyphenol content increased 3 times (passing from 0.11 to 0.33 mg GAE/g for pasta formulated respectively with 0 and 7.5% of PPS) while the IC50 decreased from 97.5% for the control to 43.6% for 7.5% PPS pasta. Mixolab determination of rheological properties revealed that the gluten and retrogradation indexes increase with PPS incorporation, whereas the mixing index, amylolysis, and viscosity indexes decrease with the PPS increase. A significant variation in pasta color was noted; the ΔE highest value (13.55) was observed for pasta containing 7.5% PPS versus 3.55 for pasta with 2.5% PPS. The PPS quantity significantly affected the optimal cooking time, ranging from 570 s for control pasta to 535 s for 7.5% PPS. Sensory evaluation revealed that appreciation of color and elasticity decreased significantly from 4.08 to 1.92 and 5.48 to 3.96, respectively, for 5 and 7.5% of PPS supplementation, making the pasta obtained with 5% PPS the most acceptable by consumers
Synthesizing Liquid Fuels Over Carbon-Based Catalysts Via Co <sub>2</sub> Conversion.
No full textInternational audienceThe unique characteristics of carbon materials make them flexible for applications in heterogeneous catalysis. Their interest is expanding in the conscious efforts being made toward sustainable fuel production. A notable application is the heterogenous conversion of CO2 to liquid fuels, which exploits the characteristics of carbon materials, taking advantage of their electronic configurations, high surface area, pore properties, and synergistic role in catalysis. In this review, a critical overview of this rapidly developing field is presented. Various carbon allotropes and derivatives, as well as some strategies for fabricating carbon-based catalysts are keenly highlighted within thermal-, electro-, and photocatalytic CO2 conversion to liquid fuels. Distinct emphasis is placed on the role of different carbon materials by investigating the unique synergy attained at catalyst interfaces, the physicochemical properties attained, and their influence in enhancing the specific liquid fuels synthesis. Finally, the work is concluded, followed by an outlook detailing key challenges that need addressing
State-of-the-art and perspectives of hydrogen generation from waste plastics.
No full textInternational audienceWaste plastic utilization and hydrogen production present significant economic and social challenges but also offer opportunities for research and innovation. This review provides a comprehensive analysis of the latest advancements and innovations in hydrogen generation coupled with waste plastic recycling. It explores various strategies, including pyrolysis, gasification, aqueous phase reforming, photoreforming, and electrocatalysis. Pyrolysis and gasification in combination with catalytic reforming or water gas-shift are currently the most feasible and scalable technologies for hydrogen generation from waste plastics, with pyrolysis operating in an oxygen-free environment and gasification in the presence of steam, though both require high energy inputs. Aqueous phase reforming operates at moderate temperatures and pressures, making it suitable for oxygenated plastics, but it faces challenges related to feedstock limitations, catalyst costs and deactivation. Photoreforming and electrocatalytic reforming are emerging, sustainable methods that use sunlight and electricity, respectively, to convert plastics into hydrogen. Still, they suffer from low efficiency, scalability issues, and limitations to specific plastic types like oxygenated polymers. The challenges and solutions to commercializing plastic-to-hydrogen technologies, drawing on global industrial case studies have been outlined. Maximizing hydrogen productivity and selectivity, minimizing energy consumption, and ensuring stable operation and scaleup of plastic recycling are crucial parameters for achieving commercial viability
Stoichiometric Selective Carbonylation of Methane to Acetic Acid byChemical Looping
No full textInternational audienceThe conversion of methane to valuable products is one of the main challenges of modern chemistry. Acetic acid (AcOH) is a key chemical reagent in industry, produced nowadays by the carbonylation of methanol over homogeneous Rh and Ir catalysts. Here, we propose a stepwise chemical looping approach for the highly selective stoichiometric synthesis of AcOH by carbonylation of methane with CO using single-site Pt over isolated phosphotungstic anions on a titania support (Pt-HPW-TiO2). The reaction proceeds by methane activation, which coincides with the reduction of initially oxidized Pt species in the presence of CO at 423 K and results in surface acetates attached to TiO2. Subsequent hydrolysis by water at ambient temperature results in the synthesis of AcOH in a stoichiometric amount corresponding to 1.5 Pt. Spent Pt-HPW-TiO2 is restored to the initial state by subsequent calcination in air. This approach provides an opportunity for the selective synthesis of AcOH (>99% in liquid phase) from methane, carbon monoxide, and air. A high concentration of AcOH (1.1 wt %) in an aqueous solution can be obtained at a high conversion of methane (4.5%)
Production and coopetition strategies in remanufacturing involving knowledge spillovers
No full textInternational audienceKnowledge spillovers often occur naturally through remanufacturing in practice. We explore production and coopetition strategies in remanufacturing systems, considering the impact of knowledge spillovers. In the remanufacturing system addressed in this study, a third-party remanufacturer (TPR, he) can potentially remanufacture used products initially produced by an original equipment manufacturer (OEM, she), either in cooperation with her (coopetition scenario) or on his own (competition scenario). Meanwhile, the TPR may also produce and sell his self-branded new products in the same market as the OEM’s products and his own remanufactured products. Regarding this, TPR’s new product cannibalises his and OEM’s market shares. The OEM’s general and innovation knowledge spillovers to the TPR are unavoidable. In examining how knowledge spillovers influence the two firms’ production strategies and decisions, we develop analytical models describing competition and coopetition scenarios. Our results highlight the conditions under which the TPR engages in new product production and ceases remanufacturing in each scenario. Additionally, although innovation knowledge spillover motivates the TPR to engage in new product production and weakens the OEM’s competitiveness, both firms can be better off compared to the competition scenario. Moreover, we point out that coopetition improves consumer surplus and the environment under certain conditions
Extended guest editorial: Smart product platforming in the industry 4.0 era and beyond
No full textInternational audienceSince 1990s, product platforming has been extensively pursued in many industries to design and offer personalized products and services tailored for specific needs. The recent emergence of advanced technologies extends platforming to both integrate different units within a firm and connect different firms in the entire chain of value creation. The resulting process and activity expansion creates new opportunities and challenges in fulfilling personalized requirements based on smart platforms. We launched the special issue: Smart product platforming in the Industry 4.0 era to collect promising research and developments in this topic. The aim of this extended editorial is threefold: 1) introducing the context of the special issue, 2) presenting collected papers, and 3) offering our reflections and future research perspectives on the topic. In presenting the collected papers, we transversally classify them from different lenses, including product lifecycle stages, methodologies, and performance indicators. Based on these papers, we highlight our reflections and point out future perspectives, in hope of inspiring more research in the domain
Significance of Industry 4.0 in Achieving Sustainable Performance Across Supply Chains—A Research Perspective
No full texte70064International audienceThe enabling technologies in Industry 4.0 (I4.0) are leading to dramatic transformations of supply chains and helping organizations achieve sustainable development goals. With ever‐increasing pressure from regulators and customers to adopt environment‐friendly business practices, achieving sustainable development goals has become critical for any organization. Thus, the seamless deployment of various enabling technologies in I4.0 is vital for managing and enhancing sustainable supply chain performance (SSCP). Adopting enabling technologies across supply chains and their implications on sustainable performance is an emerging area that needs extensive academic research and lasting attention from the practice. This paper examines the adoption of I4.0's digital technologies in the context of SSCP. Bibliometric literature review (SLR) methodology and bibliometric analysis are conducted to analyze the existing literature in SSCP. Moreover, cocitation network analysis and coword analysis are carried out to determine different themes of the literature. Integrating I4.0's enabling technologies is indispensable for enhancing supply chains' social, economic, and environmental performance. The conceptual framework proposed for realizing SSCP based on the I4.0's enabling technologies is a novel contribution. It encompasses competitive advantages, supply chain strategies, and all three aspects of sustainability across a supply chain. This study suggests a framework that contributes to SSCP by adopting I4.0's enabling technologies. Moreover, it identifies a future scope for quantitative research on the contribution of particular I4.0 technologies in dimensions of sustainable supply chains
From collaborative filtering to deep learning: Advancing recommender systems with longitudinal data in the financial services industry
No full textInternational audienceRecommender systems (RS) are highly relevant for multiple domains, allowing to construct personalized suggestions for consumers. Previous studies have strongly focused on collaborative filtering approaches, but the inclusion of longitudinal data (LD) has received limited attention. To address this gap, we investigate the impact of incorporating LD for recommendations, comparing traditional collaborative filtering approaches, multi-label classifier (MLC) algorithms, and a deep learning model (DL) in the form of gated recurrent units (GRU). Additional analysis for the best performing model is provided through SHapley Additive exPlanations (SHAP), to uncover relations between the different recommended products and features. Thus, this article contributes to operational research literature by (1) comparing several MLC techniques and RS, including state-of-the-art DL models in a real-life scenario, (2) the comparison of various featurization techniques to assess the impact of incorporating LD on MLC performance, (3) the evaluation of LD as sequential input through the use of DL models, (4) offering interpretable model insights to improve the understanding of RS with LD. The results uncover that DL models are capable of extracting information from longitudinal features for overall higher and statistically significant performance. Further, SHAP values reveal that LD has the higher impact on model output and managerial relevant temporal patterns emerge across product categories