New Open-loop Recycling Approaches for Disposable Diaper Waste

2021 ◽  
Author(s):  
Jee Khan Lim ◽  
Julian Müller ◽  
Fatin Norsuaidah Mahdi ◽  
Soo Kien Chen ◽  
Kar Ban Tan ◽  
...  
Keyword(s):  
Closed Loop ◽  
Raw Materials ◽  
Lithium Ion ◽  
Open Loop ◽  
Environmental Damage ◽  
Waste Generation ◽  
Commercial Scale ◽  
Practical Strategy ◽  
Single Use ◽  
Disposable Diapers

Today's disposable diapers have become an indispensable choice among hygiene products, reflected in their massive global consumption and waste generation. Most of the diaper waste is neither segregated nor treated and ends up in landfills or incinerators. The reported life cycle assessment highlights that the diaper waste is not solely generated after single-use but begins as early as the raw materials acquisition stage. Although what is done cannot be undone, diaper waste can be recycled. Diaper waste valorization has been explored on laboratory- and commercial-scales for years, with varying degrees of success. Leading diaper manufacturers such as Procter & Gamble, Kimberley-Clark and Unicharm are making progress in establishing closed-loop recycling of used diapers and converting diaper waste into new diapers. However, the wide window of possible new products made from diaper waste has yet to be fully exploited. This review focuses on the enormous promise of diaper waste from the perspective of emerging open-loop recycling pathways. We demonstrate that diaper waste was harnessed and converted into non-diaper products, including energy pellets, anode material for lithium-ion batteries, concrete admixture, catalysts, soil amendment, and mushroom cultivation substrates. We also explore several active, commercial-scale diaper recycling approaches and provide a comprehensive blueprint to encourage open-loop recycling. Open-loop recycling is a practical strategy for managing diaper waste, rectifying environmental damage, and contributing to circular supply chains.

scholarly journals Life Cycle Assessment of the Closed-Loop Recycling of Used Disposable Diapers

Resources ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 34 ◽  
Author(s):  
Norihiro Itsubo ◽  
Mitsuhiro Wada ◽  
Shigeo Imai ◽  
Akira Myoga ◽  
Naoki Makino ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Closed Loop ◽  
New Technology ◽  
Open Loop ◽  
Raw Material ◽  
Recycled Pulp ◽  
Greenhouse Gas Reduction ◽  
Using Data ◽  
Disposable Diapers

In Japan, approximately 23.5 billion paper diapers are produced annually (total of diapers for infants and adults produced in 2018). The majority of used paper diapers are disposed of through incineration; in certain regions, some paper diapers are recycled, mostly by open-loop recycling or thermal recycling. To date, several methods of recycling used paper diapers have been proposed and developed, but these methods are considered to have different types and amounts of recycled materials and different environmental performances. In this study, a new technology was developed for the closed-loop recycling of used paper diapers, and the use of the recycled pulp and superabsorbent polymer (SAP) as materials for paper diapers was evaluated via the environmental impact using the life cycle assessment (LCA) method, using data obtained from experimental facilities for recycling. The results between the comparison of the new method with the landfill and incineration processes demonstrate a greenhouse gas reduction of 47% and 39%, respectively. The results also show that such recycling is expected to reduce land-use occupation and water consumption, closely related to the pulp, main raw material of paper diapers.

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

scholarly journals Parallel Point Clouds: Hybrid Point Cloud Generation and 3D Model Enhancement via Virtual–Real Integration

2021 ◽  
Vol 13 (15) ◽  
pp. 2868
Author(s):  
Yonglin Tian ◽  
Xiao Wang ◽  
Yu Shen ◽  
Zhongzheng Guo ◽  
Zilei Wang ◽  
...  
Keyword(s):  
Point Cloud ◽  
Closed Loop ◽  
Real Data ◽  
Point Clouds ◽  
Autonomous Driving ◽  
Training Model ◽  
Labor Cost ◽  
Open Loop ◽  
Training Dataset ◽  
Data Annotation

Three-dimensional information perception from point clouds is of vital importance for improving the ability of machines to understand the world, especially for autonomous driving and unmanned aerial vehicles. Data annotation for point clouds is one of the most challenging and costly tasks. In this paper, we propose a closed-loop and virtual–real interactive point cloud generation and model-upgrading framework called Parallel Point Clouds (PPCs). To our best knowledge, this is the first time that the training model has been changed from an open-loop to a closed-loop mechanism. The feedback from the evaluation results is used to update the training dataset, benefiting from the flexibility of artificial scenes. Under the framework, a point-based LiDAR simulation model is proposed, which greatly simplifies the scanning operation. Besides, a group-based placing method is put forward to integrate hybrid point clouds, via locating candidate positions for virtual objects in real scenes. Taking advantage of the CAD models and mobile LiDAR devices, two hybrid point cloud datasets, i.e., ShapeKITTI and MobilePointClouds, are built for 3D detection tasks. With almost zero labor cost on data annotation for newly added objects, the models (PointPillars) trained with ShapeKITTI and MobilePointClouds achieved 78.6% and 60.0% of the average precision of the model trained with real data on 3D detection, respectively.

scholarly journals Coordinated Planning in Closed-loop Supply Chains and its Implications on the Production and Recycling of Lithium-ion Batteries

Procedia CIRP ◽  
2021 ◽  
Vol 98 ◽  
pp. 464-469
Author(s):  
Christian Scheller ◽  
Steffen Blömeke ◽  
Mathias Nippraschk ◽  
Kerstin Schmidt ◽  
Mark Mennenga ◽  
...  
Keyword(s):  
Supply Chains ◽  
Lithium Ion Batteries ◽  
Closed Loop ◽  
Lithium Ion ◽  
Closed Loop Supply Chains

scholarly journals Regeneration of LiFePO4 from spent lithium-ion battery by a facile closed-loop process featuring acid leaching and hydrothermal synthesis

2021 ◽  
Author(s):  
Yifan Song ◽  
Boyi Xie ◽  
Shuya Lei ◽  
Shaole Song ◽  
Wei Sun ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lithium Ion Battery ◽  
Closed Loop ◽  
Acid Leaching ◽  
Lithium Ion ◽  
Power Battery

As a widely used power battery, the scrapping boom of LiFePO4 (LFP) battery is coming. Both pyrometallurgical repair and hydrometallurgical processes have been applied in the recycling of spent LFP...

scholarly journals Global Warming Potential of a New Waterjet-Based Recycling Process for Cathode Materials of Lithium-Ion Batteries

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 29
Author(s):  
Leonard Kurz ◽  
Mojtaba Faryadras ◽  
Ines Klugius ◽  
Frederik Reichert ◽  
Andreas Scheibe ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Waste Treatment ◽  
Raw Materials ◽  
Lithium Ion ◽  
Primary Data ◽  
Recycling Process ◽  
Use Of Resources ◽  
Mechanical Removal ◽  
Increasing Demand

Due to the increasing demand for battery electric vehicles (BEVs), the need for vehicle battery raw materials is increasing. The traction battery (TB) of an electric vehicle, usually a lithium-ion battery (LIB), represents the largest share of a BEV’s CO2 footprint. To reduce this carbon footprint sustainably and to keep the raw materials within a closed loop economy, suitable and efficient recycling processes are essential. In this life cycle assessment (LCA), the ecological performance of a waterjet-based direct recycling process with minimal use of resources and energy is evaluated; only the recycling process is considered, waste treatment and credits for by-products are not part of the analysis. Primary data from a performing recycling company were mainly used for the modelling. The study concludes that the recycling of 1 kg of TB is associated with a global warming potential (GWP) of 158 g CO2 equivalents (CO2e). Mechanical removal using a water jet was identified as the main driver of the recycling process, followed by an air purification system. Compared to conventional hydro- or pyrometallurgical processes, this waterjet-based recycling process could be attributed an 8 to 26 times lower GWP. With 10% and 20% reuse of recyclate in new cells, the GWP of TBs could be reduced by 4% and 8%, respectively. It has been shown that this recycling approach can be classified as environmentally friendly.

scholarly journals Converting MST to TSP Path by Branch Elimination

2020 ◽  
Vol 11 (1) ◽  
pp. 177
Author(s):  
Pasi Fränti ◽  
Teemu Nenonen ◽  
Mingchuan Yuan
Keyword(s):  
Spanning Tree ◽  
Closed Loop ◽  
Minimum Spanning Tree ◽  
Travelling Salesman Problem ◽  
Open Loop ◽  
Travelling Salesman ◽  
Elimination Algorithm ◽  
Number Of Iterations ◽  
Number Of Branches

Travelling salesman problem (TSP) has been widely studied for the classical closed loop variant but less attention has been paid to the open loop variant. Open loop solution has property of being also a spanning tree, although not necessarily the minimum spanning tree (MST). In this paper, we present a simple branch elimination algorithm that removes the branches from MST by cutting one link and then reconnecting the resulting subtrees via selected leaf nodes. The number of iterations equals to the number of branches (b) in the MST. Typically, b << n where n is the number of nodes. With O-Mopsi and Dots datasets, the algorithm reaches gap of 1.69% and 0.61 %, respectively. The algorithm is suitable especially for educational purposes by showing the connection between MST and TSP, but it can also serve as a quick approximation for more complex metaheuristics whose efficiency relies on quality of the initial solution.

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