Reuse Process Research Articles

Reuse of Carbon Fibers and a Mechanically Recycled CFRP as Rod-like Fillers for New Composites: Optimization and Process Development

The rising amount of carbon fiber reinforced polymer (CFRP) composite waste requires new processes for reintroducing waste into the production cycle. In the present research, the objective is the design and study of a reuse process for carbon fibers and CFRP by mechanical recycling consisting of length and width reduction, obtaining rods and reintegrating them as fillers into a polymeric matrix. Preliminary studies are carried out with continuous and discontinuous unidirectional fibers of various lengths. The processing conditions are then optimized, including the length of the reinforcement, the need for a plasma surface treatment and/or for resin post-curing. The resin is thermally characterized by differential scanning calorimetry (DSC), while the composites are mechanically characterized by tensile strength tests, completed by a factorial design. In addition, the composites tested are observed by scanning electron microscopy (SEM) to study the fracture mechanics. Optimal processing conditions have been found to reduce the reinforcement length to 40 mm while maintaining the mechanical properties of continuous reinforcement. Furthermore, the post-curing of the epoxy resin used as matrix is required, but a low-pressure plasma treatment (LPPT) is not recommended on the reinforcement.

A Multicriteria Approach to Adaptive Reuse of Industrial Heritage: Case Studies of Riverside Power Plants

City riverbanks usually have great landscape value and are iconic public spaces. However, there are many cities with large abandoned industrial buildings, such as power plants, on their riverbanks. Such buildings run the risk of being demolished in order to recover the surrounding natural landscape, despite having an important presence in the collective memory of the citizens and in the history of the city. This article seeks to analyse the reuse and refurbishment of industrial power plants on riversides from a modern artistic/recreational approach in order to restore and enhance the landscape value of the site by regenerating the environs and turning them into hubs of activity. Two case studies from different locations are considered in order to extract the information. A methodology is used that allows us to analyse and study a complex reality in a straightforward, concise and direct way. That means it can be used by many agents currently involved in those reuse processes to compare and to monitor the different cases over time. This research has sought to highlight the power plant typology, its relationship with the riverside, and subsequently, to extrapolate the criteria used to study other industrial buildings.

Life cycle energy use and greenhouse gas emissions for a novel algal-osmosis membrane system versus conventional advanced potable water reuse processes: Part I

This study applied a life cycle assessment (LCA) methodology for a comparative environmental analysis between an innovative algae resource recovery and near zero-liquid discharge potable reuse system (i.e., the main system) versus a conventional potable reuse system (i.e., the benchmark system) through energy use and greenhouse gas (GHG) emissions. The objective of this study is to demonstrate that pilot-scale data coupled with LCA would provide valuable information for system optimization, integration, and improvements for the design of environmentally sustainable full-scale systems. This study also provides decision-makers valuable information regarding the energy demand and environmental impact of this innovative main system compared to a typical tried-and-true system for potable water reuse. The main system consists of a novel algal-based wastewater treatment coupled with a dual forward osmosis and seawater reverse osmosis (Algal FO-SWRO) membranes system for potable water recovery and hydrothermal liquefaction (HTL) to recover biofuels and valuable nutrients from the harvested algal biomass. The benchmark system refers to the current industry standard technologies for potable water reuse and waste management including a secondary biological treatment, microfiltration (MF), brackish water reverse osmosis (BWRO), ultraviolet/advanced oxidation process (UV-AOP), and granular activated carbon (GAC), as well as anaerobic digestion for sludge treatment. Respective energy and GHG emissions of both systems were normalized and compared considering 1 m3 of water recovered. Based on an overall water recovery of 76% designed for the benchmark system, the energy consumption totaled 4.83 kWh/m3, and the system was estimated to generate 2.42 kg of CO2 equivalent/m3 with most of the emissions coming from the biological treatment. The main system, based on an overall water recovery of 88%, was estimated to consume 4.76 kWh/m3 and emit 1.49 kg of CO2 eq/m3. The main system has high environmental resilience and can recover bioenergy and nutrients from wastewater with zero waste disposal. With the application of energy recovery devices for the HTL and the SWRO, increase in water recovery of the FO membrane, and replacement of the SWRO membrane with BWRO, the main system provides an energy-competitive and environmentally positive alternative with an energy demand of 2.57 kWh/m3 and low GHG emissions of 0.94 kg CO2 eq/m3.

Sustainability assessment of feedstock powder reuse for Directed Laser Deposition

In this paper, the results of a sustainability assessment for the study of the reuse of un-melted feedstock powder in Directed Laser Deposition are reported. Ti6Al4V ELI powder was employed as material for the study and the un-melted powder was collected and reused as raw material for subsequent cycles of deposition. A total of three deposition cycles were completed and data for a Life Cycle Assessment were compiled. From the experimental work results, the un-melted powder suffered minimal changes that did not affect the critical characteristics analysed. The Life Cycle Assessment showed that reusing the powder, and consequently reducing the total mass of raw material consumed, resulted in significant environmental benefits. All the categories considered saw approximately a 15%–25% environmental impact reduction when reusing the powder as compared to a scenario when only virgin material is used. Most of the environmental footprint was seen in the production of the powder as compared to the transportation and manufacturing stages. The production phase, when reusing and when using only virgin powder, accounted for 89% and 95% of the total environmental impact respectively. This meant the environmental benefits due to the lower mass of powder used far outweighed the increase in water and energy required for the powder reuse process in the manufacturing stage. Thus, feedstock powder reuse in Directed Laser Deposition process is seen to have a significant environmental benefit as compared to the usage of virgin powder alone.

Design architecture and algorithm of wireless network integrated circuit based on 5G+AI

In the current integrated circuit (IC) design process, research on its design process is relatively backward. This paper mainly adopts 5G + artificial intelligence technology, and conducts an in-depth discussion on the structure and algorithm of wireless network integrated circuits. The article analyzes the development of IC industry and the application of EDA software, and puts forward some problems that China’s IC industry is currently facing. The article discusses the realization of IC design flow, which is realized from five aspects: design input, function simulation, layout realization, physical verification, and post-parasitic simulation. Then, in view of the problems existing in the current IC design process, specific solutions for improvement and strengthening are given. Four parts are designed in detail, namely multi-mode simulation, realization of fully automated layout, feature extraction and modeling, IR Drop and EM analysis. Combined with the widely used characteristics of IP design reuse technology, this paper conducts a targeted research on the process of IP design reuse. From the IP circuit transplantation and IP layout transplantation, the specific discussion is carried out. From the perspective of IP design reuse, the design process of the wireless network integrated circuit is further improved. This paper turns to the design of RF IC from the perspective of IC design process, giving the flow chart of RF chip. The test results showed that over the full temperature range, the total current was about 2.45 mA, which met the design requirements. When the load resistance is 4KΩ, the ascending propagation delay is 92tns and the descending propagation delay is 65tns, both of which increase significantly. The article can provide further reference for the design of wireless network integrated circuits.

Techno-economic assessment of a novel algal-membrane system versus conventional wastewater treatment and advanced potable reuse processes: Part II

This study developed a comprehensive techno-economic assessment (TEA) framework to evaluate an innovative algae resource recovery and near zero-liquid discharge potable reuse system (i.e., the main system) in comparison with a conventional potable water reuse system (i.e., the benchmark system). The TEA study aims to estimate the levelized costs of water of individual units and integrated processes including secondary wastewater treatment, advanced water purification for potable reuse, and sludge treatment. This would provide decision-makers valuable information regarding the capital and operational costs of the innovative main system versus a typical potable water reuse treatment train, along with possible routes of cost optimization and improvements for the design of full-scale facilities. The main system consists of (i) a novel algal-based wastewater treatment coupled with a dual forward osmosis and seawater reverse osmosis (Algal FO-SWRO) membranes system for potable water reuse and hydrothermal liquefaction (HTL) to produce bioenergy and subsequent nutrients extraction from the harvested algal biomass. The benchmark system includes (ii) an advanced water purification facility (AWPF) that consists of a conventional activated sludge biological treatment (CAS), microfiltration (MF), brackish water reverse osmosis (BWRO), ultraviolet/advanced oxidation process (UV-AOP), and granular activated carbon (GAC), with anaerobic digestion for sludge treatment. Capital expenditures (CAPEX) and operational expenditures (OPEX) were calculated for each unit of both systems (i.e., sub-systems). Based on a 76% overall water recovery designed for the benchmark system, the water cost was estimated at $2.03/m3. The highest costs in the benchmark system were found on the CAS and the anaerobic digester, with the UV-AOP combined with GAC for hydrogen peroxide (H2O2) quenching as the driving factor in the increased costs of the system. The cost of the main system, based on an overall 88% water recovery, was estimated to be $1.97/m3, with costs mostly driven by the FO and SWRO membranes. With further cost reduction and optimization for FO membranes such as membrane cost, water recovery, and flux, the main system can provide a much more economically viable alternative in its application than a typical benchmark system.

Craft breweries as hermit crabs: Adaptive reuse and the revaluation of place

ABSTRACT This paper explores the relationship between craft breweries and adaptive reuse processes in small town Ontario, Canada. Drawing together semi-structured interviews, site analysis, and secondary newspaper and planning sources, this paper illustrates that, despite a diversity of structures and locations, there is a consistency in interior design and aesthetics across small town breweries. The visual symbolism and spatial references, included as part of the internal décor, produce a new story of place within the buildings. We argue that these repurposed sites should be valued regardless of age, location, or building type: their interior adaptation signals a revaluation and revival that spills over beyond the shell.

An Intelligent Platform for Software Component Mining and Retrieval

The development of robotic applications necessitates the availability of useful, adaptable, and accessible programming frameworks. Robotic, IoT, and sensor-based systems open up new possibilities for the development of innovative applications, taking advantage of existing and new technologies. Despite much progress, the development of these applications remains a complex, time-consuming, and demanding activity. Development of these applications requires wide utilization of software components. In this paper, we propose a platform that efficiently searches and recommends code components for reuse. To locate and rank the source code snippets, our approach uses a machine learning approach to train the schema. Our platform uses trained schema to rank code snippets in the top k results. This platform facilitates the process of reuse by recommending suitable components for a given query. The platform provides a user-friendly interface where developers can enter queries (specifications) for code search. The evaluation shows that our platform effectively ranks the source code snippets and outperforms existing baselines. A survey is also conducted to affirm the viability of the proposed methodology.

Sustainable recovery of phenolic antioxidants from real olive vegetation water with natural hydrophobic eutectic solvents and terpenoids

Olive oil production leads to the generation of olive mill wastewater (OMWW). Due to the presence of phenolic compounds, they are difficult to process, but they represent a source of high-added value chemicals since they have antioxidant and therapeutic properties. This work has studied the extraction of phenolic compounds from a type of OMWW, olive vegetation water, which presents these compounds in a more diluted dosage than in other studied to date, to revalue this waste stream. A real olive vegetation water from a Spanish olive oil producer was used, and liquid-liquid extraction was applied. Terpenoids and terpene-based hydrophobic eutectic solvents were systematically used to extract phenolic compounds following the concentrations of tyrosol, catechol, caffeic acid, and total phenolic content. By molecular simulation with the COSMO-RS method, 4 terpenoids, and 2 eutectic solvents were selected and compared with 2 conventional solvents. The Solvent/Feed ratio in the extraction of phenolic compounds was studied, showing that the solvents with the highest extraction results were geraniol, eucalyptol, and eutectic solvent menthol + camphor, which outperformed conventional solvents methyl isobutyl ketone and diisopropyl ether. Menthol + camphor gave total phenol extraction yields of 88.73% at a Solvent/Feed ratio in volume of 0.50, surpassing all solvents tested. A solvent reuse and regeneration process was applied by back-extraction of the 4 solvents: FTIR results showed the stability of the solvents while maintaining yields in the solvent reuse process. The phenolic compounds could be concentrated in the alkaline phase to factors up to 49.3 to the initial concentration in olive vegetation water. The alkaline phases were neutralized to obtain a precipitate with a caffeic acid content of up to 26 % wt%, and a tyrosol-rich supernatant with a concentration of up to 6.54 g/L. This work proposes a process using natural solvents to extract phenolic compounds from olive vegetation water.

Rationalisation of Costs in the Collection, Segregation and Transport of Municipal Waste

The article contains answers to three "why" questions: - why the waste management system still does not bring the expected results, and the Polish state is one of the lowest-ranking in the European score regarding the amount of segregated waste; - why the sale of selected secondary raw materials and their material reuse in production processes do not cover the costs related to waste management; - why it does not bring additional profits. The article is based on research conducted in Wroclaw from 1998 to 2018. There is a cost model that can be adapted to similar cases. The article deals with removing organisational and/or technical reasons causing the stagnation of selective waste collection.

Study for the evaluation of the processes of reuse and recycling of reverse osmosis components and membranes in the Canary Islands and Macaronesia

Study for the evaluation of the processes of reuse and recycling of reverse osmosis components and membranes in the Canary Islands and Macaronesia

Research on Key Technologies for Measuring the Recovery Rate and Gas Measurement of SF6 Gas On-site Maintenance Surface

Carrying out full lifecycle management of SF6 gas recovery, purification, and recycling, developing new digital control technologies, and eliminating SF6 gas emissions from the source are of great significance for achieving the “dual carbon” goal. Given the low level of digital control of SF6 gas at present, especially in the situation, the SF6 gas recovery rate, the effective volume of the gas chamber, and gas weight cannot be accurately measured at an on-site inspection surface, this paper carries out research on SF6 gas recovery rate measurement at on-site inspection surface and key technologies of gas measurement. An intelligent online monitoring device such as SF6 gas recovery rate and effective chamber volume of high voltage electrical equipment was developed, which can quickly identify SF6 gas density, recovery rate, effective chamber volume, weight, and other parameters in high voltage electrical equipment, and evaluate the detection methods such as gas recovery rate and effective chamber volume. The results show that when the recovery rate was about 96.5%, the maximum positive deviation between the recovery rate measured by the detection device and that measured by the weighing method was 0.32% and the maximum negative deviation was -0.24%, both of which are less than 0.50%. When the container to be tested was 1000 L, the maximum indication error was -1.51%, which can meet the requirements of digital control in the SF6 gas recycling and reuse process of high-voltage electrical equipment.

Business-IT Alignment in Cloud environment Proposed Framework

Nowadays, business process reuse is becoming a trendy topic in the enterprise as well as in scientific research to reduce the cost and time of process development for the benefit of the enterprise. Moreover, with the emergence of cloud environments and the various advantageous and competitive aspects of cloud computing, it becomes necessary to develop non-installable or so-called multi-tenant applications. In this sense, BPM researchers are working on improving the BPaaS (Business Process as Service) model, which enables business processes to be managed in the context of the cloud. However, the problem of aligning IT operations in the cloud, bridging the gap between business requirements and technical cloud solutions, remains an emerging issue in digital transformation, as cloud solutions are purely technical and do not allow stakeholders, who are usually not fluent in the language of business, to properly evaluate or choose the most appropriate cloud solution. Identifying the most appropriate cloud solutions in this context, therefore, requires specifying service requirements and capabilities at both the business and IT levels.

Switchable deep eutectic solvents for sustainable extraction of β-carotene from millet

Switchable deep eutectic solvents (DESs) were combined with phenolic antioxidants to extract β-carotene from millet, and the recovery and reuse capacities of DESs were evaluated. The pre-treatment of millet using ultrafine grinding is beneficial to the extraction of β-carotene. The hydrophobic DESs synthesized from N,N-dimethylcyclohexylamine and n-butanol were used as the extractants for grinding-assisted extraction of β-carotene from millet, and phenolic antioxidants were used to improve the stability of β-carotene. The hydrophobic DESs were switched to hydrophilic DESs by adjusting pH to recover the hydrophobic β-carotene solid. The remaining hydrophilic DESs could be switched to hydrophobic DESs by adjusting pH to extract new millet samples. In five DES recovery and reuse processes, the yield did not decrease, and more than 91.0% of β-carotene from millet could be directly recovered in solid state each time. In summary, a rapid, efficient, and sustainable method for β-carotene extraction was developed.

Reuse process for timber elements to optimise residual performances in subsequent life cycles

The reuse of wooden elements is a sustainable operation, which makes the best use of the material’s grey energy. Currently, structural timber from selective demolition is mainly used for non-structural functions, with a lowering of its performance, due to the lack of standard and specific regulation. In fact, the visual grading used to define the structural characteristics of wood does not evaluate information deriving from the previous life cycles of the component. In the paper, taking samples of rectangular timber elements from selective demolitions made in the Valencian Community, the structural values that are assigned by visual strength grading legislation were compared with the real resistance values identified by experimental analysis to verify their compliance. The verification showed that the visual grading is not able to optimize the performance of the timber element in its reuse. Therefore, the purpose of the research, illustrated in the paper, is to find a reuse process for structural wooden elements to enhance residual performances. The identified process introduces additional steps compared in the current visual grading, that include a consideration of the effective modalities of reuse evaluated according to the worst defects and information arising from previous life cycles.

Reuse process for timber elements to optimise residual performances in subsequent life cycles

The reuse of wooden elements is a sustainable operation, which makes the best use of the material’s grey energy. Currently, structural timber from selective demolition is mainly used for non-structural functions, with a lowering of its performance, due to the lack of standard and specific regulation. In fact, the visual grading used to define the structural characteristics of wood does not evaluate information deriving from the previous life cycles of the component. In the paper, taking samples of rectangular timber elements from selective demolitions made in the Valencian Community, the structural values that are assigned by visual strength grading legislation were compared with the real resistance values identified by experimental analysis to verify their compliance. The verification showed that the visual grading is not able to optimize the performance of the timber element in its reuse. Therefore, the purpose of the research, illustrated in the paper, is to find a reuse process for structural wooden elements to enhance residual performances. The identified process introduces additional steps compared in the current visual grading, that include a consideration of the effective modalities of reuse evaluated according to the worst defects and information arising from previous life cycles.

Recovering and reuse of textile dyes from dyebath effluent using surfactant driven forward osmosis to achieve zero hazardous chemical discharge

This experimental study explores the feasibility of the reuse of dyes recovered from denim and polyester dyebath effluents using forward osmosis (FO) system to achieve zero hazardous material discharge. In batch experiments, the sodium dodecyl sulfate (SDS) at 0.5 M concentration generated an average flux of 3.5 L/m2/h (LMH) and reverse salt flux (RSF) of only 0.012 g/m2/h (GMH), while maintaining 100% dye rejection. This flux stability comes from the property of surfactants to form micelles and exert a stable osmotic pressure (π) above their critical micelle concentration (CMC). The low RSF is due to the greater micelle size. A colored fouling layer was formed on the membrane active layer (AL), which was easily removed using sodium hydroxide (NaOH) and citric acid. According to Fourier transform infrared spectra and atomic forces microscopy images of the AL, the interaction between foulants and membrane active groups did not significantly affect the physiochemical properties of the membrane. In the semi-continuous experiment, a very stable average flux of 7.3 LMH and RSF of 0.03 GMH was obtained using 0.75 M SDS as draw solution. The stacked 1D proton nuclear magnetic resonance analysis (1HNMR) spectra of both original and recovered disperse dyes showed 100% similarity, which validates the concept that the recovered dyes maintained their integrity during reconcentration and can be reused in the next batch dyeing process. Importantly, the diluted SDS concentration can be directly reused within the same textile industry in scouring and finishing processes. The processes of dye recovery and reuse developed in this study do not produce any waste or hazardous by-products and are suitable for scale-up and onsite industrial applications.

SOLID WASTE MANAGEMENT AT GAS FIRED ELECTRIC POWERED PLANT: A CASE OF KARACHI, SINDH, PAKISTAN

This paper aims to provide an overview of current solid waste management practices at gas fired powered plant in Karachi, Pakistan. During the annual maintenance activities at gas powered plant it is obvious that different type of waste is generated such as metal waste including, aluminum, copper, iron and other metals, electronic waste, non-metal waste such as cotton rags, wood, paper, hand gloves and other miscellaneous waste. Three gas powered plants located in Karachi were surveyed and interviews were conducted to comprehend the existing practices of solid waste management there. Waste disposal and storage scraps yard of the selected power plants were also visited to study the process of waste segregation, reuse and recycling and final disposal. The results of this study indicate that highest amount of solid waste generated form selected power plants includes the heavy metals; aluminum, copper and iron comprising about 15% each. Cotton rags/ gloves, rubber and plastic make 11%, 6% and 4% respectively of the total waste stream. Study indicate that out of the total waste generated, approximately 70% is being disposed to scrap yard which is the source of revenue collection and remaining 30% is being lost as it is not being collected, segregated, and disposed as per the current practice of gas-powered plants. Study also finds that the waste that is currently not being disposed properly, can result in revenue increase of almost 27% (metal waste), 0.63% (cotton rags/hand gloves) and almost 4% (miscellaneous waste).

Intelligent template based die face design method for process reuse of automotive panel

Die face design of automotive panel is a tedious repeated process and depends heavily on experience of engineers, which leads to increase of lead time and production costs. An intelligent template based die face design method is presented for process reuse of automotive panel. In this method, the new part is extracted as feature parameters to match the existing process in the template library automatically and the similar process model is applied to the new part adaptively. Finally, a process reuse system for die face is developed and a typical automotive panel is employed to verify the effectiveness of the proposed method. The results show a favourable effectiveness and practicability in reducing design period and reliance on experience.

Progress and prospect on the recycling of spent lithium‐ion batteries: Ending is beginning

AbstractThe new energy vehicle market has grown rapidly due to the promotion of electric vehicles. Considering the average effective lives and calendar lives of power batteries, the world is gradually ushering in the retirement peak of spent lithium‐ion batteries (SLIBs). Without proper disposal, such a large number of SLIBs can be grievous waste of resources and serious pollution for the environment. This review provides a systematic overview of current solutions for SLIBs recycling, ranging from battery failure assessment, disassembly, and component separation to derived material recovery and reuse. In this review, several pretreatment methods for SLIBs are introduced. Subsequently, novel recovery and reuse processes are discussed to develop sustainable and efficient recycling processes. Finally, different scientific approaches are investigated, aiming at promoting the transformation of the SLIBs recycling industry to a circular economy. Based on this review, it is possible to improve existing processes or develop sustainable environmentally friendly and efficient alternative processes for recycling end‐of‐life batteries.