Pub Date : 2026-02-01Epub Date: 2026-01-03DOI: 10.1016/j.clet.2026.101143
K. Bhavinlal , Veena Venudharan
Rice Husk Ash (RHA), an agro-industrial byproduct, has recently gained global attention as a promising asphalt modifier, owing to its potential to improve the asphalt performance while promoting waste valorisation. Although previous studies have predominantly focused on the high-temperature performance of RHA-modified asphalt (RMA), its behaviour under intermediate and low temperatures remains largely unexplored. Moreover, the interlinking of the physicochemical properties of RMA with asphalt performance is still unclear. This study aimed to investigate the physicochemical, thermal, and viscoelastic properties of RMA and evaluate its performance over a wide range of temperatures and frequencies using advanced micro-level characterisation techniques and potential rheological parameters. Thermal sensitivity and workability of RMA were analysed using the consistency indices and activation energy concepts. Cole-Cole plots, master curves, and black space diagrams were effectively utilised to evaluate the rheological behaviour and performance characteristics of RMA. Furthermore, the significance of the key findings concluded from the experimental analyses was statistically assessed using MANOVA. Overall, it was observed that RHA incorporation impacts the physicochemical, thermal, and viscoelastic properties of asphalt, leading to its potential usage in high temperatures and controlled usage in intermediate and low-temperature regions.
{"title":"Holistic characterisation of rice husk ash-modified asphalt: Integrating chemical, thermal, and rheological perspectives","authors":"K. Bhavinlal , Veena Venudharan","doi":"10.1016/j.clet.2026.101143","DOIUrl":"10.1016/j.clet.2026.101143","url":null,"abstract":"<div><div>Rice Husk Ash (RHA), an agro-industrial byproduct, has recently gained global attention as a promising asphalt modifier, owing to its potential to improve the asphalt performance while promoting waste valorisation. Although previous studies have predominantly focused on the high-temperature performance of RHA-modified asphalt (RMA), its behaviour under intermediate and low temperatures remains largely unexplored. Moreover, the interlinking of the physicochemical properties of RMA with asphalt performance is still unclear. This study aimed to investigate the physicochemical, thermal, and viscoelastic properties of RMA and evaluate its performance over a wide range of temperatures and frequencies using advanced micro-level characterisation techniques and potential rheological parameters. Thermal sensitivity and workability of RMA were analysed using the consistency indices and activation energy concepts. Cole-Cole plots, master curves, and black space diagrams were effectively utilised to evaluate the rheological behaviour and performance characteristics of RMA. Furthermore, the significance of the key findings concluded from the experimental analyses was statistically assessed using MANOVA. Overall, it was observed that RHA incorporation impacts the physicochemical, thermal, and viscoelastic properties of asphalt, leading to its potential usage in high temperatures and controlled usage in intermediate and low-temperature regions.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"30 ","pages":"Article 101143"},"PeriodicalIF":6.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prevulcanization of natural rubber (NR) latex is a key process in producing diverse rubber products, as it governs their mechanical performance. Conventional sulfur prevulcanization is widely used owing to its simplicity and low cost, yet it poses environmental and health concerns due to zinc-based accelerators and sulfur compounds. This study compared five prevulcanization processes (sulfur-based; UV irradiation from fluorescent lamps, UV-Flu; UV from light emitting diodes, UV-LED; electron beam, EB; X-ray irradiation) using life cycle analysis (LCA) and life cycle cost analysis (LCCA). Laboratory experiments established the life cycle inventory (LCI) for processes that were then scaled up to industrial production scenarios. Measurements confirmed that all processes produced films that met ASTM requirements (Standard D3578–19). The LCA showed that EB irradiation minimized the environmental burdens because of short irradiation times and high throughput. X-ray prevulcanization resulted in the highest impact, driven by a high energy requirement and low productivity. UV-LED outperformed UV-Flu, reflecting higher efficiency of LED lamps and their longer life compared to fluorescent lights. The LCCA revealed sulfur-based process to be the most economic (US$ 1.48 kg−1), followed by UV-LED (US$ 4.38 kg−1) and the EB (US$ 10.56 kg−1). The X-ray process was prohibitively expensive (US$ 203.83 kg−1) and environmentally the most burdensome. Overall, the UV-LED and EB processes were most sustainable, especially if these technologies were developed further to reduce energy input and the hardware costs.
天然橡胶（NR）胶乳的预硫化是生产各种橡胶制品的关键工序，它决定着橡胶制品的力学性能。传统的硫预硫化因其简单、成本低而被广泛应用，但由于锌基促进剂和硫化合物的存在，造成了环境和健康问题。本研究使用生命周期分析（LCA）和生命周期成本分析（LCCA）比较了五种预硫化工艺（硫基；荧光灯紫外线照射，UV- flu；发光二极管紫外线照射，UV- led；电子束，EB； x射线照射）。实验室实验建立了过程的生命周期清单（LCI），然后将其扩展到工业生产场景。测量证实所有工艺生产的薄膜都符合ASTM要求（标准D3578-19）。LCA结果表明，EB辐照时间短，辐照通量高，对环境的影响最小。x射线预硫化的影响最大，因为能量需求高，产能低。UV-LED的表现优于UV-Flu，反映出LED灯的效率更高，与荧光灯相比寿命更长。LCCA显示，硫基工艺最经济（1.48 kg - 1美元），其次是UV-LED （4.38 kg - 1美元）和EB （10.56 kg - 1美元）。x射线过程非常昂贵（203.83 kg - 1美元），并且环境负担最重。总的来说，UV-LED和EB工艺是最可持续的，特别是如果这些技术进一步发展，以减少能源投入和硬件成本。
{"title":"Sustainability of prevulcanization of natural rubber latex: a comparative assessment of sulfur-based and radiation-based processes","authors":"Sutthinee Keawmaungkom , Supatra Patrawoot , Panithi Wiroonpochit , Chotiros Dokkhan , Suthathip Sichumphuang , Kasidit Kongdit , Somkit Chowchanglag , Yusuf Chisti , Nanthiya Hansupalak","doi":"10.1016/j.clet.2026.101142","DOIUrl":"10.1016/j.clet.2026.101142","url":null,"abstract":"<div><div>Prevulcanization of natural rubber (NR) latex is a key process in producing diverse rubber products, as it governs their mechanical performance. Conventional sulfur prevulcanization is widely used owing to its simplicity and low cost, yet it poses environmental and health concerns due to zinc-based accelerators and sulfur compounds. This study compared five prevulcanization processes (sulfur-based; UV irradiation from fluorescent lamps, UV-Flu; UV from light emitting diodes, UV-LED; electron beam, EB; X-ray irradiation) using life cycle analysis (LCA) and life cycle cost analysis (LCCA). Laboratory experiments established the life cycle inventory (LCI) for processes that were then scaled up to industrial production scenarios. Measurements confirmed that all processes produced films that met ASTM requirements (Standard D3578–19). The LCA showed that EB irradiation minimized the environmental burdens because of short irradiation times and high throughput. X-ray prevulcanization resulted in the highest impact, driven by a high energy requirement and low productivity. UV-LED outperformed UV-Flu, reflecting higher efficiency of LED lamps and their longer life compared to fluorescent lights. The LCCA revealed sulfur-based process to be the most economic (US$ 1.48 kg<sup>−1</sup>), followed by UV-LED (US$ 4.38 kg<sup>−1</sup>) and the EB (US$ 10.56 kg<sup>−1</sup>). The X-ray process was prohibitively expensive (US$ 203.83 kg<sup>−1</sup>) and environmentally the most burdensome. Overall, the UV-LED and EB processes were most sustainable, especially if these technologies were developed further to reduce energy input and the hardware costs.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"30 ","pages":"Article 101142"},"PeriodicalIF":6.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-11-27DOI: 10.1016/j.clet.2025.101123
Óscar Crespo , Mehrez Hermassi , Oriol Gibert , Jordi Cama , José Luis Cortina
This study focuses on the recovery of rare earth elements (REEs) from acid mine water (AMW) through a two-step selective process, which consists of a selective extraction with ion exchange followed by a precipitation stage using oxalic acid. Optimization of the effective REE recovery from sulphuric ion-exchange concentrates results in sustainable AMW management, providing a secondary resource for critical metals towards green transition. Experimental results indicate that (1) the use of oxalic acid facilitates the formation of REE-oxalate crystals, yielding recovery efficiencies in light rare earth elements (LREEs) much higher than for heavy rare earth elements (HREEs) at specific excess doses, and that (2) LREEs act as precursors for HREE precipitation. Moreover, REE-oxalate crystallization depends on the oxalic acid dose, pH, and precipitation time (PT). The longer the PT, the larger the crystals, which are economically advantageous. The study highlights that AMW is a potential secondary source for the REE recovery, which contributes to sustainable mining practices and provides confidence for further optimization of REE recovery processes.
{"title":"Optimizing the recovery of rare earth elements from acid mine water: A sustainable approach using selective precipitation","authors":"Óscar Crespo , Mehrez Hermassi , Oriol Gibert , Jordi Cama , José Luis Cortina","doi":"10.1016/j.clet.2025.101123","DOIUrl":"10.1016/j.clet.2025.101123","url":null,"abstract":"<div><div>This study focuses on the recovery of rare earth elements (REEs) from acid mine water (AMW) through a two-step selective process, which consists of a selective extraction with ion exchange followed by a precipitation stage using oxalic acid. Optimization of the effective REE recovery from sulphuric ion-exchange concentrates results in sustainable AMW management, providing a secondary resource for critical metals towards green transition. Experimental results indicate that (1) the use of oxalic acid facilitates the formation of REE-oxalate crystals, yielding recovery efficiencies in light rare earth elements (LREEs) much higher than for heavy rare earth elements (HREEs) at specific excess doses, and that (2) LREEs act as precursors for HREE precipitation. Moreover, REE-oxalate crystallization depends on the oxalic acid dose, pH, and precipitation time (PT). The longer the PT, the larger the crystals, which are economically advantageous. The study highlights that AMW is a potential secondary source for the REE recovery, which contributes to sustainable mining practices and provides confidence for further optimization of REE recovery processes.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"30 ","pages":"Article 101123"},"PeriodicalIF":6.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145791205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-13DOI: 10.1016/j.clet.2025.101124
Ivo Reetz , Francina Izquierdo , Grau Baquero , Anna Bacardit
This study evaluates zeolite-based tanning systems as sustainable alternatives to conventional methods from both life cycle and end-of-life perspectives. Zeolite formulations combined with masking agents, hydrotropic substances, and vegetable tanning compounds were tested for biodegradability, compostability, and environmental impact. Results show that zeolite-tanned leathers achieved biodegradability rates above 94 % and complete compostability within 10–28 days, outperforming glutaraldehyde (54 %) and chromium tanning (6 %). Hydrolysable tannins such as tara enhanced compostability, whereas condensed tannins (mimosa) inhibited degradation. Life cycle assessment showed zeolite systems reduced global warming potential by 54 %, ecotoxicity by 76 %, and carcinogenic toxicity by 98 % compared with chrome tanning, while also eliminating heavy metal contamination in compost. These results highlight the importance of holistic evaluation of tanning chemistries, where environmental trade-offs extend beyond carbon footprint to include toxicity, land use, and circularity. Overall, zeolite-based tanning stands out as a viable pathway for large-scale, chrome-free leather production aligned with sustainable development and circular economy principles.
{"title":"Zeolite versus other tanning systems: A life cycle and end-of-life perspective","authors":"Ivo Reetz , Francina Izquierdo , Grau Baquero , Anna Bacardit","doi":"10.1016/j.clet.2025.101124","DOIUrl":"10.1016/j.clet.2025.101124","url":null,"abstract":"<div><div>This study evaluates zeolite-based tanning systems as sustainable alternatives to conventional methods from both life cycle and end-of-life perspectives. Zeolite formulations combined with masking agents, hydrotropic substances, and vegetable tanning compounds were tested for biodegradability, compostability, and environmental impact. Results show that zeolite-tanned leathers achieved biodegradability rates above 94 % and complete compostability within 10–28 days, outperforming glutaraldehyde (54 %) and chromium tanning (6 %). Hydrolysable tannins such as tara enhanced compostability, whereas condensed tannins (mimosa) inhibited degradation. Life cycle assessment showed zeolite systems reduced global warming potential by 54 %, ecotoxicity by 76 %, and carcinogenic toxicity by 98 % compared with chrome tanning, while also eliminating heavy metal contamination in compost. These results highlight the importance of holistic evaluation of tanning chemistries, where environmental trade-offs extend beyond carbon footprint to include toxicity, land use, and circularity. Overall, zeolite-based tanning stands out as a viable pathway for large-scale, chrome-free leather production aligned with sustainable development and circular economy principles.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"30 ","pages":"Article 101124"},"PeriodicalIF":6.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145738403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-12DOI: 10.1016/j.clet.2025.101136
Majid Dekamin , Amin Toranjian , Mehdi Shafiei
Efficient water and resource management is crucial in semi-arid agriculture, where irrigation practices strongly affect productivity, profitability, and environmental outcomes. This study applied the Material Flow Cost Accounting (MFCA) framework to compare potato production under sprinkler and furrow irrigation in Iran. MFCA has rarely been applied to potato production, and the hidden economic, energy, and environmental costs of different irrigation systems in semi-arid regions remain largely unexplored. Results showed that sprinkler irrigation required less water (9110 m3 ha−1 vs. 13587 m3 ha−1) and fertilizers (300 vs. 350 kg N ha−1), while achieving a higher yield (40000 vs. 27500 kg ha−1). Economically, sprinkler irrigation reduced production costs ($1304.2 ha-1 vs. $1531.2 ha-1), increased gross incomes ($8088 vs. $6196 ha−1), and improved the benefit-to-cost ratio (7.7 vs. 5.05). Hidden costs were also lower ($1392 ha−1 vs. $2227 ha−1). Energy analysis further confirmed the efficiency of sprinkler systems, with lower input energy (102,743 vs. 131,990 MJ ha−1), higher positive output energy (144000 vs. 99000 MJ ha−1), and a positive net energy balance (11581 vs. −82628 MJ ha−1). MFCA-adjusted Energy Ratio (1.11 vs. 0.37), energy productivity (0.39 vs. 0.21 kg MJ−1), and specific energy (2.57 vs. 4.80 MJ kg−1) all favored sprinkler irrigation. Although limited to farm-level processes in one region, the findings demonstrate that sprinkler irrigation provides significant environmental, economic, and energy benefits, offering a sustainable pathway for potato production in semi-arid areas. Overall, the MFCA framework effectively revealed internal inefficiencies, quantified recoverable loss costs, and provided complementary insight beyond conventional economic and energy metrics. The findings indicate that while sprinkler irrigation improves productivity and resource-use efficiency, its adoption remains sensitive to financing structures. These results underscore the need for supportive credit mechanisms and targeted subsidies to facilitate efficient irrigation transitions and maximize both economic and environmental benefits.
在半干旱农业中，有效的水资源和资源管理至关重要，因为灌溉做法对生产力、盈利能力和环境结果有很大影响。本研究应用物料流成本核算（MFCA）框架比较了伊朗喷灌和沟灌下的马铃薯产量。MFCA很少应用于马铃薯生产，半干旱地区不同灌溉系统的潜在经济、能源和环境成本在很大程度上仍未得到探索。结果表明，喷灌需水量较少（9110 m3 ha - 1比13587 m3 ha - 1），化肥用量较少（300比350 kg N ha - 1），但产量较高（40000比27500 kg ha - 1）。从经济角度来看，喷灌降低了生产成本（分别为1304.2公顷-1美元和1531.2公顷-1美元），增加了毛收入（分别为8088美元和6196公顷-1美元），提高了效益成本比（分别为7.7美元和5.05美元）。隐性成本也较低（分别为1392美元和2227美元）。能量分析进一步证实了喷水灭火系统的效率，其输入能量较低（102,743 vs. 131,990 MJ ha - 1），输出能量较高（144,000 vs. 99000 MJ ha - 1），净能量平衡为正（11581 vs. - 82628 MJ ha - 1）。mfca调整后的能量比（1.11 vs. 0.37）、能量生产率（0.39 vs. 0.21 kg MJ - 1）和比能（2.57 vs. 4.80 MJ kg - 1）均有利于喷灌。虽然仅限于一个地区的农场层面的过程，但研究结果表明，喷灌提供了显著的环境、经济和能源效益，为半干旱地区的马铃薯生产提供了一条可持续的途径。总体而言，MFCA框架有效地揭示了内部效率低下，量化了可收回的损失成本，并提供了超越传统经济和能源指标的补充见解。研究结果表明，虽然喷灌提高了生产力和资源利用效率，但其采用对融资结构仍然敏感。这些结果强调需要支持性信贷机制和有针对性的补贴，以促进有效的灌溉转型，并最大限度地提高经济和环境效益。
{"title":"Energy and economic analysis of potato production under furrow and sprinkler irrigation systems using material flow cost accounting","authors":"Majid Dekamin , Amin Toranjian , Mehdi Shafiei","doi":"10.1016/j.clet.2025.101136","DOIUrl":"10.1016/j.clet.2025.101136","url":null,"abstract":"<div><div>Efficient water and resource management is crucial in semi-arid agriculture, where irrigation practices strongly affect productivity, profitability, and environmental outcomes. This study applied the Material Flow Cost Accounting (MFCA) framework to compare potato production under sprinkler and furrow irrigation in Iran. MFCA has rarely been applied to potato production, and the hidden economic, energy, and environmental costs of different irrigation systems in semi-arid regions remain largely unexplored. Results showed that sprinkler irrigation required less water (9110 m<sup>3</sup> ha<sup>−1</sup> vs. 13587 m<sup>3</sup> ha<sup>−1</sup>) and fertilizers (300 vs. 350 kg N ha<sup>−1</sup>), while achieving a higher yield (40000 vs. 27500 kg ha<sup>−1</sup>). Economically, sprinkler irrigation reduced production costs ($1304.2 ha<sup>-1</sup> vs. $1531.2 ha<sup>-1</sup>), increased gross incomes ($8088 vs. $6196 ha<sup>−1</sup>), and improved the benefit-to-cost ratio (7.7 vs. 5.05). Hidden costs were also lower ($1392 ha<sup>−1</sup> vs. $2227 ha<sup>−1</sup>). Energy analysis further confirmed the efficiency of sprinkler systems, with lower input energy (102,743 vs. 131,990 MJ ha<sup>−1</sup>), higher positive output energy (144000 vs. 99000 MJ ha<sup>−1</sup>), and a positive net energy balance (11581 vs. −82628 MJ ha<sup>−1</sup>). MFCA-adjusted Energy Ratio (1.11 vs. 0.37), energy productivity (0.39 vs. 0.21 kg MJ<sup>−1</sup>), and specific energy (2.57 vs. 4.80 MJ kg<sup>−1</sup>) all favored sprinkler irrigation. Although limited to farm-level processes in one region, the findings demonstrate that sprinkler irrigation provides significant environmental, economic, and energy benefits, offering a sustainable pathway for potato production in semi-arid areas. Overall, the MFCA framework effectively revealed internal inefficiencies, quantified recoverable loss costs, and provided complementary insight beyond conventional economic and energy metrics. The findings indicate that while sprinkler irrigation improves productivity and resource-use efficiency, its adoption remains sensitive to financing structures. These results underscore the need for supportive credit mechanisms and targeted subsidies to facilitate efficient irrigation transitions and maximize both economic and environmental benefits.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"30 ","pages":"Article 101136"},"PeriodicalIF":6.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145791203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-15DOI: 10.1016/j.clet.2025.101101
Andrés Mauricio Oviedo Pinzón, Vladimir Rafael Melian Cobas
This paper presents the optimal sizing of a microgrid that combines hybrid photovoltaic and Organic Rankine Cycle systems, along with either lead-acid or lithium-ion batteries. The optimization, employing the Particle Swarm Optimization technique, aims to minimize the levelized cost of energy consumed by Matias Cardoso town, located in northern Minas Gerais, Brazil, while maintaining a loss of power supply probability below 1 %. The paper presents technical and economic models for all microgrid components. It also details the particle swarm optimization parameter settings and analyzes the impact of population size variations optimization algorithm's performance. The base case optimal sizing points to a microgrid with a levelized cost of energy of 0.5319 R$/kWh using lithium-ion batteries. Lead-acid batteries were outperformed economically by the lithium-ion ones, due to their longer lifespan. Results also indicate that the microgrid's economic performance greatly depends on the considered discount rate.
{"title":"Sizing a PV/battery/ORC isolated hybrid microgrid using particle swarm optimization: A case study in Brazil","authors":"Andrés Mauricio Oviedo Pinzón, Vladimir Rafael Melian Cobas","doi":"10.1016/j.clet.2025.101101","DOIUrl":"10.1016/j.clet.2025.101101","url":null,"abstract":"<div><div>This paper presents the optimal sizing of a microgrid that combines hybrid photovoltaic and Organic Rankine Cycle systems, along with either lead-acid or lithium-ion batteries. The optimization, employing the Particle Swarm Optimization technique, aims to minimize the levelized cost of energy consumed by Matias Cardoso town, located in northern Minas Gerais, Brazil, while maintaining a loss of power supply probability below 1 %. The paper presents technical and economic models for all microgrid components. It also details the particle swarm optimization parameter settings and analyzes the impact of population size variations optimization algorithm's performance. The base case optimal sizing points to a microgrid with a levelized cost of energy of 0.5319 R$/kWh using lithium-ion batteries. Lead-acid batteries were outperformed economically by the lithium-ion ones, due to their longer lifespan. Results also indicate that the microgrid's economic performance greatly depends on the considered discount rate.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"29 ","pages":"Article 101101"},"PeriodicalIF":6.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145325212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-08DOI: 10.1016/j.clet.2025.101076
Daniel O.F. Silva , Valdir M. Pereira , Antônio C.V. Coelho , Sérgio C. Angulo
Concrete slurry waste (CSW) is a by-product generated from returned concrete and the mixer truck washing process, accounting for approximately 3–5% of total concrete production. Although various strategies for recycling CSW have been developed, large-scale recovery of its anhydrous cement fraction, such implemented in the present study, has not been previously reported. Moreover, prior studies have focused almost exclusively on the use of low-reactivity CSW as a supplementary cementitious material (SCM). In this study, a filtering and rapid drying procedure was applied to CSW upon its return to the ready-mixed concrete plant (RMCP). The influence of the recovery time and type of concrete waste on the preservation of the anhydrous cement fraction was evaluated. The recovered material was subsequently used to partially replace Portland cement in cementitious paste formulations. The samples were characterized using analytical methods, such X-ray fluorescence, HCl leaching assay, thermogravimetric analysis, isothermal calorimetry, and quantitative X-ray diffraction (QXRD). The results demonstrated that the anhydrous cement content in CSW was significant, approximately 30% by mass, due to the efficiency of the filtering and rapid drying process. Furthermore, the time exposure to water had no notable effect on the preserved anhydrous cement fraction. Three CSW samples were selected and incorporated into cement pastes, replacing 35 %–75% (by mass) of Portland cement. The resulting pastes exhibited mechanical strength values comparable to, or statistically equivalent to, those of the reference paste made with 100 % Portland cement. The recovery methodology has potential for the development of zero-waste ready-mix concrete plants, and the low emission concrete formulation proposed in this study enabled a reduction of up to 55% in specific CO2 emissions. This approach could reduce Portland cement consumption by approximately 15% (by mass) in ready-mix operations, contributing significantly to sustainability in the concrete industry.
{"title":"High recovery of anhydrous cement in dried concrete slurry waste for use as supplementary cementitious material in low-CO2 concretes","authors":"Daniel O.F. Silva , Valdir M. Pereira , Antônio C.V. Coelho , Sérgio C. Angulo","doi":"10.1016/j.clet.2025.101076","DOIUrl":"10.1016/j.clet.2025.101076","url":null,"abstract":"<div><div>Concrete slurry waste (CSW) is a by-product generated from returned concrete and the mixer truck washing process, accounting for approximately 3–5% of total concrete production. Although various strategies for recycling CSW have been developed, large-scale recovery of its anhydrous cement fraction, such implemented in the present study, has not been previously reported. Moreover, prior studies have focused almost exclusively on the use of low-reactivity CSW as a supplementary cementitious material (SCM). In this study, a filtering and rapid drying procedure was applied to CSW upon its return to the ready-mixed concrete plant (RMCP). The influence of the recovery time and type of concrete waste on the preservation of the anhydrous cement fraction was evaluated. The recovered material was subsequently used to partially replace Portland cement in cementitious paste formulations. The samples were characterized using analytical methods, such X-ray fluorescence, HCl leaching assay, thermogravimetric analysis, isothermal calorimetry, and quantitative X-ray diffraction (QXRD). The results demonstrated that the anhydrous cement content in CSW was significant, approximately 30% by mass, due to the efficiency of the filtering and rapid drying process. Furthermore, the time exposure to water had no notable effect on the preserved anhydrous cement fraction. Three CSW samples were selected and incorporated into cement pastes, replacing 35 %–75% (by mass) of Portland cement. The resulting pastes exhibited mechanical strength values comparable to, or statistically equivalent to, those of the reference paste made with 100 % Portland cement. The recovery methodology has potential for the development of zero-waste ready-mix concrete plants, and the low emission concrete formulation proposed in this study enabled a reduction of up to 55% in specific CO<sub>2</sub> emissions. This approach could reduce Portland cement consumption by approximately 15% (by mass) in ready-mix operations, contributing significantly to sustainability in the concrete industry.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"29 ","pages":"Article 101076"},"PeriodicalIF":6.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-20DOI: 10.1016/j.clet.2025.101098
Stefan Puschnigg , Daniel Patauner , Hans Böhm , Eduard Doujak , Christoph Müller
The Water-Energy Nexus highlights the interdependence of water and energy systems. Optimizing this nexus through digital solutions enhances water supply resilience, boosts renewable energy generation, reduces greenhouse gas emissions, and supports carbon neutrality by 2050.
This study digitalizes a water supply system (WSS) of a typical rural Austrian municipality, including pipes, pumps, valves, junctions, tanks, and reservoirs. The digital WSS model, developed using EPANET simulations, identifies hydropower potential and supports the integration of digital solutions such as sensors for leakage reduction and monitoring. To structure these opportunities, a categorization approach is introduced for WSSs, divided into three sections (I – III) based on the available head along the water flow. Each section has its specific objectives and focus areas, ranging from energy generation for sale to powering monitoring devices. Hydraulic turbine types such as Pelton, Francis, Kaplan, pump-as-turbine (PAT), and emerging in-pipe turbines as well as energy harvesters are assigned accordingly. Techno-economic assessments evaluate energy recovery opportunities and cost-saving potentials from digitization, while SWOT and PESTLE analyses support strategic risk management.
Results revealed that section I focus on energy sales as an additional revenue stream for the WSS, achieving a use-case-specific levelized cost of electricity (LCoE) of 103 €/MWh with a Pelton turbine. In section II, several hidden hydropower potential points were identified, including a maximum single-point potential of approx. 6.9 kW at a pressure reduction valve, yielding LCoE of 26 €/MWh with a PAT. This potential is found suitable for local supply and to increase self-sufficiency of the WSS. In section III, digitized monitoring enables earlier leakage detection, with potentially savings up to 30 % of revenue water.
Digitalized WSSs are essential for optimizing both energy and water efficiency. They foster the development of smarter WSSs, enhance resilience and ensure a secure and reliable water supply.
{"title":"Digitalization and hydropower integration in water supply systems: Unlocking energy potential, efficiency, and resilience","authors":"Stefan Puschnigg , Daniel Patauner , Hans Böhm , Eduard Doujak , Christoph Müller","doi":"10.1016/j.clet.2025.101098","DOIUrl":"10.1016/j.clet.2025.101098","url":null,"abstract":"<div><div>The Water-Energy Nexus highlights the interdependence of water and energy systems. Optimizing this nexus through digital solutions enhances water supply resilience, boosts renewable energy generation, reduces greenhouse gas emissions, and supports carbon neutrality by 2050.</div><div>This study digitalizes a water supply system (WSS) of a typical rural Austrian municipality, including pipes, pumps, valves, junctions, tanks, and reservoirs. The digital WSS model, developed using EPANET simulations, identifies hydropower potential and supports the integration of digital solutions such as sensors for leakage reduction and monitoring. To structure these opportunities, a categorization approach is introduced for WSSs, divided into three sections (I – III) based on the available head along the water flow. Each section has its specific objectives and focus areas, ranging from energy generation for sale to powering monitoring devices. Hydraulic turbine types such as Pelton, Francis, Kaplan, pump-as-turbine (PAT), and emerging in-pipe turbines as well as energy harvesters are assigned accordingly. Techno-economic assessments evaluate energy recovery opportunities and cost-saving potentials from digitization, while SWOT and PESTLE analyses support strategic risk management.</div><div>Results revealed that section I focus on energy sales as an additional revenue stream for the WSS, achieving a use-case-specific levelized cost of electricity (LCoE) of 103 €/MWh with a Pelton turbine. In section II, several hidden hydropower potential points were identified, including a maximum single-point potential of approx. 6.9 kW at a pressure reduction valve, yielding LCoE of 26 €/MWh with a PAT. This potential is found suitable for local supply and to increase self-sufficiency of the WSS. In section III, digitized monitoring enables earlier leakage detection, with potentially savings up to 30 % of revenue water.</div><div>Digitalized WSSs are essential for optimizing both energy and water efficiency. They foster the development of smarter WSSs, enhance resilience and ensure a secure and reliable water supply.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"29 ","pages":"Article 101098"},"PeriodicalIF":6.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The construction boom of the 21st century has heightened demand for natural aggregates, leading to significant environmental degradation worldwide. On the contrary, there is a substantial generation of industrial waste and by-products like ceramic tile waste and stone dust, which are merely disposed of and stored in landfills. While both materials have the potential to be viable alternatives to natural aggregate in concrete production, their combined effects on concrete remain unexplored. This study aims to predict and optimize concrete properties incorporating stone dust (SD) and ceramic tile aggregate (CTA) as partial replacements for natural fine and coarse aggregates, respectively. Regression models were developed using response surface methodology (RSM) to assess the physical (fresh density and slump), mechanical (compressive strength, splitting tensile strength and bond strength) and durability (water absorption and carbonation depth) properties of concrete, with volumetric percentages of SD and CTA as independent variables. The analysis of variance (ANOVA) for all the desired responses indicated that the developed regression models were statistically significant in predicting the concrete properties. Based on multi-objective optimization, optimal replacement proportions of SD and CTA for enhanced concrete properties were obtained to be 30 % and 30.867 %, respectively. Hence, our findings highlight the insights of utilizing CTA and SD as viable substitutes for natural aggregate, offering a practical pathway to sustainable concrete production.
{"title":"Optimizing properties of concrete containing stone dust and ceramic tile: a response surface methodology approach","authors":"Ayesha Ferdous Mita, Miftahul Jannat Labiba, Sayeeda Rafia Maliha, Mohaiminul Haque, Sourav Ray","doi":"10.1016/j.clet.2025.101083","DOIUrl":"10.1016/j.clet.2025.101083","url":null,"abstract":"<div><div>The construction boom of the 21st century has heightened demand for natural aggregates, leading to significant environmental degradation worldwide. On the contrary, there is a substantial generation of industrial waste and by-products like ceramic tile waste and stone dust, which are merely disposed of and stored in landfills. While both materials have the potential to be viable alternatives to natural aggregate in concrete production, their combined effects on concrete remain unexplored. This study aims to predict and optimize concrete properties incorporating stone dust (SD) and ceramic tile aggregate (CTA) as partial replacements for natural fine and coarse aggregates, respectively. Regression models were developed using response surface methodology (RSM) to assess the physical (fresh density and slump), mechanical (compressive strength, splitting tensile strength and bond strength) and durability (water absorption and carbonation depth) properties of concrete, with volumetric percentages of SD and CTA as independent variables. The analysis of variance (ANOVA) for all the desired responses indicated that the developed regression models were statistically significant in predicting the concrete properties. Based on multi-objective optimization, optimal replacement proportions of SD and CTA for enhanced concrete properties were obtained to be 30 % and 30.867 %, respectively. Hence, our findings highlight the insights of utilizing CTA and SD as viable substitutes for natural aggregate, offering a practical pathway to sustainable concrete production.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"29 ","pages":"Article 101083"},"PeriodicalIF":6.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145417115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-07DOI: 10.1016/j.clet.2025.101084
Ihunanya Udodiri Ajakwe , Victor Ikenna Kanu , Simeon Okechukwu Ajakwe , Dong-Seong Kim
The Korean Emission Trading Scheme (K-ETS) is vital for reducing carbon emissions in South Korea. However, issues in transparency, security, and computational overhead limit its effectiveness. This work proposes an energy-efficient blockchain-based framework (eBCTC) to enhance the system with a decentralized blockchain architecture, Purechain. The framework leverages an improved consensus mechanism, the Proof of Authority and Association (PoA2). This is to address key challenges in the current K-ETS, such as centralization, lack of transparency, and high energy consumption. The PoA2 significantly reduces gas usage, with experimental results showing a 22 % reduction in gas consumption compared to traditional Proof of Work (PoW) and Proof of Authority (PoA) mechanisms. Also, PoA2 recorded a ×6 and ×2 reduction in gas price compared to PoW and PoA. The system also achieves faster transaction finality and lower computational costs, with transaction costs reduced by up to 83 % across the key K-ETS activities, including emissions reporting, credit allocation, and trading. Also, the system achieved moderate throughput, high latency, doubling scalability, high reliability, and a high success rate compared with DPoS and PBFT based on transaction stress validation tests. With an improved smart contract, intelligent automation of key functions, the system achieved a high energy gain for improved incentives. The proposed framework not only enhances the scalability and transparency of K-ETS but also aligns with South Korea's carbon neutrality goals by minimizing the environmental impact of blockchain operations. This study provides a solid foundation for sustainable carbon trading systems and an accountable carbon economy, contributing to global efforts to combat climate change in achieving the 2050 net-zero carbon emissions goal.
{"title":"eBCTC: Energy-efficient hybrid blockchain architecture for smart and secured K-ETS","authors":"Ihunanya Udodiri Ajakwe , Victor Ikenna Kanu , Simeon Okechukwu Ajakwe , Dong-Seong Kim","doi":"10.1016/j.clet.2025.101084","DOIUrl":"10.1016/j.clet.2025.101084","url":null,"abstract":"<div><div>The Korean Emission Trading Scheme (K-ETS) is vital for reducing carbon emissions in South Korea. However, issues in transparency, security, and computational overhead limit its effectiveness. This work proposes an energy-efficient blockchain-based framework (eBCTC) to enhance the system with a decentralized blockchain architecture, Purechain. The framework leverages an improved consensus mechanism, the Proof of Authority and Association (PoA<sup>2</sup>). This is to address key challenges in the current K-ETS, such as centralization, lack of transparency, and high energy consumption. The PoA<sup>2</sup> significantly reduces gas usage, with experimental results showing a 22 % reduction in gas consumption compared to traditional Proof of Work (PoW) and Proof of Authority (PoA) mechanisms. Also, PoA<sup>2</sup> recorded a ×6 and ×2 reduction in gas price compared to PoW and PoA. The system also achieves faster transaction finality and lower computational costs, with transaction costs reduced by up to 83 % across the key K-ETS activities, including emissions reporting, credit allocation, and trading. Also, the system achieved moderate throughput, high latency, doubling scalability, high reliability, and a high success rate compared with DPoS and PBFT based on transaction stress validation tests. With an improved smart contract, intelligent automation of key functions, the system achieved a high energy gain for improved incentives. The proposed framework not only enhances the scalability and transparency of K-ETS but also aligns with South Korea's carbon neutrality goals by minimizing the environmental impact of blockchain operations. This study provides a solid foundation for sustainable carbon trading systems and an accountable carbon economy, contributing to global efforts to combat climate change in achieving the 2050 net-zero carbon emissions goal.</div></div>","PeriodicalId":34618,"journal":{"name":"Cleaner Engineering and Technology","volume":"29 ","pages":"Article 101084"},"PeriodicalIF":6.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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