Renewable Energy最新文献

英文中文

Preparation and optimization of highly active Co3O4 catalyst for hydrogen generation from NaBH4 hydrolysis

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-20 DOI: 10.1016/j.renene.2025.122943

Qiaochu Zhou, Yiyang Wang, Zhe Zhang, Chi Zhang, Fang Li, Qiming Li

The oxidation state and phase structure of oxide catalysts play a crucial role in NaBH₄ hydrolysis. In this study, diverse Co₃O₄ catalysts were synthesized via the EDTA-citric acid complexing method and employed for hydrogen production from NaBH₄ hydrolysis. The impacts of different calcination temperatures on crystalline structure, microstructure, and catalytic performance of Co₃O₄ catalysts were examined systematically. It was observed that the calcination temperature cannot affect the crystal structure of Co₃O₄ catalysts, but it significantly influences their crystallinity, induction period and catalytic performance. The bulk crystallization of Co₃O₄ remained unaltered after reduction by NaBH₄, while its surface layer would transform into an amorphous phase, forming a core-shell structure. Moreover, the ratio of Co²⁺/Co³⁺ on the surface of the Co₃O₄ catalyst is substantially enhanced and more oxygen defects can be obtained through an in-situ reduction. The experimental results demonstrated that all Co₃O₄ catalysts exhibit an induction period before attaining a higher hydrogen generation rate. And the intrinsic catalytic activity of Co₃O₄ catalysts initially increases and then declines with the ascending calcination temperature, whereas their cyclic stability monotonically increases with calcination temperature. The Co₃O₄ catalyst achieves its highest catalytic activity at 1000 °C and the maximum cyclic stability at 1100 °C.

{"title":"Preparation and optimization of highly active Co3O4 catalyst for hydrogen generation from NaBH4 hydrolysis","authors":"Qiaochu Zhou, Yiyang Wang, Zhe Zhang, Chi Zhang, Fang Li, Qiming Li","doi":"10.1016/j.renene.2025.122943","DOIUrl":"10.1016/j.renene.2025.122943","url":null,"abstract":"<div><div>The oxidation state and phase structure of oxide catalysts play a crucial role in NaBH<sub>4</sub> hydrolysis. In this study, diverse Co<sub>3</sub>O<sub>4</sub> catalysts were synthesized via the EDTA-citric acid complexing method and employed for hydrogen production from NaBH<sub>4</sub> hydrolysis. The impacts of different calcination temperatures on crystalline structure, microstructure, and catalytic performance of Co<sub>3</sub>O<sub>4</sub> catalysts were examined systematically. It was observed that the calcination temperature cannot affect the crystal structure of Co<sub>3</sub>O<sub>4</sub> catalysts, but it significantly influences their crystallinity, induction period and catalytic performance. The bulk crystallization of Co<sub>3</sub>O<sub>4</sub> remained unaltered after reduction by NaBH<sub>4</sub>, while its surface layer would transform into an amorphous phase, forming a core-shell structure. Moreover, the ratio of Co<sup>2+</sup>/Co<sup>3+</sup> on the surface of the Co<sub>3</sub>O<sub>4</sub> catalyst is substantially enhanced and more oxygen defects can be obtained through an <em>in-situ</em> reduction. The experimental results demonstrated that all Co<sub>3</sub>O<sub>4</sub> catalysts exhibit an induction period before attaining a higher hydrogen generation rate. And the intrinsic catalytic activity of Co<sub>3</sub>O<sub>4</sub> catalysts initially increases and then declines with the ascending calcination temperature, whereas their cyclic stability monotonically increases with calcination temperature. The Co<sub>3</sub>O<sub>4</sub> catalyst achieves its highest catalytic activity at 1000 °C and the maximum cyclic stability at 1100 °C.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122943"},"PeriodicalIF":9.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the combustion and emission characteristics of a compression ignition engine using diesel/ethanol blend with carbon nanoadditives

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-20 DOI: 10.1016/j.renene.2025.122941

Jinyang Li , Jiangjun Wei , Hao Chen , Yao Xu , Ye Liu , Qian Dai

This article focuses on the effects of adding different types (graphene oxides, multi-layered graphene oxides, multi-walled carbon nanotubes) and dosages (25 ppm, 100 ppm) of renewable carbon nanoparticles to the diesel/ethanol blend towards the combustion and emission characteristics of a compression-ignition engine. The research showed that a shortened ignition delay was brought about due to the presence of carbon nanoparticles, with the most pronounced effect achieved by multi-walled carbon nanotubes. Regarding in-cylinder combustion, the inclusion of carbon nanoparticles induced an enhancement to the combustion progress, associated with increments in peak cylinder gas pressure and peak heat release rate and a decrement in combustion duration, most notably accomplished by graphene oxides. Moreover, the engine exhibits lower fuel consumption and better fuel utilization based on the carbon nanoparticles addition, where the nano-fuels with graphene oxides possess the minimum brake specific fuel consumption and maximum brake thermal efficiency. Concerning the abatement effect, by applying carbon nanoparticles, emissions of CO, HC and soot were decreased by 37.95 %, 45.18 % and 47.83 %, respectively, however, a slight increase in NOx emissions also occurred. In particular, multi-walled carbon nanotubes offered the most significant mitigations in CO and HC, while graphene oxides achieved the greatest abatement in soot emissions.

{"title":"Study on the combustion and emission characteristics of a compression ignition engine using diesel/ethanol blend with carbon nanoadditives","authors":"Jinyang Li , Jiangjun Wei , Hao Chen , Yao Xu , Ye Liu , Qian Dai","doi":"10.1016/j.renene.2025.122941","DOIUrl":"10.1016/j.renene.2025.122941","url":null,"abstract":"<div><div>This article focuses on the effects of adding different types (graphene oxides, multi-layered graphene oxides, multi-walled carbon nanotubes) and dosages (25 ppm, 100 ppm) of renewable carbon nanoparticles to the diesel/ethanol blend towards the combustion and emission characteristics of a compression-ignition engine. The research showed that a shortened ignition delay was brought about due to the presence of carbon nanoparticles, with the most pronounced effect achieved by multi-walled carbon nanotubes. Regarding in-cylinder combustion, the inclusion of carbon nanoparticles induced an enhancement to the combustion progress, associated with increments in peak cylinder gas pressure and peak heat release rate and a decrement in combustion duration, most notably accomplished by graphene oxides. Moreover, the engine exhibits lower fuel consumption and better fuel utilization based on the carbon nanoparticles addition, where the nano-fuels with graphene oxides possess the minimum brake specific fuel consumption and maximum brake thermal efficiency. Concerning the abatement effect, by applying carbon nanoparticles, emissions of CO, HC and soot were decreased by 37.95 %, 45.18 % and 47.83 %, respectively, however, a slight increase in NOx emissions also occurred. In particular, multi-walled carbon nanotubes offered the most significant mitigations in CO and HC, while graphene oxides achieved the greatest abatement in soot emissions.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122941"},"PeriodicalIF":9.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Adaptive optimization of wave energy conversion in oscillatory wave surge converters via SPH simulation and deep reinforcement learning

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-20 DOI: 10.1016/j.renene.2025.122887

Mai Ye , Chi Zhang , Yaru Ren , Ziyuan Liu , Oskar J. Haidn , Xiangyu Hu

The nonlinear damping characteristics of the oscillating wave surge converter (OWSC) significantly impact the performance of the power take-off system. This study presents a framework by integrating deep reinforcement learning (DRL) with numerical simulations of OWSC to identify optimal adaptive damping policy under varying wave conditions, thereby enhancing wave energy harvesting efficiency. The open-source multiphysics library SPHinXsys establishes the numerical environment for wave interaction with OWSCs. Subsequently, a comparative analysis of three DRL algorithms is conducted using the two-dimensional (2D) numerical study of OWSC interacting with regular waves. The results reveal that artificial neural networks capture the nonlinear characteristics of wave–structure interactions and provide efficient PTO policies. Notably, the soft actor–critic algorithm demonstrates exceptional robustness and accuracy, achieving a 10.61% improvement in wave energy harvesting. Furthermore, policies trained in a 2D environment are successfully applied to the three-dimensional study, with an improvement of 22.54% in energy harvesting. The optimization effect becomes more significant with longer wave periods under regular waves with consistent wave height. Additionally, the study shows that energy harvesting is improved by 6.42% for complex irregular waves. However, for the complex dual OWSC system, optimizing the damping characteristics alone is insufficient to enhance energy harvesting.

{"title":"Adaptive optimization of wave energy conversion in oscillatory wave surge converters via SPH simulation and deep reinforcement learning","authors":"Mai Ye , Chi Zhang , Yaru Ren , Ziyuan Liu , Oskar J. Haidn , Xiangyu Hu","doi":"10.1016/j.renene.2025.122887","DOIUrl":"10.1016/j.renene.2025.122887","url":null,"abstract":"<div><div>The nonlinear damping characteristics of the oscillating wave surge converter (OWSC) significantly impact the performance of the power take-off system. This study presents a framework by integrating deep reinforcement learning (DRL) with numerical simulations of OWSC to identify optimal adaptive damping policy under varying wave conditions, thereby enhancing wave energy harvesting efficiency. The open-source multiphysics library SPHinXsys establishes the numerical environment for wave interaction with OWSCs. Subsequently, a comparative analysis of three DRL algorithms is conducted using the two-dimensional (2D) numerical study of OWSC interacting with regular waves. The results reveal that artificial neural networks capture the nonlinear characteristics of wave–structure interactions and provide efficient PTO policies. Notably, the soft actor–critic algorithm demonstrates exceptional robustness and accuracy, achieving a 10.61% improvement in wave energy harvesting. Furthermore, policies trained in a 2D environment are successfully applied to the three-dimensional study, with an improvement of 22.54% in energy harvesting. The optimization effect becomes more significant with longer wave periods under regular waves with consistent wave height. Additionally, the study shows that energy harvesting is improved by 6.42% for complex irregular waves. However, for the complex dual OWSC system, optimizing the damping characteristics alone is insufficient to enhance energy harvesting.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122887"},"PeriodicalIF":9.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A hybrid-driven control strategy for optimized wind farm power dispatch

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-20 DOI: 10.1016/j.renene.2025.122940

Luobin Wang , Sheng Huang , Guan Bai , Pengda Wang , Ji Zhang

This paper proposes a hybrid-driven active power control strategy for large-scale wind farm (WF) that integrates data-driven and model-driven approaches to optimize power dispatch while reducing fatigue loads and enhancing noise resistance. The strategy employs an encoder-decoder framework in which the encoder, based on a Mixture of Experts (MoE) and Bidirectional Gated Recurrent Unit (BiGRU), captures temporal dependencies from WF time series data, and the decoder, using Graph Attention Networks (GAT), models wind turbine (WT) coupling without explicit mathematical formulations. A Deep Neural Network (DNN) adaptively fuses outputs from the data-driven and Model Predictive Control (MPC)-based strategies, delivering the best overall performance. MATLAB simulations on a WF with 32 × 5 MW WTs show that the proposed method reduces the standard deviation (SD) of shaft torque and thrust force by 21.59 % and 25.64 %, respectively, demonstrating the significant improvements of the proposed method in fatigue load reduction.

引用次数: 0

Solar energy-powered wireless charging system for three-wheeled e-scooter applications

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-19 DOI: 10.1016/j.renene.2025.122933

Mehmet Zahid Erel , Mehmet Akif Özdemir , Mehmet Timur Aydemir

Wireless power transfer (WPT) is a remarkable charging technology that addresses the range limitations and complexity of light electric vehicles. This study presents a novel approach to a solar-powered WPT system designed for three-wheeled e-scooter applications. The proposed system offers compact, lightweight, and cost-effective solution with a ferrite-less structure and a series-series (SS) compensation topology, resulting in enhanced system efficiency and adaptability. The compact and efficient converters are designed to enhance performance and reduce system size. A Proportional-Integral (PI) controlled Perturb and Observe (P&O) maximum power point tracking (MPPT) method is implemented to optimize energy extraction from three solar panels. The design is validated through comprehensive simulations and demonstrates a superior dynamic response over the Incremental Conductance MPPT (ICM) method. Performance tests confirm the reliability of the experimental prototype, achieving a system efficiency of 88.5 % at 300-W output power over a 100 mm transfer distance under fully aligned condition. Comparative analyses with existing solar-powered e-cycle systems highlight the proposed design's superiority in efficiency, cost-effectiveness, and adherence to safety standards. The results indicate that the proposed design enhances sustainable urban transportation by reducing carbon emissions and decreasing reliance on fossil fuels, facilitating the wider integration of renewable energy sources.

{"title":"Solar energy-powered wireless charging system for three-wheeled e-scooter applications","authors":"Mehmet Zahid Erel , Mehmet Akif Özdemir , Mehmet Timur Aydemir","doi":"10.1016/j.renene.2025.122933","DOIUrl":"10.1016/j.renene.2025.122933","url":null,"abstract":"<div><div>Wireless power transfer (WPT) is a remarkable charging technology that addresses the range limitations and complexity of light electric vehicles. This study presents a novel approach to a solar-powered WPT system designed for three-wheeled e-scooter applications. The proposed system offers compact, lightweight, and cost-effective solution with a ferrite-less structure and a series-series (SS) compensation topology, resulting in enhanced system efficiency and adaptability. The compact and efficient converters are designed to enhance performance and reduce system size. A Proportional-Integral (PI) controlled Perturb and Observe (P&O) maximum power point tracking (MPPT) method is implemented to optimize energy extraction from three solar panels. The design is validated through comprehensive simulations and demonstrates a superior dynamic response over the Incremental Conductance MPPT (ICM) method. Performance tests confirm the reliability of the experimental prototype, achieving a system efficiency of 88.5 % at 300-W output power over a 100 mm transfer distance under fully aligned condition. Comparative analyses with existing solar-powered e-cycle systems highlight the proposed design's superiority in efficiency, cost-effectiveness, and adherence to safety standards. The results indicate that the proposed design enhances sustainable urban transportation by reducing carbon emissions and decreasing reliance on fossil fuels, facilitating the wider integration of renewable energy sources.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122933"},"PeriodicalIF":9.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High proportion of biofuel replacement for conventional diesel using safflower biodiesel and diethyl ether blends in a CNG-powered RCCI operation of a diesel engine

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-19 DOI: 10.1016/j.renene.2025.122919

Ali İhsan Ülgen , Yahya Çelebi , Hüseyin Aydın

Reactivity-controlled compression ignition operation was used for this experimental work. In the study, biodiesel derived from safflower was blended with diethyl ether at concentrations of 5 %, 10 %, and 15 % and utilized as the primary fuel while compressed natural gas was used as the low-reactivity fuel, injected inside the intake manifold with a substitution rate of 50 %. The study focused on the influence of high-percentage biofuel on compressed natural gas-powered reactivity-controlled compression ignition operation. The engine was held under the same engine speed of 1500 rpm and the engine load of 7.2 kW. The test results obtained from the experiments showed an increase in brake thermal efficiency, brake specific fuel consumption, and brake specific energy consumption, while exhaust gas temperature was decreased. There was an average reduction of 61.36 % and 20.7 % in nitrogen oxides and carbon dioxide, respectively. On contrary, a remarkable increase was observed in carbon oxide by 22.9 % and hydrocarbons emissions by 33.1 % on average compared to petrodiesel with exception for the blend of biodiesel with high content of diethyl ether which showed a significant reduction of 83.3 % on hydrocarbons. The combustion parameters for alternate fuel modes quite similar to diesel fuel combustion.

{"title":"High proportion of biofuel replacement for conventional diesel using safflower biodiesel and diethyl ether blends in a CNG-powered RCCI operation of a diesel engine","authors":"Ali İhsan Ülgen , Yahya Çelebi , Hüseyin Aydın","doi":"10.1016/j.renene.2025.122919","DOIUrl":"10.1016/j.renene.2025.122919","url":null,"abstract":"<div><div>Reactivity-controlled compression ignition operation was used for this experimental work. In the study, biodiesel derived from safflower was blended with diethyl ether at concentrations of 5 %, 10 %, and 15 % and utilized as the primary fuel while compressed natural gas was used as the low-reactivity fuel, injected inside the intake manifold with a substitution rate of 50 %. The study focused on the influence of high-percentage biofuel on compressed natural gas-powered reactivity-controlled compression ignition operation. The engine was held under the same engine speed of 1500 rpm and the engine load of 7.2 kW. The test results obtained from the experiments showed an increase in brake thermal efficiency, brake specific fuel consumption, and brake specific energy consumption, while exhaust gas temperature was decreased. There was an average reduction of 61.36 % and 20.7 % in nitrogen oxides and carbon dioxide, respectively. On contrary, a remarkable increase was observed in carbon oxide by 22.9 % and hydrocarbons emissions by 33.1 % on average compared to petrodiesel with exception for the blend of biodiesel with high content of diethyl ether which showed a significant reduction of 83.3 % on hydrocarbons. The combustion parameters for alternate fuel modes quite similar to diesel fuel combustion.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122919"},"PeriodicalIF":9.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study on high-precision detection technology for the freezing front height in brine on a horizontal cold plate surface in cold regions

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-19 DOI: 10.1016/j.renene.2025.122928

Han Shi , Mengjie Song , Fumio Narita , Seyyed Hossein Hosseini , Long Zhang , Christopher Yu Hang Chao

The formation of ice on wind turbines blades or ship's hull is one of the main problems that energy and transport companies have in cold climates. To ascertain the thickness of brine ice on a horizontal low-temperature cold plate surface, an experimental system based on a capacitively coupled split-ring resonator for detecting the average height of the freezing front in brine has been devised. A static and dynamic freezing front with a 3.5 % salinity and varying heights was prepared and tested at a temperature of −20 °C. The resonant amplitude of the transmission scattering parameter for the resonator exhibited an increase from −19.9 dB to −5.0 dB as the height of the static freezing front increased from 3.2 mm to 21.5 mm. The resonant amplitude demonstrates a monotonic increase with an average sensitivity of 0.51 dB/mm and 4.584 dB/mm as the height of the dynamic freezing front increases within the range of 0–9.5 mm and 9.5–10.5 mm, respectively. The sensor displays an excellent accuracy of 87.8 % in detecting the height of saltwater freezing front in the range of 0–21.5 mm. This method represents a reference in ice detection technology and an effective solution to reduce energy loss due to icing.

{"title":"Experimental study on high-precision detection technology for the freezing front height in brine on a horizontal cold plate surface in cold regions","authors":"Han Shi , Mengjie Song , Fumio Narita , Seyyed Hossein Hosseini , Long Zhang , Christopher Yu Hang Chao","doi":"10.1016/j.renene.2025.122928","DOIUrl":"10.1016/j.renene.2025.122928","url":null,"abstract":"<div><div>The formation of ice on wind turbines blades or ship's hull is one of the main problems that energy and transport companies have in cold climates. To ascertain the thickness of brine ice on a horizontal low-temperature cold plate surface, an experimental system based on a capacitively coupled split-ring resonator for detecting the average height of the freezing front in brine has been devised. A static and dynamic freezing front with a 3.5 % salinity and varying heights was prepared and tested at a temperature of −20 °C. The resonant amplitude of the transmission scattering parameter for the resonator exhibited an increase from −19.9 dB to −5.0 dB as the height of the static freezing front increased from 3.2 mm to 21.5 mm. The resonant amplitude demonstrates a monotonic increase with an average sensitivity of 0.51 dB/mm and 4.584 dB/mm as the height of the dynamic freezing front increases within the range of 0–9.5 mm and 9.5–10.5 mm, respectively. The sensor displays an excellent accuracy of 87.8 % in detecting the height of saltwater freezing front in the range of 0–21.5 mm. This method represents a reference in ice detection technology and an effective solution to reduce energy loss due to icing.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122928"},"PeriodicalIF":9.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of copper stearate on the premixed combustion and emission performance of jatropha biodiesel

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-19 DOI: 10.1016/j.renene.2025.122925

Li Zhou , Fashe Li , Meng Sui , Wenchao Wang , Hua Wang

Metal-organic complexes can significantly improve the combustion efficiency of fuels and reduce harmful emissions. In this study, the pyrolysis, oxidation, and combustion characteristics of Jatropha biodiesel containing 200 ppm copper stearate were systematically investigated using thermogravimetry-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS), spectral analysis, flue gas analysis, high-resolution transmission electron microscopy (HRTEM), and ReaxFF-MD simulations. The results revealed that with the addition of copper stearate, the activation energy (E_a) for pyrolysis and oxidation reactions decreased by 8.04 and 9.40 kJ/mol, respectively. This promoted the generation of C₂ and CH free radicals and increased the OH intensity at the left and middle axial positions of the flame by 66.11 % and 69.56 %, respectively. In addition, the CO, PM2.5, and PM > 10 emissions decreased by 4.0 %, 7.5 %, and 13.2 %, respectively. Further, the average size of soot particles decreased by 3.2 %, and the spacing between polycyclic aromatic hydrocarbons (PAHs) layers increased by 7.2 %. However, the NOx emissions increased by 7.8 %. These findings indicate that copper stearate significantly improves the combustion efficiency of Jatropha biodiesel and reduces the emission of various pollutants, though its impact on NOx emissions should also be considered. Overall, this study provides useful theoretical insights for optimizing biodiesel combustion performance and pollutant control.

{"title":"Effects of copper stearate on the premixed combustion and emission performance of jatropha biodiesel","authors":"Li Zhou , Fashe Li , Meng Sui , Wenchao Wang , Hua Wang","doi":"10.1016/j.renene.2025.122925","DOIUrl":"10.1016/j.renene.2025.122925","url":null,"abstract":"<div><div>Metal-organic complexes can significantly improve the combustion efficiency of fuels and reduce harmful emissions. In this study, the pyrolysis, oxidation, and combustion characteristics of Jatropha biodiesel containing 200 ppm copper stearate were systematically investigated using thermogravimetry-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS), spectral analysis, flue gas analysis, high-resolution transmission electron microscopy (HRTEM), and ReaxFF-MD simulations. The results revealed that with the addition of copper stearate, the activation energy (<em>E</em><sub><em>a</em></sub>) for pyrolysis and oxidation reactions decreased by 8.04 and 9.40 kJ/mol, respectively. This promoted the generation of C<sub>2</sub> and CH free radicals and increased the OH intensity at the left and middle axial positions of the flame by 66.11 % and 69.56 %, respectively. In addition, the CO, PM2.5, and PM > 10 emissions decreased by 4.0 %, 7.5 %, and 13.2 %, respectively. Further, the average size of soot particles decreased by 3.2 %, and the spacing between polycyclic aromatic hydrocarbons (PAHs) layers increased by 7.2 %. However, the NOx emissions increased by 7.8 %. These findings indicate that copper stearate significantly improves the combustion efficiency of Jatropha biodiesel and reduces the emission of various pollutants, though its impact on NOx emissions should also be considered. Overall, this study provides useful theoretical insights for optimizing biodiesel combustion performance and pollutant control.</div></div>","PeriodicalId":419,"journal":{"name":"Renewable Energy","volume":"246 ","pages":"Article 122925"},"PeriodicalIF":9.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A holistic approach for harnessing multifarious pretreatment techniques and transesterification process optimization of Coelastrella biomass for biodiesel via central composite design

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-19 DOI: 10.1016/j.renene.2025.122936

Peng Yin , Cong Thanh Nguyen

A cost-effective and energy-efficient pretreatment method and solvent system is imperative for economically viable lipid extraction from microalgae. Additionally, optimizing the transesterification process to select optimal parameters that aid in enhanced biodiesel production is also a crucial obstacle. Therefore, the present study compares and optimizes several lipid extraction methods and solvents based on their total lipid extraction efficiency from the test culture Coelastrella sp. using a central composite design (CCD). Further, optimization of acid-catalyzed transesterification parameters was also investigated using CCD, and the produced biodiesel was analyzed for fatty acid composition. Among the methods and solvents, the Soxhlet method and Chloroform: Methanol (2:1) solvent system showed higher lipid recovery at about 24.55 % over other pretreatment methods and solvents studied. CCD optimization reveals that the optimal variables for high lipid recovery are 50 rpm stirring speed, 45 mL chloroform: methanol solvent volume, 80 °C temperature, and 150 min reaction time. Further, the relative abundance of neutral lipids, phospholipids, and glycolipids in the total lipids of the Coelastrella sp. are estimated to be 56.47, 19.42, and 24.10 %, respectively. Acid-catalyzed transesterification process optimization by CCD reveals 120 min reaction time, 80 °C temperature, 11 mL methanol, and 5 % HCl concentration are optimal factors for achieving higher biodiesel yield at about 69 %. Eventually, the fatty acid compositional analysis showed C16:0 and C18:1 as vital fatty acids in the biodiesel at about 20 % and 14.56 %, respectively.

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引用次数: 0

Effect of spacing ratio on FIV response of multiple cylindrical oscillators supported by maglev

IF 9 1区工程技术 Q1 ENERGY & FUELS

Renewable Energy

Pub Date : 2025-03-19 DOI: 10.1016/j.renene.2025.122918

Xu Bai , Wen Zhang , Jialu Wang , Zhenbang Yang

Utilizing flow-induced vibrations for low-velocity ocean current energy generation is effective. Replacing metal springs with magnetic levitation systems to support the oscillators offers advantages such as easy stiffness adjustment and better underwater maintenance. This makes it significant for flow-induced ocean current energy harvesting. A multi-oscillator design can further enhance energy output capacity, but the mutual interference between oscillators results in vibration responses that differ significantly from those of a single oscillator. This paper employs the RANS method and equivalent magnetic charge methods to develop a coupled model of FIV of rigid cylindrical oscillators supported by magnetic levitation. Numerical simulations analyze the effect of spacing ratio on oscillation amplitude ratio, vibration frequency, and vortex shedding patterns. The results show that in double tandem cylindrical oscillators with identical diameters supported by magnetic levitation, the spacing ratio significantly affects the vibration response of the upstream and downstream oscillators. Under the characteristics of the magnetic spring, the interference between upstream and downstream oscillators is stronger with a small spacing ratio, leading to peak amplitude ratios even at moderate to low flow velocities. When G/D = 2 and U = 0.5 m/s, the downstream oscillator reaches a maximum amplitude ratio of A* = 1.06, 2.26 times that of a single oscillator at the same flow velocity. In three tandem cylindrical oscillators with identical diameters supported by magnetic levitation, the vibration response fluctuates more than in the two-oscillator case, exhibiting distinct three-stage branching characteristics. With G₁/D = 2 fixed, when G₂/D = 2 and U = 0.6 m/s, the downstream oscillator reaches a maximum amplitude ratio of A* = 1.2, 2.45 times that of a single oscillator at the same flow velocity. Vortex analysis indicates that under appropriate spacing ratios and flow conditions, the interference among multiple oscillators is amplified, enabling the downstream oscillators to better absorb and utilize the coherent vortices from the upstream oscillators, thus optimizing the vibration response.

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