The Experts below are selected from a list of 8907 Experts worldwide ranked by ideXlab platform
Yiwu Weng - One of the best experts on this subject based on the ideXlab platform.
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effect of operating parameters on performance and safety evaluation of a biogas fueled sofc gt hybrid system
Energy Procedia, 2019Co-Authors: Xiaoyi Ding, Xiaojing Lv, Yiwu WengAbstract:Abstract In this work, a detailed model of solid oxide fuel cell (SOFC)/micro gas turbine (GT) hybrid system with a Recirculation process is established on MATLAB/Simulink platform. A typical farm biogas is chosen as fuel for the hybrid system, and the coupling effects of Recirculation Ratio, steam/carbon (S/C) Ratio and fuel/air Ratio on the operating performances and safety characteristics of the hybrid system and components (such as fuel cell, reformer and gas turbine) are carefully studied. Among the calculated results, the Recirculation Ratio of 0.4, the S/C Ratio of 2.5 and the fuel/air Ratio of 0.13 are selected as appropriate parameters for opeRation, in this case the total output work of hybrid system is 177 kW, and electrical efficiency could reach 59.4%. Results show that under properly selected opeRation parameters, the biogas-fueled hybrid system has good performance characteristics with both high efficiency and enough safety range.
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Coupling Effect of Operating Parameters on Performance of a Biogas-fueled Solid Oxide Fuel Cell/Gas Turbine Hybrid System
Applied Energy, 2019Co-Authors: Xiaoyi Ding, Yiwu WengAbstract:Abstract The correlation between effectiveness of multiple operating parameters is a complicated issue and significant to the safe opeRation of solid oxide fuel cell/gas turbine (SOFC/GT) hybrid system. This paper presents a numerical analysis on biogas-fueled SOFC/GT hybrid system with a Recirculation process using combustor exhaust gas. With consideRation of safety constraints for critical components (fuel cell thermal crack, reformer carbon deposition, turbine blade overheat), the interaction mechanism of Recirculation Ratio, steam/carbon Ratio and fuel/air Ratio is studied from the perspective of thermodynamic analysis. Results show that the Recirculation process could increase the electrical efficiency of system from 58.18% to 62.8%. However, for the safety consideRation of SOFC, the acceptable Recirculation Ratio should be controlled between 0.17 and 0.32. Meanwhile, there exists a minimum point of turbine inlet temperature at the Recirculation Ratio of 0.3. With Recirculation Ratio switched from 0.1 to 0.3, impact of steam/carbon Ratio variation on SOFC temperature gradient shrinks from 52.5% to 17.9% of the reference value. On the other hand, effect of fuel/air Ratio variation on SOFC temperature gradient is promoted from 20.8% to 44.3% of the reference value, due to that oxidation reaction of biogas becomes a dominant factor. Based on these results, a parametric comparison is carried out to quantitatively describe the impact of Recirculation process on the effectiveness of other parameters. Short discussion is conducted on parameter selection to acquire higher system efficiency and sufficient safety range, in which case the total output power of 176.8 kW and electrical efficiency of 61.78% could be achieved.
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Effect of Operating Parameters on Performance and Safety Evaluation of a Biogas-fueled SOFC/GT Hybrid System
Energy Procedia, 2019Co-Authors: Xiaoyi Ding, Yiwu WengAbstract:Abstract In this work, a detailed model of solid oxide fuel cell (SOFC)/micro gas turbine (GT) hybrid system with a Recirculation process is established on MATLAB/Simulink platform. A typical farm biogas is chosen as fuel for the hybrid system, and the coupling effects of Recirculation Ratio, steam/carbon (S/C) Ratio and fuel/air Ratio on the operating performances and safety characteristics of the hybrid system and components (such as fuel cell, reformer and gas turbine) are carefully studied. Among the calculated results, the Recirculation Ratio of 0.4, the S/C Ratio of 2.5 and the fuel/air Ratio of 0.13 are selected as appropriate parameters for opeRation, in this case the total output work of hybrid system is 177 kW, and electrical efficiency could reach 59.4%. Results show that under properly selected opeRation parameters, the biogas-fueled hybrid system has good performance characteristics with both high efficiency and enough safety range.
Xiaoyi Ding - One of the best experts on this subject based on the ideXlab platform.
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effect of operating parameters on performance and safety evaluation of a biogas fueled sofc gt hybrid system
Energy Procedia, 2019Co-Authors: Xiaoyi Ding, Xiaojing Lv, Yiwu WengAbstract:Abstract In this work, a detailed model of solid oxide fuel cell (SOFC)/micro gas turbine (GT) hybrid system with a Recirculation process is established on MATLAB/Simulink platform. A typical farm biogas is chosen as fuel for the hybrid system, and the coupling effects of Recirculation Ratio, steam/carbon (S/C) Ratio and fuel/air Ratio on the operating performances and safety characteristics of the hybrid system and components (such as fuel cell, reformer and gas turbine) are carefully studied. Among the calculated results, the Recirculation Ratio of 0.4, the S/C Ratio of 2.5 and the fuel/air Ratio of 0.13 are selected as appropriate parameters for opeRation, in this case the total output work of hybrid system is 177 kW, and electrical efficiency could reach 59.4%. Results show that under properly selected opeRation parameters, the biogas-fueled hybrid system has good performance characteristics with both high efficiency and enough safety range.
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Coupling Effect of Operating Parameters on Performance of a Biogas-fueled Solid Oxide Fuel Cell/Gas Turbine Hybrid System
Applied Energy, 2019Co-Authors: Xiaoyi Ding, Yiwu WengAbstract:Abstract The correlation between effectiveness of multiple operating parameters is a complicated issue and significant to the safe opeRation of solid oxide fuel cell/gas turbine (SOFC/GT) hybrid system. This paper presents a numerical analysis on biogas-fueled SOFC/GT hybrid system with a Recirculation process using combustor exhaust gas. With consideRation of safety constraints for critical components (fuel cell thermal crack, reformer carbon deposition, turbine blade overheat), the interaction mechanism of Recirculation Ratio, steam/carbon Ratio and fuel/air Ratio is studied from the perspective of thermodynamic analysis. Results show that the Recirculation process could increase the electrical efficiency of system from 58.18% to 62.8%. However, for the safety consideRation of SOFC, the acceptable Recirculation Ratio should be controlled between 0.17 and 0.32. Meanwhile, there exists a minimum point of turbine inlet temperature at the Recirculation Ratio of 0.3. With Recirculation Ratio switched from 0.1 to 0.3, impact of steam/carbon Ratio variation on SOFC temperature gradient shrinks from 52.5% to 17.9% of the reference value. On the other hand, effect of fuel/air Ratio variation on SOFC temperature gradient is promoted from 20.8% to 44.3% of the reference value, due to that oxidation reaction of biogas becomes a dominant factor. Based on these results, a parametric comparison is carried out to quantitatively describe the impact of Recirculation process on the effectiveness of other parameters. Short discussion is conducted on parameter selection to acquire higher system efficiency and sufficient safety range, in which case the total output power of 176.8 kW and electrical efficiency of 61.78% could be achieved.
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Effect of Operating Parameters on Performance and Safety Evaluation of a Biogas-fueled SOFC/GT Hybrid System
Energy Procedia, 2019Co-Authors: Xiaoyi Ding, Yiwu WengAbstract:Abstract In this work, a detailed model of solid oxide fuel cell (SOFC)/micro gas turbine (GT) hybrid system with a Recirculation process is established on MATLAB/Simulink platform. A typical farm biogas is chosen as fuel for the hybrid system, and the coupling effects of Recirculation Ratio, steam/carbon (S/C) Ratio and fuel/air Ratio on the operating performances and safety characteristics of the hybrid system and components (such as fuel cell, reformer and gas turbine) are carefully studied. Among the calculated results, the Recirculation Ratio of 0.4, the S/C Ratio of 2.5 and the fuel/air Ratio of 0.13 are selected as appropriate parameters for opeRation, in this case the total output work of hybrid system is 177 kW, and electrical efficiency could reach 59.4%. Results show that under properly selected opeRation parameters, the biogas-fueled hybrid system has good performance characteristics with both high efficiency and enough safety range.
Qi Zhou - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous carbon and nitrogen removal from anaerobic effluent of the cassava ethanol industry.
Journal of bioscience and bioengineering, 2017Co-Authors: Zhixuan Yin, Li Xie, Qi ZhouAbstract:This study investigated the simultaneous carbon and nitrogen removal from anaerobic effluent of cassava stillage using a lab-scale integrated system consisting of an upflow anaerobic sludge blanket (UASB) reactor and an activated sludge (AS) process. Simultaneous denitrification and methanogenesis (SDM) was observed in the UASB with nitrate Recirculation. Compared with the blank reactor without Recirculation, the overall chemical oxygen demand (COD) removal efficiencies in the combined system with nitrate Recirculation were similar (80–90%), while the TN removal efficiencies were significantly improved from 4.7% to 71.0%. Additionally, the anaerobic COD removal efficiencies increased from 21% to 40% as the Recirculation Ratio decreased from 3 to 1. Although the influent nitrate concentRations fluctuated (60–140 mg N/L), the nitrate removal efficiencies could be maintained at about 97% under different Recirculation conditions. With the decreasing Recirculation Ratio from 3 to 1, the CH4 content in biogas improved from 2% to 40% while the N2 content reduced from 95.8% to 50.6%. The 16S rDNA sequencing results indicated that bacteria diversity in anaerobic SDM granular sludge was much higher than archaea. The effect of Recirculation Ratios on the bacterial and archaeal communities in SDM granular sludge could be further confirmed by the relative abundance of denitrifying bacteria.
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Effective carbon and nitrogen removal with reduced sulfur oxidation in an anaerobic baffled reactor for fresh leachate treatment.
Journal of bioscience and bioengineering, 2016Co-Authors: Zhixuan Yin, Li Xie, Cui Xinwei, Qi ZhouAbstract:The application of an anaerobic baffled reactor (ABR) with four compartments was investigated for the simultaneous removal of carbon and nitrogen from leachate. The nitrified effluent was recycled to compartment 3 of the ABR, thereby avoiding the adverse influence of nitrogen oxides on anaerobic methanogenesis in compartment 1. Nitrified effluent Recirculation not only enhanced chemical oxygen demand removal (>95.6%) but also improved the total nitrogen removal efficiency from 12.7% to 67.4% with increasing Recirculation Ratio from 0.25 to 2. The challenge of insufficient carbon sources for heterotrophic denitrification in compartment 3 with a high Recirculation Ratio could be overcome by step feeding of leachate. Moreover, various reduced sulfurs (e.g., sulfide, elemental sulfur, and organic sulfur) were involved in nitrate reduction via sulfur-based autotrophic denitrification. The addition of sulfide to compartment 3 further confirmed nitrate reduction using reduced sulfur as an electron donor. The interaction of organic carbon, reduced sulfur, and nitrate in leachate treatment needs further study.
Aijie Wang - One of the best experts on this subject based on the ideXlab platform.
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Recirculation Ratio regulates denitrifying sulfide removal and elemental sulfur recovery by altering sludge characteristics and microbial community composition in an egsb reactor
Environmental Research, 2020Co-Authors: Fan Chen, Cong Huang, Bin Liang, Ye Yuan, Xiaoqiu Lin, Xiangyu Gao, Aijie WangAbstract:Abstract Expanded granular sludge blanket (EGSB) is regarded as a promising reactor to carry out denitrifying sulfide removal (DSR) and elemental sulfur (S0) recovery. Although the Recirculation Ratio is an essential parameter for EGSB reactors, how it impacts the DSR process remains poorly understood. Here, three lab-scale DSR-EGSB reactors were established with the different Recirculation Ratios (3:1, 6:1 and 9:1) to evaluate the corresponding variations in pollutant removal, S0 recovery, anaerobic granular sludge (AGS) characteristics and microbial community composition. It was found that an intermediate Recirculation Ratio (6:1) could facilitate long-term reactor stability. Adequate Recirculation Ratio could enhance S0 recovery, but an excessive Recirculation Ratio (9:1) was likely to cause AGS fragmentation and biomass loss. The S0 desorbed more from sludge at higher Recirculation Ratios, probably due to the enhanced hydraulic disturbance caused by the increased Recirculation Ratios. At the low Recirculation Ratio (3:1), S0 accumulation as inorganic suspended solids in AGS led to a decrease in VSS/TSS Ratio and mass transfer efficiency. Although typical denitrifying and sulfide-oxidizing bacteria (e.g., Azoarcus, Thauera and Arcobacter) were predominant in all conditions, facultative and heterotrophic functional bacteria (e.g., Azoarcus and Thauera) were more adaptable to higher Recirculation Ratios than autotrophs (e.g., Arcobacter, Thiobacillus and Vulcanibacillus), which was conducive to the formation of bacterial aggregates to response to the increased Recirculation Ratio. The study revealed Recirculation Ratio regulation significantly impacted the DSR-EGSB reactor performance by altering AGS characteristics and microbial community composition, which provides a novel strategy to improve DSR performance and S0 recovery.
Zhixuan Yin - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous carbon and nitrogen removal from anaerobic effluent of the cassava ethanol industry.
Journal of bioscience and bioengineering, 2017Co-Authors: Zhixuan Yin, Li Xie, Qi ZhouAbstract:This study investigated the simultaneous carbon and nitrogen removal from anaerobic effluent of cassava stillage using a lab-scale integrated system consisting of an upflow anaerobic sludge blanket (UASB) reactor and an activated sludge (AS) process. Simultaneous denitrification and methanogenesis (SDM) was observed in the UASB with nitrate Recirculation. Compared with the blank reactor without Recirculation, the overall chemical oxygen demand (COD) removal efficiencies in the combined system with nitrate Recirculation were similar (80–90%), while the TN removal efficiencies were significantly improved from 4.7% to 71.0%. Additionally, the anaerobic COD removal efficiencies increased from 21% to 40% as the Recirculation Ratio decreased from 3 to 1. Although the influent nitrate concentRations fluctuated (60–140 mg N/L), the nitrate removal efficiencies could be maintained at about 97% under different Recirculation conditions. With the decreasing Recirculation Ratio from 3 to 1, the CH4 content in biogas improved from 2% to 40% while the N2 content reduced from 95.8% to 50.6%. The 16S rDNA sequencing results indicated that bacteria diversity in anaerobic SDM granular sludge was much higher than archaea. The effect of Recirculation Ratios on the bacterial and archaeal communities in SDM granular sludge could be further confirmed by the relative abundance of denitrifying bacteria.
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Effective carbon and nitrogen removal with reduced sulfur oxidation in an anaerobic baffled reactor for fresh leachate treatment.
Journal of bioscience and bioengineering, 2016Co-Authors: Zhixuan Yin, Li Xie, Cui Xinwei, Qi ZhouAbstract:The application of an anaerobic baffled reactor (ABR) with four compartments was investigated for the simultaneous removal of carbon and nitrogen from leachate. The nitrified effluent was recycled to compartment 3 of the ABR, thereby avoiding the adverse influence of nitrogen oxides on anaerobic methanogenesis in compartment 1. Nitrified effluent Recirculation not only enhanced chemical oxygen demand removal (>95.6%) but also improved the total nitrogen removal efficiency from 12.7% to 67.4% with increasing Recirculation Ratio from 0.25 to 2. The challenge of insufficient carbon sources for heterotrophic denitrification in compartment 3 with a high Recirculation Ratio could be overcome by step feeding of leachate. Moreover, various reduced sulfurs (e.g., sulfide, elemental sulfur, and organic sulfur) were involved in nitrate reduction via sulfur-based autotrophic denitrification. The addition of sulfide to compartment 3 further confirmed nitrate reduction using reduced sulfur as an electron donor. The interaction of organic carbon, reduced sulfur, and nitrate in leachate treatment needs further study.