Pub Date : 2024-09-14DOI: 10.1016/j.psep.2024.09.031
Although technically challenging, effective, safe, and economical transport is crucial for enabling a widespread rollout of hydrogen technologies. A promising option to transport large amounts of hydrogen lies in employing retrofitted natural gas pipelines. Nevertheless, H2-rich environments tend to degrade pipeline steels, reducing their load-bearing capability and accelerating crack propagation. Regular inspection and maintenance activities can preserve the pipelines’ integrity and guarantee safe operations. The risk-based inspection (RBI) approach is based on estimating the risk for each component item. It focuses most inspection activities on high-risk components to reduce costs while maximizing the plant’s safety and availability. However, the RBI standards do not consider hydrogen-induced degradations and cannot be adopted for industrial equipment operating in H2 environments. This study proposes a novel ad-hoc methodology for the risk-based inspection planning of hydrogen handling equipment. A machine-learning model to predict the fatigue crack growth in gaseous hydrogen environments is developed and integrated with the conventional RBI approach. The proposed methodology is validated on three pipelines transporting hydrogen and natural gas in different concentrations. The results show how similar operating conditions can determine different degradation rates depending on the environment and highlight how hydrogen-enhanced fatigue can reduce the pipelines’ lifetime.
{"title":"Machine learning-aided risk-based inspection strategy for hydrogen technologies","authors":"","doi":"10.1016/j.psep.2024.09.031","DOIUrl":"10.1016/j.psep.2024.09.031","url":null,"abstract":"<div><p>Although technically challenging, effective, safe, and economical transport is crucial for enabling a widespread rollout of hydrogen technologies. A promising option to transport large amounts of hydrogen lies in employing retrofitted natural gas pipelines. Nevertheless, H<sub>2</sub>-rich environments tend to degrade pipeline steels, reducing their load-bearing capability and accelerating crack propagation. Regular inspection and maintenance activities can preserve the pipelines’ integrity and guarantee safe operations. The risk-based inspection (RBI) approach is based on estimating the risk for each component item. It focuses most inspection activities on high-risk components to reduce costs while maximizing the plant’s safety and availability. However, the RBI standards do not consider hydrogen-induced degradations and cannot be adopted for industrial equipment operating in H<sub>2</sub> environments. This study proposes a novel ad-hoc methodology for the risk-based inspection planning of hydrogen handling equipment. A machine-learning model to predict the fatigue crack growth in gaseous hydrogen environments is developed and integrated with the conventional RBI approach. The proposed methodology is validated on three pipelines transporting hydrogen and natural gas in different concentrations. The results show how similar operating conditions can determine different degradation rates depending on the environment and highlight how hydrogen-enhanced fatigue can reduce the pipelines’ lifetime.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S095758202401156X/pdfft?md5=8e25adb3a12f7105fa1c0d47c011df10&pid=1-s2.0-S095758202401156X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1016/j.psep.2024.09.037
Air quality index (AQI) forecasting is complex due to its variability, instability, and inconsistent trends resulting from dynamic atmospheric conditions, various contaminants, and interactions between environmental factors. Advanced modeling techniques are needed to accurately forecast AQI values to capture subtle patterns and variations in air quality data. Thus, a new forecasting model is suggested in this study to improve the accuracy of AQI forecasting. The model integrates three-phase decomposition technique, a feature selection approach, and ensemble Deep Random Vector Functional Link (EDRVFL), optimized using adaptive teaching-learning-based optimization and differential evolution (ATLDE). The AQI series was first broken down into a group of intrinsic mode functions (IMFs) with different frequencies using multivariate variational mode decomposition (MVMD). Subsequently, a feature selection method based on the Boruta technique was applied to identify the most significant input variables. Finally, for daily AQI levels forecasting, ATLDE optimized the EDRVFL model (EDRVFL-ATLDE). Three daily AQI series gathered from Chengdu, Wuhan, and Taiyuan in China from January 1, 2018, to December 30, 2022, were used to test and confirm the proposed model via empirical research. Based on the results, the proposed model can yield the superior results for three cities (Chengdu: correlation coefficient (R = 0.987), root mean square error (RMSE = 5.583), Wuhan: (R = 0.987), (RMSE = 3.299), and Taiyuan: (R = 0.996), (RMSE = 4.521)) in China. The experimental findings demonstrated the feasibility of the three-phase hybrid methodology, outperforming all other models regarding forecast accuracy.
{"title":"Optimized ensemble deep random vector functional link with nature inspired algorithm and boruta feature selection: Multi-site intelligent model for air quality index forecasting","authors":"","doi":"10.1016/j.psep.2024.09.037","DOIUrl":"10.1016/j.psep.2024.09.037","url":null,"abstract":"<div><div>Air quality index (AQI) forecasting is complex due to its variability, instability, and inconsistent trends resulting from dynamic atmospheric conditions, various contaminants, and interactions between environmental factors. Advanced modeling techniques are needed to accurately forecast AQI values to capture subtle patterns and variations in air quality data. Thus, a new forecasting model is suggested in this study to improve the accuracy of AQI forecasting. The model integrates three-phase decomposition technique, a feature selection approach, and ensemble Deep Random Vector Functional Link (EDRVFL), optimized using adaptive teaching-learning-based optimization and differential evolution (ATLDE). The AQI series was first broken down into a group of intrinsic mode functions (IMFs) with different frequencies using multivariate variational mode decomposition (MVMD). Subsequently, a feature selection method based on the Boruta technique was applied to identify the most significant input variables. Finally, for daily AQI levels forecasting, ATLDE optimized the EDRVFL model (EDRVFL-ATLDE). Three daily AQI series gathered from Chengdu, Wuhan, and Taiyuan in China from January 1, 2018, to December 30, 2022, were used to test and confirm the proposed model via empirical research. Based on the results, the proposed model can yield the superior results for three cities (Chengdu: correlation coefficient (R = 0.987), root mean square error (RMSE = 5.583), Wuhan: (R = 0.987), (RMSE = 3.299), and Taiyuan: (R = 0.996), (RMSE = 4.521)) in China. The experimental findings demonstrated the feasibility of the three-phase hybrid methodology, outperforming all other models regarding forecast accuracy.</div></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1016/j.psep.2024.09.013
This study focuses on the comparative modeling and refueling simulations of hydrogen refueling stations for hydrogen-powered vehicles and high-pressure hydrogen storage options in tanks. The study further aims to simulate these under actual conditions in Ontario, Canada for better assessment which can be treated as a case study as well. The specific tests explore the modeling of hydrogen flow between the recharging station to the car's tank, as well as the optimization of transient variations in temperature, pressure and mass flow rate of hydrogen throughout the process of refueling a fuel cell electric vehicle. The H2FILLS program is utilized to assist for the simulation studies. The primary objective is to replicate various practical weather conditions, tank pressures, flow rates, and refueling periods for different categories of high-pressure hydrogen storage tanks and analyze their storage efficiency. The three different commercially available high-pressure type-IV hydrogen storage tanks were considered in the study as tank-I, tank-II and tank-III with working pressures of 500 bar, 700 bar, 700 bar, and hydrogen storage capacity of 9.5 kg, 4.6 kg, and 5 kg, respectively. Seven different ambient temperatures were selected to mimic seasonal effects. When the power output is constant, with temperature increases, flow rate decreases, and therefore time required to refuel also increases. There is a linear relationship between the final mass flow rate and the ambient temperature, where the mass flow rate drops by approximately 1.8 kg/h for every 10 °C rise in temperature. The variation in ultimate mass flow rate between the highest and lowest ambient temperatures is roughly 5.4 kg/h. Based on the refueling time and docking, undocking, downtime it’s been found that approximately five minutes is wasted between each vehicle. This can help reduce average of 230.02 kt, 231.70 kt, and 235.06 kt CO2 emission per year for vehicle-III, vehicle-II, and vehicle-I, respectively. Lastly, yearly CO2 reduction forecast shows that it may reach 0.9 Mt, 1.6 Mt, 2.7Mt, 3.76 Mt, and 4.73 Mt in the year 2030, 2035, 2040, 2045, and 2050, respectively corresponding to the Global Net-Zero scenario.
{"title":"Hydrogen storage and refueling options: A performance evaluation","authors":"","doi":"10.1016/j.psep.2024.09.013","DOIUrl":"10.1016/j.psep.2024.09.013","url":null,"abstract":"<div><div>This study focuses on the comparative modeling and refueling simulations of hydrogen refueling stations for hydrogen-powered vehicles and high-pressure hydrogen storage options in tanks. The study further aims to simulate these under actual conditions in Ontario, Canada for better assessment which can be treated as a case study as well. The specific tests explore the modeling of hydrogen flow between the recharging station to the car's tank, as well as the optimization of transient variations in temperature, pressure and mass flow rate of hydrogen throughout the process of refueling a fuel cell electric vehicle. The H2FILLS program is utilized to assist for the simulation studies. The primary objective is to replicate various practical weather conditions, tank pressures, flow rates, and refueling periods for different categories of high-pressure hydrogen storage tanks and analyze their storage efficiency. The three different commercially available high-pressure type-IV hydrogen storage tanks were considered in the study as tank-I, tank-II and tank-III with working pressures of 500 bar, 700 bar, 700 bar, and hydrogen storage capacity of 9.5 kg, 4.6 kg, and 5 kg, respectively. Seven different ambient temperatures were selected to mimic seasonal effects. When the power output is constant, with temperature increases, flow rate decreases, and therefore time required to refuel also increases. There is a linear relationship between the final mass flow rate and the ambient temperature, where the mass flow rate drops by approximately 1.8 kg/h for every 10 °C rise in temperature. The variation in ultimate mass flow rate between the highest and lowest ambient temperatures is roughly 5.4 kg/h. Based on the refueling time and docking, undocking, downtime it’s been found that approximately five minutes is wasted between each vehicle. This can help reduce average of 230.02 kt, 231.70 kt, and 235.06 kt CO<sub>2</sub> emission per year for vehicle-III, vehicle-II, and vehicle-I, respectively. Lastly, yearly CO<sub>2</sub> reduction forecast shows that it may reach 0.9 Mt, 1.6 Mt, 2.7Mt, 3.76 Mt, and 4.73 Mt in the year 2030, 2035, 2040, 2045, and 2050, respectively corresponding to the Global Net-Zero scenario.</div></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1016/j.psep.2024.09.058
This paper examines the spatiotemporal evolution and convergence of energy-related carbon emission efficiency in the Yangtze River Economic Belt (YREB) using prefecture-level data from 2012 to 2021. Employing the SBM-GML strategy, kernel density estimation, the Dagum decomposition method, and the spatial econometric model, the study identifies three main findings: (1) The energy-related carbon emission efficiency in the YREB demonstrates a phased upward trend, particularly after 2014. (2) Pronounced regional disparities are observed, with downstream areas displaying higher efficiency compared to midstream and upstream regions, driven primarily by notable density variations and intra-regional disparities. (3) The analysis reveals both σ-convergence and β-convergence dynamics, highlighting varied spatial effects across regions. Factors such as economic development, industrial structure, and financial incentives exhibit diverse impacts on efficiency, underscoring substantial heterogeneity. This study offers empirical insights crucial for enhancing energy-related carbon emission efficiency in pivotal economic zones.
{"title":"Assessing the evolution and convergence of energy-related carbon emission efficiency in the Yangtze River Economic Belt","authors":"","doi":"10.1016/j.psep.2024.09.058","DOIUrl":"10.1016/j.psep.2024.09.058","url":null,"abstract":"<div><div>This paper examines the spatiotemporal evolution and convergence of energy-related carbon emission efficiency in the Yangtze River Economic Belt (YREB) using prefecture-level data from 2012 to 2021. Employing the SBM-GML strategy, kernel density estimation, the Dagum decomposition method, and the spatial econometric model, the study identifies three main findings: (1) The energy-related carbon emission efficiency in the YREB demonstrates a phased upward trend, particularly after 2014. (2) Pronounced regional disparities are observed, with downstream areas displaying higher efficiency compared to midstream and upstream regions, driven primarily by notable density variations and intra-regional disparities. (3) The analysis reveals both σ-convergence and β-convergence dynamics, highlighting varied spatial effects across regions. Factors such as economic development, industrial structure, and financial incentives exhibit diverse impacts on efficiency, underscoring substantial heterogeneity. This study offers empirical insights crucial for enhancing energy-related carbon emission efficiency in pivotal economic zones.</div></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1016/j.psep.2024.09.054
With the development of the new energy industry, battery life and rapid charge-discharge capacity have attracted much attention. At the same time, the high temperature inside the cell during high-rate charging and discharging may increase the probability of the battery thermal runaway. This paper studied the thermal runaway reaction of Li-ion batteries under different state of charge (SOC) and charge rates using a self-made experimental platform. The experimental phenomena and the changes in the temperature field were recorded. The key parameters, such as trigger temperature (T1, Lithium battery back thermal runaway triggers temperature), maximum temperature (Tmax),voltage, and mass loss (ML) of thermal runaway, were measured. The morphology changes of electrode materials, the battery remains, and the dynamics of thermal runaway reaction after high rate charge and discharge were further analyzed. The results show that for the 4 C-100 % battery, the T1 and Ea are reduced by 22.6 ℃ and 82.2 %, and the Tmax and maximum mass loss rate (MLRmax) are increased by 218.14 ℃ and five times, compared with the 1 C-50 % battery. With the increase of charge-discharge rate, the thermal stability of the battery decreases, and the gravity degree of accident increases.
{"title":"Study on the influence of high rate charge and discharge on thermal runaway behavior of lithium-ion battery","authors":"","doi":"10.1016/j.psep.2024.09.054","DOIUrl":"10.1016/j.psep.2024.09.054","url":null,"abstract":"<div><p>With the development of the new energy industry, battery life and rapid charge-discharge capacity have attracted much attention. At the same time, the high temperature inside the cell during high-rate charging and discharging may increase the probability of the battery thermal runaway. This paper studied the thermal runaway reaction of Li-ion batteries under different state of charge (SOC) and charge rates using a self-made experimental platform. The experimental phenomena and the changes in the temperature field were recorded. The key parameters, such as trigger temperature (T<sub>1,</sub> Lithium battery back thermal runaway triggers temperature), maximum temperature (T<sub>max</sub>),voltage, and mass loss (ML) of thermal runaway, were measured. The morphology changes of electrode materials, the battery remains, and the dynamics of thermal runaway reaction after high rate charge and discharge were further analyzed. The results show that for the 4 C-100 % battery, the T<sub>1</sub> and E<sub>a</sub> are reduced by 22.6 ℃ and 82.2 %, and the T<sub>max</sub> and maximum mass loss rate (MLR<sub>max</sub>) are increased by 218.14 ℃ and five times, compared with the 1 C-50 % battery. With the increase of charge-discharge rate, the thermal stability of the battery decreases, and the gravity degree of accident increases.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1016/j.psep.2024.09.042
Background
Cogeneration power plants traditionally rely on fossil fuels to produce stable power and heat. However, increasing energy demand and population growth have intensified the emission of biological pollutants due to fossil fuel use. The Global Alliance on Health and Pollution advocates for integrating renewable energy sources to mitigate these issues.
Objectives
This study aims to evaluate the integration of a solar-biomass polygeneration system with a hybrid solar-waste-fossil fuel cogeneration system. The goal is to analyze the system from technical, economic, and environmental perspectives, focusing on optimizing energy demand and minimizing environmental impact.
Methods
To assess energy demand and supply, the R-curve methodology was applied to the hybrid cogeneration system, with a specific focus on solar and biomass renewable energies. Various scenarios were analyzed, including total annual costs, pollutant emissions, water footprint, and overall environmental impact based on life cycle assessment. The study examined and compared the performance of three types of biomass waste (Municipal solid waste, mixed paper waste, and date palm waste). Multi-objective optimization was performed using artificial intelligence and machine learning techniques, employing four meta-heuristic algorithms. The conditions generated by each algorithm were analyzed and compared.
Results
Municipal solid waste, being the most readily available fuel, provided the most favorable economic conditions for the system. Environmentally, municipal solid waste ranked in the middle compared to other fuels. Among the optimization algorithms, the Salps swarm algorithm proved to be the most efficient in terms of calculation time and system efficiency improvements. The optimization improved net power generation by 5.25 %, overall energy efficiency by 16.27 %, total cost rate by 10.19 %, and total environmental impact rate by 14.02 %.
Conclusion
The integrated system's performance was analyzed across different climatic change throughout the year. The multi-objective Salps swarm algorithm optimization demonstrated significant benefits in enhancing system efficiency and reducing costs and environmental impacts.
背景热电联产发电厂传统上依靠化石燃料生产稳定的电力和热能。然而,日益增长的能源需求和人口增长加剧了化石燃料使用所导致的生物污染物排放。全球健康与污染联盟提倡整合可再生能源,以缓解这些问题。本研究旨在评估太阳能-生物质多联产系统与太阳能-废物-化石燃料混合热电联产系统的整合情况。方法为了评估能源需求和供应情况,对混合热电联产系统采用了 R 曲线方法,重点关注太阳能和生物质可再生能源。对各种方案进行了分析,包括年度总成本、污染物排放、水足迹以及基于生命周期评估的总体环境影响。研究考察并比较了三种生物质废物(城市固体废物、混合废纸和椰枣废料)的性能。利用人工智能和机器学习技术,采用四种元启发式算法进行了多目标优化。结果城市固体废物是最容易获得的燃料,为系统提供了最有利的经济条件。在环境方面,城市固体废物与其他燃料相比处于中间位置。在各种优化算法中,Salps 蜂群算法在计算时间和提高系统效率方面被证明是最有效的。通过优化,净发电量提高了 5.25%,总体能源效率提高了 16.27%,总成本率提高了 10.19%,总环境影响率提高了 14.02%。多目标萨尔普斯蜂群算法优化在提高系统效率、降低成本和环境影响方面取得了显著成效。
{"title":"Optimal 4E design and innovative R-curve approach for a gas-solar- biological waste polygeneration system for power, freshwater, and methanol production","authors":"","doi":"10.1016/j.psep.2024.09.042","DOIUrl":"10.1016/j.psep.2024.09.042","url":null,"abstract":"<div><h3>Background</h3><p>Cogeneration power plants traditionally rely on fossil fuels to produce stable power and heat. However, increasing energy demand and population growth have intensified the emission of biological pollutants due to fossil fuel use. The Global Alliance on Health and Pollution advocates for integrating renewable energy sources to mitigate these issues.</p></div><div><h3>Objectives</h3><p>This study aims to evaluate the integration of a solar-biomass polygeneration system with a hybrid solar-waste-fossil fuel cogeneration system. The goal is to analyze the system from technical, economic, and environmental perspectives, focusing on optimizing energy demand and minimizing environmental impact.</p></div><div><h3>Methods</h3><p>To assess energy demand and supply, the R-curve methodology was applied to the hybrid cogeneration system, with a specific focus on solar and biomass renewable energies. Various scenarios were analyzed, including total annual costs, pollutant emissions, water footprint, and overall environmental impact based on life cycle assessment. The study examined and compared the performance of three types of biomass waste (Municipal solid waste, mixed paper waste, and date palm waste). Multi-objective optimization was performed using artificial intelligence and machine learning techniques, employing four meta-heuristic algorithms. The conditions generated by each algorithm were analyzed and compared.</p></div><div><h3>Results</h3><p>Municipal solid waste, being the most readily available fuel, provided the most favorable economic conditions for the system. Environmentally, municipal solid waste ranked in the middle compared to other fuels. Among the optimization algorithms, the Salps swarm algorithm proved to be the most efficient in terms of calculation time and system efficiency improvements. The optimization improved net power generation by 5.25 %, overall energy efficiency by 16.27 %, total cost rate by 10.19 %, and total environmental impact rate by 14.02 %.</p></div><div><h3>Conclusion</h3><p>The integrated system's performance was analyzed across different climatic change throughout the year. The multi-objective Salps swarm algorithm optimization demonstrated significant benefits in enhancing system efficiency and reducing costs and environmental impacts.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1016/j.psep.2024.09.041
High-pressure steam and hot water often coexist as industrial waste heat. In this study, dual loop and single loop ORC systems are designed for 700 kPa, 4.1 kg/s steam, and 90 ℃, 122.36 kg/s hot water conditions to study the off-design performance when steam or hot water conditions change. To maximize net output power, we employ a particle swarm optimization algorithm to optimize the evaporation and condensation temperatures. The results show that within the specified hot water conditions, the evaporation and condensation temperatures of D-ORC's low-pressure loop and S-ORC increase with rising hot water inlet temperature and flow rate. The S-ORC demonstrates a higher net output power growth rate as hot water flow rate and temperature rise. Under specific steam conditions, when the steam outlet is in a gas-liquid two-phase state, D-ORC's maximum net output power is 1.7 % higher than that of the S-ORC, with little variation in optimal evaporation and condensation temperatures with respect to steam inlet pressure. At a 3.5 kg/s steam flow rate, the D-ORC's high-pressure loop becomes ineffective, whereas S-ORC efficiently adjusts heat exchange capacity under diverse steam-water conditions, Consequently, the D-ORC's average net output power is 34.2 % lower than that of the S-ORC.
{"title":"Off-design performance optimization for steam-water dual heat source ORC systems","authors":"","doi":"10.1016/j.psep.2024.09.041","DOIUrl":"10.1016/j.psep.2024.09.041","url":null,"abstract":"<div><p>High-pressure steam and hot water often coexist as industrial waste heat. In this study, dual loop and single loop ORC systems are designed for 700 kPa, 4.1 kg/s steam, and 90 ℃, 122.36 kg/s hot water conditions to study the off-design performance when steam or hot water conditions change. To maximize net output power, we employ a particle swarm optimization algorithm to optimize the evaporation and condensation temperatures. The results show that within the specified hot water conditions, the evaporation and condensation temperatures of D-ORC's low-pressure loop and S-ORC increase with rising hot water inlet temperature and flow rate. The S-ORC demonstrates a higher net output power growth rate as hot water flow rate and temperature rise. Under specific steam conditions, when the steam outlet is in a gas-liquid two-phase state, D-ORC's maximum net output power is 1.7 % higher than that of the S-ORC, with little variation in optimal evaporation and condensation temperatures with respect to steam inlet pressure. At a 3.5 kg/s steam flow rate, the D-ORC's high-pressure loop becomes ineffective, whereas S-ORC efficiently adjusts heat exchange capacity under diverse steam-water conditions, Consequently, the D-ORC's average net output power is 34.2 % lower than that of the S-ORC.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1016/j.psep.2024.09.027
Seyni YOUNOUSSI SAIDOU, Gamze GENÇ
The integration of solar thermal energy into a coal-fired power plant is one of the best ways to reduce the environmental impact of the latter linked to the release of carbon dioxide (CO2) into the atmosphere. In this paper, solar energy is used before the boiler, just after the first high-pressure feed water heater via a solar preheater (Water/Heat Transfer Fluid exchanger). It should be noted that in this study, there is no feed water heater displacement, and so the plant will operate in pure fuel-saving mode. To carry out an analysis of the integration of solar thermal energy in a coal-fired power plant, a 330 MW Solar Aided Coal Power Plant (SACPP) in northern Niger was studied. The results bring out that the annual solar energy production is 208 GWh, and solar energy can contribute up to approximately 15 % in the production of electricity. The considered SACPP significantly reduces the environmental impact of coal-fired power plants, leading to a reduction in CO2 emissions of around 381358 tons/year. In addition, the annual energy production cost from solar energy in the hybrid system is obtained as 0.0357 $/kWh and the investment payback period is around 12 months.
{"title":"Thermodynamic, economical and environmental performance evaluation of a 330 MW solar-aided coal-fired power plant located in Niger","authors":"Seyni YOUNOUSSI SAIDOU, Gamze GENÇ","doi":"10.1016/j.psep.2024.09.027","DOIUrl":"https://doi.org/10.1016/j.psep.2024.09.027","url":null,"abstract":"The integration of solar thermal energy into a coal-fired power plant is one of the best ways to reduce the environmental impact of the latter linked to the release of carbon dioxide (CO<ce:inf loc=\"post\">2</ce:inf>) into the atmosphere. In this paper, solar energy is used before the boiler, just after the first high-pressure feed water heater via a solar preheater (Water/Heat Transfer Fluid exchanger). It should be noted that in this study, there is no feed water heater displacement, and so the plant will operate in pure fuel-saving mode. To carry out an analysis of the integration of solar thermal energy in a coal-fired power plant, a 330 MW Solar Aided Coal Power Plant (SACPP) in northern Niger was studied. The results bring out that the annual solar energy production is 208 GWh, and solar energy can contribute up to approximately 15 % in the production of electricity. The considered SACPP significantly reduces the environmental impact of coal-fired power plants, leading to a reduction in CO<ce:inf loc=\"post\">2</ce:inf> emissions of around 381358 tons/year. In addition, the annual energy production cost from solar energy in the hybrid system is obtained as 0.0357 $/kWh and the investment payback period is around 12 months.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142275707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1016/j.psep.2024.09.033
The production of polyvinyl chloride (PVC) encounters challenges stemming from the temporal and spatial coupling characteristics inherent in the fixed bed ethylene oxychlorination process. Consequently, the implementation of enhanced safety measures and risk reduction strategies becomes imperative. This study introduces a pioneering methodology leveraging a spectral temporal graph neural network. By leveraging reactor temperature data, spatial variable decoupling facilitated by the Fourier transform, and a self-attentive mechanism within graph neural networks, the proposed approach adeptly forecasts future reactor states. The model's seamless alignment with the physical knowledge of reaction processes, validated through the adjacency matrix and hotspot region identification, underscores its efficacy in ensuring process safety and mitigating operational risks in PVC production. Empirical findings further validate the effectiveness of the approach, with predictions demonstrating an error margin of less than 0.5°C in forecasting future reactor temperatures.
{"title":"Enhancing predictive monitoring of ethylene oxychlorination reactor states through spatiotemporal coupling analysis","authors":"","doi":"10.1016/j.psep.2024.09.033","DOIUrl":"10.1016/j.psep.2024.09.033","url":null,"abstract":"<div><p>The production of polyvinyl chloride (PVC) encounters challenges stemming from the temporal and spatial coupling characteristics inherent in the fixed bed ethylene oxychlorination process. Consequently, the implementation of enhanced safety measures and risk reduction strategies becomes imperative. This study introduces a pioneering methodology leveraging a spectral temporal graph neural network. By leveraging reactor temperature data, spatial variable decoupling facilitated by the Fourier transform, and a self-attentive mechanism within graph neural networks, the proposed approach adeptly forecasts future reactor states. The model's seamless alignment with the physical knowledge of reaction processes, validated through the adjacency matrix and hotspot region identification, underscores its efficacy in ensuring process safety and mitigating operational risks in PVC production. Empirical findings further validate the effectiveness of the approach, with predictions demonstrating an error margin of less than 0.5°C in forecasting future reactor temperatures.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1016/j.psep.2024.09.029
Harmful Microcystis blooms and microcystins have become a major hidden threat to the safety of the water environment. The application of enzymatic degradation of microcystins has been severely limited by the complex environment. In this study, chitosan-graphene (CG), prepared from green biomass, was employed as matrix material, loaded with 100–200 nm Fe3O4 nanoparticles (MCG) and immobilized microcystinase A (MlrA@MCG). The preparation of MlrA@MCG was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and fluorescence labelling. The results of the activity analysis demonstrated that MlrA@MCG exhibited superior degradation activity for MCs, as well as enhanced heat and alkaline resistance in comparison to free MlrA. Furthermore, MlrA@MCG can be recovered simply by means of a magnetic field, and its activity remains at 48.6 % after 10 repeated uses. More importantly, MlrA@MCG and the degradation products of MC-LR were not found to be cytotoxic to human cells. It is interesting that the immobilization of MlrA resulted in a reduction in the cytotoxicity of MCG. 0.2 U of MlrA@MCG can still degrade MC-LR from 232.64 μg L−1 to 94.39 μg L−1 in water from simulated severe Microcystis blooms within 24 h, showing excellent catalytic activity and stability. The study proposed a secure and efficacious approach for the elimination of microcystins from harmful Microcystis blooms, offering a promising avenue for the improvement of environmental safety.
{"title":"Magnetic recyclable chitosan-graphene immobilized microcystinase A: Removal of microcystins from harmful microcystis blooms","authors":"","doi":"10.1016/j.psep.2024.09.029","DOIUrl":"10.1016/j.psep.2024.09.029","url":null,"abstract":"<div><p>Harmful Microcystis blooms and microcystins have become a major hidden threat to the safety of the water environment. The application of enzymatic degradation of microcystins has been severely limited by the complex environment. In this study, chitosan-graphene (CG), prepared from green biomass, was employed as matrix material, loaded with 100–200 nm Fe<sub>3</sub>O<sub>4</sub> nanoparticles (MCG) and immobilized microcystinase A (MlrA@MCG). The preparation of MlrA@MCG was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and fluorescence labelling. The results of the activity analysis demonstrated that MlrA@MCG exhibited superior degradation activity for MCs, as well as enhanced heat and alkaline resistance in comparison to free MlrA. Furthermore, MlrA@MCG can be recovered simply by means of a magnetic field, and its activity remains at 48.6 % after 10 repeated uses. More importantly, MlrA@MCG and the degradation products of MC-LR were not found to be cytotoxic to human cells. It is interesting that the immobilization of MlrA resulted in a reduction in the cytotoxicity of MCG. 0.2 U of MlrA@MCG can still degrade MC-LR from 232.64 μg L<sup>−1</sup> to 94.39 μg L<sup>−1</sup> in water from simulated severe Microcystis blooms within 24 h, showing excellent catalytic activity and stability. The study proposed a secure and efficacious approach for the elimination of microcystins from harmful Microcystis blooms, offering a promising avenue for the improvement of environmental safety.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}