Pub Date : 2024-11-12DOI: 10.1016/j.cherd.2024.11.012
Viet Hung Nguyen, Arto Laari, Tuomas Koiranen
Methanol is a promising fuel and important intermediate chemical in the transformation of renewable power to chemical products since it can be directly synthesized from captured CO2 and electrolytic H2. However, the intermittency of renewable power generation poses challenges to green methanol production process design and operation, necessitating high operational flexibility to facilitate coupling with intermittent renewable power. In this study, a green crude methanol (a mixture of methanol and water from methanol synthesis) production process was dynamically modeled. The results show that the minimum load of the model is 20 %, with maximum allowable ramping rates of 3.25 %/minute for ramp-down and 2.10 %/minute for ramp-up between full and minimum load. The introduction of a standby mode, in which a make-up H2 stream is supplied when electrolytic H2 is unavailable, allows continuous operation of the process at the minimum load. With the constructed control structure, the model demonstrates that the process can effectively handle continuous variations of electrolytic H2 input.
{"title":"The effect of green hydrogen feed rate variations on e-methanol synthesis by dynamic simulation","authors":"Viet Hung Nguyen, Arto Laari, Tuomas Koiranen","doi":"10.1016/j.cherd.2024.11.012","DOIUrl":"10.1016/j.cherd.2024.11.012","url":null,"abstract":"<div><div>Methanol is a promising fuel and important intermediate chemical in the transformation of renewable power to chemical products since it can be directly synthesized from captured CO<sub>2</sub> and electrolytic H<sub>2</sub>. However, the intermittency of renewable power generation poses challenges to green methanol production process design and operation, necessitating high operational flexibility to facilitate coupling with intermittent renewable power. In this study, a green crude methanol (a mixture of methanol and water from methanol synthesis) production process was dynamically modeled. The results show that the minimum load of the model is 20 %, with maximum allowable ramping rates of 3.25 %/minute for ramp-down and 2.10 %/minute for ramp-up between full and minimum load. The introduction of a standby mode, in which a make-up H<sub>2</sub> stream is supplied when electrolytic H<sub>2</sub> is unavailable, allows continuous operation of the process at the minimum load. With the constructed control structure, the model demonstrates that the process can effectively handle continuous variations of electrolytic H<sub>2</sub> input.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 293-306"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.cherd.2024.11.010
Sampath Suranjan Salins , Shiva Kumar , Kota Reddy , Sawan Shetty , Ana Tejero-González
Cooling towers are used in industries to remove the excess heat produced by industrial processes and machineries. This cooling phenomenon and its rate can be improved by mixing it with the nanoparticles. The present work focuses on the design and construction of a counter flow forced draft cooling tower with the addition of aluminum oxide (Al2O3) nanoparticles with water to enhance heat & mass transfer. Experiments are performed with the variation of the flow rate of water, water temperature, and the volume fraction of nanoparticles from 0 % to 2 % by volume fraction. The output parameters like coefficient of performance (COP), cooling characteristics coefficient (CCC), Rate of evaporation (ER), cooling tower efficiency & range have been analyzed. Nanofluid properties like viscosity, density & thermal conductivity for different volume fractions have been examined. It is observed that viscosity and thermal conductivity increased with an increase in volume fractions. Viscosity decreased whereas conductivity increased with temperature rise. Results obtained from cooling tower experiments indicated a maximum COP, CCC, ER, efficiency, and range equal to 7.12, 3.54, 3.95 g/s, 75.55 %, and 29.8ᵒC, respectively. For the various volume fractions studied, nanofluid with 2 % outperformed others with higher heat transfer rates and range values. For the 2 % volume fraction of the nanoparticles, make-up water requirements reduced by 76.19 % when it is compared to the normal water without the nanoparticles. Also, it is found that the cooling tower range, heat transfer rate, and efficiency increased by 10 %, 10.2 %, and 4.16 % when nanofluid concentration is varied from 0 % to 2 % by volume for the air velocity and water flow rate of 13 m/s and 3.5 Liters per minute (LPM) respectively.
{"title":"Experimental investigation in a forced draft wet cooling tower using aluminum oxide nano particles","authors":"Sampath Suranjan Salins , Shiva Kumar , Kota Reddy , Sawan Shetty , Ana Tejero-González","doi":"10.1016/j.cherd.2024.11.010","DOIUrl":"10.1016/j.cherd.2024.11.010","url":null,"abstract":"<div><div>Cooling towers are used in industries to remove the excess heat produced by industrial processes and machineries. This cooling phenomenon and its rate can be improved by mixing it with the nanoparticles. The present work focuses on the design and construction of a counter flow forced draft cooling tower with the addition of aluminum oxide (Al2O3) nanoparticles with water to enhance heat & mass transfer. Experiments are performed with the variation of the flow rate of water, water temperature, and the volume fraction of nanoparticles from 0 % to 2 % by volume fraction. The output parameters like coefficient of performance (COP), cooling characteristics coefficient (CCC), Rate of evaporation (ER), cooling tower efficiency & range have been analyzed. Nanofluid properties like viscosity, density & thermal conductivity for different volume fractions have been examined. It is observed that viscosity and thermal conductivity increased with an increase in volume fractions. Viscosity decreased whereas conductivity increased with temperature rise. Results obtained from cooling tower experiments indicated a maximum COP, CCC, ER, efficiency, and range equal to 7.12, 3.54, 3.95 g/s, 75.55 %, and 29.8ᵒC, respectively. For the various volume fractions studied, nanofluid with 2 % outperformed others with higher heat transfer rates and range values. For the 2 % volume fraction of the nanoparticles, make-up water requirements reduced by 76.19 % when it is compared to the normal water without the nanoparticles. Also, it is found that the cooling tower range, heat transfer rate, and efficiency increased by 10 %, 10.2 %, and 4.16 % when nanofluid concentration is varied from 0 % to 2 % by volume for the air velocity and water flow rate of 13 m/s and 3.5 Liters per minute (LPM) respectively.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 281-292"},"PeriodicalIF":3.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.cherd.2024.11.004
Bin Wang , Weitong Pan , Zichao Hu , Guoyu Zhang , Longfei Tang , Xueli Chen , Fuchen Wang
The flow distribution in the Flow Field Plate (FFP) has a significant impact on the performance and durability of large-scale Proton Exchange Membrane (PEM) fuel cells. Most of the existing studies focused only on gas-phase flow, while the actual cell operation is gas-liquid two-phase flow. In this study, numerical simulations of single- and two-phase flow distributions are performed for three-dimensional FFPs. The Coefficient of Variation (CV), defined as the ratio between the standard deviation and the mean of the velocities in channels, serves as the indicator of flow uniformity. Firstly, the differences between gas- and two-phase flow distribution characteristics of the FFP with the combined-mesh-type transition zone we previously constructed are elucidated. Secondly, a re-optimized layout with horizontal mesh apertures in the distribution zone and the addition of horizontal mesh in the collection zone is proposed. The design philosophy and methodology based on the coupled flow and resistance regulation mechanism are elucidated. The single- and two-phase CV values are further reduced by 41.25 % and 6.05 %, respectively. Thirdly, the re-optimized structure is applied to different FFP geometries, including smaller development spaces and larger cell areas, where the superior effects on flow distribution are validated.
{"title":"A re-optimized design of mesh-type transition zone for large-scale PEM fuel cells considering two-phase flow distribution","authors":"Bin Wang , Weitong Pan , Zichao Hu , Guoyu Zhang , Longfei Tang , Xueli Chen , Fuchen Wang","doi":"10.1016/j.cherd.2024.11.004","DOIUrl":"10.1016/j.cherd.2024.11.004","url":null,"abstract":"<div><div>The flow distribution in the Flow Field Plate (FFP) has a significant impact on the performance and durability of large-scale Proton Exchange Membrane (PEM) fuel cells. Most of the existing studies focused only on gas-phase flow, while the actual cell operation is gas-liquid two-phase flow. In this study, numerical simulations of single- and two-phase flow distributions are performed for three-dimensional FFPs. The Coefficient of Variation (<em>CV</em>), defined as the ratio between the standard deviation and the mean of the velocities in channels, serves as the indicator of flow uniformity. Firstly, the differences between gas- and two-phase flow distribution characteristics of the FFP with the combined-mesh-type transition zone we previously constructed are elucidated. Secondly, a re-optimized layout with horizontal mesh apertures in the distribution zone and the addition of horizontal mesh in the collection zone is proposed. The design philosophy and methodology based on the coupled flow and resistance regulation mechanism are elucidated. The single- and two-phase <em>CV</em> values are further reduced by 41.25 % and 6.05 %, respectively. Thirdly, the re-optimized structure is applied to different FFP geometries, including smaller development spaces and larger cell areas, where the superior effects on flow distribution are validated.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 217-229"},"PeriodicalIF":3.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As emerging pollutants in water, microplastics pose potential risks to aquatic organisms and human health. Previous studies have shown that traditional metal coagulants are effective in removing microplastics from water, but they come with drawbacks such as high chemical dosage and metal residues. Therefore, it is important to explore more efficient coagulation systems. This study utilized laminarin (LA) as a coagulant aid in combination with polyaluminum chloride (PAC) to investigate its enhanced coagulation performance on polyethylene microplastics in water. The performance of coagulation systems for the removal of microplastics was evaluated for different agent dosages, pH, anion and HA content. Experimental results demonstrated that the compounded system (PAC-LA) significantly improved the removal efficiency of PE microplastics compared to the single PAC system, achieving a removal rate of 91.5 % while reducing the dosage of PAC. The enhanced coagulation mechanism of LA was analyzed using various techniques including scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis. The results indicated that charge neutralization and sweep flocculation were the primary coagulation mechanisms in the presence of PAC alone. The effect of charge neutralization and adsorption was strengthened with the introduction of LA. The coagulation system of PAC-LA showed higher removal rates of PE microplastics under different environmental conditions such as varying pH levels, co-existing anions, and humic acid, suggesting a promising application for microplastic control in water.
作为水中新出现的污染物，微塑料对水生生物和人类健康构成潜在风险。以往的研究表明，传统的金属混凝剂能有效去除水中的微塑料，但也存在化学用量大和金属残留等缺点。因此，探索更高效的混凝系统非常重要。本研究利用层皮素（LA）作为助凝剂，并结合聚合氯化铝（PAC），研究其对水中聚乙烯微塑料的增强混凝性能。针对不同的助凝剂用量、pH 值、阴离子和 HA 含量，对混凝系统去除微塑料的性能进行了评估。实验结果表明，与单一 PAC 系统相比，复合系统（PAC-LA）显著提高了对聚乙烯微塑料的去除效率，在减少 PAC 用量的同时，去除率达到 91.5%。利用扫描电子显微镜（SEM）、傅立叶变换红外光谱（FTIR）、X 射线光电子能谱（XPS）和 zeta 电位分析等多种技术分析了 LA 的增强凝结机理。结果表明，在单独使用 PAC 的情况下，电荷中和与扫掠絮凝是主要的混凝机制。引入 LA 后，电荷中和与吸附作用得到加强。在不同的环境条件下（如不同的 pH 值、共存阴离子和腐殖酸），PAC-LA 混凝系统对 PE 微塑料的去除率更高，这表明其在水中微塑料控制方面具有广阔的应用前景。
{"title":"Coagulative removal of polyethylene microplastics using polyaluminum chloride in conjunction with laminarin","authors":"Jinlei Chen, Jiajing Lin, Wenjin Li, Yanyun Wang, Huabin Huang","doi":"10.1016/j.cherd.2024.11.015","DOIUrl":"10.1016/j.cherd.2024.11.015","url":null,"abstract":"<div><div>As emerging pollutants in water, microplastics pose potential risks to aquatic organisms and human health. Previous studies have shown that traditional metal coagulants are effective in removing microplastics from water, but they come with drawbacks such as high chemical dosage and metal residues. Therefore, it is important to explore more efficient coagulation systems. This study utilized laminarin (LA) as a coagulant aid in combination with polyaluminum chloride (PAC) to investigate its enhanced coagulation performance on polyethylene microplastics in water. The performance of coagulation systems for the removal of microplastics was evaluated for different agent dosages, pH, anion and HA content. Experimental results demonstrated that the compounded system (PAC-LA) significantly improved the removal efficiency of PE microplastics compared to the single PAC system, achieving a removal rate of 91.5 % while reducing the dosage of PAC. The enhanced coagulation mechanism of LA was analyzed using various techniques including scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis. The results indicated that charge neutralization and sweep flocculation were the primary coagulation mechanisms in the presence of PAC alone. The effect of charge neutralization and adsorption was strengthened with the introduction of LA. The coagulation system of PAC-LA showed higher removal rates of PE microplastics under different environmental conditions such as varying pH levels, co-existing anions, and humic acid, suggesting a promising application for microplastic control in water.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 230-239"},"PeriodicalIF":3.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.cherd.2024.10.035
Léa Pierrat, Pablo García-Triñanes
This review critically examines the state of the art in furfural production technologies from biomass-derived resources, focusing on recent advancements aimed at enhancing process efficiency. Beginning with an overview of current methodologies, the study explores and maps the diversity of available feedstocks, assessing their suitability for optimised furfural generation. Conversion efficiency is analysed with attention to yield optimisation, highlighting the influence of catalysts, temperature control, and enzymatic processes. Recent advancements in process intensification—such as hybrid systems, heat integration, and innovative technologies—are discussed as key pathways for achieving scalable and sustainable production. A review of techno-economic analysis (TEA) sources assesses the commercial feasibility of furfural production from various feedstocks, with a specific focus on bagasse. Additionally, a review of available life cycle assessments (LCAs) offers insights into the environmental impacts of different production methods, contributing to the sustainable development of the industry. The review concludes by summarising critical findings and identifying research priorities essential for advancing towards the ultimate goal of economically feasible and commercially scalable furfural production from lignocellulosic biomass.
{"title":"Optimising furfural production from lignocellulosic biomass: Feedstock selection, Process enhancement, and Techno-Economic and Environmental viability","authors":"Léa Pierrat, Pablo García-Triñanes","doi":"10.1016/j.cherd.2024.10.035","DOIUrl":"10.1016/j.cherd.2024.10.035","url":null,"abstract":"<div><div>This review critically examines the state of the art in furfural production technologies from biomass-derived resources, focusing on recent advancements aimed at enhancing process efficiency. Beginning with an overview of current methodologies, the study explores and maps the diversity of available feedstocks, assessing their suitability for optimised furfural generation. Conversion efficiency is analysed with attention to yield optimisation, highlighting the influence of catalysts, temperature control, and enzymatic processes. Recent advancements in process intensification—such as hybrid systems, heat integration, and innovative technologies—are discussed as key pathways for achieving scalable and sustainable production. A review of techno-economic analysis (TEA) sources assesses the commercial feasibility of furfural production from various feedstocks, with a specific focus on bagasse. Additionally, a review of available life cycle assessments (LCAs) offers insights into the environmental impacts of different production methods, contributing to the sustainable development of the industry. The review concludes by summarising critical findings and identifying research priorities essential for advancing towards the ultimate goal of economically feasible and commercially scalable furfural production from lignocellulosic biomass.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 261-280"},"PeriodicalIF":3.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.cherd.2024.10.028
Hao Hu, Peng Li, Qijun Wang, Jun Wang
U-tubes are widely applied in gas–liquid two-phase transportation in chemical engineering. The diverse flow patterns within these tubes significantly affect the pressure loss, heat transfer efficiency, and even the fluid-induced vibration amplitude of the tubes. This study explores the complex flow pattern features in a U-tube in a vertical plane and focuses on recognizing them. For the acquisition and classification of flow patterns, a Computational Fluid Dynamics (CFD) model for gas–liquid two-phase flow is first established, and its quantitative calculation error is ensured to be less than 5%. Then, the spatiotemporal evolution characteristics of flow patterns is analyzed. The real-time pressure drop response is chosen as the representation signal, and its nonlinear features in the time and frequency domain under different flow patterns are explored. A nonlinear time series is constructed by extracting a segment from the real-time pressure drop data, and six entropy measures are applied to analyze and identify them. Finally, the sensitivity of entropy measures to both the time series lengths and the tested sections are evaluated. Results show that there are six typical flow patterns in a U-tube. According to most entropy measures, the bubble flow has the highest complexity; however, the plug flow presents the lowest complexity. In the U-bend, pressure drop signals for the bubble and annular flows show random fluctuations within a specific range, in contrast to the marked periodicity in plug flow signals, while wavy and slug flows exhibit intermittent peak values. Including the upstream and downstream straight pipes in the analysis, rather than focusing solely on the U-bend, significantly increases the complexity of the stratified, plug, and slug flows. Fuzzy entropy is an effective tool for identifying the six flow patterns, demonstrating good resilience to variations in the length of the data series. This characteristic makes it highly useful for real-time identification of flow patterns in the U-bend sections of non-transparent U-tubes, offering considerable potential in chemical equipment.
U 型管广泛应用于化学工程中的气液两相输送。这些管内的各种流型会对管子的压力损失、传热效率，甚至流体引起的振动幅度产生重大影响。本研究探讨了 U 型管在垂直面上的复杂流型特征，并重点对其进行了识别。为了获取流型并对其进行分类，首先建立了气液两相流的计算流体动力学（CFD）模型，并确保其定量计算误差小于 5%。然后，分析流动模式的时空演变特征。选取实时压降响应作为表示信号，探讨其在不同流态下的时域和频域非线性特征。通过从实时压降数据中提取一个片段来构建非线性时间序列，并应用六种熵指标对其进行分析和识别。最后，评估了熵指标对时间序列长度和测试断面的敏感性。结果表明，U 型管中有六种典型的流动模式。根据大多数熵值，气泡流的复杂性最高；然而，堵塞流的复杂性最低。在 U 型弯管中，气泡流和环形流的压降信号在特定范围内随机波动，而塞流信号则具有明显的周期性，而波浪形流和蛞蝓流则表现出断断续续的峰值。将上下游直管也纳入分析范围，而不是只关注 U 形弯管，这大大增加了分层流、堵塞流和蛞蝓流的复杂性。模糊熵是识别六种流动模式的有效工具，对数据序列长度的变化具有良好的适应性。这一特点使其在实时识别非透明 U 形管 U 形弯曲部分的流动模式方面非常有用，在化工设备中具有相当大的潜力。
{"title":"An entropy measure-based study on flow pattern of gas–liquid two-phase flow in a U-Tube","authors":"Hao Hu, Peng Li, Qijun Wang, Jun Wang","doi":"10.1016/j.cherd.2024.10.028","DOIUrl":"10.1016/j.cherd.2024.10.028","url":null,"abstract":"<div><div>U-tubes are widely applied in gas–liquid two-phase transportation in chemical engineering. The diverse flow patterns within these tubes significantly affect the pressure loss, heat transfer efficiency, and even the fluid-induced vibration amplitude of the tubes. This study explores the complex flow pattern features in a U-tube in a vertical plane and focuses on recognizing them. For the acquisition and classification of flow patterns, a Computational Fluid Dynamics (CFD) model for gas–liquid two-phase flow is first established, and its quantitative calculation error is ensured to be less than 5%. Then, the spatiotemporal evolution characteristics of flow patterns is analyzed. The real-time pressure drop response is chosen as the representation signal, and its nonlinear features in the time and frequency domain under different flow patterns are explored. A nonlinear time series is constructed by extracting a segment from the real-time pressure drop data, and six entropy measures are applied to analyze and identify them. Finally, the sensitivity of entropy measures to both the time series lengths and the tested sections are evaluated. Results show that there are six typical flow patterns in a U-tube. According to most entropy measures, the bubble flow has the highest complexity; however, the plug flow presents the lowest complexity. In the U-bend, pressure drop signals for the bubble and annular flows show random fluctuations within a specific range, in contrast to the marked periodicity in plug flow signals, while wavy and slug flows exhibit intermittent peak values. Including the upstream and downstream straight pipes in the analysis, rather than focusing solely on the U-bend, significantly increases the complexity of the stratified, plug, and slug flows. Fuzzy entropy is an effective tool for identifying the six flow patterns, demonstrating good resilience to variations in the length of the data series. This characteristic makes it highly useful for real-time identification of flow patterns in the U-bend sections of non-transparent U-tubes, offering considerable potential in chemical equipment.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 201-216"},"PeriodicalIF":3.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.cherd.2024.11.009
Sheng Ma , Yu-xiang Jia , Xiao-guang Xu , Meng Wang
This study provides a proof-of-concept investigation into the direct utilization of low-concentration recovered acid as a proton source for the efficient recovery of organic acids via Donnan dialysis, a scenario of particular significance in industrial parks. A primary objective is to examine the implications of waste acid concentration on the coupling process. To evaluate the technological feasibility, process simulations are performed utilizing a mathematical model grounded in the Nernst-Planck equation and associated equilibrium relationships. Furthermore, a variety of experimental conditions, encompassing different types of organic acids and varying concentrations of waste acid, are explored to analyze the ion substitution behaviors involved. The findings from both simulations and experiments indicate that weaker organic acids demonstrate superior performance, particularly regarding recovery rates and process efficiency. Additionally, it is revealed that merely increasing the concentration of the draw solution does not constitute an effective approach for improving the DD-based organic acid recovery process, thereby suggesting the potential for the direct application of low-concentration recovered acid. Given its significant advantages, the proposed DD-based coupling technology shows considerable promise for future applications.
{"title":"Donnan dialysis-based approach for reclamation of waste acid with a low concentration","authors":"Sheng Ma , Yu-xiang Jia , Xiao-guang Xu , Meng Wang","doi":"10.1016/j.cherd.2024.11.009","DOIUrl":"10.1016/j.cherd.2024.11.009","url":null,"abstract":"<div><div>This study provides a proof-of-concept investigation into the direct utilization of low-concentration recovered acid as a proton source for the efficient recovery of organic acids via Donnan dialysis, a scenario of particular significance in industrial parks. A primary objective is to examine the implications of waste acid concentration on the coupling process. To evaluate the technological feasibility, process simulations are performed utilizing a mathematical model grounded in the Nernst-Planck equation and associated equilibrium relationships. Furthermore, a variety of experimental conditions, encompassing different types of organic acids and varying concentrations of waste acid, are explored to analyze the ion substitution behaviors involved. The findings from both simulations and experiments indicate that weaker organic acids demonstrate superior performance, particularly regarding recovery rates and process efficiency. Additionally, it is revealed that merely increasing the concentration of the draw solution does not constitute an effective approach for improving the DD-based organic acid recovery process, thereby suggesting the potential for the direct application of low-concentration recovered acid. Given its significant advantages, the proposed DD-based coupling technology shows considerable promise for future applications.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 191-200"},"PeriodicalIF":3.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.cherd.2024.11.003
Xiaoqing Zheng, Baofan Wu, Huiming Chen, Anke Xue, Song Zheng, Ming Ge, Yaguang Kong
Real-time acquisition of quality variables is paramount for enhancing control and optimization of industrial processes. Process modeling methods, such as soft sensors, offer a means to predict difficult-to-obtain quality variables using easily measurable process parameters. However, the dynamic nature of industrial processes poses significant challenges to modeling. For instance, conventional models are typically trained offline using historical data, rendering them incapable of adapting to real-time changes in data distribution or environmental conditions. To tackle this challenge, we introduce a novel approach termed the Residual Temporal Attention Temporal Convolution Network (RTA-TCN) and propose a just-in-time learning method based on RTA-TCN for industrial process modeling. The RTA-TCN model incorporates temporal attention into TCN, enabling the integration of previous time-step process variables into the current ones, as well as the fusion of internally relevant features among inputs. Moreover, to prevent the partial loss of original information during feature integration, residual connections are introduced into the temporal attention mechanism. These connections facilitate the retention of original feature information to a maximal extent while integrating relevant features. Consequently, the proposed RTA-TCN demonstrates significant advantages in handling the non-linearity and long-term dynamic dependencies inherent in industrial variables. Additionally, the proposed just-in-time learning method leverages RTA-TCN as a local model and updates it in real-time using online industrial data. This just-in-time learning method enables effective adaptation to varying data distributions and environmental conditions. We validate the performance of our method using two industrial datasets (Debutanizer Column and Sulfur Recovery Unit).
{"title":"A temporal convolution network-based just-in-time learning method for industrial quality variable prediction","authors":"Xiaoqing Zheng, Baofan Wu, Huiming Chen, Anke Xue, Song Zheng, Ming Ge, Yaguang Kong","doi":"10.1016/j.cherd.2024.11.003","DOIUrl":"10.1016/j.cherd.2024.11.003","url":null,"abstract":"<div><div>Real-time acquisition of quality variables is paramount for enhancing control and optimization of industrial processes. Process modeling methods, such as soft sensors, offer a means to predict difficult-to-obtain quality variables using easily measurable process parameters. However, the dynamic nature of industrial processes poses significant challenges to modeling. For instance, conventional models are typically trained offline using historical data, rendering them incapable of adapting to real-time changes in data distribution or environmental conditions. To tackle this challenge, we introduce a novel approach termed the Residual Temporal Attention Temporal Convolution Network (RTA-TCN) and propose a just-in-time learning method based on RTA-TCN for industrial process modeling. The RTA-TCN model incorporates temporal attention into TCN, enabling the integration of previous time-step process variables into the current ones, as well as the fusion of internally relevant features among inputs. Moreover, to prevent the partial loss of original information during feature integration, residual connections are introduced into the temporal attention mechanism. These connections facilitate the retention of original feature information to a maximal extent while integrating relevant features. Consequently, the proposed RTA-TCN demonstrates significant advantages in handling the non-linearity and long-term dynamic dependencies inherent in industrial variables. Additionally, the proposed just-in-time learning method leverages RTA-TCN as a local model and updates it in real-time using online industrial data. This just-in-time learning method enables effective adaptation to varying data distributions and environmental conditions. We validate the performance of our method using two industrial datasets (Debutanizer Column and Sulfur Recovery Unit).</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 168-184"},"PeriodicalIF":3.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.cherd.2024.11.002
Chengwei Xu , Yifu Wang , Yan Yu , Lirong Li
The wettability has an important effect on coalescence performance of filter. In this paper, we utilized a commercial glass fiber filter as the substrate to prepared the Janus filter through dip-coating and electrospraying. The Janus filter exhibited a remarkable reduction in pressure drop, with only 2.8 kPa of wet pressure drop compared to 6.1 kPa for the original filter and 5.4 kPa for the oleophilic filter. Notably, the coating depth played a critical role in enhancing the coalescence performance of the Janus filter. Furthermore, when placing the Janus filter in reverse direction, its quality factor increased by 2.87 times, highlighting that orientation is an essential factor for coalescence performance of Janus filters. The results indicate great potential in the application of Janus filters for coalescence filtration.
{"title":"Coalescence performance of Janus filter for the removal of oil mist","authors":"Chengwei Xu , Yifu Wang , Yan Yu , Lirong Li","doi":"10.1016/j.cherd.2024.11.002","DOIUrl":"10.1016/j.cherd.2024.11.002","url":null,"abstract":"<div><div>The wettability has an important effect on coalescence performance of filter. In this paper, we utilized a commercial glass fiber filter as the substrate to prepared the Janus filter through dip-coating and electrospraying. The Janus filter exhibited a remarkable reduction in pressure drop, with only 2.8 kPa of wet pressure drop compared to 6.1 kPa for the original filter and 5.4 kPa for the oleophilic filter. Notably, the coating depth played a critical role in enhancing the coalescence performance of the Janus filter. Furthermore, when placing the Janus filter in reverse direction, its quality factor increased by 2.87 times, highlighting that orientation is an essential factor for coalescence performance of Janus filters. The results indicate great potential in the application of Janus filters for coalescence filtration.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 185-190"},"PeriodicalIF":3.7,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.cherd.2024.10.031
Zhen Liang , Zhimei Liu , Lian Yu , Wenjuan Wang
The innovative utilization of fly ash for synthesizing zeolites presents notable environmental and economic benefits, positioning it as a pivotal area of research. This review distinguishes itself by offering a critical and up-to-date synthesis of the latest advancements in fly ash-based zeolite production, surpassing existing literature in both depth and breadth. It meticulously explores not only the fundamental principles and conventional synthesis methods—such as hydrothermal and sol-gel techniques—but also delves into emerging approaches like microwave-assisted, ultrasound-enhanced, fusion and melting, and ionothermal synthesis. A unique contribution of this paper is its comprehensive analysis of the interplay between synthesis parameters (composition, temperature, reaction time, and pH) and their nuanced effects on the crystal structure, morphology, and functional properties of the resulting zeolites. Furthermore, the review introduces novel classifications of zeolites derived from varied fly ash sources, highlighting their tailored applications in cutting-edge fields such as advanced soil remediation, precision nutrient retention systems, next-generation wastewater treatment technologies, and efficient removal of emerging gaseous pollutants. By identifying and discussing the latest trends and gaps in the current research landscape, this paper not only synthesizes existing knowledge but also proposes future directions, including the development of hybrid zeolite materials and the integration of machine learning techniques for optimized synthesis. This comprehensive and forward-looking perspective significantly advances the understanding of fly ash-derived zeolites and sets the stage for future innovations in sustainable material science.
{"title":"Fly ash-based zeolites: from waste to value – A comprehensive overview of synthesis, properties, and applications","authors":"Zhen Liang , Zhimei Liu , Lian Yu , Wenjuan Wang","doi":"10.1016/j.cherd.2024.10.031","DOIUrl":"10.1016/j.cherd.2024.10.031","url":null,"abstract":"<div><div>The innovative utilization of fly ash for synthesizing zeolites presents notable environmental and economic benefits, positioning it as a pivotal area of research. This review distinguishes itself by offering a critical and up-to-date synthesis of the latest advancements in fly ash-based zeolite production, surpassing existing literature in both depth and breadth. It meticulously explores not only the fundamental principles and conventional synthesis methods—such as hydrothermal and sol-gel techniques—but also delves into emerging approaches like microwave-assisted, ultrasound-enhanced, fusion and melting, and ionothermal synthesis. A unique contribution of this paper is its comprehensive analysis of the interplay between synthesis parameters (composition, temperature, reaction time, and pH) and their nuanced effects on the crystal structure, morphology, and functional properties of the resulting zeolites. Furthermore, the review introduces novel classifications of zeolites derived from varied fly ash sources, highlighting their tailored applications in cutting-edge fields such as advanced soil remediation, precision nutrient retention systems, next-generation wastewater treatment technologies, and efficient removal of emerging gaseous pollutants. By identifying and discussing the latest trends and gaps in the current research landscape, this paper not only synthesizes existing knowledge but also proposes future directions, including the development of hybrid zeolite materials and the integration of machine learning techniques for optimized synthesis. This comprehensive and forward-looking perspective significantly advances the understanding of fly ash-derived zeolites and sets the stage for future innovations in sustainable material science.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 240-260"},"PeriodicalIF":3.7,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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