Abstract The term ‘digital twin’ refers to a virtual simulation/model (virtual twin) of a physical plant or object (physical twin), where data flows between the virtual and physical twins. A digital twin can be used for different purposes, such as process optimisation/control, design, training, and maintenance/service. This manuscript found an increasing number of simulation and modelling publications in literature year on year, which illustrates the current trend towards implementing digital twins in a broad range of process engineering applications. A targeted literature review into the area found several commercial off-the-shelf software solutions (COTS) for different industrial applications providing the necessary flexibility to analyse a broad range of industries. However, most of the process modelling software is designed for petroleum and fine chemicals processes. There is still a need for software solutions that can model a broader range of applications. While most of the software found was licensed, open source process modelling software was also available. There is a lack of independent research into the accuracy of these software solutions. The literature review also found that 37% of the research based on process simulations is carried out to improve energy efficiencies. In comparison, 27% of the research found Decarbonization to be a secondary "added" benefit. It can be concluded that digital twins are ideally suited for driving energy efficiency improvements and decarbonisation goals. However, none of the COTS identified in the literature meets all the requirements for a digital twin. A solution to this problem is to create a layered digital twin, combining and interfacing different tools to accomplish a visually similar, self-optimising, self-learning virtual plant.
{"title":"Flexible digital twins from commercial off-the-shelf software solutions: a driver for energy efficiency and decarbonisation in process industries?","authors":"Molly Alford, Isuru A. Udugama, Wei Yu, B. Young","doi":"10.1515/cppm-2021-0045","DOIUrl":"https://doi.org/10.1515/cppm-2021-0045","url":null,"abstract":"Abstract The term ‘digital twin’ refers to a virtual simulation/model (virtual twin) of a physical plant or object (physical twin), where data flows between the virtual and physical twins. A digital twin can be used for different purposes, such as process optimisation/control, design, training, and maintenance/service. This manuscript found an increasing number of simulation and modelling publications in literature year on year, which illustrates the current trend towards implementing digital twins in a broad range of process engineering applications. A targeted literature review into the area found several commercial off-the-shelf software solutions (COTS) for different industrial applications providing the necessary flexibility to analyse a broad range of industries. However, most of the process modelling software is designed for petroleum and fine chemicals processes. There is still a need for software solutions that can model a broader range of applications. While most of the software found was licensed, open source process modelling software was also available. There is a lack of independent research into the accuracy of these software solutions. The literature review also found that 37% of the research based on process simulations is carried out to improve energy efficiencies. In comparison, 27% of the research found Decarbonization to be a secondary \"added\" benefit. It can be concluded that digital twins are ideally suited for driving energy efficiency improvements and decarbonisation goals. However, none of the COTS identified in the literature meets all the requirements for a digital twin. A solution to this problem is to create a layered digital twin, combining and interfacing different tools to accomplish a visually similar, self-optimising, self-learning virtual plant.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"17 1","pages":"395 - 407"},"PeriodicalIF":0.9,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41830094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Effective use of waste lignin is always a challenging task, technologies have been applied in the past to get value-added compounds from waste lignin. However, the existing technologies are not economical and efficient to produce the value-added chemicals. Alkali soluble lignin from rice straw hydrolysis residue (RSHR) is subjected to photocatalytic conversion into value-added compounds. Photocatalysis is one of the multifarious advanced oxidation processes (AOPs), carried out with TiO2 nanoparticles under a 125 W UV bulb. Gas chromatography mass spectroscopy (GCMS) confirmed the formation of vanillin and 4-hydroxybenzaldehyde. RSM and ANN techniques are adopted to optimize the process conditions for the maximization of the products. The response one (Y 1) vanillin (24.61 mg) and second response (Y 2) 4-hydroxybenzaldehyde (19.51 mg) is obtained at the optimal conditions as 7.0 h irradiation time, 2.763 g/L catalyst dose, 15 g/L lignin concentration, and 14.26 g/L NaOH dose for alkali treatment, suggested by face-centered central composite design (CCD). RSM and ANN models are statistically analyzed in terms of RMSE, R 2 and AAD. For RSM the R 2 0.9864 and 0.9787 while for ANN 0.9875 and 0.9847, closer to one warrant the good fitting of the models. Therefore, in terms of higher precision and predictive ability of both models the ANN model showed excellence for both responses as compared to the RSM model.
{"title":"Response surface methodology (RSM) and artificial neural network (ANN) approach to optimize the photocatalytic conversion of rice straw hydrolysis residue (RSHR) into vanillin and 4-hydroxybenzaldehyde","authors":"K. Ahmad, H. R. Ghatak, S. Ahuja","doi":"10.1515/cppm-2022-0003","DOIUrl":"https://doi.org/10.1515/cppm-2022-0003","url":null,"abstract":"Abstract Effective use of waste lignin is always a challenging task, technologies have been applied in the past to get value-added compounds from waste lignin. However, the existing technologies are not economical and efficient to produce the value-added chemicals. Alkali soluble lignin from rice straw hydrolysis residue (RSHR) is subjected to photocatalytic conversion into value-added compounds. Photocatalysis is one of the multifarious advanced oxidation processes (AOPs), carried out with TiO2 nanoparticles under a 125 W UV bulb. Gas chromatography mass spectroscopy (GCMS) confirmed the formation of vanillin and 4-hydroxybenzaldehyde. RSM and ANN techniques are adopted to optimize the process conditions for the maximization of the products. The response one (Y 1) vanillin (24.61 mg) and second response (Y 2) 4-hydroxybenzaldehyde (19.51 mg) is obtained at the optimal conditions as 7.0 h irradiation time, 2.763 g/L catalyst dose, 15 g/L lignin concentration, and 14.26 g/L NaOH dose for alkali treatment, suggested by face-centered central composite design (CCD). RSM and ANN models are statistically analyzed in terms of RMSE, R 2 and AAD. For RSM the R 2 0.9864 and 0.9787 while for ANN 0.9875 and 0.9847, closer to one warrant the good fitting of the models. Therefore, in terms of higher precision and predictive ability of both models the ANN model showed excellence for both responses as compared to the RSM model.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"391 - 409"},"PeriodicalIF":0.9,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45060563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tivya Sarawanan, N. Mahat, Nurfarhain Mohamed Rusli, M. A. Ahmad Zaini
Abstract The objective of the present work was to evaluate the performance of two-stage adsorber of activated carbon from oil palm empty fruit bunch for methylene blue removal. The model was developed to predict optimum adsorbent mass and time at a specified volumes and concentrations of dye solution. Results show that the adsorbent mass can be reduced by 6.67%. Operating time taken to attain the equilibrium in a two-stage adsorber has dramatically decreased from 22 h to 0.52 h. In the performance evaluation, the adsorbent mass in stage-1 is higher than in stage-2, which lessen the workload to achieve equilibrium. A two-stage adsorber aids to optimize the mass and contact time for different percentage of dye removal that economically feasible for industrial applications.
{"title":"Two-stage adsorber optimization of NaOH-prewashed oil palm empty fruit bunch activated carbon for methylene blue removal","authors":"Tivya Sarawanan, N. Mahat, Nurfarhain Mohamed Rusli, M. A. Ahmad Zaini","doi":"10.1515/cppm-2022-0010","DOIUrl":"https://doi.org/10.1515/cppm-2022-0010","url":null,"abstract":"Abstract The objective of the present work was to evaluate the performance of two-stage adsorber of activated carbon from oil palm empty fruit bunch for methylene blue removal. The model was developed to predict optimum adsorbent mass and time at a specified volumes and concentrations of dye solution. Results show that the adsorbent mass can be reduced by 6.67%. Operating time taken to attain the equilibrium in a two-stage adsorber has dramatically decreased from 22 h to 0.52 h. In the performance evaluation, the adsorbent mass in stage-1 is higher than in stage-2, which lessen the workload to achieve equilibrium. A two-stage adsorber aids to optimize the mass and contact time for different percentage of dye removal that economically feasible for industrial applications.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"383 - 390"},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43544409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mouad Hachhach, H. Akram, Mounir Hanafi, O. Achak, Tarik Chafik
Abstract The design of large-scale nanomaterial production is nowadays a major research topic that requires efficient tools for appropriate decision-making and process simulation is considered among the rational approach to address such difficult issue. The present study deals with process design and economic assessment of Molybdenum Disulfide (MoS2) nanomaterials production at large-scale via solvothermal method basing on our previous bench scale results. The commercial simulator Aspen Plus was used for process modelling and assuming a plant capacity of 100 tonnes/year. The simulation results were used to perform the cost assessment and profitability analysis while taking into account two relevant cases with (Recycle Case) and without recycling of Ethylenediamine and Hydrazine (Base Case). Note that for the technological and economical assessment the effluent treatment system was not taken into account. The total capital investment was estimated to be ca.14.3 M$ for the base case and ca. 17.4 M$ for recycle case, while the total operating costs were about 2945 $ for the base case and 503 $ for the recycle case for the production of 1 kg of MoS2. Thus, in addition to intrinsic advantages associated with the easier preparation and lower environmental impact of solvothermal method, larger production with recycling option can make the process more economically profitable.
{"title":"Process design and economic assessment of large-scale production of molybdenum disulfide nanomaterials","authors":"Mouad Hachhach, H. Akram, Mounir Hanafi, O. Achak, Tarik Chafik","doi":"10.1515/cppm-2022-0004","DOIUrl":"https://doi.org/10.1515/cppm-2022-0004","url":null,"abstract":"Abstract The design of large-scale nanomaterial production is nowadays a major research topic that requires efficient tools for appropriate decision-making and process simulation is considered among the rational approach to address such difficult issue. The present study deals with process design and economic assessment of Molybdenum Disulfide (MoS2) nanomaterials production at large-scale via solvothermal method basing on our previous bench scale results. The commercial simulator Aspen Plus was used for process modelling and assuming a plant capacity of 100 tonnes/year. The simulation results were used to perform the cost assessment and profitability analysis while taking into account two relevant cases with (Recycle Case) and without recycling of Ethylenediamine and Hydrazine (Base Case). Note that for the technological and economical assessment the effluent treatment system was not taken into account. The total capital investment was estimated to be ca.14.3 M$ for the base case and ca. 17.4 M$ for recycle case, while the total operating costs were about 2945 $ for the base case and 503 $ for the recycle case for the production of 1 kg of MoS2. Thus, in addition to intrinsic advantages associated with the easier preparation and lower environmental impact of solvothermal method, larger production with recycling option can make the process more economically profitable.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"355 - 368"},"PeriodicalIF":0.9,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46031956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salman S. Alsaeed, M. Nelson, M. Edwards, A. Msmali
Abstract We develop and investigate a model for sludge production in the activated sludge process when a biological reactor is coupled to a sludge disintegration unit (SDU). The model for the biological reactor is a slimmed down version of the activated sludge model 1 in which only processes related to carbon are retained. Consequently, the death-regeneration concept is included in our model which is an improvement on almost all previous models. This provides an improved representation of the total suspended solids in the biological reactor, which is the key parameter of interest. We investigate the steady-state behaviour of this system as a function of the residence time within the biological reactor and as a function of parameters associated with the operation of the SDU. A key parameter is the sludge disintegration factor. As this parameter is increased the concentration of total suspended solids within the biological reactor decreases at the expense increasing the chemical oxygen demand in the effluent stream. The existence of a maximum acceptable chemical oxygen demand in the effluent stream therefore imposes a maximum achievable reduction in the total suspended solids. This paper improves our theoretical understanding of the utility of sludge disintegration as a means to reduce excess sludge formation. As an aside to the main thrust of our paper we investigate the common assumption that the sludge disintegration processes occur on a much shorter timescale than the biological processes. We show that the disintegration processes must be exceptional slow before the inclusion of the biological processes becomes important.
{"title":"A mathematical model for the activated sludge process with a sludge disintegration unit","authors":"Salman S. Alsaeed, M. Nelson, M. Edwards, A. Msmali","doi":"10.1515/cppm-2021-0064","DOIUrl":"https://doi.org/10.1515/cppm-2021-0064","url":null,"abstract":"Abstract We develop and investigate a model for sludge production in the activated sludge process when a biological reactor is coupled to a sludge disintegration unit (SDU). The model for the biological reactor is a slimmed down version of the activated sludge model 1 in which only processes related to carbon are retained. Consequently, the death-regeneration concept is included in our model which is an improvement on almost all previous models. This provides an improved representation of the total suspended solids in the biological reactor, which is the key parameter of interest. We investigate the steady-state behaviour of this system as a function of the residence time within the biological reactor and as a function of parameters associated with the operation of the SDU. A key parameter is the sludge disintegration factor. As this parameter is increased the concentration of total suspended solids within the biological reactor decreases at the expense increasing the chemical oxygen demand in the effluent stream. The existence of a maximum acceptable chemical oxygen demand in the effluent stream therefore imposes a maximum achievable reduction in the total suspended solids. This paper improves our theoretical understanding of the utility of sludge disintegration as a means to reduce excess sludge formation. As an aside to the main thrust of our paper we investigate the common assumption that the sludge disintegration processes occur on a much shorter timescale than the biological processes. We show that the disintegration processes must be exceptional slow before the inclusion of the biological processes becomes important.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"325 - 353"},"PeriodicalIF":0.9,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41822691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This article contributes to handling the Non-Minimum Phase (NMP) system with time delay in the existence of uncertainty and disturbances. The series cascade control scheme is used to overcome such problems. The secondary loop architecture in a series cascade scheme is formulated in the Internal Model Control (IMC) framework. The tuning of fractional-filter via a delayed version of Bodes’ ideal transfer function approach of primary loop controller in a series cascade arrangement shows the novelty of this work. The primary loop controller is designed in the IMC framework after accountability of inverse response and dead-time compensator. Furthermore, Particle Swarm Optimization (PSO) is adapted to accomplish the optimal value of controller settings. The Riemann sheet principle is used to determine stability. The sensitivity investigation is performed to know the robustness of the offered controller. For the effectiveness of the suggested scheme, two case studies are revealed in this paper.
{"title":"Modified optimal series cascade control for non-minimum phase system","authors":"Manish Yadav, H. Patel","doi":"10.1515/cppm-2022-0001","DOIUrl":"https://doi.org/10.1515/cppm-2022-0001","url":null,"abstract":"Abstract This article contributes to handling the Non-Minimum Phase (NMP) system with time delay in the existence of uncertainty and disturbances. The series cascade control scheme is used to overcome such problems. The secondary loop architecture in a series cascade scheme is formulated in the Internal Model Control (IMC) framework. The tuning of fractional-filter via a delayed version of Bodes’ ideal transfer function approach of primary loop controller in a series cascade arrangement shows the novelty of this work. The primary loop controller is designed in the IMC framework after accountability of inverse response and dead-time compensator. Furthermore, Particle Swarm Optimization (PSO) is adapted to accomplish the optimal value of controller settings. The Riemann sheet principle is used to determine stability. The sensitivity investigation is performed to know the robustness of the offered controller. For the effectiveness of the suggested scheme, two case studies are revealed in this paper.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"369 - 381"},"PeriodicalIF":0.9,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45726764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Kokoro as a broadly acknowledge maize snack is being consumed every day by both the children and grown-ups, but it is characterized by the low protein content required for survival. The blending of maize flour (MF), sesame flour (SF) and moringa flour (mF) to enhance the nutritional values of kokoro was optimize with response surface technique (RSM) and artificial neural network (ANN). MF, SF and mF were mixed at diverse proportion and the optimal blending ratio was gotten using D-optimal design method. The protein and carbohydrate actual contents were compared with their predicted values using RSM and ANN models. The performance of the developed RSM and ANN models were validated with coefficient of determination (R2) and mean square error (MSE). The optimal blending ratio of MF: SF: mF was 54.11: 37.06: 8.83. The optimal blending ratio gave 25.53% of protein content and 45.99% of carbohydrate content. The statistical analysis of the experimental data obtained using different statistical techniques shows that regression models by RSM gave R2 of 0.999 for protein yield and 0.983 for carbohydrate yield while ANN gave R2 of 0.999 with MSE 9.24184 × 10−1. Therefore, it can be concluded from the results that both the RSM and ANN gave good prediction of the model.
{"title":"Development of binary models for prediction and optimization of nutritional values of enriched kokoro: a case of response surface methodology (RSM) and artificial neural network (ANN)","authors":"B. K. Adeoye, Olajide Olukayode Ajala, E. Oke","doi":"10.1515/cppm-2022-0011","DOIUrl":"https://doi.org/10.1515/cppm-2022-0011","url":null,"abstract":"Abstract Kokoro as a broadly acknowledge maize snack is being consumed every day by both the children and grown-ups, but it is characterized by the low protein content required for survival. The blending of maize flour (MF), sesame flour (SF) and moringa flour (mF) to enhance the nutritional values of kokoro was optimize with response surface technique (RSM) and artificial neural network (ANN). MF, SF and mF were mixed at diverse proportion and the optimal blending ratio was gotten using D-optimal design method. The protein and carbohydrate actual contents were compared with their predicted values using RSM and ANN models. The performance of the developed RSM and ANN models were validated with coefficient of determination (R2) and mean square error (MSE). The optimal blending ratio of MF: SF: mF was 54.11: 37.06: 8.83. The optimal blending ratio gave 25.53% of protein content and 45.99% of carbohydrate content. The statistical analysis of the experimental data obtained using different statistical techniques shows that regression models by RSM gave R2 of 0.999 for protein yield and 0.983 for carbohydrate yield while ANN gave R2 of 0.999 with MSE 9.24184 × 10−1. Therefore, it can be concluded from the results that both the RSM and ANN gave good prediction of the model.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"313 - 324"},"PeriodicalIF":0.9,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46681488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this work, a dynamic non-isothermal adsorption process of CH4 and CO2 in a fixed bed of SAPO-34 particles was modeled by coupled DEM-CFD. This Euler–Lagrange method gives access to specification of each adsorbent pellet including location, temperature and concentrations, and facilitates study of phenomena like adsorption. Transport phenomena including heat and mass transfer in fluid and between solid and gas were taken into account. Eventually the model was validated by experimental results of breakthrough curve. Especially near wall channeling effect and the role of inlet feed velocity on the bed efficiency were addressed in this work. Local and bulk porosity values calculated using DEM model showed an acceptable agreement with previous empirical equations. Results indicated that this coupled method can be applied as a promising tool to study the mass transfer zone and efficiency of the adsorption process. The results revealed that as the feed continues to flow into the column, the lower layers of the adsorbent particles become practically saturated and then the mass transfer zone starts moving upward to a region of fresher adsorbent in the column. Also, the results showed that, at a low inlet velocity with a low Peclet number (Pe = 0.195), channeling effect is reduced and the diffusion mechanism controls the mass transfer. However, HETP enhances with increase in the feed gas velocity (Pe = 2.25) as well as increase in deviation from plug flow regime, and consequently the adsorption efficiency decreases. HETP decreases drastically at the beginning with increase in interstitial velocity. Increase in the interstitial velocity beyond a particular value of 0.5 cm s−1 leads to increase in the HETP value. This trend and presence of a minimum in this graph were explained based on Van Deemter concept.
摘要在这项工作中，通过耦合DEM-CFD模拟了CH4和CO2在SAPO-34颗粒固定床中的动态非等温吸附过程。这种欧拉-拉格朗日方法可以访问每个吸附剂颗粒的规格，包括位置、温度和浓度，并有助于研究吸附等现象。考虑了流体中以及固体与气体之间的传热传质等传输现象。最后通过穿透曲线的实验结果验证了该模型的正确性。特别是近壁窜流效应和入口进料速度对床层效率的影响。使用DEM模型计算的局部和整体孔隙度值与以前的经验方程显示出可接受的一致性。结果表明，该耦合方法可作为研究吸附过程传质区和效率的一种很有前途的工具。结果表明，随着进料继续流入柱中，吸附剂颗粒的下层实际上变得饱和，然后传质区开始向上移动到柱中较新鲜的吸附剂区域。此外，结果表明，在低Peclet数（Pe=0.195）的低入口速度下，沟道效应降低，扩散机制控制了传质。然而，HETP随着进料气体速度（Pe=2.25）的增加以及与塞流状态的偏差的增加而增强，因此吸附效率降低。HETP在开始时随着间隙速度的增加而急剧下降。间隙速度的增加超过0.5 cm s−1的特定值会导致HETP值的增加。这一趋势和该图中最小值的存在是基于Van Deemter的概念来解释的。
{"title":"Dynamic behavior of CO2 adsorption from CH4 mixture in a packed bed of SAPO-34 by CFD-based modeling","authors":"Ahmad Hoghooghi Bonyad, S. Fatemi, Z. Mansourpour","doi":"10.1515/cppm-2021-0071","DOIUrl":"https://doi.org/10.1515/cppm-2021-0071","url":null,"abstract":"Abstract In this work, a dynamic non-isothermal adsorption process of CH4 and CO2 in a fixed bed of SAPO-34 particles was modeled by coupled DEM-CFD. This Euler–Lagrange method gives access to specification of each adsorbent pellet including location, temperature and concentrations, and facilitates study of phenomena like adsorption. Transport phenomena including heat and mass transfer in fluid and between solid and gas were taken into account. Eventually the model was validated by experimental results of breakthrough curve. Especially near wall channeling effect and the role of inlet feed velocity on the bed efficiency were addressed in this work. Local and bulk porosity values calculated using DEM model showed an acceptable agreement with previous empirical equations. Results indicated that this coupled method can be applied as a promising tool to study the mass transfer zone and efficiency of the adsorption process. The results revealed that as the feed continues to flow into the column, the lower layers of the adsorbent particles become practically saturated and then the mass transfer zone starts moving upward to a region of fresher adsorbent in the column. Also, the results showed that, at a low inlet velocity with a low Peclet number (Pe = 0.195), channeling effect is reduced and the diffusion mechanism controls the mass transfer. However, HETP enhances with increase in the feed gas velocity (Pe = 2.25) as well as increase in deviation from plug flow regime, and consequently the adsorption efficiency decreases. HETP decreases drastically at the beginning with increase in interstitial velocity. Increase in the interstitial velocity beyond a particular value of 0.5 cm s−1 leads to increase in the HETP value. This trend and presence of a minimum in this graph were explained based on Van Deemter concept.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"215 - 229"},"PeriodicalIF":0.9,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47519133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The thermal-hydraulic characteristics and performance of the circular and flattened straight tubes with longitudinal inward microfins are studied with isothermal wall condition and Reynold numbers (Re) between 10,000 and 30,000. The geometric models with fins (8, 12, and 16 fins) and three flattening ratios (1.4, 2, and 3.4) are considered for the simulation. The results indicate that the longitudinal microfins have a limited effect on the improvement of heat transfer, but the application of microfins increases the pressure drop significantly. Furthermore, an increase in Reynolds number increases the heat transfer characteristics. Therefore, a discriminative use of longitudinal microfins for circular tubes to improve thermal performance is advised. Flattening the microfin tubes has shown a significant increase in heat transfer coefficient and friction factor compared to circular cross-section tubes with microfins. The percentage gain in heat transfer with the flattening ratio of 3.4 is about 52% compared to the circular fin tube at Re = 30,000. A 61% increase in centreline velocity is observed at Re = 10,000. Area-based Enhancement Factor (AEF) and performance evolution factor (PEF) are more than 1 for flattened tubes with microfins. It shows an improvement in the overall thermal-hydraulic characteristics of tubes.
{"title":"Numerical study on thermal-hydraulic characteristics of flattened microfin tubes","authors":"Ankit R. Singh, A. K. Solanki","doi":"10.1515/cppm-2022-0005","DOIUrl":"https://doi.org/10.1515/cppm-2022-0005","url":null,"abstract":"Abstract The thermal-hydraulic characteristics and performance of the circular and flattened straight tubes with longitudinal inward microfins are studied with isothermal wall condition and Reynold numbers (Re) between 10,000 and 30,000. The geometric models with fins (8, 12, and 16 fins) and three flattening ratios (1.4, 2, and 3.4) are considered for the simulation. The results indicate that the longitudinal microfins have a limited effect on the improvement of heat transfer, but the application of microfins increases the pressure drop significantly. Furthermore, an increase in Reynolds number increases the heat transfer characteristics. Therefore, a discriminative use of longitudinal microfins for circular tubes to improve thermal performance is advised. Flattening the microfin tubes has shown a significant increase in heat transfer coefficient and friction factor compared to circular cross-section tubes with microfins. The percentage gain in heat transfer with the flattening ratio of 3.4 is about 52% compared to the circular fin tube at Re = 30,000. A 61% increase in centreline velocity is observed at Re = 10,000. Area-based Enhancement Factor (AEF) and performance evolution factor (PEF) are more than 1 for flattened tubes with microfins. It shows an improvement in the overall thermal-hydraulic characteristics of tubes.","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"295 - 312"},"PeriodicalIF":0.9,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46486400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Jarullah, Mustafa A. Ahmed, Ban A. Al-Tabbakh, I. Mujtaba
Abstract In order to meet the environmental legislations related to sulfur content, it is important to find an alternative techniques for deep removal of sulfur components from fuels. So, in this study, a novel nano-catalyst based on iron oxide (Fe2O3) as active component prepared over composite support (γ-Alumina + HY-zeolite) is developed here for efficient removal of sulfur compounds from fuel via oxidation process. The precipitation method is employed first to prepare the composite support and then the impregnation method is utilized to generate a novel synthetic homemade (Fe2O3/composite support) nanocatalysts that has not been developed in the literature (iron oxide over composite support). The characterizations of the prepared catalysts display that the surface area of the catalyst increases with increasing the amount of Y-zeolite in composite support. The effectiveness of the catalysts is tested by utilizing oxidative desulfurization (ODS) operation under several operating conditions. The results of the experimental work show that the activity of oxidative desulfurization enhances with increasing Y-zeolite, temperature, and batch time under moderate operating conditions. The oxidative desulfurization efficiency followed the order: CAT-1 < CAT-2 < CAT-3. The CAT-3 performed the high removal of sulfur compounds (90.73%) at 100 min and 423 K. The best values of the kinetic parameters of the ODS process are then determined based on experimental data and model based techniques within gPROMS package. Finally, the reactor model is used to determine the optimal operating conditions while maximizing the removal of sulfur compounds leading to cleaner fuel. Where, 99.3% of the sulfur removal has achieved at batch time of 190.6 min, temperature of 543.56 K and initial sulfur content at 0.8668 wt% in the presence of CAT-3 based on the optimal kinetic parameters (order of reaction (n) of 1.9865719, activation energy (EA) at 29.942 kJ/mol and pre-exponential factor (k 0) with 622.926 wt−0.9865719 min−1).
{"title":"Design of a new synthetic nanocatalyst resulting high fuel quality based on multiple supports: experimental investigation and modeling","authors":"A. Jarullah, Mustafa A. Ahmed, Ban A. Al-Tabbakh, I. Mujtaba","doi":"10.1515/cppm-2021-0073","DOIUrl":"https://doi.org/10.1515/cppm-2021-0073","url":null,"abstract":"Abstract In order to meet the environmental legislations related to sulfur content, it is important to find an alternative techniques for deep removal of sulfur components from fuels. So, in this study, a novel nano-catalyst based on iron oxide (Fe2O3) as active component prepared over composite support (γ-Alumina + HY-zeolite) is developed here for efficient removal of sulfur compounds from fuel via oxidation process. The precipitation method is employed first to prepare the composite support and then the impregnation method is utilized to generate a novel synthetic homemade (Fe2O3/composite support) nanocatalysts that has not been developed in the literature (iron oxide over composite support). The characterizations of the prepared catalysts display that the surface area of the catalyst increases with increasing the amount of Y-zeolite in composite support. The effectiveness of the catalysts is tested by utilizing oxidative desulfurization (ODS) operation under several operating conditions. The results of the experimental work show that the activity of oxidative desulfurization enhances with increasing Y-zeolite, temperature, and batch time under moderate operating conditions. The oxidative desulfurization efficiency followed the order: CAT-1 < CAT-2 < CAT-3. The CAT-3 performed the high removal of sulfur compounds (90.73%) at 100 min and 423 K. The best values of the kinetic parameters of the ODS process are then determined based on experimental data and model based techniques within gPROMS package. Finally, the reactor model is used to determine the optimal operating conditions while maximizing the removal of sulfur compounds leading to cleaner fuel. Where, 99.3% of the sulfur removal has achieved at batch time of 190.6 min, temperature of 543.56 K and initial sulfur content at 0.8668 wt% in the presence of CAT-3 based on the optimal kinetic parameters (order of reaction (n) of 1.9865719, activation energy (EA) at 29.942 kJ/mol and pre-exponential factor (k 0) with 622.926 wt−0.9865719 min−1).","PeriodicalId":9935,"journal":{"name":"Chemical Product and Process Modeling","volume":"18 1","pages":"265 - 293"},"PeriodicalIF":0.9,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46358372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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