Hui Li, Xuexue Wei, J. Liang, Weigang Cao, Zongying Cai, Yu Yang
CaCl2 molten salt, as a common electrolyte in the process of molten salt electrolysis, has a high decomposition potential and a strong ability to bind O2−. So the study of the structure and properties of CaCl2 is significant for the molten salt electrolysis. In this paper, molecular dynamics simulations (MD) method was used to investigate the variation rule of the local structure and physicochemical properties of CaCl2 molten salt with temperature. The results show that the temperature has less effect on the heterozygous ion pairs and more effect on the homozygous ion pair. With the increase of temperature, the interaction between ion pairs is weakened, the coordination number decreases, the local structure changes a little, and the structural configuration tends to be an irregular octahedral structure with vacancies. The calculated self-diffusion coefficients, viscosities, and ionic conductivities are consistent well with the reality, but there is a significant error in densities due to the strong polarization effect of Ca2+ compared to the reality. The local structure directly determines the thermodynamic properties of the molten salts. This study promotes the basic theoretical research on alkaline earth metal-containing molten salts and is an important reference for the study of molten salt electrolysis process.
{"title":"Molecular dynamics simulations of the local structure and physicochemical properties of CaCl2 molten salt","authors":"Hui Li, Xuexue Wei, J. Liang, Weigang Cao, Zongying Cai, Yu Yang","doi":"10.1515/ijcre-2023-0228","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0228","url":null,"abstract":"\u0000 CaCl2 molten salt, as a common electrolyte in the process of molten salt electrolysis, has a high decomposition potential and a strong ability to bind O2−. So the study of the structure and properties of CaCl2 is significant for the molten salt electrolysis. In this paper, molecular dynamics simulations (MD) method was used to investigate the variation rule of the local structure and physicochemical properties of CaCl2 molten salt with temperature. The results show that the temperature has less effect on the heterozygous ion pairs and more effect on the homozygous ion pair. With the increase of temperature, the interaction between ion pairs is weakened, the coordination number decreases, the local structure changes a little, and the structural configuration tends to be an irregular octahedral structure with vacancies. The calculated self-diffusion coefficients, viscosities, and ionic conductivities are consistent well with the reality, but there is a significant error in densities due to the strong polarization effect of Ca2+ compared to the reality. The local structure directly determines the thermodynamic properties of the molten salts. This study promotes the basic theoretical research on alkaline earth metal-containing molten salts and is an important reference for the study of molten salt electrolysis process.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"201 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139848629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hui Li, Xuexue Wei, J. Liang, Weigang Cao, Zongying Cai, Yu Yang
CaCl2 molten salt, as a common electrolyte in the process of molten salt electrolysis, has a high decomposition potential and a strong ability to bind O2−. So the study of the structure and properties of CaCl2 is significant for the molten salt electrolysis. In this paper, molecular dynamics simulations (MD) method was used to investigate the variation rule of the local structure and physicochemical properties of CaCl2 molten salt with temperature. The results show that the temperature has less effect on the heterozygous ion pairs and more effect on the homozygous ion pair. With the increase of temperature, the interaction between ion pairs is weakened, the coordination number decreases, the local structure changes a little, and the structural configuration tends to be an irregular octahedral structure with vacancies. The calculated self-diffusion coefficients, viscosities, and ionic conductivities are consistent well with the reality, but there is a significant error in densities due to the strong polarization effect of Ca2+ compared to the reality. The local structure directly determines the thermodynamic properties of the molten salts. This study promotes the basic theoretical research on alkaline earth metal-containing molten salts and is an important reference for the study of molten salt electrolysis process.
{"title":"Molecular dynamics simulations of the local structure and physicochemical properties of CaCl2 molten salt","authors":"Hui Li, Xuexue Wei, J. Liang, Weigang Cao, Zongying Cai, Yu Yang","doi":"10.1515/ijcre-2023-0228","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0228","url":null,"abstract":"\u0000 CaCl2 molten salt, as a common electrolyte in the process of molten salt electrolysis, has a high decomposition potential and a strong ability to bind O2−. So the study of the structure and properties of CaCl2 is significant for the molten salt electrolysis. In this paper, molecular dynamics simulations (MD) method was used to investigate the variation rule of the local structure and physicochemical properties of CaCl2 molten salt with temperature. The results show that the temperature has less effect on the heterozygous ion pairs and more effect on the homozygous ion pair. With the increase of temperature, the interaction between ion pairs is weakened, the coordination number decreases, the local structure changes a little, and the structural configuration tends to be an irregular octahedral structure with vacancies. The calculated self-diffusion coefficients, viscosities, and ionic conductivities are consistent well with the reality, but there is a significant error in densities due to the strong polarization effect of Ca2+ compared to the reality. The local structure directly determines the thermodynamic properties of the molten salts. This study promotes the basic theoretical research on alkaline earth metal-containing molten salts and is an important reference for the study of molten salt electrolysis process.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":" 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139788864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to promote the yield and calorific value of combustible gas products in the pyrolysis, a CaO-based biochar (CSC) derived from waste crab shell was used as a low-cost sorption-enhanced catalyst to enhance oil-fried sludge (OS) pyrolysis. The effects of CSC addition and pyrolysis temperature on OS pyrolysis characteristics were analyzed in detail. The results indicated that adding CSC significantly enhanced OS pyrolysis and produced more combustible gas products with CO2 removal. At 700 °C, adding CSC promoted the combustible gas yields and greatly reduced CO2 by 96.9 %. And the corresponding LHV of pyrolysis gas products increased by 26.8 % and reached up to 33.7 MJ/N m3. Additionally, TG-FTIR analysis revealed that adding CSC reduced the formation temperature of CH4. Importantly, although there was only 35.5 wt% of Ca in CSC, CSC exhibited almost the same sorption-catalysis-enhanced effects compared to pure CaO. These findings suggest that biochar derived from crab shell has the potential to replace CaO for enhancing sludge pyrolysis into value-added fuel products.
{"title":"Sorption-catalysis-enhanced effects of crab shell derived CaO-based biochar addition on the pyrolysis of waste cooking oil fried sludge","authors":"Yanhua Li, Long Wu, Qing Xu, Zhanyong Li","doi":"10.1515/ijcre-2023-0107","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0107","url":null,"abstract":"\u0000 In order to promote the yield and calorific value of combustible gas products in the pyrolysis, a CaO-based biochar (CSC) derived from waste crab shell was used as a low-cost sorption-enhanced catalyst to enhance oil-fried sludge (OS) pyrolysis. The effects of CSC addition and pyrolysis temperature on OS pyrolysis characteristics were analyzed in detail. The results indicated that adding CSC significantly enhanced OS pyrolysis and produced more combustible gas products with CO2 removal. At 700 °C, adding CSC promoted the combustible gas yields and greatly reduced CO2 by 96.9 %. And the corresponding LHV of pyrolysis gas products increased by 26.8 % and reached up to 33.7 MJ/N m3. Additionally, TG-FTIR analysis revealed that adding CSC reduced the formation temperature of CH4. Importantly, although there was only 35.5 wt% of Ca in CSC, CSC exhibited almost the same sorption-catalysis-enhanced effects compared to pure CaO. These findings suggest that biochar derived from crab shell has the potential to replace CaO for enhancing sludge pyrolysis into value-added fuel products.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":" 14","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139791079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to promote the yield and calorific value of combustible gas products in the pyrolysis, a CaO-based biochar (CSC) derived from waste crab shell was used as a low-cost sorption-enhanced catalyst to enhance oil-fried sludge (OS) pyrolysis. The effects of CSC addition and pyrolysis temperature on OS pyrolysis characteristics were analyzed in detail. The results indicated that adding CSC significantly enhanced OS pyrolysis and produced more combustible gas products with CO2 removal. At 700 °C, adding CSC promoted the combustible gas yields and greatly reduced CO2 by 96.9 %. And the corresponding LHV of pyrolysis gas products increased by 26.8 % and reached up to 33.7 MJ/N m3. Additionally, TG-FTIR analysis revealed that adding CSC reduced the formation temperature of CH4. Importantly, although there was only 35.5 wt% of Ca in CSC, CSC exhibited almost the same sorption-catalysis-enhanced effects compared to pure CaO. These findings suggest that biochar derived from crab shell has the potential to replace CaO for enhancing sludge pyrolysis into value-added fuel products.
{"title":"Sorption-catalysis-enhanced effects of crab shell derived CaO-based biochar addition on the pyrolysis of waste cooking oil fried sludge","authors":"Yanhua Li, Long Wu, Qing Xu, Zhanyong Li","doi":"10.1515/ijcre-2023-0107","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0107","url":null,"abstract":"\u0000 In order to promote the yield and calorific value of combustible gas products in the pyrolysis, a CaO-based biochar (CSC) derived from waste crab shell was used as a low-cost sorption-enhanced catalyst to enhance oil-fried sludge (OS) pyrolysis. The effects of CSC addition and pyrolysis temperature on OS pyrolysis characteristics were analyzed in detail. The results indicated that adding CSC significantly enhanced OS pyrolysis and produced more combustible gas products with CO2 removal. At 700 °C, adding CSC promoted the combustible gas yields and greatly reduced CO2 by 96.9 %. And the corresponding LHV of pyrolysis gas products increased by 26.8 % and reached up to 33.7 MJ/N m3. Additionally, TG-FTIR analysis revealed that adding CSC reduced the formation temperature of CH4. Importantly, although there was only 35.5 wt% of Ca in CSC, CSC exhibited almost the same sorption-catalysis-enhanced effects compared to pure CaO. These findings suggest that biochar derived from crab shell has the potential to replace CaO for enhancing sludge pyrolysis into value-added fuel products.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"77 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139850980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explores and analyzes the mixing efficiency of five innovative micromixers, each featuring serpentine microchannels, through comprehensive experimentation. The mixing experiments were conducted on micromixers with distinct shapes: backward arrow, loop, square, circular, and box waves, all equipped with backward arrow-shaped inlets, using the Villermaux–Dushman protocol. The assessment of mixing performance was carried out across a range of Reynolds numbers (Re) from 100 to 700, accompanied by varying pressure drop measurements. The efficiency of mixing was determined using ultraviolet spectrophotometry to measure the absorbance values and times for mixed fluids from the five micromixers. At Re values greater than 100, the mixing performance ranked as follows: Square-wave > Circular-wave > Box-wave > Loop-wave > Backward Arrow-shaped micromixers. Factors such as repeated perturbations, the presence of crests and troughs, the angle of the channels, and the split and recombination effects played significant roles in these outcomes. With increasing Re from 100 to 700, we observed progressive and consistent results across all microchannels. Remarkably, at a broad range of Reynolds numbers, the five micromixers demonstrated superior mixing performance compared to designs based on unbalanced split and collisions, achieving an impressive mixing efficiency of over 93 %, while keeping the pressure drop under 80 kPa. This pressure drop range is suitable for a variety of lab-on-a-chip and micro-total analysis systems. Furthermore, the experimental results show that the mixing performance of microfluidic systems can be improved by incorporating the presented design method of microchannel shapes, especially the Square-wave.
{"title":"Investigations of the mixing efficiency of five novel micromixer designs with backward arrow inlet using the Villermaux Dushman protocol","authors":"Kingsley Safo, Joshua Anani, A. H. El-Shazly","doi":"10.1515/ijcre-2023-0110","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0110","url":null,"abstract":"\u0000 This study explores and analyzes the mixing efficiency of five innovative micromixers, each featuring serpentine microchannels, through comprehensive experimentation. The mixing experiments were conducted on micromixers with distinct shapes: backward arrow, loop, square, circular, and box waves, all equipped with backward arrow-shaped inlets, using the Villermaux–Dushman protocol. The assessment of mixing performance was carried out across a range of Reynolds numbers (Re) from 100 to 700, accompanied by varying pressure drop measurements. The efficiency of mixing was determined using ultraviolet spectrophotometry to measure the absorbance values and times for mixed fluids from the five micromixers. At Re values greater than 100, the mixing performance ranked as follows: Square-wave > Circular-wave > Box-wave > Loop-wave > Backward Arrow-shaped micromixers. Factors such as repeated perturbations, the presence of crests and troughs, the angle of the channels, and the split and recombination effects played significant roles in these outcomes. With increasing Re from 100 to 700, we observed progressive and consistent results across all microchannels. Remarkably, at a broad range of Reynolds numbers, the five micromixers demonstrated superior mixing performance compared to designs based on unbalanced split and collisions, achieving an impressive mixing efficiency of over 93 %, while keeping the pressure drop under 80 kPa. This pressure drop range is suitable for a variety of lab-on-a-chip and micro-total analysis systems. Furthermore, the experimental results show that the mixing performance of microfluidic systems can be improved by incorporating the presented design method of microchannel shapes, especially the Square-wave.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"168 1-4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139877885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explores and analyzes the mixing efficiency of five innovative micromixers, each featuring serpentine microchannels, through comprehensive experimentation. The mixing experiments were conducted on micromixers with distinct shapes: backward arrow, loop, square, circular, and box waves, all equipped with backward arrow-shaped inlets, using the Villermaux–Dushman protocol. The assessment of mixing performance was carried out across a range of Reynolds numbers (Re) from 100 to 700, accompanied by varying pressure drop measurements. The efficiency of mixing was determined using ultraviolet spectrophotometry to measure the absorbance values and times for mixed fluids from the five micromixers. At Re values greater than 100, the mixing performance ranked as follows: Square-wave > Circular-wave > Box-wave > Loop-wave > Backward Arrow-shaped micromixers. Factors such as repeated perturbations, the presence of crests and troughs, the angle of the channels, and the split and recombination effects played significant roles in these outcomes. With increasing Re from 100 to 700, we observed progressive and consistent results across all microchannels. Remarkably, at a broad range of Reynolds numbers, the five micromixers demonstrated superior mixing performance compared to designs based on unbalanced split and collisions, achieving an impressive mixing efficiency of over 93 %, while keeping the pressure drop under 80 kPa. This pressure drop range is suitable for a variety of lab-on-a-chip and micro-total analysis systems. Furthermore, the experimental results show that the mixing performance of microfluidic systems can be improved by incorporating the presented design method of microchannel shapes, especially the Square-wave.
{"title":"Investigations of the mixing efficiency of five novel micromixer designs with backward arrow inlet using the Villermaux Dushman protocol","authors":"Kingsley Safo, Joshua Anani, A. H. El-Shazly","doi":"10.1515/ijcre-2023-0110","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0110","url":null,"abstract":"\u0000 This study explores and analyzes the mixing efficiency of five innovative micromixers, each featuring serpentine microchannels, through comprehensive experimentation. The mixing experiments were conducted on micromixers with distinct shapes: backward arrow, loop, square, circular, and box waves, all equipped with backward arrow-shaped inlets, using the Villermaux–Dushman protocol. The assessment of mixing performance was carried out across a range of Reynolds numbers (Re) from 100 to 700, accompanied by varying pressure drop measurements. The efficiency of mixing was determined using ultraviolet spectrophotometry to measure the absorbance values and times for mixed fluids from the five micromixers. At Re values greater than 100, the mixing performance ranked as follows: Square-wave > Circular-wave > Box-wave > Loop-wave > Backward Arrow-shaped micromixers. Factors such as repeated perturbations, the presence of crests and troughs, the angle of the channels, and the split and recombination effects played significant roles in these outcomes. With increasing Re from 100 to 700, we observed progressive and consistent results across all microchannels. Remarkably, at a broad range of Reynolds numbers, the five micromixers demonstrated superior mixing performance compared to designs based on unbalanced split and collisions, achieving an impressive mixing efficiency of over 93 %, while keeping the pressure drop under 80 kPa. This pressure drop range is suitable for a variety of lab-on-a-chip and micro-total analysis systems. Furthermore, the experimental results show that the mixing performance of microfluidic systems can be improved by incorporating the presented design method of microchannel shapes, especially the Square-wave.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"21 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139817847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Chloride molten salt systems are widely used as electrolytes for molten salt electrolysis because of their relatively low eutectic temperatures and good thermal stability, but there is a serious lack of data on the thermophysical properties of chloride molten salts at elevated temperatures, whereas the nature of the electrolyte is very important for the electrolysis process. In this paper, the variation of the microstructure and thermophysical properties of the binary mixed LiCl–CaCl2 molten salt system with temperature and composition is calculated using molecular dynamics (MD) simulations based on the BMH potential. The microscopic conformations observed in LiCl–CaCl2 molten salts are mainly irregular, distorted tetrahedra and octahedra, which dynamically coexist, as analyzed by the radial distribution function, coordination number and angular distribution function. In addition, the effects of temperature and composition on the density, ionic self-diffusion coefficient, shear viscosity, and ionic conductivity of the molten salts were investigated, and the relationships of the thermophysical properties of LiCl–CaCl2 molten salts with temperature and composition were obtained, which provide fundamental thermophysical data for the molten salt electrolytes.
{"title":"Molecular dynamics simulation of microstructure and thermophysical properties of LiCl–CaCl2 eutectic molten salt","authors":"J. Liang, Huilin Zhang, Dongxing Huo, Hui Li","doi":"10.1515/ijcre-2023-0221","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0221","url":null,"abstract":"Abstract Chloride molten salt systems are widely used as electrolytes for molten salt electrolysis because of their relatively low eutectic temperatures and good thermal stability, but there is a serious lack of data on the thermophysical properties of chloride molten salts at elevated temperatures, whereas the nature of the electrolyte is very important for the electrolysis process. In this paper, the variation of the microstructure and thermophysical properties of the binary mixed LiCl–CaCl2 molten salt system with temperature and composition is calculated using molecular dynamics (MD) simulations based on the BMH potential. The microscopic conformations observed in LiCl–CaCl2 molten salts are mainly irregular, distorted tetrahedra and octahedra, which dynamically coexist, as analyzed by the radial distribution function, coordination number and angular distribution function. In addition, the effects of temperature and composition on the density, ionic self-diffusion coefficient, shear viscosity, and ionic conductivity of the molten salts were investigated, and the relationships of the thermophysical properties of LiCl–CaCl2 molten salts with temperature and composition were obtained, which provide fundamental thermophysical data for the molten salt electrolytes.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"12 12","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139380186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rahul V. Prajapati, Sanjay Srivastava, G. Jadeja, J. Parikh
Abstract In the present work, furfuryl alcohol (FAL) alcoholysis towards ethyl levulinate (EL) was studied over a mesoporous SO3H-SBA-15 catalyst. The effect of various operating parameters i.e., temperature, catalyst dose, furfuryl alcohol amount, and time was studied and optimized via robust Response Surface Methodology through central composite rotatable designs (CCRD) method on the conversion of FAL to EL. According to Response Surface Methodology, under optimum reaction conditions viz. temperature 110 °C, catalyst dose 0.42 g, time 3 h, and FAL amount of 1.46 g, maximum EL yield (95 %) was recorded. Further, the effect of reaction parameters on the kinetics of the said reaction was also examined, suggesting the second-order kinetic concerning all operating parameters. Eventually, the reusability of the catalyst is evident in a decrease of almost 40 % yield towards EL in the fourth cycle.
{"title":"Optimization and kinetics study for the conversion of furfuryl alcohol towards ethyl levulinate using sulfonic acid functionalized catalyst","authors":"Rahul V. Prajapati, Sanjay Srivastava, G. Jadeja, J. Parikh","doi":"10.1515/ijcre-2023-0133","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0133","url":null,"abstract":"Abstract In the present work, furfuryl alcohol (FAL) alcoholysis towards ethyl levulinate (EL) was studied over a mesoporous SO3H-SBA-15 catalyst. The effect of various operating parameters i.e., temperature, catalyst dose, furfuryl alcohol amount, and time was studied and optimized via robust Response Surface Methodology through central composite rotatable designs (CCRD) method on the conversion of FAL to EL. According to Response Surface Methodology, under optimum reaction conditions viz. temperature 110 °C, catalyst dose 0.42 g, time 3 h, and FAL amount of 1.46 g, maximum EL yield (95 %) was recorded. Further, the effect of reaction parameters on the kinetics of the said reaction was also examined, suggesting the second-order kinetic concerning all operating parameters. Eventually, the reusability of the catalyst is evident in a decrease of almost 40 % yield towards EL in the fourth cycle.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"21 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139380120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shenzhou Ni, Tong Zhao, Zehui Sun, Wei Wang, Kuizu Su
Abstract The operational efficiency of the airlift reactors relies significantly on the aeration and mixing provided by the inlet system. The diffused aeration system is the most energy-intensive component affecting the operation of the bioreactor, accounting for 45–75 % of the energy costs. This study presents a coupled CFD-PBM to investigate the collective impacts of multiple bubble diameters, variations in inlet gas distribution types, and flow rates on the hydrodynamic characteristics of bubble columns. The simulation results were validated through comprehensive comparisons with experimental data. The experimental data and simulations of the single bubble size model (SBSM) and multi-bubble size model (MBSM) were compared, proposing an enhanced inlet gas distribution type. The results indicate a close resemblance between the MBSM data and the experimental results, with an error margin not exceeding 5 %. Moreover, different flow rates were found to cause varying sensitivities in the bubble size distribution (BSD) within the column. Furthermore, the simulation results validate the similarity between lift coefficients and critical diameters to experiments and shed light on favorable conditions for reactor design. The key findings of this study encompass: (1) the use of MBSM can accurately predict the tower system characteristics; (2) the column circulation is intensified with small inlet bubble size and high gas velocity, which is favorable for chemical reactions and microbial aggregation to proceed; and (3) the BSD is not sensitive to the inlet gas distribution type at high flow rates.
{"title":"CFD simulation for comparative of hydrodynamic effects in biochemical reactors using population balance model with varied inlet gas distribution profiles","authors":"Shenzhou Ni, Tong Zhao, Zehui Sun, Wei Wang, Kuizu Su","doi":"10.1515/ijcre-2023-0167","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0167","url":null,"abstract":"Abstract The operational efficiency of the airlift reactors relies significantly on the aeration and mixing provided by the inlet system. The diffused aeration system is the most energy-intensive component affecting the operation of the bioreactor, accounting for 45–75 % of the energy costs. This study presents a coupled CFD-PBM to investigate the collective impacts of multiple bubble diameters, variations in inlet gas distribution types, and flow rates on the hydrodynamic characteristics of bubble columns. The simulation results were validated through comprehensive comparisons with experimental data. The experimental data and simulations of the single bubble size model (SBSM) and multi-bubble size model (MBSM) were compared, proposing an enhanced inlet gas distribution type. The results indicate a close resemblance between the MBSM data and the experimental results, with an error margin not exceeding 5 %. Moreover, different flow rates were found to cause varying sensitivities in the bubble size distribution (BSD) within the column. Furthermore, the simulation results validate the similarity between lift coefficients and critical diameters to experiments and shed light on favorable conditions for reactor design. The key findings of this study encompass: (1) the use of MBSM can accurately predict the tower system characteristics; (2) the column circulation is intensified with small inlet bubble size and high gas velocity, which is favorable for chemical reactions and microbial aggregation to proceed; and (3) the BSD is not sensitive to the inlet gas distribution type at high flow rates.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"50 31","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139382211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Anaerobic digestion is a prevailing technology for the treatment and utilization of municipal organic solid waste (MOSW). In this technology, the macromolecular organic matter in waste degrades into small molecular substances through the anaerobic decomposition of microorganisms, producing biogas that can provide enormous energy. This paper focuses on the research progress of anaerobic digestion of various organic wastes for biogas production. The principle and process of anaerobic digestion for biogas production are introduced, along with the key factors affecting anaerobic digestion efficiency, such as temperature, pH, and sealing conditions. At the same time, the current cycle treatment technology and comprehensive treatment system of MOSW are also summarized. Furthermore, the paper explores biogas purification technologies, including desulfurization, deoxidation, drying, and decarbonization. Finally, the state-of-the-art of the utilization of MOSW for biogas production in the world and the problems faced by the utilization of MOSW for biogas production in China are reviewed. By summarizing the anaerobic digestion technology of MOSW, this review hopes to provide some reasonable solutions for the high-value utilization of MOSW.
{"title":"Research progress and perspectives of biogas production from municipal organic solid waste","authors":"Jianbo Zhao, Shan Ren, Chenghong Li, Mengjiao Jiao, Guanzhou Wu, Hongsheng Chen","doi":"10.1515/ijcre-2023-0082","DOIUrl":"https://doi.org/10.1515/ijcre-2023-0082","url":null,"abstract":"Abstract Anaerobic digestion is a prevailing technology for the treatment and utilization of municipal organic solid waste (MOSW). In this technology, the macromolecular organic matter in waste degrades into small molecular substances through the anaerobic decomposition of microorganisms, producing biogas that can provide enormous energy. This paper focuses on the research progress of anaerobic digestion of various organic wastes for biogas production. The principle and process of anaerobic digestion for biogas production are introduced, along with the key factors affecting anaerobic digestion efficiency, such as temperature, pH, and sealing conditions. At the same time, the current cycle treatment technology and comprehensive treatment system of MOSW are also summarized. Furthermore, the paper explores biogas purification technologies, including desulfurization, deoxidation, drying, and decarbonization. Finally, the state-of-the-art of the utilization of MOSW for biogas production in the world and the problems faced by the utilization of MOSW for biogas production in China are reviewed. By summarizing the anaerobic digestion technology of MOSW, this review hopes to provide some reasonable solutions for the high-value utilization of MOSW.","PeriodicalId":51069,"journal":{"name":"International Journal of Chemical Reactor Engineering","volume":"52 7","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139386389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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