Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1863
Dahai Sun, Hui Tian, J. Sun, W. Xu
Cyclohexanol is an organic chemical intermediate product widely used in chemical industry and commonly produced by cyclohexene hydration. Because of the low mutual solubility of cyclohexene and water, the reaction is limited by chemical equilibrium, which has the disadvantage of low conversion of cyclohexene. In this paper, the hydration reaction of cyclohexene catalysed by A-36 cation exchange resin catalyst was analysed by Aspen Plus V8.6 simulation software in the presence of isophorone as cosolvent. The process model of synthesising cyclohexanol by catalytic distillation was verified by process experiments. The simulation experiments were carried out using the process model, and suitable operating conditions of the catalytic distillation column were obtained. These are: ketene feed ratio 1.5, alkene/water ratio 0.5, distillation stage trays 5, reaction stage trays 12, stripping stage trays 6, cyclohexene feed at the 18th tray, water and isophorone feed at the 5th tray, reflux ratio 3, feed ratio (D/F) 0.25. Under these operating conditions, the conversion of cyclohexene can reach 40.63 %.
环己醇是一种广泛应用于化工行业的有机化工中间体产品，通常采用环己烯水化法生产。由于环己烯与水的相互溶解度低，反应受到化学平衡的限制，具有环己烯转化率低的缺点。本文采用Aspen Plus V8.6模拟软件，对A-36阳离子交换树脂催化剂催化环己烯在异佛尔酮为助溶剂下的水化反应进行了分析。通过工艺实验验证了催化精馏法合成环己醇的工艺模型。利用该工艺模型进行了模拟实验，得到了适宜的催化精馏塔操作条件。这些是:烯酮进料比1.5，烯烃/水比0.5，蒸馏级塔板5，反应级塔板12，汽提级塔板6，环己烯进料在第18塔板，水和异佛尔酮进料在第5塔板，回流比3，进料比(D/F) 0.25。在此操作条件下，环己烯的转化率可达40.63%。
{"title":"Reactive Distillation for the Production of Cyclohexanol","authors":"Dahai Sun, Hui Tian, J. Sun, W. Xu","doi":"10.15255/CABEQ.2020.1863","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1863","url":null,"abstract":"Cyclohexanol is an organic chemical intermediate product widely used in chemical industry and commonly produced by cyclohexene hydration. Because of the low mutual solubility of cyclohexene and water, the reaction is limited by chemical equilibrium, which has the disadvantage of low conversion of cyclohexene. In this paper, the hydration reaction of cyclohexene catalysed by A-36 cation exchange resin catalyst was analysed by Aspen Plus V8.6 simulation software in the presence of isophorone as cosolvent. The process model of synthesising cyclohexanol by catalytic distillation was verified by process experiments. The simulation experiments were carried out using the process model, and suitable operating conditions of the catalytic distillation column were obtained. These are: ketene feed ratio 1.5, alkene/water ratio 0.5, distillation stage trays 5, reaction stage trays 12, stripping stage trays 6, cyclohexene feed at the 18th tray, water and isophorone feed at the 5th tray, reflux ratio 3, feed ratio (D/F) 0.25. Under these operating conditions, the conversion of cyclohexene can reach 40.63 %.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1864
Kavita Sharmaa, A. Srivastava, T. Sreekrishnan
The present study focuses on sustainable production of biodegradable polymers by Cupriavidus necator DSMZ 545 using glycerol as substrate. The batch growth and biopolymer production kinetics were established in a 7-L bioreactor, which resulted in a total biomass of 8.88 g L–1 and poly(3-hydroxybutyrate) (PHB) accumulation of 6.76 g L–1. The batch kinetic and independently acquired substrate inhibition data were then used to develop a mathematical model for PHB production process. This was eventually used to design different nutrient feeding strategies under constant feed rate, decreasing feed rate, and pseudo steady state of substrate (glycerol) to optimize the PHB production during fed-batch cultivation. Among all the fed-batch cultivation strategies, the highest PHB accumulation and productivity of 13.12 g L–1 and 0.27 g L–1 h–1, respectively, was achieved in fed-batch bioreactor cultivation where a pseudo steady state with respect to glycerol was maintained.
本文主要研究了以甘油为底物，利用Cupriavidus necator DSMZ 545可持续生产生物可降解聚合物。在7-L的生物反应器中建立了间歇生长和生物聚合物生产动力学，总生物量为8.88 g L-1，聚(3-羟基丁酸酯)(PHB)积累量为6.76 g L-1。然后利用间歇动力学和独立获得的底物抑制数据建立了PHB生产过程的数学模型。最终设计了定投喂率、降低投喂率和底物(甘油)伪稳态下的不同营养投料策略，以优化分批投料培养过程中PHB的产量。在所有补料间歇培养策略中，PHB积累量和生产力最高的是补料间歇生物反应器培养，分别为13.12 g L-1和0.27 g L-1 h-1，并保持甘油的准稳态。
{"title":"Model-based Optimization of Biopolymer Production from Glycerol","authors":"Kavita Sharmaa, A. Srivastava, T. Sreekrishnan","doi":"10.15255/CABEQ.2020.1864","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1864","url":null,"abstract":"The present study focuses on sustainable production of biodegradable polymers by Cupriavidus necator DSMZ 545 using glycerol as substrate. The batch growth and biopolymer production kinetics were established in a 7-L bioreactor, which resulted in a total biomass of 8.88 g L–1 and poly(3-hydroxybutyrate) (PHB) accumulation of 6.76 g L–1. The batch kinetic and independently acquired substrate inhibition data were then used to develop a mathematical model for PHB production process. This was eventually used to design different nutrient feeding strategies under constant feed rate, decreasing feed rate, and pseudo steady state of substrate (glycerol) to optimize the PHB production during fed-batch cultivation. Among all the fed-batch cultivation strategies, the highest PHB accumulation and productivity of 13.12 g L–1 and 0.27 g L–1 h–1, respectively, was achieved in fed-batch bioreactor cultivation where a pseudo steady state with respect to glycerol was maintained.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1825
S. Herceg, Z. U. Andrijic, N. Bolf
This paper presents the development of soft sensor empirical models using support vector machine (SVM) for the continual assessment of 2,3-dimethylbutane and 2-methylpentane mole percentage as important product quality indicators in the refinery isomerisation process. During the model development, critical steps were taken, including selection and pre-processing of the industrial process data, which are broadly discussed in this paper. The SVM model results were compared with dynamic linear output error model and nonlinear Hammerstein-Wiener model. Evaluation of the developed models on independent data sets showed their reliability in the assessment of the component contents. The soft sensors are to be embedded into the process control system, and serve primarily as a replacement during the process analysersb failure and service periods.
{"title":"Support Vector Machine-based Soft Sensors in the Isomerisation Process","authors":"S. Herceg, Z. U. Andrijic, N. Bolf","doi":"10.15255/CABEQ.2020.1825","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1825","url":null,"abstract":"This paper presents the development of soft sensor empirical models using support vector machine (SVM) for the continual assessment of 2,3-dimethylbutane and 2-methylpentane mole percentage as important product quality indicators in the refinery isomerisation process. During the model development, critical steps were taken, including selection and pre-processing of the industrial process data, which are broadly discussed in this paper. The SVM model results were compared with dynamic linear output error model and nonlinear Hammerstein-Wiener model. Evaluation of the developed models on independent data sets showed their reliability in the assessment of the component contents. The soft sensors are to be embedded into the process control system, and serve primarily as a replacement during the process analysersb failure and service periods.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67063840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1901
H. S. Khwayyir, G. Maria, D. Dinculescu
Model-based evaluation of major accident consequences and effects occurring during the transport of dangerous substances presents a great interest, because it allows derivation of relevant conclusions on the cause-effect close relationship. Such a numerical (in-silico) analysis helps to improve safety regulations for the transport of hazardous substances aimed at preventing dramatic accidents causing many deaths, injuries, and structural damage. By using the standard TNT equivalency math model, coupled with the Probit functions technique, the consequences and effects of an accidental blast have been estimated.1,2 The approached case study here refers to the accidental explosion of a truck while transporting 20 t of ammonium nitrate (AN) in the proximity of Mihăileşti village (Romania) on 24 May 2004. The model-based simulated accident consequences and effects match the data taken on the spot after the accident. Multiple simulations lead to deriving relevant conclusions of practiced value for improving the transport safety of hazardous substances.
{"title":"Simulation of the Consequences of the Ammonium Nitrate Explosion Following the Truck Accident Next to MihDileEti Village (Romania) in 2004","authors":"H. S. Khwayyir, G. Maria, D. Dinculescu","doi":"10.15255/CABEQ.2020.1901","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1901","url":null,"abstract":"Model-based evaluation of major accident consequences and effects occurring during the transport of dangerous substances presents a great interest, because it allows derivation of relevant conclusions on the cause-effect close relationship. Such a numerical (in-silico) analysis helps to improve safety regulations for the transport of hazardous substances aimed at preventing dramatic accidents causing many deaths, injuries, and structural damage. By using the standard TNT equivalency math model, coupled with the Probit functions technique, the consequences and effects of an accidental blast have been estimated.1,2 The approached case study here refers to the accidental explosion of a truck while transporting 20 t of ammonium nitrate (AN) in the proximity of Mihăileşti village (Romania) on 24 May 2004. The model-based simulated accident consequences and effects match the data taken on the spot after the accident. Multiple simulations lead to deriving relevant conclusions of practiced value for improving the transport safety of hazardous substances.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1865
Bahareh Feizi-Afshar, A. Farzi
In this study, a reactive distillation column for production of isopropanol was investigated. Firstly, a dynamic model was developed for the process. The model of the process was then programmed, and the process simulated using a base case obtained from the literature. Results showed that distillate contained more than 58 mol% propylene-free isopropanol. In the next step, optimization of some operating variables was performed to maximize concentration of isopropanol in distillate with condenser temperature as constraint, which was considered to be above the freezing point of water. Several simulations were performed by changing operating parameters, and finally optimum isopropanol content in distillate was obtained above 58 mol%. Results of using classic controllers showed that PID controller had the best performance for both condenser temperature set-point tracking and disturbance rejection.
{"title":"Dynamic Simulation, Parameter Optimization, and Control of a Reactive Distillation Column for Production of Isopropanol via Propylene Hydration","authors":"Bahareh Feizi-Afshar, A. Farzi","doi":"10.15255/CABEQ.2020.1865","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1865","url":null,"abstract":"In this study, a reactive distillation column for production of isopropanol was investigated. Firstly, a dynamic model was developed for the process. The model of the process was then programmed, and the process simulated using a base case obtained from the literature. Results showed that distillate contained more than 58 mol% propylene-free isopropanol. In the next step, optimization of some operating variables was performed to maximize concentration of isopropanol in distillate with condenser temperature as constraint, which was considered to be above the freezing point of water. Several simulations were performed by changing operating parameters, and finally optimum isopropanol content in distillate was obtained above 58 mol%. Results of using classic controllers showed that PID controller had the best performance for both condenser temperature set-point tracking and disturbance rejection.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1849
O. Bég, B. Vasu, A. Ray, T. Bég, A. Kadir, H. Leonard, R. Gorla
Non-Newtonian flow from a wedge constitutes a fundamental problem in chemical engineering systems and is relevant to processing of polymers, coating systems, etc. Motivated by such applications, the homotopy analysis method (HAM) was employed to obtain semi-analytical solutions for thermal convection boundary layer flow of incompressible micropolar fluid from a two-dimensional body (wedge). Viscous dissipation and heat sink effects were included. The non-dimensional boundary value problem emerges as a system of nonlinear coupled ordinary differential equations, by virtue of suitable coordinate transformations. The so-called Falkner-Skan flow cases are elaborated. Validation of the HAM solutions was achieved with earlier simpler models, as well as with a Nakamura finite difference method for the general model. The micropolar model employed simulates certain polymeric solutions quite accurately, and features rotary motions of micro-elements. Primary and secondary shear stress, wall couple stress, Nusselt number, microrotation velocity, and temperature were computed for the effect of vortex viscosity parameter (micropolar rheological), Eckert number (viscous dissipation), Falkner-Skan (pressure gradient) parameter, micro-inertia density, and heat sink parameter. The special cases of Blasius and stagnation flow were also addressed. It was observed from the study that the temperature and thermal boundary layer thickness are both suppressed with increasing wedge parameter and wall heat sink effect, which is beneficial to temperature regulation in polymer coating dynamics. Further, strong reverse spin was generated in the microrotation with increasing vortex viscosity, which resulted in increase in angular momentum boundary layer thickness. Also, both primary and secondary skin friction components were reduced with increasing wedge parameter. Nusselt number was also enhanced substantially with greater wedge parameter.
{"title":"Homotopy Simulation of Dissipative Micropolar Flow and Heat Transfer from a Two-Dimensional Body with Heat Sink Effect","authors":"O. Bég, B. Vasu, A. Ray, T. Bég, A. Kadir, H. Leonard, R. Gorla","doi":"10.15255/CABEQ.2020.1849","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1849","url":null,"abstract":"Non-Newtonian flow from a wedge constitutes a fundamental problem in chemical engineering systems and is relevant to processing of polymers, coating systems, etc. Motivated by such applications, the homotopy analysis method (HAM) was employed to obtain semi-analytical solutions for thermal convection boundary layer flow of incompressible micropolar fluid from a two-dimensional body (wedge). Viscous dissipation and heat sink effects were included. The non-dimensional boundary value problem emerges as a system of nonlinear coupled ordinary differential equations, by virtue of suitable coordinate transformations. The so-called Falkner-Skan flow cases are elaborated. Validation of the HAM solutions was achieved with earlier simpler models, as well as with a Nakamura finite difference method for the general model. The micropolar model employed simulates certain polymeric solutions quite accurately, and features rotary motions of micro-elements. Primary and secondary shear stress, wall couple stress, Nusselt number, microrotation velocity, and temperature were computed for the effect of vortex viscosity parameter (micropolar rheological), Eckert number (viscous dissipation), Falkner-Skan (pressure gradient) parameter, micro-inertia density, and heat sink parameter. The special cases of Blasius and stagnation flow were also addressed. It was observed from the study that the temperature and thermal boundary layer thickness are both suppressed with increasing wedge parameter and wall heat sink effect, which is beneficial to temperature regulation in polymer coating dynamics. Further, strong reverse spin was generated in the microrotation with increasing vortex viscosity, which resulted in increase in angular momentum boundary layer thickness. Also, both primary and secondary skin friction components were reduced with increasing wedge parameter. Nusselt number was also enhanced substantially with greater wedge parameter.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87365451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1899
M. Matsumoto, K. Nakao, Y. Tahara
The effect of bio-imprinting and water activity on catalytic activities and the thermostability of lipases was investigated for transesterification using vinyl acetate and benzyl alcohol as substrates in ionic liquid, [Cnmim][PF6] (n=4,6,8), and benzene. The catalytic activities were enhanced by imprinting in benzene and [C4mim][PF6], and the relations between the transesterification activities and the water activity in both solvents were approximately bell shaped. The reactivity of the transesterification in benzene was higher than that in [C4mim][PF6]. The effects of water activity and imprinting on the kinetic parameters in [C4mim][PF6] were examined. Without controlling the water content, the values of Km,VA and Km,BA (Michaelis constants of vinyl acetate and benzyl alcohol, respectively) decreased, and the values of Vm (maximum rate) increased by imprinting. On the other hand, by controlling the water content in the organic media, the values of Vm, Km,VA, and Km,BA increased by imprinting. The activities of lipase in ionic liquid are more strongly affected by water activity and imprinting than those in benzene. We observed effects of water activity on thermostability but none from imprinting.
{"title":"Effects of Imprinting and Water Activity on Transesterification and Thermostability with Lipases in Ionic Liquid","authors":"M. Matsumoto, K. Nakao, Y. Tahara","doi":"10.15255/CABEQ.2020.1899","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1899","url":null,"abstract":"The effect of bio-imprinting and water activity on catalytic activities and the thermostability of lipases was investigated for transesterification using vinyl acetate and benzyl alcohol as substrates in ionic liquid, [Cnmim][PF6] (n=4,6,8), and benzene. The catalytic activities were enhanced by imprinting in benzene and [C4mim][PF6], and the relations between the transesterification activities and the water activity in both solvents were approximately bell shaped. The reactivity of the transesterification in benzene was higher than that in [C4mim][PF6]. The effects of water activity and imprinting on the kinetic parameters in [C4mim][PF6] were examined. Without controlling the water content, the values of Km,VA and Km,BA (Michaelis constants of vinyl acetate and benzyl alcohol, respectively) decreased, and the values of Vm (maximum rate) increased by imprinting. On the other hand, by controlling the water content in the organic media, the values of Vm, Km,VA, and Km,BA increased by imprinting. The activities of lipase in ionic liquid are more strongly affected by water activity and imprinting than those in benzene. We observed effects of water activity on thermostability but none from imprinting.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1909
M. Dükkancı
Efficient decolorization of Rhodamine 6G dye (Rh 6G) using magnetic TiO2@ Fe3O4/FeZSM-5 photocatalyst was carried out in a batch reactor equipped with two visible lights (high-pressure Na lamps). The photocatalyst was synthesized and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, diffuse reflectance spectroscopy and vibrating sample magnetometry. The effects of initial Rh 6G concentration, catalyst loading, and pH were investigated on photocatalytic oxidation of Rh 6G. Maximum decolorization of 98.2 % was found at optimum conditions of 20 ppm Rh 6G, 1 g L–1 of catalyst, and pH of 13.04. Central composite design was used for the optimization of photocatalytic degradation of Rh 6G. Predicted decolorization efficiencies were found to be in good agreement with experimental values with high regression coefficient of 98.8 %. In addition to color removal, the toxicity of the Rh 6G aqueous solution was significantly reduced after photocatalytic oxidation. Small reduction of activity (from 34.6 % to 30.5 %) showed the stability of the catalyst after three consecutive runs. Due to the magnetic property of the catalyst, it could be removed from the solution with the help of external magnetic field. This prevents the loss of catalyst and reduces the extra separation cost, which is desired in industrial or large-scale applications.
在配备两盏可见光(高压钠灯)的间歇式反应器中，采用磁性TiO2@ Fe3O4/FeZSM-5光催化剂对罗丹明6G染料(Rh 6G)进行了高效脱色。合成了光催化剂，并用x射线衍射、扫描电镜、x射线能谱、漫反射光谱和振动样品磁强计对其进行了表征。考察了初始Rh 6G浓度、催化剂负载和pH对Rh 6G光催化氧化的影响。在Rh为20 ppm、催化剂为1 g L-1、pH为13.04的条件下，脱色率达到98.2%。采用中心复合设计优化光催化降解Rh 6G的工艺。预测脱色效率与实验值吻合良好，回归系数高达98.8%。除除颜色外，光催化氧化后的Rh 6G水溶液的毒性也显著降低。连续运行三次后，活性略有下降(从34.6%降至30.5%)，表明催化剂的稳定性。由于催化剂的磁性，它可以在外加磁场的帮助下从溶液中去除。这防止了催化剂的损失，降低了额外的分离成本，这是工业或大规模应用所需要的。
{"title":"Photocatalytic Oxidation of Rhodamine 6G Dye Using Magnetic TiO2@Fe3O4/FeZSM-5","authors":"M. Dükkancı","doi":"10.15255/CABEQ.2020.1909","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1909","url":null,"abstract":"Efficient decolorization of Rhodamine 6G dye (Rh 6G) using magnetic TiO2@ Fe3O4/FeZSM-5 photocatalyst was carried out in a batch reactor equipped with two visible lights (high-pressure Na lamps). The photocatalyst was synthesized and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, diffuse reflectance spectroscopy and vibrating sample magnetometry. The effects of initial Rh 6G concentration, catalyst loading, and pH were investigated on photocatalytic oxidation of Rh 6G. Maximum decolorization of 98.2 % was found at optimum conditions of 20 ppm Rh 6G, 1 g L–1 of catalyst, and pH of 13.04. Central composite design was used for the optimization of photocatalytic degradation of Rh 6G. Predicted decolorization efficiencies were found to be in good agreement with experimental values with high regression coefficient of 98.8 %. In addition to color removal, the toxicity of the Rh 6G aqueous solution was significantly reduced after photocatalytic oxidation. Small reduction of activity (from 34.6 % to 30.5 %) showed the stability of the catalyst after three consecutive runs. Due to the magnetic property of the catalyst, it could be removed from the solution with the help of external magnetic field. This prevents the loss of catalyst and reduces the extra separation cost, which is desired in industrial or large-scale applications.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15255/CABEQ.2020.1834
Emi Govorčin Bajsić, T. Grgurić, B. Mijović, I. Vrgoč Zimić, Tamara Dolenec, S. Kuzmić, Nikolina Mrkonjić, M. T. Trcin, I. Slivac, E. Zdraveva
Natural polymer-based scaffolds are generally considered as favourable matrices for the adhesion and growth of cells in tissue repair. One of the most popular materials in this respect is silk fibroin, known for its wide usage in biomedical applications. This work focuses on the development of electrospun scaffolds based on poly(ε-caprolactone) (PCL) and silk fibroin (SF) evaluated regarding the SF effect on their morphology, surface wetting ability, thermal properties, and HaCaT model cell line biocompatibility. The study revealed that the lowest PCL/SF concentration resulted in highest bead-like morphology formation, relatively thick fibers with the presence of random beads in the case of PCL, while uniform and thinner fibers in the case of increasing PCL/SF content scaffolds. The addition of SF reduced the degree of crystallinity in the PCL due to the less organized crystal structure, and decreased its thermal stability. Both SEM and MTT analyses showed cell presence on all scaffolds three days after cell seeding. Although SF improved PCL hydrophilicity, as shown quantitatively by the MTT assay for improved cytocompatibility properties, more structured electrospun PCL/SF scaffold strategies are required.
{"title":"Preparation and Characterization of Electrospun PCL/Silk Fibroin Scaffolds","authors":"Emi Govorčin Bajsić, T. Grgurić, B. Mijović, I. Vrgoč Zimić, Tamara Dolenec, S. Kuzmić, Nikolina Mrkonjić, M. T. Trcin, I. Slivac, E. Zdraveva","doi":"10.15255/CABEQ.2020.1834","DOIUrl":"https://doi.org/10.15255/CABEQ.2020.1834","url":null,"abstract":"Natural polymer-based scaffolds are generally considered as favourable matrices for the adhesion and growth of cells in tissue repair. One of the most popular materials in this respect is silk fibroin, known for its wide usage in biomedical applications. This work focuses on the development of electrospun scaffolds based on poly(ε-caprolactone) (PCL) and silk fibroin (SF) evaluated regarding the SF effect on their morphology, surface wetting ability, thermal properties, and HaCaT model cell line biocompatibility. The study revealed that the lowest PCL/SF concentration resulted in highest bead-like morphology formation, relatively thick fibers with the presence of random beads in the case of PCL, while uniform and thinner fibers in the case of increasing PCL/SF content scaffolds. The addition of SF reduced the degree of crystallinity in the PCL due to the less organized crystal structure, and decreased its thermal stability. Both SEM and MTT analyses showed cell presence on all scaffolds three days after cell seeding. Although SF improved PCL hydrophilicity, as shown quantitatively by the MTT assay for improved cytocompatibility properties, more structured electrospun PCL/SF scaffold strategies are required.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67064297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-04DOI: 10.15255/cabeq.2020.1819
M. Koller, A. Mukherjee
When it comes to “bioplastics”, we currently notice an immense complexity of this topic, and, most of all, a plethora of contradictory legislations, which confuses or even misleads insufficiently informed consumers. The present article therefore showcases microbial polyhydroxyalkanoate (PHA) biopolyesters as the prime class of “bioplastics” sensu stricto. In particular, biodegradability of PHA as its central benefit in elevating the current plastic waste scenario is elaborated on the biochemical basis: this covers aspects of the enzymatic machinery involved both in intra- and extracellular PHA degradation, and environmental factors impacting biodegradability. Importantly, PHA degradability is contextualized with potential fields of application of these materials. It is further shown how the particularities of PHA in terms of feedstocks, mode of synthesis, degradability, and compostability differ from other polymeric materials sold as “bioplastics”, highlighting the unique selling points of PHA as “green” plastic products in the circular economy. Moreover, current standards, norms, and certificates applicable to PHA are presented as basis for a straight-forward, scientifically grounded classification of “bioplastics”.
{"title":"Polyhydroxyalkanoates – Linking Properties, Applications and End-of-life Options","authors":"M. Koller, A. Mukherjee","doi":"10.15255/cabeq.2020.1819","DOIUrl":"https://doi.org/10.15255/cabeq.2020.1819","url":null,"abstract":"When it comes to “bioplastics”, we currently notice an immense complexity of this topic, and, most of all, a plethora of contradictory legislations, which confuses or even misleads insufficiently informed consumers. The present article therefore showcases microbial polyhydroxyalkanoate (PHA) biopolyesters as the prime class of “bioplastics” sensu stricto. In particular, biodegradability of PHA as its central benefit in elevating the current plastic waste scenario is elaborated on the biochemical basis: this covers aspects of the enzymatic machinery involved both in intra- and extracellular PHA degradation, and environmental factors impacting biodegradability. Importantly, PHA degradability is contextualized with potential fields of application of these materials. It is further shown how the particularities of PHA in terms of feedstocks, mode of synthesis, degradability, and compostability differ from other polymeric materials sold as “bioplastics”, highlighting the unique selling points of PHA as “green” plastic products in the circular economy. Moreover, current standards, norms, and certificates applicable to PHA are presented as basis for a straight-forward, scientifically grounded classification of “bioplastics”.","PeriodicalId":9765,"journal":{"name":"Chemical and Biochemical Engineering Quarterly","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47243964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：