Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaO...Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.展开更多
Study on gas–liquid flow in stirred tank with two combinations of dual-impeller(six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine(6 ITD),the six-bent-bladed turbine(6BT)+six-inclinedblade up-pumpin...Study on gas–liquid flow in stirred tank with two combinations of dual-impeller(six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine(6 ITD),the six-bent-bladed turbine(6BT)+six-inclinedblade up-pumping turbine(6ITU))was conducted using computational fluid dynamics(CFD)and population balance model(PBM)(CFD-PBM)coupled model.The local bubble size was captured by particle image velocimetry(PIV)measurement.The gas holdup,bubble size distribution and gas–liquid interfacial area were explored at different conditions through numerical simulation.The results showed that the 4 mm bubbles accounted for the largest proportion of 33%at the gas flow rates Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1) for combined impeller of 6BT+6ITU,while the bubbles of 4.7 mm and 5.5 mm were the largest proportion for 6BT+6ITD combination,i.e.25%at Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1),respectively,which indicated that 6BT+6ITU could reduce bubble size effectively and promote gas dispersion.In addition,the gas holdup around impellers was increased obviously with the speed compared with gas flow rate.So it was concluded that 6ITU impeller could be more conductive to the bubble dispersion with more uniform bubble size,which embodied the advantages of 6BT+6ITU combination in gas–liquid mixing.展开更多
An experimental characterization of the Van der Waals forces involved in volatile organic compounds (VOC) dissolved into stationary phases of gas liquid chromatography (GLC) has been started at the beginning of the se...An experimental characterization of the Van der Waals forces involved in volatile organic compounds (VOC) dissolved into stationary phases of gas liquid chromatography (GLC) has been started at the beginning of the seventies. This field has been reactivated from 1994 thanks to a fruitful cooperation between our CNRS team and the group of Ervin Kováts at the Federal Polytechnic School of Lausanne. The applied strategy can be summarized, in the first instance, as the experimental measurement of accurate and superabundant mutual affinities of a limited number of VOC and stationary phases and their processing using an original tool named Multiplicative Matrix Analysis (MMA). Then, in the second stage, the obtained results have been compared with molecular properties well established, as the Van der Waals molecular volume, the refraction index and the polar surface area (PSA), in order to get generalized values for any compound. The present study summarizes the positive results developed in our three last papers on this topic (2013, 2016 and 2018), as well as the attempt to overcome the negative ones using enthalpies of vaporization.展开更多
采用恒界面池法研究了从硫酸介质中萃取In3+和Fe3+的动力学,考察了搅拌速度、界面面积、温度、萃取剂浓度、氢离子活度及硫酸根浓度对In3+,Fe3+萃取速率的影响.结果表明,在温度25℃、搅拌转速70～240 r/min条件下,In3+以三价离子形式被...采用恒界面池法研究了从硫酸介质中萃取In3+和Fe3+的动力学,考察了搅拌速度、界面面积、温度、萃取剂浓度、氢离子活度及硫酸根浓度对In3+,Fe3+萃取速率的影响.结果表明,在温度25℃、搅拌转速70～240 r/min条件下,In3+以三价离子形式被萃取,萃取活化能为17.54 k J/mol,萃取过程为扩散控制;Fe3+以Fe SO4+形式被萃取,萃取活化能为52.87 k J/mol,萃取过程为界面化学反应控制.增加D2EHPA浓度可增大正向反应动力,提高萃取速率.萃取过程为阳离子交换,氢离子活度增加会导致萃取速率降低,硫酸根与金属离子的络合效应会降低萃取速率.通过动力学研究得到In3+萃取的正向速率方程为-d CIn3+/dt=10-0.378[In3+](aq)[H+](aq)-0.376[H2A2](org)0.158,Fe3+萃取的正向速率方程为-d CFe3+/dt=10-2.413[Fe3+](aq)[H+](aq)-1.526[H2A2](org)0.600.展开更多
基金the support from the National Natural Science Foundation of China (22008157,21978178)。
文摘Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.
文摘重非水相液体(Dense Non-Aqueous Phase Liquid,DNAPL)与水相的界面面积是影响DNAPL在地下水中溶解速率的关键参数。通过设计二维砂箱实验,运用界面分配示踪法测定DNAPL残余饱和态下的界面面积。为量化分析保守示踪剂Br^-的存在对实验结果的影响,共进行两组实验,Br^-和界面分配示踪剂的注入方式分别为依次注入和同时注入。结果表明:(1)两组实验测定的固液相分配系数K_d值分别为0.079 m L/g和0.142 m L/g,表明Br^-的存在增大了介质对界面分配示踪剂的吸附作用;(2)两组实验测定的单位体积多孔介质中界面面积值分别为215 cm^2和237 cm^2,表明Br^-的存在增大了DNAPL与水相交界面对界面分配示踪剂的吸附作用;(3)在本实验范围内(Br^-浓度C_(Br)≤200mg/L),K_d值与Br^-浓度呈良好的线性关系(K_d=0.00032C_(Br)+0.0798),可用于对砂介质的K_d值进行估算和验证。
基金supported by the National Natural Science Foundation of China(52176040)Shandong Provincial Natural Science Foundation of China(ZR2018LE015)。
文摘Study on gas–liquid flow in stirred tank with two combinations of dual-impeller(six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine(6 ITD),the six-bent-bladed turbine(6BT)+six-inclinedblade up-pumping turbine(6ITU))was conducted using computational fluid dynamics(CFD)and population balance model(PBM)(CFD-PBM)coupled model.The local bubble size was captured by particle image velocimetry(PIV)measurement.The gas holdup,bubble size distribution and gas–liquid interfacial area were explored at different conditions through numerical simulation.The results showed that the 4 mm bubbles accounted for the largest proportion of 33%at the gas flow rates Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1) for combined impeller of 6BT+6ITU,while the bubbles of 4.7 mm and 5.5 mm were the largest proportion for 6BT+6ITD combination,i.e.25%at Q=0.76 m^(3)·h^(-1) and 22%at Q=1.52 m^(3)·h^(-1),respectively,which indicated that 6BT+6ITU could reduce bubble size effectively and promote gas dispersion.In addition,the gas holdup around impellers was increased obviously with the speed compared with gas flow rate.So it was concluded that 6ITU impeller could be more conductive to the bubble dispersion with more uniform bubble size,which embodied the advantages of 6BT+6ITU combination in gas–liquid mixing.
文摘An experimental characterization of the Van der Waals forces involved in volatile organic compounds (VOC) dissolved into stationary phases of gas liquid chromatography (GLC) has been started at the beginning of the seventies. This field has been reactivated from 1994 thanks to a fruitful cooperation between our CNRS team and the group of Ervin Kováts at the Federal Polytechnic School of Lausanne. The applied strategy can be summarized, in the first instance, as the experimental measurement of accurate and superabundant mutual affinities of a limited number of VOC and stationary phases and their processing using an original tool named Multiplicative Matrix Analysis (MMA). Then, in the second stage, the obtained results have been compared with molecular properties well established, as the Van der Waals molecular volume, the refraction index and the polar surface area (PSA), in order to get generalized values for any compound. The present study summarizes the positive results developed in our three last papers on this topic (2013, 2016 and 2018), as well as the attempt to overcome the negative ones using enthalpies of vaporization.
文摘采用恒界面池法研究了从硫酸介质中萃取In3+和Fe3+的动力学,考察了搅拌速度、界面面积、温度、萃取剂浓度、氢离子活度及硫酸根浓度对In3+,Fe3+萃取速率的影响.结果表明,在温度25℃、搅拌转速70～240 r/min条件下,In3+以三价离子形式被萃取,萃取活化能为17.54 k J/mol,萃取过程为扩散控制;Fe3+以Fe SO4+形式被萃取,萃取活化能为52.87 k J/mol,萃取过程为界面化学反应控制.增加D2EHPA浓度可增大正向反应动力,提高萃取速率.萃取过程为阳离子交换,氢离子活度增加会导致萃取速率降低,硫酸根与金属离子的络合效应会降低萃取速率.通过动力学研究得到In3+萃取的正向速率方程为-d CIn3+/dt=10-0.378[In3+](aq)[H+](aq)-0.376[H2A2](org)0.158,Fe3+萃取的正向速率方程为-d CFe3+/dt=10-2.413[Fe3+](aq)[H+](aq)-1.526[H2A2](org)0.600.
