The gas-liquid mass transfer of H2 and CO in a high temperature and high-pressure three-phase slurry bubble column reactor is studied. The gas-liquid volumetric mass transfer coefficients kLa are obtained by measuring...The gas-liquid mass transfer of H2 and CO in a high temperature and high-pressure three-phase slurry bubble column reactor is studied. The gas-liquid volumetric mass transfer coefficients kLa are obtained by measuring the dissolution rate of H2 and CO. The influences of the main operation conditions, such as temperature, pressure,superficial gas velocity and solid concentration, are studied systematically. Two empirical correlations are proposed to predict kLa values for H2 and CO in liquid paraffln/solid particles slurry bubble column reactors.展开更多
A rotating packed bed(RPB) reactor has substantially potential for the process intensification of heterogeneous catalytic reactions. However, the scarce knowledge of the liquid–solid mass transfer in the RPB reactor ...A rotating packed bed(RPB) reactor has substantially potential for the process intensification of heterogeneous catalytic reactions. However, the scarce knowledge of the liquid–solid mass transfer in the RPB reactor is a barrier for its design and scale-up. In this work, the liquid–solid mass transfer in a RPB reactor installed with structured foam packing was experimentally studied using copper dissolution by potassium dichromate. Effects of rotational speed, liquid and gas volumetric flow rate on the liquid–solid mass transfer coefficient(kLS) have been investigated. The correlation for predicting kLSwas proposed, and the deviation between the experimental and predicted values was within±12%. The liquid–solid volumetric mass transfer coefficient(kLSaLS) ranged from 0.04–0.14 1^-1, which was approximately 5 times larger than that in the packed bed reactor. This work lays the foundation for modeling of the RPB reactor packed with structured foam packing for heterogeneous catalytic reaction.展开更多
This paper describes the application of ultrasound waves on hydrodynamics and mass transfer characteristics in the gas–liquid flow in a T-shape microreactor with a diameter of 800 μm. A 1.7 MHz piezoelectric transdu...This paper describes the application of ultrasound waves on hydrodynamics and mass transfer characteristics in the gas–liquid flow in a T-shape microreactor with a diameter of 800 μm. A 1.7 MHz piezoelectric transducer(PZT) was employed to induce the vibration in this microreactor. Liquid side volumetric mass transfer coefficients were measured by physical and chemical methods of CO_2 absorption into water and Na OH solution. The approach of absorption of CO_2 into a 1 mol·L^(-1) Na OH solution was used for analysis of interfacial areas. With the help of a photography system, the fluid flow patterns inside the microreactor were analyzed. The effects of superficial liquid velocity, initial concentration of Na OH, superficial CO_2 gas velocity and length of microreactor on the mass transfer rate were investigated. The comparison between sonicated and plain microreactors(microreactor with and without ultrasound) shows that the ultrasound wave irradiation has a significant effect on kLa and interfacial area at various operational conditions. For the microreactor length of 12 cm, ultrasound waves improved kLa and interfacial area about 21% and 22%, respectively. From this study, it can be concluded that ultrasound wave irradiation in microreactor has a great effect on the mass transfer rate. This study suggests a new enhancement technique to establish high interfacial area and kLa in microreactors.展开更多
Ionic liquids (ILs) based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts (PTCs) for the base-promoted monoalkylatio...Ionic liquids (ILs) based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts (PTCs) for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system (IL-hase) could also be recycled after the extraction of products with ether.展开更多
The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on electron transfer (ET) reaction between ferricyanide aqueous solution and decamethylferrocene (DMFc) located on the adjacen...The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on electron transfer (ET) reaction between ferricyanide aqueous solution and decamethylferrocene (DMFc) located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer (ket) increased monotonically as the SDBS concentrations increased from 0 to 200 p, moFL. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer. 2009 Xiao Quan Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer
for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial evaporative ...The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer
for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial evaporative heat
transfer in the turbulent model would lower the predicted convective heat transfer coefficient. Predictions of the
new model resulted in a prominent deviation from that predictions of the normal model in the case of large mass
flow rate and low wall heat flux. This deviation will be decreased with increasing wall heat flux, such that it will be
asymptotic zero at very high wall heat flux. Predictions of the new model agreed well with the current experimental
measurements. This study has verified that the Reynolds number is not the sole crucial parameter for heat transfer
of falling liquid film flow, and wall heat flux will be another important independent parameter. This result is
consistent with our previous studies.展开更多
Experiments have been done on mass transfer to a liquid-liquid interface on which inert gas bubbles are sparged.To simulate the pyrometallurgy system of melten slag-metal(or matte),aqueous solution-mercury(or zinc ama...Experiments have been done on mass transfer to a liquid-liquid interface on which inert gas bubbles are sparged.To simulate the pyrometallurgy system of melten slag-metal(or matte),aqueous solution-mercury(or zinc amalgam) system was used.The mass transfer coefficients of indicator ions as a function of bubble parameters have been determined.The experimental results show satisfactory agreement with the mass transfer model proposed Previously.展开更多
Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively....Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively. Effects of liquid velocity, particle size, surface tension of liquid phase and solid circulation rate on the overall heat transfer coefficient were examined. The heat transfer coefficient increased with increasing particle size or solid circulation rate due to the higher potential of particles to contact with the heater surface and promote turbulence near the heater surface. The value of heat transfer coefficient increased gradually with increase in the surface tension of liquid phase, due to the slight increase of solid holdup. The heat transfer coefficient increased with the liquid velocity even in the higher range, due to the solid circulation prevented the decrease in solid holdup, in contrast to that in the conventional liquid-solid fluidized beds. The values of heat transfer coefficient were well correlated in terms of dimensionless groups as well as operating variables.展开更多
1 INTRODUCTIONTrickle bed reactors are widely used in the process industry,particularly in petroleumhydroprocessing operations,and have been extensively studied by chemical engineers.In atrickle bed reactor,the gas an...1 INTRODUCTIONTrickle bed reactors are widely used in the process industry,particularly in petroleumhydroprocessing operations,and have been extensively studied by chemical engineers.In atrickle bed reactor,the gas and liquid flow cocurrently down through the packed bedand undergo chemical reactions.However,there exist multiple hydrodynamic stateswhich correspond to either uniform or,in most cases,nonuniform radial distributionof the gas and liquid flows in the packed section.Moreover,the hydrodynamic state展开更多
The hysteresis of gas-liquid mass transfer rate and the corresponding radial liquiddistribution in a trickle bed reactor are measured to provide evidence for the correlation between thesetwo behaviors.Experimental res...The hysteresis of gas-liquid mass transfer rate and the corresponding radial liquiddistribution in a trickle bed reactor are measured to provide evidence for the correlation between thesetwo behaviors.Experimental results indicate that the hysteresis of gas-liquid mass transfer originatesfrom the nonuniformity of the hydrodynamic state of gas-liquid flow and the radial maldistributionof local k<sub>gia</sub> corresponds very well to the radial maldistribution of liquid flow in the bed.The localliquid flow rate is also found to be nonuniform in the azimuthal direction.In view of maldistributedliquid flow even in the pulsing flow regime,the conventional plug flow model seems oversimplifiedfor describing the behavior of a trickle bed.展开更多
The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry a...The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.展开更多
The skin friction and heat transfer occurring in the laminar boundary layerwhich caused by a vertical liquid jet impinging on a continuously moving horizontal plate werestudied. Similarity solutions for shear stress a...The skin friction and heat transfer occurring in the laminar boundary layerwhich caused by a vertical liquid jet impinging on a continuously moving horizontal plate werestudied. Similarity solutions for shear stress and heat distribution were obtained by using thehooting technique. The results show that the skin friction decreases with an increase of velocityparameter, the evolving of thermal boundary decrease with increasing in Prandtl number, but increasewith increasing of velocity parameter.展开更多
Wall-liquid mass transfer for Taylor bubbles rising through liquid column in vertical tubes is an important and fundamental topic in industrial processes.In this work,the characteristics of wall-liquid mass transfer f...Wall-liquid mass transfer for Taylor bubbles rising through liquid column in vertical tubes is an important and fundamental topic in industrial processes.In this work,the characteristics of wall-liquid mass transfer for this special case of slug flow were studied experimentally by limiting diffusion current technique (LDCT). Based on the experimental results and the analysis of hydrodynamic mechanisms,it was proposed that four different zones exist,i.e.the laminar falling film zone,the turbulent falling film zone,the wake region and the remaining liquid slug zone.The corresponding correlations for all these zones were developed.展开更多
The transfer of trivalent europium ion in a liquid surfactant membrane system is investigated in order toclarify the characteristics of liquid membrane separation process and the availability of this technique forreco...The transfer of trivalent europium ion in a liquid surfactant membrane system is investigated in order toclarify the characteristics of liquid membrane separation process and the availability of this technique forrecovering trivalent lanthanides and actinides.A layered structure model for the emulsion globule is sug-gested.The equations describing the relationship among the effective membrane thickness,the time andother factors are derived and verified experimentally.Results show that under certain conditions the decreas-ing concentration of europium ion in the external phase is proportional to the square root of the time,the acidity of the internal phase and the carrier concentration in the membrane phase.The membrane phase consists of kerosene(solvent),Span-80(surfactant)and di-(2-ethylhexyl) phosphoricacid(HDEHP,carrier).The internal phase is dilute nitric acid and the external phase is aqueous solu-tion containing Eu(NO3)3.The mass transfer rate of europium in this system is high and the recovery ofeuropium may be more than 99%.展开更多
Recovery of carbon monoxide from flue gases by selective absorption of carbon monoxide in an imidazolium chlorocuprate(I) ionic liquid is considered in this work as an alternative to the use of molecular volatile solv...Recovery of carbon monoxide from flue gases by selective absorption of carbon monoxide in an imidazolium chlorocuprate(I) ionic liquid is considered in this work as an alternative to the use of molecular volatile solvents such as aromatic hydrocarbons. The present work evaluates the CO mass transfer rates from the gas phase to the ionic liquid solutions in the absence of chemical reaction. To that end, carbon dioxide was employed as an inert model gas and absorption experiments were performed to assess the influence of different process variables in a batch reactor with flat gas–liquid interface. The experimental mass transfer coefficients showed significant variation with temperature,(3.4–10.9) × 10-7m·s-1between 293 and 313 K; stirring speed,(10.2–33.1) × 10-7m·s-1between 100 and 300 r·min-1; and concentration of copper(I),(6.6–10.2) × 10-7m·s-1between 0.25 and 2 mol·L-1. In addition, the mass transfer coefficients were eventually found to follow a potential proportionality of the type kL∝μ-0.5and the dimensionless correlation that makes the estimation of the mass transfer coefficients possible in the studied range of process variables was obtained: Sh = 10-2.64· Re1.07·Sc0.75.These results constitute the first step in the kinetic analysis of the reaction between CO and imidazolium chlorocuprate(I) ionic liquid that determines the design of the separation units.展开更多
The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization ...The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization of three single-component NAPLs in a sandy soil, constant initial lumped mass transfer coefficient (λgN,0) canbe obtained if the relative saturation (ξ) between NAPL phase and gas phase is higher than a critical value (ξc), andthe lumped mass transfer coefficient decreases with ξ when ξ<ξc. It is also shown that the lumped mass transfercoefficient can be increased by blending porous micro-particles into the sandy soil because of the increasing of theinterfacial area.展开更多
基金the National Natural Science Foundation of China (No. 29870619).
文摘The gas-liquid mass transfer of H2 and CO in a high temperature and high-pressure three-phase slurry bubble column reactor is studied. The gas-liquid volumetric mass transfer coefficients kLa are obtained by measuring the dissolution rate of H2 and CO. The influences of the main operation conditions, such as temperature, pressure,superficial gas velocity and solid concentration, are studied systematically. Two empirical correlations are proposed to predict kLa values for H2 and CO in liquid paraffln/solid particles slurry bubble column reactors.
基金supported by the National Natural Science Foundation of China(Nos.21676009 and 21725601)。
文摘A rotating packed bed(RPB) reactor has substantially potential for the process intensification of heterogeneous catalytic reactions. However, the scarce knowledge of the liquid–solid mass transfer in the RPB reactor is a barrier for its design and scale-up. In this work, the liquid–solid mass transfer in a RPB reactor installed with structured foam packing was experimentally studied using copper dissolution by potassium dichromate. Effects of rotational speed, liquid and gas volumetric flow rate on the liquid–solid mass transfer coefficient(kLS) have been investigated. The correlation for predicting kLSwas proposed, and the deviation between the experimental and predicted values was within±12%. The liquid–solid volumetric mass transfer coefficient(kLSaLS) ranged from 0.04–0.14 1^-1, which was approximately 5 times larger than that in the packed bed reactor. This work lays the foundation for modeling of the RPB reactor packed with structured foam packing for heterogeneous catalytic reaction.
文摘This paper describes the application of ultrasound waves on hydrodynamics and mass transfer characteristics in the gas–liquid flow in a T-shape microreactor with a diameter of 800 μm. A 1.7 MHz piezoelectric transducer(PZT) was employed to induce the vibration in this microreactor. Liquid side volumetric mass transfer coefficients were measured by physical and chemical methods of CO_2 absorption into water and Na OH solution. The approach of absorption of CO_2 into a 1 mol·L^(-1) Na OH solution was used for analysis of interfacial areas. With the help of a photography system, the fluid flow patterns inside the microreactor were analyzed. The effects of superficial liquid velocity, initial concentration of Na OH, superficial CO_2 gas velocity and length of microreactor on the mass transfer rate were investigated. The comparison between sonicated and plain microreactors(microreactor with and without ultrasound) shows that the ultrasound wave irradiation has a significant effect on kLa and interfacial area at various operational conditions. For the microreactor length of 12 cm, ultrasound waves improved kLa and interfacial area about 21% and 22%, respectively. From this study, it can be concluded that ultrasound wave irradiation in microreactor has a great effect on the mass transfer rate. This study suggests a new enhancement technique to establish high interfacial area and kLa in microreactors.
文摘Ionic liquids (ILs) based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts (PTCs) for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system (IL-hase) could also be recycled after the extraction of products with ether.
基金supported by the National Science Foundation of China(No.20775060 and No.20875077)the National Science Foundation of Gansu(No.0701RJZA109 and No.0803RJZA105)and the Key Laboratory of Polymer Materials of Gansu Province
文摘The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on electron transfer (ET) reaction between ferricyanide aqueous solution and decamethylferrocene (DMFc) located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer (ket) increased monotonically as the SDBS concentrations increased from 0 to 200 p, moFL. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer. 2009 Xiao Quan Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Supported by the National Natural Science Foundation of China (No. 59995550-3) and Science Funds from the Ministry of Education (No. 97000357).
文摘The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer
for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial evaporative heat
transfer in the turbulent model would lower the predicted convective heat transfer coefficient. Predictions of the
new model resulted in a prominent deviation from that predictions of the normal model in the case of large mass
flow rate and low wall heat flux. This deviation will be decreased with increasing wall heat flux, such that it will be
asymptotic zero at very high wall heat flux. Predictions of the new model agreed well with the current experimental
measurements. This study has verified that the Reynolds number is not the sole crucial parameter for heat transfer
of falling liquid film flow, and wall heat flux will be another important independent parameter. This result is
consistent with our previous studies.
文摘Experiments have been done on mass transfer to a liquid-liquid interface on which inert gas bubbles are sparged.To simulate the pyrometallurgy system of melten slag-metal(or matte),aqueous solution-mercury(or zinc amalgam) system was used.The mass transfer coefficients of indicator ions as a function of bubble parameters have been determined.The experimental results show satisfactory agreement with the mass transfer model proposed Previously.
基金Supported by Korea Institute of Energy Technology Evaluation and Planning (KETEP)GTL Technology Development Consortium (Korean National Oil Corp., Korea Gas Corp., Daelim Industrial Co. and Hyundai Engineering Co.) under "Energy Efficiency & Resources Programs" of the Ministry of Knowledge Economy, Republic of Korea
文摘Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively. Effects of liquid velocity, particle size, surface tension of liquid phase and solid circulation rate on the overall heat transfer coefficient were examined. The heat transfer coefficient increased with increasing particle size or solid circulation rate due to the higher potential of particles to contact with the heater surface and promote turbulence near the heater surface. The value of heat transfer coefficient increased gradually with increase in the surface tension of liquid phase, due to the slight increase of solid holdup. The heat transfer coefficient increased with the liquid velocity even in the higher range, due to the solid circulation prevented the decrease in solid holdup, in contrast to that in the conventional liquid-solid fluidized beds. The values of heat transfer coefficient were well correlated in terms of dimensionless groups as well as operating variables.
文摘1 INTRODUCTIONTrickle bed reactors are widely used in the process industry,particularly in petroleumhydroprocessing operations,and have been extensively studied by chemical engineers.In atrickle bed reactor,the gas and liquid flow cocurrently down through the packed bedand undergo chemical reactions.However,there exist multiple hydrodynamic stateswhich correspond to either uniform or,in most cases,nonuniform radial distributionof the gas and liquid flows in the packed section.Moreover,the hydrodynamic state
基金Supported by the National Natural Science Foundation of China and SINOPEC
文摘The hysteresis of gas-liquid mass transfer rate and the corresponding radial liquiddistribution in a trickle bed reactor are measured to provide evidence for the correlation between thesetwo behaviors.Experimental results indicate that the hysteresis of gas-liquid mass transfer originatesfrom the nonuniformity of the hydrodynamic state of gas-liquid flow and the radial maldistributionof local k<sub>gia</sub> corresponds very well to the radial maldistribution of liquid flow in the bed.The localliquid flow rate is also found to be nonuniform in the azimuthal direction.In view of maldistributedliquid flow even in the pulsing flow regime,the conventional plug flow model seems oversimplifiedfor describing the behavior of a trickle bed.
基金the Scientific Research Projects (BAP) of Selcuk University, Turkey (2003/151).
文摘The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.
基金[This work was financially supported by "973" key foundation of China (No.G 1998061510).]
文摘The skin friction and heat transfer occurring in the laminar boundary layerwhich caused by a vertical liquid jet impinging on a continuously moving horizontal plate werestudied. Similarity solutions for shear stress and heat distribution were obtained by using thehooting technique. The results show that the skin friction decreases with an increase of velocityparameter, the evolving of thermal boundary decrease with increasing in Prandtl number, but increasewith increasing of velocity parameter.
文摘Wall-liquid mass transfer for Taylor bubbles rising through liquid column in vertical tubes is an important and fundamental topic in industrial processes.In this work,the characteristics of wall-liquid mass transfer for this special case of slug flow were studied experimentally by limiting diffusion current technique (LDCT). Based on the experimental results and the analysis of hydrodynamic mechanisms,it was proposed that four different zones exist,i.e.the laminar falling film zone,the turbulent falling film zone,the wake region and the remaining liquid slug zone.The corresponding correlations for all these zones were developed.
文摘The transfer of trivalent europium ion in a liquid surfactant membrane system is investigated in order toclarify the characteristics of liquid membrane separation process and the availability of this technique forrecovering trivalent lanthanides and actinides.A layered structure model for the emulsion globule is sug-gested.The equations describing the relationship among the effective membrane thickness,the time andother factors are derived and verified experimentally.Results show that under certain conditions the decreas-ing concentration of europium ion in the external phase is proportional to the square root of the time,the acidity of the internal phase and the carrier concentration in the membrane phase.The membrane phase consists of kerosene(solvent),Span-80(surfactant)and di-(2-ethylhexyl) phosphoricacid(HDEHP,carrier).The internal phase is dilute nitric acid and the external phase is aqueous solu-tion containing Eu(NO3)3.The mass transfer rate of europium in this system is high and the recovery ofeuropium may be more than 99%.
基金the projects ENE2010-15585 and CTQ2012-31639the FPI postgraduate research grant(BES-2011-046279)
文摘Recovery of carbon monoxide from flue gases by selective absorption of carbon monoxide in an imidazolium chlorocuprate(I) ionic liquid is considered in this work as an alternative to the use of molecular volatile solvents such as aromatic hydrocarbons. The present work evaluates the CO mass transfer rates from the gas phase to the ionic liquid solutions in the absence of chemical reaction. To that end, carbon dioxide was employed as an inert model gas and absorption experiments were performed to assess the influence of different process variables in a batch reactor with flat gas–liquid interface. The experimental mass transfer coefficients showed significant variation with temperature,(3.4–10.9) × 10-7m·s-1between 293 and 313 K; stirring speed,(10.2–33.1) × 10-7m·s-1between 100 and 300 r·min-1; and concentration of copper(I),(6.6–10.2) × 10-7m·s-1between 0.25 and 2 mol·L-1. In addition, the mass transfer coefficients were eventually found to follow a potential proportionality of the type kL∝μ-0.5and the dimensionless correlation that makes the estimation of the mass transfer coefficients possible in the studied range of process variables was obtained: Sh = 10-2.64· Re1.07·Sc0.75.These results constitute the first step in the kinetic analysis of the reaction between CO and imidazolium chlorocuprate(I) ionic liquid that determines the design of the separation units.
基金Supported by the National Natural Science Foundation of China (No. 20276048).
文摘The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization of three single-component NAPLs in a sandy soil, constant initial lumped mass transfer coefficient (λgN,0) canbe obtained if the relative saturation (ξ) between NAPL phase and gas phase is higher than a critical value (ξc), andthe lumped mass transfer coefficient decreases with ξ when ξ<ξc. It is also shown that the lumped mass transfercoefficient can be increased by blending porous micro-particles into the sandy soil because of the increasing of theinterfacial area.