Membrane contactor is regarded as a promising method for reaction and process intensification. The feasibility of formaldehyde carbonylation to synthesize glycolic acid using polytetrafluoroethylene(PTFE)membrane cont...Membrane contactor is regarded as a promising method for reaction and process intensification. The feasibility of formaldehyde carbonylation to synthesize glycolic acid using polytetrafluoroethylene(PTFE)membrane contactor has been proved in our previous study. In this paper, the effect of membrane microstructure on process performance was further investigated. Three porous PTFE hollow fibers with different pore sizes and one polydimethylsiloxane(PDMS)/PTFE composite membrane with dense layer were fabricated for comparison. The physical and chemical properties of four membranes, including chemical composition, morphology, contact angle, liquid entry pressure, thermodynamic analysis and gas permeability, were systemically characterized. Experiments of formaldehyde carbonylation under different reaction conditions were conducted. The results indicated that the yield of glycolic acid increased with decreasing pore size for porous membranes, which was due to the improvement of wetting behavior. The dense layer of PDMS in composite hollow fiber could effectively prevent the solvent from entering membrane pores, thus the membrane exhibited the best performance. At reaction temperature of 120℃ and operation pressure of 3.0 MPa, the yield of glycolic acid was always higher than 90% as the mass ratio of trioxane and phosphotungstic acid increased from 0.2:1 to 0.8:1. The highest turnover frequency was up to 26.37 mol·g^(-1)·h^(-1). This study provided a reference for the understanding and optimization of membrane contactors for the synthesis of glycolic acid using solvent with low surface tension.展开更多
Hydrophilic ceramic membranes would be potential candidates for membrane gas absorption if they could be applied to appropriate separation processes.This study highlights a novel concept for the practical implementati...Hydrophilic ceramic membranes would be potential candidates for membrane gas absorption if they could be applied to appropriate separation processes.This study highlights a novel concept for the practical implementation of SO_2 absorption in hydrophilic ceramic membrane that exhibits outstanding thermal and mechanical stabilities.With this aim,we investigated experimentally the performance of SO_2 absorption into aqueous sodium hydroxide (NaOH) solution in a hydrophilic alumina (Al_2O_3) membrane contactor in terms of SO_2 removal efficiency and SO_2 mass transfer flux,and compared the performance with that in a hydrophobic one.A series of experiments were performed at various conditions over a NaOH concentration range of 0–1.0 mol·L^(-1),a liquid flow rate range of 30–180 ml·min^(-1),a gas flow rate range of 120–1000 ml·min^(-1),an inlet SO_2 concentration range of 400–2000μl·L^(-1),and a temperature range of 10–35°C.It was found that the hydrophilic membrane was more competitive when using a NaOH concentration higher than 0.2 mol·L^(-1).Furthermore,it can be inferred that the hydrophilicα-Al_2O_3 membrane exhibited exceptional long-term stability under 480 h continuous operation.展开更多
A membrane contactor using ionic liquids(ILs) as solvent for pre-combustion capture CO_2 at elevated temperature(303-393 K) and pressure(20 bar) has been studied using mathematic model in the present work. A comprehen...A membrane contactor using ionic liquids(ILs) as solvent for pre-combustion capture CO_2 at elevated temperature(303-393 K) and pressure(20 bar) has been studied using mathematic model in the present work. A comprehensive two-dimensional(2 D) mass-transfer model was developed based on finite element method. The effects of liquid properties, membrane configurations, as well as operation parameters on the CO_2 removal efficiency were systematically studied. The simulation results show that CO_2 can be effectively removed in this process. In addition, it is found that the liquid phase mass transfer dominated the overall mass transfer. Membranes with high porosity and small thickness could apparently reduce the membrane resistance and thus increase the separation efficiency. On the other hand, the membrane diameter and membrane length have a relatively small influence on separation performance within the operation range.展开更多
This review compares the different types of membrane processes for air dehumidification.Three main categories of membrane-based dehumidification are identified–membrane contactors using porous membranes with concentr...This review compares the different types of membrane processes for air dehumidification.Three main categories of membrane-based dehumidification are identified–membrane contactors using porous membranes with concentrated liquid desiccants,separative membranes using dense membrane morphology with a pressure gradient to drive the separation of moisture from air,and adsorptive membranes using nanofibrous membranes which adsorb and capture moisture to realise dehumidification.Drawing upon the importance of dehumidification and humidity control for urban sustainability and energy efficacy,this review critically analyses and recognizes the three unique categories of membrane-based air dehumidification technologies.Essentially,the discussion is broken into three sections-one for each category-discriminating in terms of the driving force,membrane structure and properties,and its performance indicators.Readers will notice that despite having the same objective to dehumidify air,the polymers used amongst each category differs to suit the operating requirements and optimize dehumidification performance.At the end of each section,a performance table or summary of dehumidifying membranes in its class is provided.The final section concludes with a comparative review of the three categories on membrane-based air dehumidification technologies and draw inspiration from parallel research to rationalise the potential and innovative use of promising materials in membrane fabrication for air dehumidification.展开更多
Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor. The effects of Ca(OH)2 concentration, CO2 pressure and liquid flow velocity on the particles morphology, pressure dr...Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor. The effects of Ca(OH)2 concentration, CO2 pressure and liquid flow velocity on the particles morphology, pressure drop and membrane fouling were studied. With rising Ca(OH)2 concentrations, the average size of the particles increased. The effects of Ca(OH)2 concentration and CO2 pressure on particles were not apparent under the experimental conditions. When the Ca(OH)2 concentration and liquid flow velocity were high, or the CO2 pressure was low, the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage, whereas the fouling was slight at exit. The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials. The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration.展开更多
Wastewater containing high concentrations of ammonia can be harmful to aquatic life and degrade the water quality. Wastewater containing ammonia is usually removed by conventional methods such as aeration in towers, b...Wastewater containing high concentrations of ammonia can be harmful to aquatic life and degrade the water quality. Wastewater containing ammonia is usually removed by conventional methods such as aeration in towers, biological treatment and adsorption of the ammonium ion to the zeolite surface. However, these methods are less effective and relatively expensive. Therefore there is a need for alternative technologies that can improve the efficiency of ammonia removal from wastewater. This study aims to obtain the process of ammonia removal through a combination of absorption in the membrane contactor and the advance oxidation process in the hybrid plasma-ozone reactor. Wastewater containing ammonia used in the study was a synthetic wastewater with a concentration of about 800 ppm. In the experiment, the wastewater fi＇om the reservoir was firstly passed into the membrane contactor on the shell side, and then mixed with ozone from the ozonator befbre entering the plasma reactor, and finally was circulated back to the reservoir. Meanwhile, the absorbent solution was sent to the lumen fiber in membrane contactor. Experimental results showed that the ammonia removal efficiency increases with increasing in circulation rate and temperature of the wastewater. The highest efficiency of ammonia removal obtained from the experimental results was 77%.展开更多
In membrane contactors,maintaining a high SO_(2)absorption flux and an excellent wetting resistance are crucial for hazardous gas removal.In this study,we adopted an electrospinning strategy to fabricate highly robust...In membrane contactors,maintaining a high SO_(2)absorption flux and an excellent wetting resistance are crucial for hazardous gas removal.In this study,we adopted an electrospinning strategy to fabricate highly robust superhydrophobic dual-layer Elec-PVDF/SiO_(2)composite membrane contactors used for flue gas desulfurization.The composite membrane contactor consisted of a durable and ultrathin three-dimensional(3D)superhydrophobic surface and a porous supporting layer,where the formulation was optimized by regulating the PVDF concentration,solvent ratio and SiO_(2)particles content in electrospinning solution.The scanning electronic microscopy(SEM),EDS-mapping,water contact angle(WCA)and surface roughness of as-prepared Elec-PVDF/SiO_(2)composite membrane contactors were conducted to explore the physical and chemical structure.The SiO_(2)nanoparticles were uniformly loaded in ElecPVDF/SiO_(2)composite membrane contactor,and constructed micro-nano dual-coarse lotus-leaf-like morphology,which noticeably elevated surface roughness(Ra).The SiO_(2)nanoparticles also functioned as hydrophobic modifiers,which boosted the WAC up to 155.The SO_(2)absorption fluxes and SO_(2)removal efficiencies were investigated.In particular,the membrane contactor doped with 20 wt%SiO_(2)nanoparticles significantly elevated the stability of desulfurization performance.Besides,the membrane mass transfer coefficient(Km)and corresponding membrane mass transfer resistance(H/Km)were explored.展开更多
A membrane-based gas absorption （MGA） process was evaluated for the removal of volatile organic compounds （VOCs） based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hyd...A membrane-based gas absorption （MGA） process was evaluated for the removal of volatile organic compounds （VOCs） based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine （NFM） as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.展开更多
The article presents a review of new techniques being used for the preparation of liposomes.A total of 28 publications were examined.In addition to the theories,characteristics and problems associated with traditional...The article presents a review of new techniques being used for the preparation of liposomes.A total of 28 publications were examined.In addition to the theories,characteristics and problems associated with traditional methods,the advantages and drawbacks of the latest techniques were reviewed.In the light of developments in many relevant areas,a variety of new techniques are being used for liposome preparation and each of these new technique has particular advantages over conventional preparation methods.However,there are still some problems associated with these new techniques that could hinder their applications and further improvements are needed.Generally speaking,due to the introduction of these latest techniques,liposome preparation is now an improved procedure.These applications promote not only advances in liposome research but also the methods for their production on an industrial scale.展开更多
Affordable hydrophobic hollow fibre membranes were prepared using kaolin and alumina based ceramic powders via a combined phase inversion and sintering technique,followed by a grafting with fluoroalkylsilane(FAS).The ...Affordable hydrophobic hollow fibre membranes were prepared using kaolin and alumina based ceramic powders via a combined phase inversion and sintering technique,followed by a grafting with fluoroalkylsilane(FAS).The crux of the matter in this paper is to study the changes in the properties of the hollow fibre membranes(gas permeation,mechanical strength,pore size,porosity,tortuosity,morphology,and contact angle)by the addition of alumina(Al2O3)to the pure kaolin with mono or multiparticle sizes.By varying the overall loading and particle size of alumina addition,different morphologies of the membranes were obtained due to the differences in the path lengths during phase inversion process for each solvent and nonsolvent exchange.The successful grafting with FAS was evidenced by the increase in contact angle from nearly equal to zero degree before grafting to 140°after grafting.Kaolin-alumina-4,one of the hollow fibres fabricated in this work,achieved a mean pore size of 0.25μm with the bending strength of 96.4 MPa and high nitrogen permeance of 2.3×10^(-5) mol·m^(-2)·Pa^(-1)·s^(-1),which makes the hollow fibre most suitable for the membrane contactor application.展开更多
Poly(ether−ether ketone)(PEEK)is a linear aromatic macromolecule,which can form semi-crystalline aggregative status,allowing PEEK materials to have strong environment tolerance and excellent physicochemical properties...Poly(ether−ether ketone)(PEEK)is a linear aromatic macromolecule,which can form semi-crystalline aggregative status,allowing PEEK materials to have strong environment tolerance and excellent physicochemical properties.PEEK materials have become a promising alternative to fabricate particular membranes used in extreme conditions.In the past few decades,many researches and evolutions have emerged in membrane fabrication with PEEK materials and its applications for treating organic solvents and their mixtures;however,there are little systematic and comprehensive literature to summarize fabrication approaches,compile applications,and elaborate PEEK property-structure relationship.In this review,the main approaches to fabricate PEEK-based membranes are illustrated concretely,including conventional thermal-induced and non-solvent-induced phase separation,and novel chemical-induced crystallization;the representative applications in ultrafiltration,nanofiltration and membrane contactor containing organic solvents are demonstrated systematically.Meanwhile,the mechanism to tune PEEK solubility in solvents,which can be achieved by altering monomers in synthesis processes or changing membrane preparation routes,is deeply analyzed.Moreover,the existing problems and the future prospects are also discussed.This review provides positive guidance for designing and fabricating membranes using PEEK and its derivative materials for task-specific applications in harsh conditions.展开更多
Membrane technology holds great potential in gas separation applications,especially carbon dioxide capture from industrial processes.To achieve this potential,the outputs from global research endeavours into membrane ...Membrane technology holds great potential in gas separation applications,especially carbon dioxide capture from industrial processes.To achieve this potential,the outputs from global research endeavours into membrane technologies must be trialled in industrial processes,which requires membrane-based pilot plants.These pilot plants are critical to the commercialization of membrane technology,be it as gas separation membranes or membrane gas-solvent contactors,as failure at the pilot plant level may delay the development of the technology for decades.Here,the author reports on his experience of operating membrane-based pilot plants for gas separation and contactor configurations as part of three industrial carbon capture initiatives:the Mulgrave project,H3 project and Vales Point project.Specifically,the challenges of developing and operating membrane pilot plants are presented,as well as the key learnings on how to successfully manage membrane pilot plants to achieve desired performance outcomes.The purpose is to assist membrane technologists in the carbon capture field to achieve successful outcomes for their technology innovations.展开更多
Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium （Pd） nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetition...Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium （Pd） nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetitions of membranes were investigated. In reduction, the dye concentration decreased whereas the pH rose gradually. An optimal Pd loading was found. The catalytic membranes were able to be reused more than 3 times.展开更多
The effects of baffles on the operation and mass-transfer characteristics in novel hollowfiber membrane contactor used in distillation were investi-gated.Hollowfiber membranes,coated with a 7μm polydimethyl-siloxane,wer...The effects of baffles on the operation and mass-transfer characteristics in novel hollowfiber membrane contactor used in distillation were investi-gated.Hollowfiber membranes,coated with a 7μm polydimethyl-siloxane,were operated as structural packing in the separation of ethanol-water solutions.The parallelflow mode was chosen for separation due to the stronger driving force of the concentration difference,in which liquidflows through the lumens of thefibers and vaporflows countercurrent-wise outside thefibers.Two baffles were installed on the shell side of the membrane contactors to enhance separation,which had a round shape with a semi-lunar hole.The results show that both baffled and unbaffled membrane contactors gave better,more produc-tive separations than traditional packing in distillation,such as the excellent Sulzer Gauze BX structured packing.The baffled membrane contactors performed better than unbaffled ones,especially at high vapor velocities.The minimal HTU of membrane contactor with baffles could reach as low as 4.5 cm,and almost all the contactors could work well above the limit whereflooding normally occurs in conventional cases.Theoretical analysis predicted that baffles helped membrane module to obtain a higher mass-transfer coefficient and a smaller mass-transfer resistance.Finally,theoretical mass-transfer coefficient and experi-mental value were compared as well as the contribution of each individual mass-transfer coefficients among liquid,gas and membrane.展开更多
基金the financial support from Dalian Institute of Chemical Physics (DMTO201604)Focus Area Innovation Team Support Plan of Dalian (2021RT03)+1 种基金National Natural Science Foundation of China (21878284)Regional Development Young Scholars of the Chinese Academy of Sciences。
文摘Membrane contactor is regarded as a promising method for reaction and process intensification. The feasibility of formaldehyde carbonylation to synthesize glycolic acid using polytetrafluoroethylene(PTFE)membrane contactor has been proved in our previous study. In this paper, the effect of membrane microstructure on process performance was further investigated. Three porous PTFE hollow fibers with different pore sizes and one polydimethylsiloxane(PDMS)/PTFE composite membrane with dense layer were fabricated for comparison. The physical and chemical properties of four membranes, including chemical composition, morphology, contact angle, liquid entry pressure, thermodynamic analysis and gas permeability, were systemically characterized. Experiments of formaldehyde carbonylation under different reaction conditions were conducted. The results indicated that the yield of glycolic acid increased with decreasing pore size for porous membranes, which was due to the improvement of wetting behavior. The dense layer of PDMS in composite hollow fiber could effectively prevent the solvent from entering membrane pores, thus the membrane exhibited the best performance. At reaction temperature of 120℃ and operation pressure of 3.0 MPa, the yield of glycolic acid was always higher than 90% as the mass ratio of trioxane and phosphotungstic acid increased from 0.2:1 to 0.8:1. The highest turnover frequency was up to 26.37 mol·g^(-1)·h^(-1). This study provided a reference for the understanding and optimization of membrane contactors for the synthesis of glycolic acid using solvent with low surface tension.
基金Supported by the National Key R&D Plan(2016YFC0205700)the National Natural Science Foundation of China(91534108,21506093,21706114)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20150947,BK20160979)the National High Technology Research and Development Program of China(2012AA03A606)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Hydrophilic ceramic membranes would be potential candidates for membrane gas absorption if they could be applied to appropriate separation processes.This study highlights a novel concept for the practical implementation of SO_2 absorption in hydrophilic ceramic membrane that exhibits outstanding thermal and mechanical stabilities.With this aim,we investigated experimentally the performance of SO_2 absorption into aqueous sodium hydroxide (NaOH) solution in a hydrophilic alumina (Al_2O_3) membrane contactor in terms of SO_2 removal efficiency and SO_2 mass transfer flux,and compared the performance with that in a hydrophobic one.A series of experiments were performed at various conditions over a NaOH concentration range of 0–1.0 mol·L^(-1),a liquid flow rate range of 30–180 ml·min^(-1),a gas flow rate range of 120–1000 ml·min^(-1),an inlet SO_2 concentration range of 400–2000μl·L^(-1),and a temperature range of 10–35°C.It was found that the hydrophilic membrane was more competitive when using a NaOH concentration higher than 0.2 mol·L^(-1).Furthermore,it can be inferred that the hydrophilicα-Al_2O_3 membrane exhibited exceptional long-term stability under 480 h continuous operation.
基金partly supported by the Research Council of Norway through CLIMIT program (MCIL-CO_2 project, 215732)
文摘A membrane contactor using ionic liquids(ILs) as solvent for pre-combustion capture CO_2 at elevated temperature(303-393 K) and pressure(20 bar) has been studied using mathematic model in the present work. A comprehensive two-dimensional(2 D) mass-transfer model was developed based on finite element method. The effects of liquid properties, membrane configurations, as well as operation parameters on the CO_2 removal efficiency were systematically studied. The simulation results show that CO_2 can be effectively removed in this process. In addition, it is found that the liquid phase mass transfer dominated the overall mass transfer. Membranes with high porosity and small thickness could apparently reduce the membrane resistance and thus increase the separation efficiency. On the other hand, the membrane diameter and membrane length have a relatively small influence on separation performance within the operation range.
基金supported by Singapore Membrane Technology Centre(SMTC),Interdisciplinary Graduate Programme,Nanyang Environment and Water Research institute and Nanyang Technological university for this research.
文摘This review compares the different types of membrane processes for air dehumidification.Three main categories of membrane-based dehumidification are identified–membrane contactors using porous membranes with concentrated liquid desiccants,separative membranes using dense membrane morphology with a pressure gradient to drive the separation of moisture from air,and adsorptive membranes using nanofibrous membranes which adsorb and capture moisture to realise dehumidification.Drawing upon the importance of dehumidification and humidity control for urban sustainability and energy efficacy,this review critically analyses and recognizes the three unique categories of membrane-based air dehumidification technologies.Essentially,the discussion is broken into three sections-one for each category-discriminating in terms of the driving force,membrane structure and properties,and its performance indicators.Readers will notice that despite having the same objective to dehumidify air,the polymers used amongst each category differs to suit the operating requirements and optimize dehumidification performance.At the end of each section,a performance table or summary of dehumidifying membranes in its class is provided.The final section concludes with a comparative review of the three categories on membrane-based air dehumidification technologies and draw inspiration from parallel research to rationalise the potential and innovative use of promising materials in membrane fabrication for air dehumidification.
基金Supported by the National Natural Science Foundation of China （20676016, 21076024）.
文摘Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor. The effects of Ca(OH)2 concentration, CO2 pressure and liquid flow velocity on the particles morphology, pressure drop and membrane fouling were studied. With rising Ca(OH)2 concentrations, the average size of the particles increased. The effects of Ca(OH)2 concentration and CO2 pressure on particles were not apparent under the experimental conditions. When the Ca(OH)2 concentration and liquid flow velocity were high, or the CO2 pressure was low, the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage, whereas the fouling was slight at exit. The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials. The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration.
文摘Wastewater containing high concentrations of ammonia can be harmful to aquatic life and degrade the water quality. Wastewater containing ammonia is usually removed by conventional methods such as aeration in towers, biological treatment and adsorption of the ammonium ion to the zeolite surface. However, these methods are less effective and relatively expensive. Therefore there is a need for alternative technologies that can improve the efficiency of ammonia removal from wastewater. This study aims to obtain the process of ammonia removal through a combination of absorption in the membrane contactor and the advance oxidation process in the hybrid plasma-ozone reactor. Wastewater containing ammonia used in the study was a synthetic wastewater with a concentration of about 800 ppm. In the experiment, the wastewater fi＇om the reservoir was firstly passed into the membrane contactor on the shell side, and then mixed with ozone from the ozonator befbre entering the plasma reactor, and finally was circulated back to the reservoir. Meanwhile, the absorbent solution was sent to the lumen fiber in membrane contactor. Experimental results showed that the ammonia removal efficiency increases with increasing in circulation rate and temperature of the wastewater. The highest efficiency of ammonia removal obtained from the experimental results was 77%.
基金the financial support from the National Key Research and Development Plan(2017YFC0404001)National Natural Science Foundation of China(No.21676201,21706189,21978217)+1 种基金Tianjin Municipal Education Commission Scientific Research Project(2017KJ074)Science and Technology Plans of Tianjin(18JCQNJC06800,18PTSYJC00190,17PTSYJC00050).
文摘In membrane contactors,maintaining a high SO_(2)absorption flux and an excellent wetting resistance are crucial for hazardous gas removal.In this study,we adopted an electrospinning strategy to fabricate highly robust superhydrophobic dual-layer Elec-PVDF/SiO_(2)composite membrane contactors used for flue gas desulfurization.The composite membrane contactor consisted of a durable and ultrathin three-dimensional(3D)superhydrophobic surface and a porous supporting layer,where the formulation was optimized by regulating the PVDF concentration,solvent ratio and SiO_(2)particles content in electrospinning solution.The scanning electronic microscopy(SEM),EDS-mapping,water contact angle(WCA)and surface roughness of as-prepared Elec-PVDF/SiO_(2)composite membrane contactors were conducted to explore the physical and chemical structure.The SiO_(2)nanoparticles were uniformly loaded in ElecPVDF/SiO_(2)composite membrane contactor,and constructed micro-nano dual-coarse lotus-leaf-like morphology,which noticeably elevated surface roughness(Ra).The SiO_(2)nanoparticles also functioned as hydrophobic modifiers,which boosted the WAC up to 155.The SO_(2)absorption fluxes and SO_(2)removal efficiencies were investigated.In particular,the membrane contactor doped with 20 wt%SiO_(2)nanoparticles significantly elevated the stability of desulfurization performance.Besides,the membrane mass transfer coefficient(Km)and corresponding membrane mass transfer resistance(H/Km)were explored.
基金supported by the Environmental Protection Science and Technique Foundation of Jiangsu Province (No. 2005005)
文摘A membrane-based gas absorption （MGA） process was evaluated for the removal of volatile organic compounds （VOCs） based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine （NFM） as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.
文摘The article presents a review of new techniques being used for the preparation of liposomes.A total of 28 publications were examined.In addition to the theories,characteristics and problems associated with traditional methods,the advantages and drawbacks of the latest techniques were reviewed.In the light of developments in many relevant areas,a variety of new techniques are being used for liposome preparation and each of these new technique has particular advantages over conventional preparation methods.However,there are still some problems associated with these new techniques that could hinder their applications and further improvements are needed.Generally speaking,due to the introduction of these latest techniques,liposome preparation is now an improved procedure.These applications promote not only advances in liposome research but also the methods for their production on an industrial scale.
基金support from Universiti Teknologi Malaysia under Research University Grant Tier 1(Project No.Q.J130000.2546.12H25)Flagship UTMShine(Project No.Q.J130000.2446.03G29)Nippon Sheet Glass Foundation for Materials Science and Engineering under Overseas Research Grant Scheme(Project No.Q.J130000.2446.03G29)。
文摘Affordable hydrophobic hollow fibre membranes were prepared using kaolin and alumina based ceramic powders via a combined phase inversion and sintering technique,followed by a grafting with fluoroalkylsilane(FAS).The crux of the matter in this paper is to study the changes in the properties of the hollow fibre membranes(gas permeation,mechanical strength,pore size,porosity,tortuosity,morphology,and contact angle)by the addition of alumina(Al2O3)to the pure kaolin with mono or multiparticle sizes.By varying the overall loading and particle size of alumina addition,different morphologies of the membranes were obtained due to the differences in the path lengths during phase inversion process for each solvent and nonsolvent exchange.The successful grafting with FAS was evidenced by the increase in contact angle from nearly equal to zero degree before grafting to 140°after grafting.Kaolin-alumina-4,one of the hollow fibres fabricated in this work,achieved a mean pore size of 0.25μm with the bending strength of 96.4 MPa and high nitrogen permeance of 2.3×10^(-5) mol·m^(-2)·Pa^(-1)·s^(-1),which makes the hollow fibre most suitable for the membrane contactor application.
基金The authors highly thanks to Dr.Lin Du from UMASS and Siemens EDA for the impartial assistance to polish the language substantially,and acknowledge the financial supports from the National Key Research and Development Program of China(Grant No.2019YFE0119200),the National Natural Science Foundation of China(Grant Nos.21978033,22021005 and 21978035),the Liaoning Province Funds(Grant No.XLYC1907063),the Dalian Science&Technology Project(GrantNo.2021JJ12GX019).
文摘Poly(ether−ether ketone)(PEEK)is a linear aromatic macromolecule,which can form semi-crystalline aggregative status,allowing PEEK materials to have strong environment tolerance and excellent physicochemical properties.PEEK materials have become a promising alternative to fabricate particular membranes used in extreme conditions.In the past few decades,many researches and evolutions have emerged in membrane fabrication with PEEK materials and its applications for treating organic solvents and their mixtures;however,there are little systematic and comprehensive literature to summarize fabrication approaches,compile applications,and elaborate PEEK property-structure relationship.In this review,the main approaches to fabricate PEEK-based membranes are illustrated concretely,including conventional thermal-induced and non-solvent-induced phase separation,and novel chemical-induced crystallization;the representative applications in ultrafiltration,nanofiltration and membrane contactor containing organic solvents are demonstrated systematically.Meanwhile,the mechanism to tune PEEK solubility in solvents,which can be achieved by altering monomers in synthesis processes or changing membrane preparation routes,is deeply analyzed.Moreover,the existing problems and the future prospects are also discussed.This review provides positive guidance for designing and fabricating membranes using PEEK and its derivative materials for task-specific applications in harsh conditions.
基金The author thanks the C02CRC Ltd.,especially Dr.Abdul Qader and Mr.Barry HooperProcess Group(now Suez Oil&Gas Systems),especially Dr.Trina Dreher+7 种基金Pilot Plant Management&Services Pty Ltd.,especially Mr.Kurt LuttinCommonwealth Scientific and Industrial Research Organisation(CSIRO),especially Mr.Dan Maher and Mr.Phillip GreenFurnace EngineeringHRL Technology Pty Ltd.Engie(formerly GDF Suez)Delta Electricitythe Victorian Government's Energy Technology Innovation Strategy(ETIS)and Victoria Fellowshipas well as Coal Innovation New South Wales.
文摘Membrane technology holds great potential in gas separation applications,especially carbon dioxide capture from industrial processes.To achieve this potential,the outputs from global research endeavours into membrane technologies must be trialled in industrial processes,which requires membrane-based pilot plants.These pilot plants are critical to the commercialization of membrane technology,be it as gas separation membranes or membrane gas-solvent contactors,as failure at the pilot plant level may delay the development of the technology for decades.Here,the author reports on his experience of operating membrane-based pilot plants for gas separation and contactor configurations as part of three industrial carbon capture initiatives:the Mulgrave project,H3 project and Vales Point project.Specifically,the challenges of developing and operating membrane pilot plants are presented,as well as the key learnings on how to successfully manage membrane pilot plants to achieve desired performance outcomes.The purpose is to assist membrane technologists in the carbon capture field to achieve successful outcomes for their technology innovations.
基金supported by the National Natural Science Foundation of China (No. 20676016, 21076024)the State Key Laboratory of Chemical Resource Engineering
文摘Catalytic bubble-free hydrogenation reduction of azo dye by porous membranes loaded with palladium （Pd） nanoparticles was studied for the first time. The effects of Pd loading, dye concentration and reuse repetitions of membranes were investigated. In reduction, the dye concentration decreased whereas the pH rose gradually. An optimal Pd loading was found. The catalytic membranes were able to be reused more than 3 times.
基金funded by the Research Fund of the National Natural Science Foundation of China(Grants Nos.20476096,20776133)Other financial support came from the Research Fund from the Bureau of Education(Key Discipline of Environmental Engineering grants 56310503014).
文摘The effects of baffles on the operation and mass-transfer characteristics in novel hollowfiber membrane contactor used in distillation were investi-gated.Hollowfiber membranes,coated with a 7μm polydimethyl-siloxane,were operated as structural packing in the separation of ethanol-water solutions.The parallelflow mode was chosen for separation due to the stronger driving force of the concentration difference,in which liquidflows through the lumens of thefibers and vaporflows countercurrent-wise outside thefibers.Two baffles were installed on the shell side of the membrane contactors to enhance separation,which had a round shape with a semi-lunar hole.The results show that both baffled and unbaffled membrane contactors gave better,more produc-tive separations than traditional packing in distillation,such as the excellent Sulzer Gauze BX structured packing.The baffled membrane contactors performed better than unbaffled ones,especially at high vapor velocities.The minimal HTU of membrane contactor with baffles could reach as low as 4.5 cm,and almost all the contactors could work well above the limit whereflooding normally occurs in conventional cases.Theoretical analysis predicted that baffles helped membrane module to obtain a higher mass-transfer coefficient and a smaller mass-transfer resistance.Finally,theoretical mass-transfer coefficient and experi-mental value were compared as well as the contribution of each individual mass-transfer coefficients among liquid,gas and membrane.
