The mass transfer of thiophene through pervaporation（PV） membranes could be facilitated by certain transitional metal ions like Ag+, Mn2+, and Cr3+ thanks to their p complexation with thiophene. In this study, Ag+, ...The mass transfer of thiophene through pervaporation（PV） membranes could be facilitated by certain transitional metal ions like Ag+, Mn2+, and Cr3+ thanks to their p complexation with thiophene. In this study, Ag+, Mn2+, and Cr3+ ions were loaded onto the polyether block amide（PEBAX）/PAN composite membranes and were tested on the performance for separation of thiophene/n-heptane mixture. Pervaporation test results showed that the pervaporative separation index increased significantly to 73.1%, 75.5%, and 97.2% at 30 oC for the Ag+-, Mn2+-, Cr3+-loaded PEBAX membranes, respectively,as compared to the pristine PEBAX/PAN composite membrane.展开更多
Due to the low transport resistance,mullite hollow fiber(HF)could be regarded as a promising support for preparation of NaA zeolite membranes.However,insufficient coverage and undesired seed penetration often occur in...Due to the low transport resistance,mullite hollow fiber(HF)could be regarded as a promising support for preparation of NaA zeolite membranes.However,insufficient coverage and undesired seed penetration often occur in the seeding step of the mullite support due to the rough surfaces with ultra-large macropores(2-4 μm).This leads to poor intergrowth of the membrane layer.To solve this issue,cationic polyacrylamide(CPAM)was employed to modify the chemical and electrostatic properties of the mullite HF surface,where the electrostatic attraction between the surface and seed crystals could significantly promote the coating effect.In the seeding,the original seeds(3.2 μm)were mixed with the ball-milled seeds(0.3 μm)to improve the seed coverage,i.e.,the original seed was used to block the macropores on the support surface to prevent the penetration of small seeds,while the decked ball-milled seed was used to provide sufficient active sites to induce the intergrowth of the zeolite crystals.The effects of the concentration of CPAM,mixed mass ratio of seeds,and seed concentration on the preparation of NaA zeolite membranes were systematically examined,where the separation performances were characterized by pervaporation(PV)dehydration of 90%(mass)ethanol/water mixtures at 75℃.The results indicated that under a CPAM concentration of 0.7%(mass),an equivalent mass ratio of mixed seeds in a seed concentration of 1.0%(mass),the prepared mullite HF supported NaA zeolite membrane yielded the best PV performance,where the permeation flux and separation factor corresponded to 5.45 kg·m^(-2)·h^(-1)and 10000,respectively,being sufficient for industrial applications.展开更多
N-methyl-pyrrolidone(NMP)is an important solvent for the production of lithium batteries,which causes environmental pollution and wastes resources if it is directly discharged.The current commonly used vacuum distilla...N-methyl-pyrrolidone(NMP)is an important solvent for the production of lithium batteries,which causes environmental pollution and wastes resources if it is directly discharged.The current commonly used vacuum distillation recovery process suffers from high operating costs and high energy consumption.Therefore,this paper proposes a coupled pervaporation-adsorption(PV-A)process to recover NMP solvents from lithium battery production waste streams.In this process,pervaporation is used to dewater the NMP waste liquid,it was found that the water content in the raw material liquid decreased from the initial 8.3%(mass)to 0.14%(mass)after 400 min of dewatering,but the membrane separation performance decreased significantly when the water content of the raw material liquid decreased to 0.45%(mass),and at the same time,the NMP loss rate increased rapidly.An adsorption process was used to remove trace water from the remaining liquid,and the water content in the feed liquid under the optimal adsorption process conditions was reduced from 0.45%(mass)to 0.014%,which fully meets the purity requirements of electronics-grade NMP for the production of lithium batteries.Steady-state modeling and techno-economic evaluation of the proposed coupled process were carried out,and compared with vacuum distillation and pervaporation technologies,the results showed the PV-A process yielded the best techno-economic performance and the lowest environmental impact,and it can be used as an alternative process to the traditional NMP recycling technology.This study provides a new method for the recycling of NMP in the lithium battery industry.展开更多
Extracting ethanol from aqueous solutions is important but challenging in industry.Pervaporation membranes show great promise for separating ethanol from water,with the design of their structure being crucial for enha...Extracting ethanol from aqueous solutions is important but challenging in industry.Pervaporation membranes show great promise for separating ethanol from water,with the design of their structure being crucial for enhancing performance.In this study,we developed an oriented bimetallic metal-organic framework(MOF)membrane,designated as ZIF-CoZn,for the pervaporation separation of ethanol from water.During crystal growth,bimetallic salts provide specific nucleation sites,and the competitive coordination between Co and Zn ions shifts the energetically favorable(100)plane to the(211)plane.This orientation enables precise molecular-level control over hydrophobic ligand arrangement,effectively repelling water molecules.Meanwhile,bimetallic competition enlarges pore sizes,facilitating ethanol permeation.When compared to single-metal MOF membranes made of cobalt or zinc,the separation factor of the ZIF-CoZn membrane for ethanol/water mixtures increased by 127%and 160%,respectively.Benefiting from the high roughness and increased exposure of hydrophobic ligands due to the preferential(211)orientation,ZIF-CoZn exhibits superhydrophobicity after vinyl-polydimethylsiloxane coating.The oriented ZIF-CoZn membrane was also scaled up to an area of 1 m^(2).This work provides valuable insights into optimizing MOF membrane structure and lays the foundation for its promotion and application in the industry.展开更多
Phenol is extensively utilized in various industries involving paints,rubber,textiles,explosives,plastics,etc.Compared to the conventional distillation or extraction technologies,pervaporation(PV)membrane process can ...Phenol is extensively utilized in various industries involving paints,rubber,textiles,explosives,plastics,etc.Compared to the conventional distillation or extraction technologies,pervaporation(PV)membrane process can be operated at a low temperature and has a low energy consumption as well as a high separation efficiency for phenol recovery.Thus,to meet the high demand for phenol recovery,the application of PV has been encouraged,and reached a new level.The PV process is governed by the properties of the membrane materials that significantly influence the energy costs associated with the separation unit,and the membrane types include polymer membranes,inorganic membranes,and mixed matrix membranes.Although recent literatures show that PV membranes have been continuously updated,no review has reported the latest development about it.In this work,the material types,separation properties and preparation methods of hydrophobic PV membranes for phenol recovery are summarized.Furthermore,the key preparation methods and application challenges associated with membranes are summarized,along with an overview of the opportunities and challenges posed by hydrophobic PV membranes for phenol recovery.展开更多
Floral and fruity aromas are vital indicators for evaluating the quality of the sauce-flavored Baijiu,however,are hard to analyze and elucidate due to the interference of other aromas in the liquor.Herein,we developed...Floral and fruity aromas are vital indicators for evaluating the quality of the sauce-flavored Baijiu,however,are hard to analyze and elucidate due to the interference of other aromas in the liquor.Herein,we developed a pervaporation membrane separation technology(PV),that effectively reduces the complexity of analyzing floral and fruity aromas and enables the identification of key flavor compounds of the floral and fruity aromas in sauceflavored Baijiu.Contributed to the separation via PV on flavor,liquor samples differing in floral and fruity aromas are efficiently separated that allows to be sensitively analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)and gas chromatography-mass spectrometry(GC-MS).We found that a total of 29 compounds that potentially contributed to floral and fruity aroma.Aroma recombination and omission/addition experiments were conducted to verify the contribution of these compounds to the overall aroma,leading to the identification of 15 key aroma compounds including affecting floral and fruity aromas.And discovered esters serving as key components for contributing floral and fruity aromas.Meanwhile,Acetals can make the aromas become more coordinated and aldehydes facilitate floral and fruity aroma release.The work contributes to a tool for elucidating complexity of flavor compounds in Baijiu.展开更多
The salt transport in a PEBA membrane used in pervaporative desalination was studied.The concentration profile of salt in the membrane during pervaporation was investigated experimentally using a multilayer membrane.T...The salt transport in a PEBA membrane used in pervaporative desalination was studied.The concentration profile of salt in the membrane during pervaporation was investigated experimentally using a multilayer membrane.The salt was found to be sorbed in the membrane but was not removed during the pervaporative desalination process,and the salt concentration in the membrane varied linearly with position.High purity water was obtained as the permeate as long as the permeate side was kept dry under vacuum.The accumulated salt uptake in the membrane follows the order of MgCl2 N NaCl N Na2 SO4.The solubility of salt in the membrane follows the order of MgCl2 N NaCl N Na2 SO4.Both the permeability and diffusivity of salt in the membrane follow the order of NaCl N MgCl2 N Na2 SO4.The permeability of salt in the membrane is not influenced by the feed salt concentration.It is mainly determined by the diffusion coefficients.展开更多
A high performance composite membrane was prepared under the inspiration of bioadhesion principles for pervaporative dehydration of ethanol.Chitosan(CS)and polyacrylonitrile(PAN)ultrafiltration membranes were used as ...A high performance composite membrane was prepared under the inspiration of bioadhesion principles for pervaporative dehydration of ethanol.Chitosan(CS)and polyacrylonitrile(PAN)ultrafiltration membranes were used as the active layer and the support layer,respectively.Guar gum(GG),a natural bioadhesive,was introduced as the intermediate bonding layer to improve the separation performance and stability of the fabricated CS/GG/PAN composite membranes.The contact angle of the GG layer was just between those of the CS layer and the PAN layer,minimizing the difference of hydrophilicity between the active layer and the support layer.The peeling strength of the composite membrane was significantly enhanced after the introduction of the GG layer.The effects of preparation conditions and operation conditions including GG concentration,operating temperature and ethanol concentration in feed on the pervaporation performance were investigated.The as-fabricated CS/GG/PAN composite membrane showed the optimum performance with a permeation flux of up to804 g·m-2·h-1and a separation factor higher than 1900.Besides,the composite membranes exhibited a desirable long-term operational stability.展开更多
Pervaporation(including vapor permeation) is a kind of new membrane separation technology, possessing the advantages of high efficiency, energy saving and convenient operation. It has promising application in the sepa...Pervaporation(including vapor permeation) is a kind of new membrane separation technology, possessing the advantages of high efficiency, energy saving and convenient operation. It has promising application in the separation and purification of organic solvents. Dehydration is an important step in the production and recovery of organic solvents. Zeolite membranes have attracted wide attention for pervaporation dehydration due to their high separation performance and good thermal/chemical stability. So far, zeolite membranes have been preliminarily industrialized for dehydration of organic solvents. This paper reviews the recent development of zeolite membranes for pervaporation dehydration, including mass transfer models, preparation and applications of zeolite membranes. The review also discusses the current industrial applications of zeolite membranes and their future development in pervaporation.展开更多
Pervaporation has attracted considerable interest owing to its potential application in recovering biobutanol from biomass acetone-butanol-ethanol (ABE) fermentation broth. In this study, butanol was recovered from it...Pervaporation has attracted considerable interest owing to its potential application in recovering biobutanol from biomass acetone-butanol-ethanol (ABE) fermentation broth. In this study, butanol was recovered from its aqueous solution using a polydimethylsiloxane (PDMS)/ceramic composite pervaporation membrane. The effects of operating temperature, feed concentration, feed flow rate and operating time on the membrane pervaporation performance were investigated. It was found that with the increase of temperature or butanol concentration in the feed, the total flux through the membrane increased while the separation factor decreased slightly. As the feed flow rate increased, the total flux increased gradually while the separation factor changed little. At 40°C and 1% (by mass) butanol in the feed, the total flux and separation factor of the membrane reached 457.4 g·m?2·h?1 and 26.1, respectively. The membrane with high flux is suitable for recovering butanol from ABE fermentation broth.展开更多
NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value i...NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value in the feed of isopropanol （IPA） solution on NaA zeolite membranes was investigated. It was found that both factors exhibited strong influence on the stability of NaA zeolite membranes. A set of pretreatment steps such as pH adjustment and distillation of the IPA solution were proposed to improve stability for pervaporation dehydration. An industrial-scale pervaporation facility with 52 m2 membrane area was built to dehydrate IPA solution from industrial cephalosporin production. The facility was continuously operated at 368-378 K to dehydrate IPA solution from water mass content of 15%-20% to less than 2% with a feed flow rate of 400-500 L·h^-1 and an average water flux of 1-1.5 kg·m^-2·h-1. The successful application of this facility suggested a promising application of NaA zeolite mem-brane for IPA recovery from pharmaceutical production.展开更多
Alcohol-permselectivity pervaporation has been arousing increasingly more attention in bioalcohol production due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentat...Alcohol-permselectivity pervaporation has been arousing increasingly more attention in bioalcohol production due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentation process. With the intrinsic feature of larger molecules preferentially permeating and the consequent inferiority in selective diffusion, the development of alcohol-permselective membrane is relatively retarded compared with water-permselective membrane. This review presents the prevalent membrane materials utilized for alcohol-permselective pervaporation and emphatically expatiates the representative and important developments in the past five years from the aspect of tuning confined structure in membranes. In particular, the diverse structure tuning methods are described with the classifications of physical structure and chemical structure. The corresponding structure-performance relationships in alcohol-permselective pervaporation membranes are also analyzed to identify the objective of structure optimization. Furthermore, the tentative perspective on the possible future directions of alcohol-permselective pervaporation membrane is briefly presented.展开更多
Thin-film zeolite-filled silicone/PVDF composite membranes were fabricated by incorporating zeolite particles into PDMS(poly(dimethylsiloxane)) membranes.The morphology of zeolite particles and zeolite filled silicone...Thin-film zeolite-filled silicone/PVDF composite membranes were fabricated by incorporating zeolite particles into PDMS(poly(dimethylsiloxane)) membranes.The morphology of zeolite particles and zeolite filled silicone composite membranes were characterized by SEM.The zeolite-filled PDMS/PVDF composite membranes were applied for the pervaporation of ethanol/water mixtures and showed higher flux compared with that reported in literatures.The effect of zeolite loading and Si/Al ratio of zeolite particles on pe...展开更多
Extraordinary mass transfer phenomenon is usually found when the small molecules pass through a confined structure, whose effective size is commensurate with the mean free path of the molecules. Small changes in the c...Extraordinary mass transfer phenomenon is usually found when the small molecules pass through a confined structure, whose effective size is commensurate with the mean free path of the molecules. Small changes in the confined mass transfer structure(including size, morphology and properties) will lead to significant fluctuations of the mass transfer coefficient. The mass transfer of the penetrant molecules in the dense membranes for pervaporation, gas separation and so on, is located in the scope of confined mass transfer. Incorporating nanofillers into polymer matrix to construct mixed matrix membranes(MMMs) is an effective approach to tune the confined mass transfer structure and enhance the performance of the widely used polymeric membranes. This review focuses on the construction and manipulation of the confined structure in the polymeric membranes via incorporating one-dimensional(1D), two-dimensional(2D) and three-dimensional(3D) fillers.The comparison of the MMMs for pervaporation is summarized, and the research prospective of the MMMs is provided.展开更多
Hybrid membranes combining the merits of both polymer matrices and fillers have drawn extensive attention. The rational design of polymer–filler interface in hybrid membranes is vitally important for reducing the occ...Hybrid membranes combining the merits of both polymer matrices and fillers have drawn extensive attention. The rational design of polymer–filler interface in hybrid membranes is vitally important for reducing the occurrence of void defects. Herein, imine-type covalent organic frameworks(COFs) were selected as the fillers due to their totally organic nature and multi-functionalities. Mussel-inspired dopamine-modified sodium alginate(Alg DA) was synthesized as the polymer matrix. The dopamine modification significantly improves the Alg DA–COF compatibility,which enhances the COF content up to 50 wt% in the hybrid membranes. The improved interfacial compatibility enhances the membrane separation selectivity. Accordingly, when utilized for dehydration of ethanol/water mixed solution(water concentration of 10 wt%), the hybrid membrane reveals high water concentration of ~98.7 wt% in permeate, and stable permeation flux larger than 1500 g·m-2·h-1. This work might afford useful insights for fabricating hybrid membranes with high separation selectivity by optimizing the polymer–filler interface.展开更多
Pervaporation(PV),as an environmental friendly and energy-saving separation technology,has been received increasing attention in recent years.This article reviews the preparation and application of macroporous ceramic...Pervaporation(PV),as an environmental friendly and energy-saving separation technology,has been received increasing attention in recent years.This article reviews the preparation and application of macroporous ceramic-supported polymer composite pervaporation membranes.The separation materials of polymer/ceramic composite membranes presented here include hydrophobic polydimethylsiloxane(PDMS) and hydrophilic poly(vinyl alcohol)(PVA),chitosan(CS) and polyelectrolytes.The effects of ceramic support treatment,polymer solution properties,interfacial adhesion and incorporating or blending modification on the membrane structure and PV performance are discussed.Two in-situ characterization methods developed for polymer/ceramic composite membranes are also covered in the discussion.The applications of these composite membranes in pervaporation process are summarized as well,which contain the bio-fuels recovery,gasoline desulfuration and PV coupled proc-ess using PDMS/ceramic composite membrane,and dehydration of alcohols and esters using ceramic-supported PVA or PVA-CS composite membrane.Finally,a brief conclusion remark on polymer/ceramic composite mem-branes is given and possible future research is outlined.展开更多
A mass transfer model in consideration of multi-layer resistances through NaA zeolite membrane and lumen pressure drop in the permeate side was developed to describe pervaporation dehydration through scaled-up hollow ...A mass transfer model in consideration of multi-layer resistances through NaA zeolite membrane and lumen pressure drop in the permeate side was developed to describe pervaporation dehydration through scaled-up hollow fiber supported NaA zeolite membrane. It was found that the transfer resistance in the lumen of the permeate side is strongly related with geometric size of hollow fiber zeolite membrane, which could not he neglected. The effect of geometric size on pervaporation dehydration could be more significant under higher vacuum pressure in the permeate side. The transfer resistance in the lumen increases with the hollow fiber length but decreases with lumen diameter. The geometric structure could be optimized in terms of the ratio of lumen diameter to membrane length. A critical value of d1/L （Rc） to achieve high permeation flux was empirically correlated with extraction pressure in the permeate side. Typically, for a hollow fiber supported NaA zeolite membrane with length of 0.40 m, the lumen diameter should be larger than 2.0 mm under the extraction pressure of 1500 Pa.展开更多
Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phe...Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phenyltrimethoxylsilane(PTMOS) and octyltrimethoxylsilane(OTMOS) as well.The cross-linking density and surface properties of the PDMS active layer were adjusted by varying cross-linking reagents.The pervaporation performance of PDMS membranes cured with different cross-linking reagents was investig...展开更多
Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh cond...Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh conditions.Development of durable and high separation performance membranes with lower fabrication and operation cost are highly demanded for industrial applications. Zeolite T membrane possesses good acid-resistance with excellent hydrophilic properties as compared to NaA zeolite membrane and can be extended to industrial organic dehydrations under an acidic environment. In the present review the research advances in development of zeolite T membranes for the dehydration of organic mixtures in acidic conditions are summarized. Especially the low temperature synthesis, and epitaxial growth of the zeolite membrane with high performance are well addressed, besides emphasis is particularly placed on ensemble synthesis of hollow fiber zeolite T membrane module and its future prospects for industrial separations.展开更多
Recovering alcohols from dilute fermentation broth is an emergent task in bio-fuel production process. Since they are primary planned for fuels, energy required to separate these alcohols should be considered in evalu...Recovering alcohols from dilute fermentation broth is an emergent task in bio-fuel production process. Since they are primary planned for fuels, energy required to separate these alcohols should be considered in evaluating the potential of a separation technology. A membrane-based process, pervaporation, is of special interest because of its environmental friendliness and easy integrating character. This review probes into the fundamentals of pervaporation especially in terms of the heat required for evaporation. Meanwhile, the separation data of the most representative alcohol-selective pervaporation membranes reported in the literatures are collected and compared with the vapor–liquid equilibrium curve, which represents the distillation selectivity. They include:inorganic membranes, silicon rubber based membranes, Mixed Matrix Membranes and some other special materials. By doing so, the status of alcohol recovery via pervaporation would be more clear for researchers.For ethanol recovery, it is selectivity rather than flux that is in urgent need of solution. While for butanol recovery,membranes with satisfactory selectivity have been developed, increasing the separation capacity would be more pressing.展开更多
基金The financial support from the Dean Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology (2013Z009)the Guangxi Natural Science Fund (2014jjAA20079)the Guangdong Province of Quality and Technical Supervision Bureau (2018ZZ01) is greatly appreciated
文摘The mass transfer of thiophene through pervaporation（PV） membranes could be facilitated by certain transitional metal ions like Ag+, Mn2+, and Cr3+ thanks to their p complexation with thiophene. In this study, Ag+, Mn2+, and Cr3+ ions were loaded onto the polyether block amide（PEBAX）/PAN composite membranes and were tested on the performance for separation of thiophene/n-heptane mixture. Pervaporation test results showed that the pervaporative separation index increased significantly to 73.1%, 75.5%, and 97.2% at 30 oC for the Ag+-, Mn2+-, Cr3+-loaded PEBAX membranes, respectively,as compared to the pristine PEBAX/PAN composite membrane.
基金supported by the National Natural Science Foundation of China(22178166)Jiangsu Provincial Special Funds of Scientific and Technological Innovation for Carbon Peak and Carbon Neutrality(BE2022033-1,BE2022033-4)Chongqing Municipal Bureau of Science and Technology(cstc2021jcyj-msxmX0748).
文摘Due to the low transport resistance,mullite hollow fiber(HF)could be regarded as a promising support for preparation of NaA zeolite membranes.However,insufficient coverage and undesired seed penetration often occur in the seeding step of the mullite support due to the rough surfaces with ultra-large macropores(2-4 μm).This leads to poor intergrowth of the membrane layer.To solve this issue,cationic polyacrylamide(CPAM)was employed to modify the chemical and electrostatic properties of the mullite HF surface,where the electrostatic attraction between the surface and seed crystals could significantly promote the coating effect.In the seeding,the original seeds(3.2 μm)were mixed with the ball-milled seeds(0.3 μm)to improve the seed coverage,i.e.,the original seed was used to block the macropores on the support surface to prevent the penetration of small seeds,while the decked ball-milled seed was used to provide sufficient active sites to induce the intergrowth of the zeolite crystals.The effects of the concentration of CPAM,mixed mass ratio of seeds,and seed concentration on the preparation of NaA zeolite membranes were systematically examined,where the separation performances were characterized by pervaporation(PV)dehydration of 90%(mass)ethanol/water mixtures at 75℃.The results indicated that under a CPAM concentration of 0.7%(mass),an equivalent mass ratio of mixed seeds in a seed concentration of 1.0%(mass),the prepared mullite HF supported NaA zeolite membrane yielded the best PV performance,where the permeation flux and separation factor corresponded to 5.45 kg·m^(-2)·h^(-1)and 10000,respectively,being sufficient for industrial applications.
基金supported by the Key Research and Development Program of Gansu Province(23YFGA0051)the Industrial Support Program for Higher Education Institutions of Gansu Province(2024CYZC-17).
文摘N-methyl-pyrrolidone(NMP)is an important solvent for the production of lithium batteries,which causes environmental pollution and wastes resources if it is directly discharged.The current commonly used vacuum distillation recovery process suffers from high operating costs and high energy consumption.Therefore,this paper proposes a coupled pervaporation-adsorption(PV-A)process to recover NMP solvents from lithium battery production waste streams.In this process,pervaporation is used to dewater the NMP waste liquid,it was found that the water content in the raw material liquid decreased from the initial 8.3%(mass)to 0.14%(mass)after 400 min of dewatering,but the membrane separation performance decreased significantly when the water content of the raw material liquid decreased to 0.45%(mass),and at the same time,the NMP loss rate increased rapidly.An adsorption process was used to remove trace water from the remaining liquid,and the water content in the feed liquid under the optimal adsorption process conditions was reduced from 0.45%(mass)to 0.014%,which fully meets the purity requirements of electronics-grade NMP for the production of lithium batteries.Steady-state modeling and techno-economic evaluation of the proposed coupled process were carried out,and compared with vacuum distillation and pervaporation technologies,the results showed the PV-A process yielded the best techno-economic performance and the lowest environmental impact,and it can be used as an alternative process to the traditional NMP recycling technology.This study provides a new method for the recycling of NMP in the lithium battery industry.
基金the funding from the National Key Research and Development Program of China(No.2022YFB3804802)the National Natural Science Foundation of China(22125801,22478012)Beijing Natural Science Foundation(Z230023)。
文摘Extracting ethanol from aqueous solutions is important but challenging in industry.Pervaporation membranes show great promise for separating ethanol from water,with the design of their structure being crucial for enhancing performance.In this study,we developed an oriented bimetallic metal-organic framework(MOF)membrane,designated as ZIF-CoZn,for the pervaporation separation of ethanol from water.During crystal growth,bimetallic salts provide specific nucleation sites,and the competitive coordination between Co and Zn ions shifts the energetically favorable(100)plane to the(211)plane.This orientation enables precise molecular-level control over hydrophobic ligand arrangement,effectively repelling water molecules.Meanwhile,bimetallic competition enlarges pore sizes,facilitating ethanol permeation.When compared to single-metal MOF membranes made of cobalt or zinc,the separation factor of the ZIF-CoZn membrane for ethanol/water mixtures increased by 127%and 160%,respectively.Benefiting from the high roughness and increased exposure of hydrophobic ligands due to the preferential(211)orientation,ZIF-CoZn exhibits superhydrophobicity after vinyl-polydimethylsiloxane coating.The oriented ZIF-CoZn membrane was also scaled up to an area of 1 m^(2).This work provides valuable insights into optimizing MOF membrane structure and lays the foundation for its promotion and application in the industry.
基金funded by National Natural Science Foundation of China(22278023,22208010)S&T Program of Hebei(24464301D)SINOPEC Group(24-ZS-0447).
文摘Phenol is extensively utilized in various industries involving paints,rubber,textiles,explosives,plastics,etc.Compared to the conventional distillation or extraction technologies,pervaporation(PV)membrane process can be operated at a low temperature and has a low energy consumption as well as a high separation efficiency for phenol recovery.Thus,to meet the high demand for phenol recovery,the application of PV has been encouraged,and reached a new level.The PV process is governed by the properties of the membrane materials that significantly influence the energy costs associated with the separation unit,and the membrane types include polymer membranes,inorganic membranes,and mixed matrix membranes.Although recent literatures show that PV membranes have been continuously updated,no review has reported the latest development about it.In this work,the material types,separation properties and preparation methods of hydrophobic PV membranes for phenol recovery are summarized.Furthermore,the key preparation methods and application challenges associated with membranes are summarized,along with an overview of the opportunities and challenges posed by hydrophobic PV membranes for phenol recovery.
基金supported by Sichuan Province Science and Tech-nology Support Program(2022YFN0057).
文摘Floral and fruity aromas are vital indicators for evaluating the quality of the sauce-flavored Baijiu,however,are hard to analyze and elucidate due to the interference of other aromas in the liquor.Herein,we developed a pervaporation membrane separation technology(PV),that effectively reduces the complexity of analyzing floral and fruity aromas and enables the identification of key flavor compounds of the floral and fruity aromas in sauceflavored Baijiu.Contributed to the separation via PV on flavor,liquor samples differing in floral and fruity aromas are efficiently separated that allows to be sensitively analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)and gas chromatography-mass spectrometry(GC-MS).We found that a total of 29 compounds that potentially contributed to floral and fruity aroma.Aroma recombination and omission/addition experiments were conducted to verify the contribution of these compounds to the overall aroma,leading to the identification of 15 key aroma compounds including affecting floral and fruity aromas.And discovered esters serving as key components for contributing floral and fruity aromas.Meanwhile,Acetals can make the aromas become more coordinated and aldehydes facilitate floral and fruity aroma release.The work contributes to a tool for elucidating complexity of flavor compounds in Baijiu.
基金the Natural Sciences and Engineering Research Council(NSERC)of Canada and Zhejiang Province Natural Science Foundation of China(LQ20B060002)。
文摘The salt transport in a PEBA membrane used in pervaporative desalination was studied.The concentration profile of salt in the membrane during pervaporation was investigated experimentally using a multilayer membrane.The salt was found to be sorbed in the membrane but was not removed during the pervaporative desalination process,and the salt concentration in the membrane varied linearly with position.High purity water was obtained as the permeate as long as the permeate side was kept dry under vacuum.The accumulated salt uptake in the membrane follows the order of MgCl2 N NaCl N Na2 SO4.The solubility of salt in the membrane follows the order of MgCl2 N NaCl N Na2 SO4.Both the permeability and diffusivity of salt in the membrane follow the order of NaCl N MgCl2 N Na2 SO4.The permeability of salt in the membrane is not influenced by the feed salt concentration.It is mainly determined by the diffusion coefficients.
基金Supported by the New Century Excellent Talents in University(NCET-10-0623)the National Natural Science Foundation for Distinguished Young Scholars(21125627)+1 种基金the National Basic Research Program of China(2009CB623404)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(Dong Hua University)
文摘A high performance composite membrane was prepared under the inspiration of bioadhesion principles for pervaporative dehydration of ethanol.Chitosan(CS)and polyacrylonitrile(PAN)ultrafiltration membranes were used as the active layer and the support layer,respectively.Guar gum(GG),a natural bioadhesive,was introduced as the intermediate bonding layer to improve the separation performance and stability of the fabricated CS/GG/PAN composite membranes.The contact angle of the GG layer was just between those of the CS layer and the PAN layer,minimizing the difference of hydrophilicity between the active layer and the support layer.The peeling strength of the composite membrane was significantly enhanced after the introduction of the GG layer.The effects of preparation conditions and operation conditions including GG concentration,operating temperature and ethanol concentration in feed on the pervaporation performance were investigated.The as-fabricated CS/GG/PAN composite membrane showed the optimum performance with a permeation flux of up to804 g·m-2·h-1and a separation factor higher than 1900.Besides,the composite membranes exhibited a desirable long-term operational stability.
基金Supported by the National Natural Science Foundation of China(21490585,21606126)National High-tech R&D Program of China(2015AA03A602)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Pervaporation(including vapor permeation) is a kind of new membrane separation technology, possessing the advantages of high efficiency, energy saving and convenient operation. It has promising application in the separation and purification of organic solvents. Dehydration is an important step in the production and recovery of organic solvents. Zeolite membranes have attracted wide attention for pervaporation dehydration due to their high separation performance and good thermal/chemical stability. So far, zeolite membranes have been preliminarily industrialized for dehydration of organic solvents. This paper reviews the recent development of zeolite membranes for pervaporation dehydration, including mass transfer models, preparation and applications of zeolite membranes. The review also discusses the current industrial applications of zeolite membranes and their future development in pervaporation.
基金Supported by the National Basic Research Program of China（2009CB623406） the National Natural Science Foundation of China（20990222）+1 种基金 the Natural Science Foundation of Jiangsu Province（SBK200930313） the“Six Kinds of Important Talents”Program of Jiangsu Province（2007007）
文摘Pervaporation has attracted considerable interest owing to its potential application in recovering biobutanol from biomass acetone-butanol-ethanol (ABE) fermentation broth. In this study, butanol was recovered from its aqueous solution using a polydimethylsiloxane (PDMS)/ceramic composite pervaporation membrane. The effects of operating temperature, feed concentration, feed flow rate and operating time on the membrane pervaporation performance were investigated. It was found that with the increase of temperature or butanol concentration in the feed, the total flux through the membrane increased while the separation factor decreased slightly. As the feed flow rate increased, the total flux increased gradually while the separation factor changed little. At 40°C and 1% (by mass) butanol in the feed, the total flux and separation factor of the membrane reached 457.4 g·m?2·h?1 and 26.1, respectively. The membrane with high flux is suitable for recovering butanol from ABE fermentation broth.
基金Supported by the National t）asic Research Program of China （2009CB623403）, the National High Technology Research and De velopment Program of China （2009AA034802）, the National Natural Science Foundation of China （20706030, U0834004）, the Science ＆ Technology Support Program （Industry） of Jiangsu Province of China （BE2008141）, the Natural Science Foundation of the Jiangsu Higher Education Institutions （09KJA530002） and 333 High-Level Personnel Training Project in Jiangsu Province. ＊＊ To whom correspondence should be addressed. E-mail： Xuehonggu@yahoo.com
文摘NaA zeolite membranes with 80 cm in length and 12.8 mm in outer diameter were prepared by our research group cooperating with Nanjing Jiusi Hi-Tech Co., China. The influence of dissolved inorganic salts and pH value in the feed of isopropanol （IPA） solution on NaA zeolite membranes was investigated. It was found that both factors exhibited strong influence on the stability of NaA zeolite membranes. A set of pretreatment steps such as pH adjustment and distillation of the IPA solution were proposed to improve stability for pervaporation dehydration. An industrial-scale pervaporation facility with 52 m2 membrane area was built to dehydrate IPA solution from industrial cephalosporin production. The facility was continuously operated at 368-378 K to dehydrate IPA solution from water mass content of 15%-20% to less than 2% with a feed flow rate of 400-500 L·h^-1 and an average water flux of 1-1.5 kg·m^-2·h-1. The successful application of this facility suggested a promising application of NaA zeolite mem-brane for IPA recovery from pharmaceutical production.
基金Supported by the National Natural Science Foundation of China(21490585,21606123)the Jiangsu Province Natural Science Foundation for the Youth(BK20160980)+2 种基金the Innovative Research Team Program by the Ministry of Education of China(IRT13070)Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Alcohol-permselectivity pervaporation has been arousing increasingly more attention in bioalcohol production due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentation process. With the intrinsic feature of larger molecules preferentially permeating and the consequent inferiority in selective diffusion, the development of alcohol-permselective membrane is relatively retarded compared with water-permselective membrane. This review presents the prevalent membrane materials utilized for alcohol-permselective pervaporation and emphatically expatiates the representative and important developments in the past five years from the aspect of tuning confined structure in membranes. In particular, the diverse structure tuning methods are described with the classifications of physical structure and chemical structure. The corresponding structure-performance relationships in alcohol-permselective pervaporation membranes are also analyzed to identify the objective of structure optimization. Furthermore, the tentative perspective on the possible future directions of alcohol-permselective pervaporation membrane is briefly presented.
基金supported by the Major State Basic Research Program of China(No.2009CB623404)National Natural Science Foundation of China(Nos.20736003,20676067)+3 种基金National High Technology Research and Development Program of China(No.2007AA06Z317)Foundation of Ministry of Education of China(No.20070003130)Foundation of the State Key Laboratory of Chemical Engineering(SKL-ChE-08A01)Postdoctor Science Foundation of China (No.023201069)
文摘Thin-film zeolite-filled silicone/PVDF composite membranes were fabricated by incorporating zeolite particles into PDMS(poly(dimethylsiloxane)) membranes.The morphology of zeolite particles and zeolite filled silicone composite membranes were characterized by SEM.The zeolite-filled PDMS/PVDF composite membranes were applied for the pervaporation of ethanol/water mixtures and showed higher flux compared with that reported in literatures.The effect of zeolite loading and Si/Al ratio of zeolite particles on pe...
基金Supported by the National Natural Science Foundation of China(21490583 and21621004)the National Science Fund for Distinguished Young Scholars(21125627)+1 种基金Tianjin Application Foundation and Research in Cutting-edge Technology Plan(15JCQNJC43300)the Programme of Introducing Talents of Discipline to Universities(B06006)
文摘Extraordinary mass transfer phenomenon is usually found when the small molecules pass through a confined structure, whose effective size is commensurate with the mean free path of the molecules. Small changes in the confined mass transfer structure(including size, morphology and properties) will lead to significant fluctuations of the mass transfer coefficient. The mass transfer of the penetrant molecules in the dense membranes for pervaporation, gas separation and so on, is located in the scope of confined mass transfer. Incorporating nanofillers into polymer matrix to construct mixed matrix membranes(MMMs) is an effective approach to tune the confined mass transfer structure and enhance the performance of the widely used polymeric membranes. This review focuses on the construction and manipulation of the confined structure in the polymeric membranes via incorporating one-dimensional(1D), two-dimensional(2D) and three-dimensional(3D) fillers.The comparison of the MMMs for pervaporation is summarized, and the research prospective of the MMMs is provided.
基金Supported by the National Natural Science Foundation of China(21621004,21490583,21878215,21878216)the Program of Introducing Talents of Discipline to Universities(B06006)the State Key Laboratory of Organic–Inorganic Composites(oic-201801003).
文摘Hybrid membranes combining the merits of both polymer matrices and fillers have drawn extensive attention. The rational design of polymer–filler interface in hybrid membranes is vitally important for reducing the occurrence of void defects. Herein, imine-type covalent organic frameworks(COFs) were selected as the fillers due to their totally organic nature and multi-functionalities. Mussel-inspired dopamine-modified sodium alginate(Alg DA) was synthesized as the polymer matrix. The dopamine modification significantly improves the Alg DA–COF compatibility,which enhances the COF content up to 50 wt% in the hybrid membranes. The improved interfacial compatibility enhances the membrane separation selectivity. Accordingly, when utilized for dehydration of ethanol/water mixed solution(water concentration of 10 wt%), the hybrid membrane reveals high water concentration of ~98.7 wt% in permeate, and stable permeation flux larger than 1500 g·m-2·h-1. This work might afford useful insights for fabricating hybrid membranes with high separation selectivity by optimizing the polymer–filler interface.
文摘Pervaporation(PV),as an environmental friendly and energy-saving separation technology,has been received increasing attention in recent years.This article reviews the preparation and application of macroporous ceramic-supported polymer composite pervaporation membranes.The separation materials of polymer/ceramic composite membranes presented here include hydrophobic polydimethylsiloxane(PDMS) and hydrophilic poly(vinyl alcohol)(PVA),chitosan(CS) and polyelectrolytes.The effects of ceramic support treatment,polymer solution properties,interfacial adhesion and incorporating or blending modification on the membrane structure and PV performance are discussed.Two in-situ characterization methods developed for polymer/ceramic composite membranes are also covered in the discussion.The applications of these composite membranes in pervaporation process are summarized as well,which contain the bio-fuels recovery,gasoline desulfuration and PV coupled proc-ess using PDMS/ceramic composite membrane,and dehydration of alcohols and esters using ceramic-supported PVA or PVA-CS composite membrane.Finally,a brief conclusion remark on polymer/ceramic composite mem-branes is given and possible future research is outlined.
基金Supported by the National Natural Science Foundation of China(21490585 and21776128)the National High-tech R&D Program of China(2015AA03A602)+1 种基金the"Six Top Talents"and"333 Talent Project"of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A mass transfer model in consideration of multi-layer resistances through NaA zeolite membrane and lumen pressure drop in the permeate side was developed to describe pervaporation dehydration through scaled-up hollow fiber supported NaA zeolite membrane. It was found that the transfer resistance in the lumen of the permeate side is strongly related with geometric size of hollow fiber zeolite membrane, which could not he neglected. The effect of geometric size on pervaporation dehydration could be more significant under higher vacuum pressure in the permeate side. The transfer resistance in the lumen increases with the hollow fiber length but decreases with lumen diameter. The geometric structure could be optimized in terms of the ratio of lumen diameter to membrane length. A critical value of d1/L （Rc） to achieve high permeation flux was empirically correlated with extraction pressure in the permeate side. Typically, for a hollow fiber supported NaA zeolite membrane with length of 0.40 m, the lumen diameter should be larger than 2.0 mm under the extraction pressure of 1500 Pa.
基金supported by the Major State Basic Research Program of China(No.2009CB623404)National NaturalScience Foundation of China(Nos.20736003,20676067)+2 种基金National High Technology Research and Development Programof China(No.2007AA06Z317)Foundation of Ministry of Education of China(No.20070003130)Foundation of theState Key Laboratory of Chemical Engineering(SKL-ChE-08A01).
文摘Ethanol perm-selective PDMS/PVDF composite membranes were prepared by curing polydimethylsiloxane (PDMS) with various cross-linking reagents,such as tetraethoxylsilane(TEOS),γ-aminopropyltriethoxylsilane(APTEOS), phenyltrimethoxylsilane(PTMOS) and octyltrimethoxylsilane(OTMOS) as well.The cross-linking density and surface properties of the PDMS active layer were adjusted by varying cross-linking reagents.The pervaporation performance of PDMS membranes cured with different cross-linking reagents was investig...
基金Supported by the Fundamental Research Funds of Panjin Industrial Technology Institute(PJYJY2016A004)the National Natural Science Foundation of China(No.21776032)+2 种基金Natural Science Foundation of Anhui Province(1808085QB51)the Key Research and Development Plan of Anhui Province(1804a09020072)the Natural Science Research Project of Anhui Colleges and Universities(KJ2017A397)
文摘Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh conditions.Development of durable and high separation performance membranes with lower fabrication and operation cost are highly demanded for industrial applications. Zeolite T membrane possesses good acid-resistance with excellent hydrophilic properties as compared to NaA zeolite membrane and can be extended to industrial organic dehydrations under an acidic environment. In the present review the research advances in development of zeolite T membranes for the dehydration of organic mixtures in acidic conditions are summarized. Especially the low temperature synthesis, and epitaxial growth of the zeolite membrane with high performance are well addressed, besides emphasis is particularly placed on ensemble synthesis of hollow fiber zeolite T membrane module and its future prospects for industrial separations.
基金Supported by the National Natural Science Foundation of China(No.21706003)The Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD20170305)
文摘Recovering alcohols from dilute fermentation broth is an emergent task in bio-fuel production process. Since they are primary planned for fuels, energy required to separate these alcohols should be considered in evaluating the potential of a separation technology. A membrane-based process, pervaporation, is of special interest because of its environmental friendliness and easy integrating character. This review probes into the fundamentals of pervaporation especially in terms of the heat required for evaporation. Meanwhile, the separation data of the most representative alcohol-selective pervaporation membranes reported in the literatures are collected and compared with the vapor–liquid equilibrium curve, which represents the distillation selectivity. They include:inorganic membranes, silicon rubber based membranes, Mixed Matrix Membranes and some other special materials. By doing so, the status of alcohol recovery via pervaporation would be more clear for researchers.For ethanol recovery, it is selectivity rather than flux that is in urgent need of solution. While for butanol recovery,membranes with satisfactory selectivity have been developed, increasing the separation capacity would be more pressing.
