Membrane Mass Transfer Coefficient Research Articles

Bioethanol production from cassava fed-batch fermentation in pervaporation membrane bioreactor with permeate fractional condensation

A new type pervaporation membrane bioreactor was developed by coupling cassava-based fed-batch fermentation and pervaporation membrane separation technology for bioethanol production. Membrane separation slowed down broth accumulation rate and mitigated ethanol product inhibition. The fermentation time, average sugar consumption rate, ethanol production and ethanol productivity were 131h, 6.6 gL-1h-1, 149.4 gL-1 and 2.5 gL-1h-1, respectively. They were improved by 55.9 %, 73.2 %, 32.3 % and 49.7 %, respectively, compared to those of conventional fed-batch fermentation. The average membrane flux and separation factor were 711.3 gm-2h-1 and 6.5, respectively, with an ethanol concentration of 24.4 wt% in the permeate. Throughout fermentation, the total mass transfer coefficient remained constant at 9.6 × 10-6 ms-1, with the convection mass transfer coefficient decreasing as the broth viscosity increasing while the membrane mass transfer coefficient slightly increasing. A two-stage condensation downstream the membrane achieved fractional vapor recovery. The primary condensate with low ethanol concentration (1.6 wt%) can be used for cassava hydrolyzation, saving 14.0 % of water requirement. Recovering ethanol from the high-concentration (32.6 wt%) secondary condensate required lower energy (46 %) compared to direct recovery from the total permeate.

Ethanol mass transfer model of spiral-wound membrane module with PDMS membrane for pervaporation considering module structure parameters

Pervaporation mass transfer model of spiral-wound membrane module with polydimethylsiloxane (PDMS) membrane considering module structure parameters has been developed for ethanol separation. Membrane intrinsic parameters involved mass transfer including limiting diffusivity of ethanol, plasticization coefficient of ethanol and partition coefficient were firstly determined, and then the model was verified by the experimental results with a correlation coefficient of 0.998. It has been calculated that bulk ethanol concentration (xe) would be decreased from 9 v/v% to 7.26 v/v% along the flow direction, under the ethanol feeding concentration of 9 v/v%, feeding velocity of 0.008 ms−1, membrane length of 1 m, membrane width of 1.5 m, channel height of 1.2 mm, if polydimethylsiloxane/polyamide (PDMS/PA) membrane was applied. Owing to the concentration-dependence of the membrane mass transfer coefficient (km), km and local ethanol flux (Je) was also decreased from 7.20 × 10-6 m·s-1to 7.07 × 10-6 m·s−1, and 386 g·m−2·h−1 to 306 g·m−2·h−1, respectively. For polydimethylsiloxane/polyvinylidene difluoride/Polyethylene terephthalate (PDMS/PVDF/PET) membrane, km and Je were decreased from 7.72 × 10-7 m·s-1to 7.65 × 10-7 m·s−1, and 137 g·m−2·h-1to 128 g·m−2·h−1, respectively, under the same condition. Higher ethanol feeding concentration and longer module would lead to more obvious change in xe, km and Je. While higher feeding velocity would lead to weaker change in xe, km and Je.

Non-Dispersive Extraction of Chromium(VI) by Cyphos IL102/Solvesso 100 Using the Pseudo-Emulsion-Based Strip Dispersion Membrane Operation.

The removal of chromium(VI) from an acidic (HCl) medium through non-dispersive extraction with strip dispersion (NDXSD) was investigated using a microporous PVDF membrane support in a permeation cell. The ionic liquid Cyphos IL102 (phosphonium salt) in Solvesso 100 was used as an organic phase. In NDXSD, the stripping phase (NaOH) is dispersed in the organic phase on the cell side with an impeller stirrer adequate to form a strip dispersion. This pseudo-emulsion phase (organic + strip solutions) provides a constant supply of the Cyphos IL102/Solvesso 100 to the membrane phase. Various hydrodynamic and chemical parameters, such as variation in the feed and pseudo-emulsion stirring speeds, HCl and Cr(VI) concentrations in the feed phase, and carrier concentration, were investigated. Results indicated that the best chromium(VI) transport was obtained under the following conditions: feed and pseudo-emulsion stirring speeds of 1000 min-1 and 600 min-1, respectively; an HCl concentration in the feed phase of 0.1 M; a chromium concentration of 0.01 g/L in the same phase; and carrier concentration in the organic phase in the 2-5-10% v/v range. From the experimental data, several mass transfer coefficients were estimated: a bulk diffusion coefficient of 3.1·10-7 cm2/s and a diffusion coefficient of 6.1·10-8 cm2/s in the membrane phase and mass transfer coefficients in the feed (5.7·10-3 cm/s) and membrane phases (2.9·10-6 cm/s). The performance of the present system against other ionic liquids and the presence of base metals in the feed phase were investigated.

Lithium solvent extraction by a novel multiframe flat membrane contactor module

Comparing to conventional liquid–liquid extraction, membrane extraction is an efficient and environmentally friendly separation technique to recover lithium from the salt-lake brine. Development of suitable hydrophilic solvent resistant nanoporous membranes for membrane extraction has been based on bench-scale small module. Because module design has significant impact on the performance, this work reported a novel multiframe flat membrane contactor module (MFMC) for lithium extraction from synthetic brine. The hydrophilic poly (ethylene-co-vinyl alcohol)/sulfonated poly(etheretherketone) membrane supported with polypropylene nonwoven (EVAL/SPEEK-NW) was prepared for module evaluation. The membrane mass transfer coefficients km of 1.1 × 10-6 m/s was obtained by Wilson plot. The global mass transfer coefficient Ke increased from 4.5 × 10-7 m/s to 9.9 × 10-7 m/s following the flow velocity from 0.4 to 1.8 cm/s in membrane extraction. We further evaluated the characteristics of MFMC via height of transfer units (HTU) and module efficiency (ME). High module efficiency of 90% was obtained, demonstrating MFMC’s efficient flow distribution. HTU of 28 m was estimated and was expected to decrease to 3 m by optimizing thickness of gasket and spacer as well as membrane performance. The MFMC module effectively reduced the loss of tributyl phosphate (TBP) by 91% comparing to liquid–liquid extraction. The research presented herein provides a flat membrane module design for potential future application of membrane extraction in wide applications.

Novel method for accurately estimating membrane transport properties and mass transfer coefficients in reverse osmosis

We present a simple and robust method to simultaneously characterize the water and salt permeability (A, B) of reverse osmosis (RO) membranes and mass transfer coefficient (k) in membrane modules. The proposed methodology comprises a set of RO experiments performed at different operating pressures or stages. The measured water and salt fluxes in each stage are simultaneously fitted to the RO transport equations by performing a non-linear regression, using A, B, and k as regression parameters. We first perform a systematic accuracy analysis of the proposed method across the full operational range of RO. The assessment shows that the method accuracy is substantially higher than current methods and increases with number of experimental stages and driving forces. This assessment is used to inform the design of an experimental protocol that minimizes errors in estimated A, B, and k. We then evaluate two commercial RO membranes following the new protocol. For both membranes, A and B parameters decrease by 17% and 15% from the dilute solution to seawater concentrations, whereas the k parameter remains constant. Our study demonstrates that the proposed method, informed by data-driven experimental designs, provides a new approach for accurately characterizing transport phenomenon in membrane processes with feeds of less than 100 g/L total dissolved solids.

Reverse osmosis membrane and module improvement roadmap for maximum impact

Advancements in Reverse osmosis (RO) membrane modules towards lowering specific cost of pure water can be quantified in terms of two non-dimensional numbers: specific cost of membrane conductance (viz., product of membrane area and permeability) relative to electricity price, and the channel mass-transfer coefficient relative to permeability. Reducing specific cost per unit conductance is more important than simply improving permeability, since high permeability at correspondingly large cost per unit area will not yield cheaper permeate production. The impact of technology improvements is assessed considering RO systems operated at an optimized average flux which minimizes the sum of capital and operating costs. Developing cheaper membrane modules is likely to be more impactful than increasing permeability or mass transfer coefficient. For example, for seawater RO, a 5× increase in permeability or mass transfer coefficient yields 6–8 % reduction in water cost, whereas, a 2× reduction in the amortized specific cost of membrane module yields more savings. Keeping membrane costs unchanged, both permeability and mass transfer coefficient have to be increased simultaneously by 2× to achieve similar savings. Multi-staged (and by extension batch) processes yield larger savings with improved membrane modules, and hence will likely become more prevalent in the future.

Novel Method for Accurately Estimating Membrane Transport Properties and Mass Transfer Coefficients in Reverse Osmosis

Novel Method for Accurately Estimating Membrane Transport Properties and Mass Transfer Coefficients in Reverse Osmosis

Modelling the effect of CO2 loading of aqueous potassium glycinate on CO2 absorption in a membrane contactor

CO2absorption into aqueous potassium glycinate in a polypropylene membrane contactor was modelled using two alternative models: a 1D model and a 1D-2D model considering axial diffusion in the liquid phase. Models were fitted to experimental data using various fitting parameters, which were compared. Experiments were carried out under industrially relevant conditions characterized by CO2-loaded absorbent entering the contactor and high degree of reactant conversion over the contactor. The experiments and models were developed to specifically investigate the effect of changes in solution CO2loading at contactor inlet. This is a key issue rarely reported in the literature, especially for amino acid salt solutions. Unexpectedly, the 1D model was found to explain the experimental results more accurately compared to the more complex 1D-2D model. This was the case for the base models, using only the membrane mass transfer coefficient as a fitting parameter, and the final models introducing secondary fitting parameters. The 1D model was found to show the best experimental fit following fitting of the equilibrium constant used in prediction of the enhancement factor. The 1D-2D model showed the best fit following correction of potassium glycinate diffusivity as a function of solution CO2loading. The 1D approach was found to result in a computationally effective model with good fit to the present experimental data. This model provides a good basis for further development and could be considered for use in contactor design and optimization studies. It is suggested that various model simplifications led to inability of the 1D-2D model to accurately predict the experimental results.

Removal of Water from Spent Phosphoric Acid Using a Sandwich Silicon Carbide Ceramic Membrane

AbstractIt is important to develop an energy‐ and cost‐efficient method of concentrating phosphoric acid because it is widely used in several industries. Three different ceramic membranes, namely, a silicon carbide (SiC) membrane, a TiO2‐coated SiC membrane, and a sandwich membrane of TiO2 between SiC, were successfully applied for the selective separation of water from spent phosphoric acid. SiC was selected as raw material, TiO2 as supporting material. The membrane was characterized by various instruments to check all parameters. Using the solution diffusion, statistical modeling of these membranes was performed and the membrane parameters, such as membrane diffusivity and mass transfer coefficient, were calculated. By reducing the porosity of the membrane, the desired separation can be improved.

Design and operation of an enhanced pervaporation device with static mixers

AbstractPervaporation has a high potential for separating miscible solutions, particularly azeotropic mixtures. However, mass transfer limitations have long been a common concern in pervaporation device design. Therefore, in this work, we design a static mixer‐based pervaporation device using water–ethanol separation as a model system and further develop computational fluid dynamics tools to investigate systematically all the influencing parameters. In the experiments, we use three‐dimensional printed helical static mixers in the feed liquid channel to enhance mass transfer and implement a Sulzer pervaporation membrane for fast removal of water from ethanol. Using flow and mass‐transfer simulations, we fit the membrane mass transfer coefficient and provide predictive models for optimal process design. Our pervaporation assembly exhibits promising performance and potential toward pervaporation processes for the removal of water from organics and is preferably scaled out by using stackable designs.

Towards simulation of gas separation modules based on hollow fiber membranes

Processes of C1-C4 hydrocarbons gas separation with membranes yielding in methane and C3+ fractions are highly attractive. The significant breakthrough on this issue can be achieved by the development of novel gas separation modules based on C3+ hydrocarbons-selective hollow fiber membranes. The efficiency of this technology significantly depends on the module design, which should take into account the mass and heat transfer processes within the module with the simultaneous external constrained flow in the fiber system, the internal flow in hollow fibers, and molecular transport in the selective membrane layer. The developed simulation model includes the theory of convective diffusion transport in the shell-side constrained flow in hollow fiber membrane modules with an ordered arrangement of fibers. The simulated dependencies of the Sherwood number for circular fiber in a fiber row arranged in a transverse laminar flow on the Reynolds, Peclet and Schmidt numbers, and membrane mass transfer coefficient will be presented.

Electrospinning in membrane contactor: manufacturing Elec-PVDF/SiO2 superhydrophobic surface for efficient flue gas desulphurization applications

In membrane contactors, maintaining a high SO2 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/SiO2 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 SiO2 particles content in electrospinning solution. The scanning electronic microscopy (SEM), EDS-mapping, water contact angle (WCA) and surface roughness of as-prepared Elec-PVDF/SiO2 composite membrane contactors were conducted to explore the physical and chemical structure. The SiO2 nanoparticles were uniformly loaded in Elec-PVDF/SiO2 composite membrane contactor, and constructed micro-nano dual-coarse lotus-leaf-like morphology, which noticeably elevated surface roughness (Ra). The SiO2 nanoparticles also functioned as hydrophobic modifiers, which boosted the WAC up to 155°. The SO2 absorption fluxes and SO2 removal efficiencies were investigated. In particular, the membrane contactor doped with 20 wt% SiO2 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.

Mass transfer characteristics of a continuously operated hollow-fiber membrane contactor and stripper unit for CO2 capture

Mass transfer performance of a polypropylene hollow-fiber membrane contactor as part of a continuously operated CO2 capture unit with amino acid salt (potassium glycinate) absorbent and vacuum solvent regeneration was studied. The effects of key operating parameters on the absorption mass transfer characteristics were explored. Without vacuum stripping, absorption rate was found to be limited by low CO2 desorption efficiency from the loaded absorbent solution in the stripping unit, resulting in high solvent CO2 loadings and limited chemical absorption rates. Introduction of vacuum stripping greatly improved desorption performance, resulting in improved steady-state absorption performance. The overall mass transfer coefficient increased at higher stripping temperatures and lower vacuum pressures in the range of 60−80 °C and 300−800 mbar (abs). The overall mass transfer coefficient increased with increasing liquid flow rate, and the highest value reached was 1.8 ∙ 10−4 m s-1. The individual mass transfer coefficients in absorption were calculated based on mass transfer correlations and experimental data, including estimation of the enhancement factor for chemical absorption. The overall mass transfer resistance was found to be dominated by the liquid-side resistance, at almost 90 % of the total resistance. The estimated membrane mass transfer coefficient was low compared to a theoretical value assuming non-wetted operation, suggesting potential partial wetting of the membrane. Stable performance of the unit and the membrane contactor was demonstrated during a stability test with over 30 h of operation.

π Electron induced separation of organic compounds using supported ionic liquid membranes

Supported ionic liquid membranes have been tested for fractionation of organic compounds. Imidazolium based ionic liquids; 1-allyl-3-vinylimidazolium bromide, 1-hexyl-3-vinylimidazolium bromide and 1-octyl-3-vinylimidazolium bromide were trapped in the pores of a polypropylene membrane. Fractionation of a feed stream consisting of benzene, naphthalene and phenanthrene in tetradecane and cis- and trans-stilbene in hexane were investigated. The receiving phase was hexane. Differences in the π electron cloud density of the aromatic solutes influence their interactions with the imidazolium cation, which can affect the rates of transport. In the case of the three aromatic solutes, the degree of conjugation and molecular weight increase in order benzene, naphthalene and phenanthrene. These opposing effects result in similar mass transfer coefficients for the three solutes for the three ionic liquids tested. However, for cis-and trans-stilbene, the mass transfer coefficient was larger for all three ionic liquids. It is likely that enhanced aromatic stacking of the trans- isomer led to a higher mass transfer coefficient. In addition, 1-hexyl-3-vinylimidazolium bis(trifluoromethylsulfonyl)imide was used as the liquid membrane phase to fractionate two nucleobases: thymine and cytosine in water. The receiving phase was also water. The membrane mass transfer coefficient for thymine was 5.5 times greater than cytosine indicating the possibility of exploiting multimodal interactions with the imidazolium group to fractionate compounds.

Hollow fiber gas membrane-based removal and recovery of ammonia from water in three different scales and types of modules

Ammonia present in many industrial process streams and effluent streams is beginning to be recovered by means of microporous hydrophobic hollow fiber-based membrane contactor devices with gas-filled pores; the process is often characterized as supported gas membrane (SGM) process. Ammonium sulfate is usually obtained in a sulfuric acid stream on the other side of the membrane. It is useful to develop a quantitative basis for the extent of ammonia removal in such devices. Unlike deoxygenation of aqueous streams in such devices, membrane resistance is quite important for ammonia transport. Ammonia transport modeling in such devices is hampered by the complexity of feed liquid flow in the shell side of commercially used devices and lack of information on membrane resistance where membrane tortuosity introduces considerable uncertainty. The approach adopted here involves studying ammonia transport with the feed solution flowing through the hollow fiber bore where the fluid mechanics is simpler than shell-side flows. Comparison of model-based predictions of overall mass transfer coefficient (ko) with experimentally observed values allows estimation of the membrane mass transfer coefficient (km). One can use such estimates of km to model the observed ammonia transport in small crossflow devices and develop an empirical guidance of the dependences of the shell side mass transfer correlations. Guided by such information and deoxygenation SGM literature, a model was developed for large modules used for ammonia recovery via SGM. Model predictions of performances of the large modules are likely to be useful for various process considerations including the effect of temperature and feed flow rate variations on ammonia removal.

Dilute chemical reaction process with membrane separation step

The subject of this work is the development of a novel vibration assisted seawater desalination approach which changes thermodynamic (mass transfer coefficient) and hydrodynamic (cross-flow velocity) properties to mitigate the inorganic fouling for RO membranes. A classical mass transport model and experimental measurements showed that an increased cross-flow velocity in the feed channel enhances the near membrane mass transfer coefficient, which promotes the back-diffusion of inorganic salts and reduces the concentration polarization (CP). Then a theoretical CP Finite Element Method (FEM) model incorporating increased cross-flow velocity reveals that a lower CP modulus forms near the membrane surface with a higher vibration frequency, which results in less fouling on the membrane surface. The vibration assisted desalination process was demonstrated using a linear motor driven, periodically oscillating desalination cell. A smaller flux decline was observed while using a higher vibration frequency (with a constant sinusoidal amplitude) and a higher vibration velocity (in multiple vibration forms). Process simulations and experimental observations validated that the proposed vibration assisted desalination process helps enhance the permeate flux and mitigate the formation of inorganic fouling on the RO membrane surface.

The Influence of Operating Parameters on Membrane Performance in Used Lube Oil Processing

Membrane process is an attractive technology for used lube oil treatment due to the advantages, i.e. relatively low energy consumption, intensive process, higher separation efficiency, and the improvement of final product quality. The performances of membrane processes depend on several factors such as feed characteristic, membrane properties, and operating parameter. In this work, the influences of solute concentration and applied pressure on the performance of hollow fiber polypropylene membrane during used lube oil filtration are investigated. The osmotic pressure model is used to simulate the influence of operating parameter on membrane performances and it results in good agreement with experimental data. By using the osmotic pressure model, the intrinsic properties of the membrane, namely membrane resistance (Rm) and mass transfer coefficient (k) are 5x106 atm.s/m and 5x10-9 m/s, respectively. Generally, the flux increases with applied pressure and decreases with solute concentration. However, when the osmotic pressure builds up, the flux decreases gradually reaching a limiting value. At this condition, increasing an applied pressure gives an insignificant effect and the flux is in the limiting flux region. When the permeate flux reaches a limiting flux, the flux will be 5% of or less than the pure solvent permeability.

Effects of internal concentration polarization and membrane roughness on phenol removal in extractive membrane bioreactor

Recent studies have proved the advantages of novel composite membranes in the extractive membrane bioreactor (EMBR) for recalcitrant organic wastewater treatment. However, more systematic research into membrane properties and mass transfer effects are required. This study investigates the role of internal concentration polarization (ICP), including concentrated and diluted ICP, in an aqueous-aqueous extractive process, and the coupled effects of membrane roughness and hydrodynamic conditions on membrane performance in both cross-flow EMBR (CF-EMBR) and submerged EMBR (S-EMBR) processes. To study these factors, a nanofibrous composite membrane with a four-tiered structure, consisting of a dense polydimethylsiloxane (PDMS) selective layer, a polyvinylidene fluoride (PVDF) nanofibrous sublayer, a non-woven mechanical support and a rough micro/nano-beaded layer, has been developed for the EMBR by electrospinning and spray-coating.A diluted ICP, which occurred when the selective layer faces receiving water (SL-Rw), was less severe than a concentrated ICP in the selective layer facing feed (SL-F) orientation. It resulted in higher overall membrane mass transfer coefficients (k0's) in the SL-Rw mode during the aqueous-aqueous extractive tests. In addition, less biofilm was observed on the smooth PDMS surface after 14-days CF-EMBR and S-EMBR operations in the selective layer facing biomedium (SL-Rbio) mode. In contrast, in the SL-F mode during EMBR operations, the ridges and valleys on the membrane surface were able to provide a more favourable micro-environment for microorganisms and protect them from external stresses. The mature micro-colonies that developed in the SL-F mode clogged the membrane support and enhanced concentrated ICP, resulting in a significant reduction of k0's by more than 58%. Moreover, as the shear force on the membrane surface due to up-flow of air bubbles in the S-EMBR could mitigate the biofilm attachment, the most effective biofilm control strategy found in this study was to operate the nanofibrous composite membrane in the S-EMBR configuration with a smooth selective layer facing the biomedium. This effectively decreased the amounts of protein by 86%, polysaccharides by 88% and total suspended solids (TSS) by 89% in the biofilms on membrane surface, and achieved the highest stable k0 of 7.0 × 10−7 m/s.

Flashed-feed VMD configuration as a novel method for eliminating temperature polarization effect and enhancing water vapor flux

The coupling of heat and mass transfer in membrane distillation (MD) process makes enhancing water vapor flux and determining MD membrane mass transfer coefficient (MTC) fairly challenging due to the development of temperature gradient near the membrane surface, referred to as temperature polarization (TP). As a result, the change in feed temperature at the membrane surface will be difficult to measure accurately. In this paper, the effect of TP was decoupled from the membrane MTC by preventing the liquid feed stream from contacting the membrane surface through the use of a novel custom-made vacuum MD (VMD) module design. Results showed that a temperature difference of 10 °C between the feed bulk and feed temperatures at the membrane surface/interface is estimated to take place in the typical VMD configuration, while the proposed flashed-feed VMD configuration eliminates TP effect and gives a flux 3.5-fold higher (200 kg/m2 h) under similar operating conditions. Therefore, it can be concluded that heat transfer coefficient is considered to be the main factor controlling resistance of water vapor flux in the typical VMD configuration. The measured MTC of the tested commercial membrane was found to be more accurate and the highest among all reported MTCs in the MD literature (2.44 × 10−6 kg/m2 s Pa). Additionally, a transmembrane temperature difference of 5 °C and 10 °C in the novel configuration can produce water vapor fluxes of about 9 kg/m2 h and 40 kg/m2 h, respectively, at a feed temperature of 70 °C, which is very attractive for scaling-up the process.

Optimization of hydrophobic modification parameters of microporous polyvinylidene fluoride hollow-fiber membrane for biogas recovery from anaerobic membrane bioreactor effluent

Tailoring the hydrophobic properties of membranes is an important requirement in gas-liquid membrane contactor processes because the membrane can be wetted by liquid. This paper describes the hydrophobic modification of the chemical surface of a polyvinylidene fluoride hollow-fiber membrane using a commercial perfluoropolyether, Fluorolink S10. The contact angle of the modified membrane was influenced by the modification parameters, and hence parameter optimization was required to obtain a highly hydrophobic membrane. The sodium hydroxide concentration (pH 8, 10 and 12), dehydrofluorination time (30, 60 and 90min), and chemical solution grafting time (30, 60 and 90min) were identified as the control parameters of this modification and were optimized using the Taguchi approach. The optimized membrane was then applied to recover methane from anaerobic membrane bioreactor effluent and benchmarked with a commercial polypropylene membrane manufactured for degasification of water. The contact angle of the polyvinylidene fluoride membrane was improved by 32% after the surface modification (under the optimal modification condition indicated by the Taguchi method). The membrane mass transfer coefficient was measured as 1.53 × 10−4m/s. Our membrane showed better methane recovery performance than the commercial polypropylene membrane and a very stable flux without pore wetting during 10 days of operation with synthetic effluent (made by saturating a 60:40 methane/carbon dioxide mixture into tap water). In addition, the membrane prepared in this study could be operated without significant fouling (7% flux drop during 8 days of operation) with real anaerobic membrane bioreactor effluent.