Membrane Contactor Technology Research Articles

Hollow Fiber Contactors with Improved Hydrophobicity for Acid Gas Removal: Progress and Recent Advances

The gas–liquid membrane contactor technology, which integrates the absorption process with membranes, is a developing membrane technology that is especially pertinent to acid gas absorption. When it comes to removing acid gases from natural gas or after combustion, membrane technology has demonstrated potential as a substitute for conventional absorption columns. The membrane contactor offers exceptional operating flexibility and a high mass transfer area. In addition to summarizing the key elements of membrane materials, absorbents, and membrane contactor design, this paper presents the working principle and wetting mechanism of hollow membrane contactors and focuses the most recent advancements in membrane contactor research in gas separation from gas mixtures. The state-of-the-art overview of highly hydrophobic microporous membranes is presented after a discussion of the main challenges to the preparation of superhydrophobic membranes.

Incorporation of main line impact into life cycle assessment of nutrient recovery from reject water using novel membrane contactor technology

Wastewater treatment plant (WWTP) nutrient recovery has recently gained traction in the search for new pathways for fertilizer production. In particular, concentrated waste streams such as reject water from sludge digestion are suitable. The environmental impact of a novel nutrient recovery technology using a membrane contactor (NPHarvest) was examined with an environmental life cycle assessment (LCA). Impact hotspots were benchmarked against a comparable technology (struvite precipitation and ammonia stripping), and the impacts of the two technologies were found to be similar for most studied environmental impact categories. To allow for the inclusion of effects on other parts of the WWTP while limiting the general system boundaries to the reject water treatment, a novel approach to capture the main line impact was developed. The effects on the main line contributed substantially to the overall results. The overall results indicated clear nutrient recovery benefits related to substituted materials in mineral fertilizer production. Additionally, reject water nutrient recovery provided even greater benefits due to reduced N2O emissions and the reduced use of precipitation chemicals in the WWTP main line. Nonetheless, both nutrient removal and recovery were necessary for the two technologies to reach a net zero climate impact in their current pilot scales. Further development of the NPHarvest technology—such as mitigating NH3 emissions, exploring alternative input chemicals and optimizing energy consumption (especially for crystallizing the ammonium salt solution that is produced)—is recommended before full-scale implementation.

Nitrogen Recovery from Landfill Leachate Using Lab- and Pilot-Scale Membrane Contactors: Research into Fouling Development and Membrane Characterization Effects.

Membrane contactor technology affords great opportunities for nitrogen recovery from waste streams. This study presents a performance comparison between lab- and pilot-scale membrane contactors using landfill leachate samples. Polypropylene (PP) and polytetrafluoroethylene (PTFE) fibers in different dimensions were compared in terms of ammonia (NH3) recovery on a lab scale using a synthetic ammonium solution. The effect of pre-treating the leachate with tannin coagulation on nitrogen recovery was also evaluated. An ammonia transfer on the lab and pilot scale was scrutinized using landfill leachate as a feed solution. It was found that PTFE fibers performed better than PP fibers. Among PTFE fibers, the most porous one (denoted as M1) had the highest NH3 flux of 19.2 g/m2.h. Tannin pre-treatment reduced fouling and increased NH3, which in turn improved nitrogen recovery. The mass transfer coefficient of the lab-scale reactor was more than double that of the pilot reactor (1.80 × 10−7 m/s vs. 4.45 × 10−7 m/s). This was likely attributed to the difference in reactor design. An analysis of the membrane surface showed that the landfill leachate caused a combination of inorganic and organic fouling. Cleaning with UV and 0.01 M H2O2 was capable of removing the fouling completely and restoring the membrane characteristics.

Wastewater Purification with Nutrient and Carbon Recovery in a Mobile Resource Container.

Water reuse from wastewater treatment plants can significantly reduce freshwater demand. Additionally municipal sewage and some industrial wastewaters could be used as sources of nutrients and carbon more effectively than they are used today. Biological treatments have attracted the most attention in wastewater purification, whereas, so far, only a little attention has been paid to the physico-chemical technologies. These technologies could, however, have great potential to recover nutrients when purifying wastewater. In this study, the main emphasis was to study the possibilities to utilize existing physico-chemical unit operations for wastewater purification and nutrients as well as carbon recovery. Unit operations were selected so that they could produce exploitable circular economy products from wastewaters and be assembled in a mobile container for carrying out recovery anywhere that is suitable. The results showed that in a mobile container, solids could be successfully separated from the studied wastewaters by flocculation-assisted solid/liquid separation and then processed into hydrochar by hydrothermal carbonization. Phosphate was precipitated using lime milk as calcium phosphate, and ammonium nitrogen was captured from the wastewater using membrane contactor technology resulting in ammonium sulphate for fertilizer use. Additionally, reverse osmosis retained residual impurities well, producing good quality water for reuse. The techno-economic feasibility seems promising.

Impact of heavy hydrocarbon impurities on polytetrafluoroethylene (PTFE) membrane stability

Membrane contactor technology has attained considerable attention as a promising technology to reduce CO2 content in natural gas. In this study, the main objective is to investigate the effect of heavy hydrocarbons impurities, often present in natural gas, on polytetrafluoroethylene (PTFE) hollow fibre membrane. The membranes were immersed for months in n-heptane, 1-decene, benzene and toluene, and analysed periodically through its surface morphology, composition, functional groups, hydrophobicity, and thermal stability. The characteristics of PTFE fibres remained unchanged even after long term exposure with heavy hydrocarbons. This study provides a better understanding of the robustness of using PTFE membrane fibre for CO2 removal in membrane contactor system.

Innovative Gas-Liquid Membrane Contactor Systems for Carbon Capture and Mineralization in Energy Intensive Industries.

CO2 mineralization is an alternative to conventional geological storage and results in permanent carbon storage as a solid, with no need for long-term monitoring and no requirements for significant energy input. Novel technologies for carbon dioxide capture and mineralization involve the use of gas-liquid membrane contactors for post-combustion capture. The scope of the present study is to investigate the application of hollow fiber membrane contactor technology for combined CO2 capture from energy-intensive industry flue gases and CO2 mineralization, in a single-step multiphase process. The process is also a key enabler of the circular economy for the cement industry, a major contributor in global industrial CO2 emissions, as CaCO3 particles, obtained through the mineralization process, can be directed back into the cement production as fillers for partially substituting cement in high-performance concrete. High CO2 capture efficiency is achieved, as well as CaCO3 particles of controlled size and crystallinity are synthesized, in every set of operating parameters employed. The intensified gas-liquid membrane process is assessed by calculating an overall process mass transfer coefficient accounting for all relevant mass transfer resistances and the enhanced mass transfer due to reactive conditions on the shell side. The obtained nanocomposite particles have been extensively characterized by DLS, XRD, TGA, SEM, TEM, and FTIR studies, revealing structured aggregates (1–2 μm average aggregate size) consisting of cubic calcite when the contactor mode is employed.

Multipurpose treatment of landfill leachate using natural coagulants – Pretreatment for nutrient recovery and removal of heavy metals and micropollutants

Landfill leachate is considered to be a potential source for nutrient recovery due to high ammonia concentration. However, it contains concerning pollutants such as metals and micropollutants in high levels. The coagulation-flocculation process is commonly used as a pretreatment technique to remove such pollutants. Plant-based materials have recently been explored as an alternative for conventional coagulants as the latter leave residuals that require further treatment. The use of natural coagulants for nutrient recovery purposes has not been investigated previously. This study evaluated the effectiveness of tannin-based product named HTH to improve landfill leachate quality to suite the requirements for nitrogen recovery using membrane contactor technology. The optimal combination of dosage and pH was determined using Response Surface Methodology (RSM). The parameters selected to evaluate the treatment were total nitrogen, total phosphorus, total organic carbon, and ammonia. The obtained optimized combination of dosage and pH were 11.1 mL/L and 7.3, respectively. This combination resulted in respective removal of TP, TOC and TN of 47%, 15%, and 4%, while NH3‒N increased by 20%. The potency of the treatment for removing micropollutants and metals was evaluated. Highest metals removal was attained for Fe, Ti, Cr, Al, Ba and V, while other metals were removed in smaller percentages. Decent removal of cationic surfactants, phenols and pharmaceuticals such as 5-methylbenzotriazole, ibuprofen, carbamazepine, and metoprolol was also achieved with the treatment. The results of this study suggest that tannin-based materials are effective coagulants for treating landfill leachate with the goal of preparing it for nitrogen recovery.

Wastewater treatment with starch-based coagulants for nutrient recovery purposes: Testing on lab and pilot scales

The interest in using natural coagulants for wastewater treatment has increased in recent years due to the environmental and health problems associated with the use of traditional coagulants. In this study, starch-based coagulants were tested to treat reject water produced by the dewatering of mesophilic digester sludge at the Viikinmäki wastewater treatment plant (WWTP) in Finland. The goal of this treatment is to prepare the stream for the nitrogen recovery process with membrane contactor technology. Screening tests showed that PrimePHASE 3545 was the best coagulant, and the effective dosage and pH ranges were 10–20 ml/l of the 25% diluted starch and 8–10 pH values, respectively. The process was optimized using Response Surface Methodology (RSM). The best dosage and pH combination generated by RSM was 14.1 ml/l and 9.1, respectively. In these conditions, TN, TP, TOC, SS and VSS removal percentages were 18 ± 0.57%, 80 ± 0.99%, 28 ± 1.19%, 90 ± 3.37%, and 89 ± 2.35%, respectively. However, NH3-N concentration increased by 20 ± 1.7%, mainly due to pH increase. These results held true when tested on a pilot scale at Viikinmäki WWTP in a continuous process. The sludge produced with natural coagulant was found to be of a better quality compared to that of conventional coagulants.

Demonstrating Commercial Hollow Fibre Membrane Contactor Performance at Industrial Scale for Biogas Upgrading at a Sewage Treatment Works

Hollow fibre membrane contactor (HFMC) technology has been developed for CO2 absorption primarily using synthetic gas, which neglects the critical impact that trace contaminants might have on separation efficiency and robustness in industrial gases. This study, therefore, commissioned a demonstration-scale HFMC for CO2 separation at a full-scale anaerobic digester facility to evaluate membrane integrity over six months of operation on real biogas. The CO2 capture efficiency identified using real biogas was benchmarked at comparable conditions on synthetic gas of an equivalent partial pressure, and an equivalent performance identified. Two HFMC were subsequently compared, one with and one without a pre-treatment stage that targeted particulates, volatile organic compounds (VOCs) and humidity. Similar CO2 separation efficiency was again demonstrated, indicating limited impact within the timescale evaluated. However, gas phase pre-treatment is advised in order to ensure robustness in the long term. Over longer-term operation, a decline in CO2 separation efficiency was observed. Membrane autopsy identified shell-side deposition, where the structural morphology and confirmation of amide I and II groups, indicated biofouling. Separation efficiency was reinstated via chemical cleaning, which demonstrated that proactive maintenance could minimise process risk.

Integrating crystallisation into transmembrane chemical absorption: Process intensification for ammonia separation from anaerobic digestate

In this study, reactive crystallisation is introduced into a liquid-liquid membrane contactor for the selective separation, purification and recovery of ammonia from concentrated waste. Whilst liquid-liquid membrane contactor technology has been previously demonstrated for ammonia absorption, further process intensification can be achieved by incorporating crystallisation into transmembrane chemisorption to recover the ammonia as crystalline ammonium sulphate. Reactive crystallisation occurred in the draw solution (sulphuric acid) which was supplied to the lumen-side of the polypropylene hollow-fibre. The ammonium sulphate concentration in the draw solution increased through ammonia mass transfer to supersaturation, at which time induction (the onset of nucleation) commenced. Ammonia mass transfer at draw concentrations above the solubility limit was not limited provided sufficient ‘free’ sulphate was available. This resulted in nucleation which occurred at a low level of supersaturation (C/C*, 1.03) to produce small crystals of around 2.5 μm, which indicated that nucleation was favoured. The nucleation rate was found to be proportional to the ammonia flux in the draw solution. As the solution became more saturated, crystal number increased but crystal growth was comparatively small; this is symptomatic of reactive crystallisation, where the rate of reaction exceeds the rate of mass transfer. Due to the large difference in the ratio between the lumen internal diameter and the mean crystal diameter (dfibre/dmean,CSD, ~180), no fibre clogging was observed despite facilitating crystallisation on the lumen-side of the membrane. Transmembrane chemisorption crystallisation presents a feasible process intensification for the selective separation of ammonia from environmental applications. For its integration into environmental applications, solutions to wetting and fouling remain due to associative interactions with the complex organic matrix that are practically achievable through engineering intervention. Subsequent transformation of ammonia into a crystalline phase of ammonium sulphate presents a new product which is of commercial interest.

Recovery and concentration of ammonia from return liquor to promote enhanced CO2 absorption and simultaneous ammonium bicarbonate crystallisation during biogas upgrading in a hollow fibre membrane contactor

In this study, thermal desorption was developed to separate and concentrate ammonia from return liquor, for use as a chemical absorbent in biogas upgrading, providing process intensification and the production of crystalline ammonium bicarbonate as the final reaction product. Applying modest temperature (50 °C) in thermal desorption suppressed water vapour pressure and increased selective transport for ammonia from return liquor (0.11MNH3) yielding a concentrated condensate (up to 1.7MNH3). Rectification was modelled through second-stage thermal processing, where higher initial ammonia concentration from the first stage increased mass transfer and delivered a saturated ammonia solution (6.4MNH3), which was sufficient to provide chemically enhanced CO2 separation and the simultaneous initiation of ammonium bicarbonate crystallisation, in a hollow fibre membrane contactor. Condensate recovered from return liquor exhibited a reduction in surface tension. We propose this is due to the stratification of surface active agents at the air-liquid interface during primary-stage thermal desorption which carried over into the condensate, ‘salting’ out CO2 and lowering the kinetic trajectory of absorption. However, crystal induction (the onset of nucleation) was comparable in both synthetic and thermally recovered condensates, indicating the thermodynamics of crystallisation to be unaffected by the recovered condensate. The membrane was evidenced to promote heterogeneous primary nucleation, and the reduction in the recovered condensate surface tension was shown to exacerbate nucleation rate, due to the reduction in activation energy. X-ray diffraction of the crystals formed, showed the product to be ammonium bicarbonate, demonstrating that thermal desorption eliminates cation competition (e.g. Ca2+) to guarantee the formation of the preferred crystalline reaction product. This study identifies an important synergy between thermal desorption and membrane contactor technology that delivers biogas upgrading, ammonia removal from wastewater and resource recovery in a complimentary process.

Membrane gas-solvent contactor pilot plant trials for post-combustion CO2 capture

Membrane gas-solvent contactors are a hybrid technology of solvent absorption with membrane separation that achieves efficient and compact carbon dioxide capture. Here, we report on a successful pilot plant trial of membrane contactor technology undertaking post-combustion carbon dioxide capture from flue gas generated by an Australian black coal fired power station. The pilot plant utilised membrane contactors to undertake CO2 absorption into 30 wt% monoethanolamine (MEA) and the subsequent solvent regeneration stage to produce a pure CO2 product. The pilot plant trials identified a commercially available non-porous poly dimethylsiloxane composite hollow fiber membrane as the most suitable for both CO2 absorption and solvent regeneration. The overall mass transfer coefficient for CO2 absorption across the membrane into the solvent was comparable to laboratory results, enabling a recovery of >90% CO2 from the flue gas. Over time the mass transfer coefficient decreased because of both solvent dilution and some MEA loss, which reduced the enhancement the reaction provides to mass transfer in the solvent boundary layer. The overall mass transfer of CO2 from the solvent into the steam sweep during solvent regeneration was greater than that observed in the laboratory for the same temperature. The energy demand of the pilot plant was higher than for conventional CO2 capture technology, given the pilot nature of the process, lack of energy integration and thermal losses from uninsulated membrane modules. Accounting for these factors, the energy duty of the membrane contactor process was evaluated to be less than 4.2 MJ/kg of CO2 captured. Critically, the pilot plant demonstrated the viability of membrane contactor technology for post-combustion carbon capture on an industrial scale.

Deep CO2 removal using high pressure membrane contactors with low liquid-to-gas ratio

Membrane contactor is a technology that intensifies conventional absorption column. However, liquid-to-gas ratios (L/G) of membrane contactor in existing reports are much higher compared to CO2 absorption column, which results in higher solvent circulation rate and higher consumption in heating energy. This makes the technology less attractive for deep CO2 removal. Direct reduction of liquid flow rate was not effective in lowering down L/G. Experimental results showed that 50% reduction in liquid flow rate could reduce L/G by 25%, but the reduction in CO2 flux (33%) was higher due to decrease in liquid phase mass transfer coefficient which was dependent on liquid velocity. An alternative method to reduce L/G through membrane module length increase was proven, where L/G was reduced 70% with only 16% flux reduction. The flux reduction was only observed when L/G dropped below 0.80L/mol and it was due to depletion of unreacted amine for CO2 absorption. The lowest L/G value obtained in this study was 36% lower than the conventional absorption column in liquefied natural gas (LNG) process, showing that membrane contactor technology is not only energy-viable and more compact for deep CO2 removal, but it also offers energy saving advantage.

Effect of Activated Alkanolamine for CO2 Absorption using Hollow Fiber Membrane Contactor

Hollow Fiber Membrane Contactor (HFMC) technology has been widely developed as an alternative technology to separate CO2 gas. HFMC technology combines gas absorption process with absorbent and membrane technology. Membrane contactor technology has advantages than conventional technology such as larger gas-liquid contact area, smaller equipment, modularity, and gas-liquid flow rates adjusted independently. In this research, the CO2 absorption experiments was conducted for absorption process at 30°C temperature and various gas flow rate from 200 - 600 mL/min, feed gas of CO2 20%vol. flowed into shell side and the absorbents flowed in tube side of membrane contactor. Piperazine (PZ) and monosodium glutamate (MSG) as activators with 1%w/w concentration, added into methyldiethanolamine (MDEA) 30% w/w solution to form aqueous solutions of activated MDEA. The membrane material used in this experiment was hydrophobic polypropylene membrane. The effect of liquid flow rate and various activators used to get CO2 absorption flux and CO2 removal in HFMC. The results showed that the best of CO2 absorption process using activated alkanolamine was MDEA-PZ, where the highest flux value was 5.5x10−4 mole/m2.s and CO2 removal reached 96.9% at a gas flow rate of 600mL/min.

CO2 capture by aqueous ammonia with hollow fiber membrane contactors: Gas phase reactions and performance stability

A critical challenge involved in developing membrane contactor technology for CO2 capture by aqueous ammonia is ensuring long-term performance stability in industrial application. When working at low temperatures and with dry inlet gas, this study demonstrates precipitation fouling due to crystallization of ammonium salts using a commercially produced composite membrane contactor (Oxyplus®). The fouling occurred on the lumen side of the membrane where the gas circulated. Experiments performed using a CO2/N2 mixture saturated with water vapor to mimic real flue gas, interestingly, showed stable performance and no fouling. Experiments were performed at different operating temperature. Under all conditions, with and without solid salt formation leading to fiber fouling, an aqueous solution formed inside the fiber lumen. In this solution, 76% of the ammonia leaking from the shell side and 12% of CO2 feed was captured. The aqueous solution formed in the lumen can be easily separated to recover the ammonia content, which under the tested conditions, resulted in lower ammonia loss than what would be expected in a packed column.

Intensification potential of hollow fiber membrane contactors for CO 2 chemical absorption and stripping using monoethanolamine solutions

Abstract In this work, the intensification potential of Hollow fiber membrane contactors (HFMC) for CO 2 capture by chemical absorption using amine solution have been evaluated by simulation, for both absorption and desorption steps. The simulations have been achieved considering typical industrial relevant conditions for post-combustion capture, based on CASTOR campaign at the Esbjerg pilot plant using packed column, operating at its energetic optimum. Rigorous adiabatic 1D simulations are achieved and revealed important temperature variation as well as significant water transmembrane fluxes in both absorber and desorber. Compared to packed column, a contactor volume reduction (i.e. intensification factor) of about 4 can be achieved in the stripping and absorption section using dry membranes corresponding to a k m value of 10 −3 m/s and external fiber radius of 200 μm. For significant absorber intensification factor, fibers should have an external radius less than 400 μm and membrane mass transfer coefficient should not be less than 5.10 −4 m s −1 . HFMC implementation for high temperature stripping is promising providing that membranes resistant to high temperature (i.e. 120 °C) and equally resistant to wetting are available. Due to important water transfer in both absorber and desorber, in addition to wetting of porous membranes by liquid breakthrough, a new possible limiting phenomenon for HFMC technology is wetting by capillary condensation. Even though net solvent losses in the membrane contactor are smaller than those calculated for packed columns, a scrubbing section after the HFMC is still required for solvent recovery in order to meet solvent concentration standard in the CO 2 depleted gas stream. This issue represents an opportunity for the membrane contactor technology based on dense-film MEA selective composite membrane.

Ammonium removal by liquid–liquid membrane contactors in water purification process for hydrogen production

In this work, a liquid–liquid membrane contactor (LLMC) was evaluated to remove ammonia traces from water used for hydrogen production by electrolysis. Three operational parameters were evaluated: the feed flow rate, the initial ammonia concentration in the water stream, and the pH of solution. Synthetic aqueous solutions with ammonium concentration of 5–25 mg L−1 and a sulfuric acid solution (pH 2) were supplied to the LLMC in countercurrent and open-loop configuration with flow rates between 2.72 × 10−6 and 22.6 × 10−6 m3 s−1 and the pH values of the solution with ammonium between 8 and 11. A 2D numerical model was developed considering advection–diffusion equation inside a single fiber of the lumen with fully developed laminar flow and liquid–gas equilibrium in the membrane–solution interface. Predictions of the model were then validated against experimental data, which were found to be in good agreement. According to both, experimental data and numerical predictions, the hollow-fiber membrane contactor technology is a suitable alternative to remove ammonium from water and to feed the membrane distillation unit in order to fulfill water quality requirements for electrolysis-based hydrogen production.

Membrane Contactor: A Nondispersive and Precise Method to Control CO2 and O2 Concentrations in Wine

The described experiments tested the membrane contactor technology in an enological context to find the principal factors that influenced CO2 and O2 transfer rates. A mathematical model was developed to predict the most influential factors for CO2 and O2 concentration changes after membrane passage. Lumen side pressure, initial CO2 concentration in the liquid, and, to a lesser degree, the temperature of the liquid and the gas flow rate had a significant effect on the CO2 concentration changes in the liquid and subsequent CO2 transfer rates through the membrane. The most influential factors for O2 concentration changes were the initial O2 concentration in the liquid and the flow rate of the liquid. All other tested factors were negligible for O2. An increasing positive pressure in the lumen side induced a linear increase in the CO2 concentration of the wine, whereas an increasing negative pressure on the lumen side induced a linear decrease in the CO2 concentration of the wine. In both cases, a linear decrease in the O2 concentration was observed.

Blend polyvinylidene fluoride/surface modifying macromolecule hollow fiber membrane contactors for CO2 absorption

Recently, membrane contactors have attracted attentions as an efficient and flexible technology for CO2 capture. In the present work, blend hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes were prepared via a dry–wet phase-inversion process. Surface modifying macromolecule (SMM) was introduced to improve the membrane properties for CO2 absorption in gas–liquid membrane contactors. The effect of SMM concentration in the polymer dope, air gap distance and bore fluid composition on the structure and performance of the membranes were investigated. By increasing SMM in the polymer dope, the membranes presented smaller mean pore sizes, higher permeability and surface hydrophobicity. Using 2wt.% SMM, the membranes prepared at 24cm air gap showed larger mean pore size, higher hydrophobicity and lower permeability compared to those prepared at 0cm air gap. By using 60wt.% DMAc aqueous solution as the bore fluid, the membrane permeability and CO2 flux significantly improved. Maximum CO2 absorption flux of 6.8×10−4mol/m2 s was achieved at absorbent velocity of 0.025m/s. The surface modified membrane demonstrated about 10% gradual CO2 flux reduction for over 140h of the long-term operation. In conclusion, by improving surface hydrophobicity of the membrane, a long-term stable operation can be achieved for practical implication of gas–liquid membrane contactor technology.

Novel method for incorporating hydrophobic silica nanoparticles on polyetherimide hollow fiber membranes for CO2 absorption in a gas–liquid membrane contactor

In a gas–liquid membrane contactor, a larger pore size can result in a lower membrane mass transfer resistance. However, the membrane pore size is usually limited by the concern of pore wetting, e.g. a large pore size means a higher wetting tendency. As a breakthrough, this paper reported a porous polyetherimide (PEI) hollow fiber membrane with high surface porosity and large pore size to minimize the membrane mass transfer resistance by using a triple-orifice spinneret in the hollow fiber spinning process, and followed by a novel approach of fluorinated silica (fSiO2) nanoparticles (NPs) incorporation to make the membrane surface highly hydrophobic and chemical resistant to prevent the membrane from wetting caused by the large pore size on the membrane surface. The newly developed composite hollow fiber membranes showed the advancing contact angle value of 123.3°, receding contact angle value of 107.2°, and contact angle hysteresis of only 15.9°, indicating the high water resistant property. The composite membrane also exhibited a higher rigidity property compared with the original PEI substrate. The CO2 absorption flux of the composite membranes was investigated in both physical and chemical absorptions in a gas–liquid membrane contactor system. The membrane contactor showed a stable performance throughout the 60d long-term operation using a 2M sodium taurinate aqueous solution as the liquid absorbent.The highly hydrophobic composite hollow fiber membrane was able to outperform a conventional polymeric hydrophobic membrane in term of superior gas absorption flux and outstanding long-term stability, suggesting that the formation of organic–inorganic composite membranes is an effective way to enhance the feasibility of membrane contactor processes for practical applications. The results demonstrated the important role of membrane fabrication and modification techniques in facilitating the commercialization of membrane contactor technology.