• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 2000년도 추계 총회 및 국제학술발표회
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• pp.123-126
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• 2000

• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.17-20
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• 2003

Separation of MEK(methylethylketone) was carried out experimentally by a flat membrane contactor using a variety of extracting organic compounds. A correlation equation of Sherwood number was determined in terms of Reynolds number and Schmidt number for the flat membrane contactor system. This correlation equation was applied to get theoretically the overall mass transfer coefficient of MEK: it was compared to the experimental one. It was found that they are in good agreement.

• Environmental Engineering Research
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• 제17권2호
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• pp.111-116
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• 2012

This study investigates the complete removal of nitrate and the recovery of valuable ammonium salt by the combination of nanoscale zero-valent iron (NZVI) and a membrane contactor system. The NZVI used for the experiments was prepared by chemical reduction without a stabilizing agent. The main end-product of nitrate reduction by NZVI was ammonia, and the solution pH was stably maintained around 10.5. Effective removal of ammonia was possible with the polytetrafluoroethylene membrane contactor system in all tested conditions. Among the various operation parameters including influent pH, concentration, temperature, and contact time, contact time and solution pH showed significant effects on the ammonia removal mechanism. Also, the osmotic distillation phenomena that deteriorate the mass transfer efficiency could be minimized by pre-heating the influent wastewater. The ammonia removal rate could be maximized by optimizing operation conditions and changing the membrane configuration. The combination of NZVI and the membrane contactor system could be a solution for nitrate removal and the recovery of valuable products.

• Journal of Korean Society of Environmental Engineers
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• 제33권5호
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• pp.353-358
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• 2011

In this study, ammonia removal characteristics in membrane contactor system under various operating conditions were evaluated. The mass transfer coefficient was used to quantitatively compare the effect of various operation conditions on ammonia removal efficiency. Effective removal of ammonia was possible with the tubular PTFE membrane contactor system at all tested conditions. Among the various operation parameters, contact time and solution pH showed significant effect on ammonia removal mechanism. Overall ammonia removal rate was not significantly affected by influent suspended solution concentration unlike other pressure driven membrane filtration processes. Also the osmotic distillation phenomena which deteriorate the mass transfer efficiency can be minimized by preheating of strip solution. Membrane contactor system can be a possible alternative to treat high strength nitrogen wastewater by optimizing operation conditions such as stripping solution flow rate, influent wastewater temperature, and influent pH.

• Membrane Journal
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• 제16권3호
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• pp.196-203
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• 2006

A flue gas emission known to cause an acid rain, containing sulfur dioxide, is tightly controlled by a regulation. The membrane contactor could be one of the alternatives which might be useful technologies for better performance of desulfurization. The fundamental sulfur dioxide separation data were obtained by a flat membrane contactor so that they could be utilized for the full scale membrane contactor. The separation of sulfur dioxide was measured in terms of the concentration of NaOH absorbent, the concentration of sulfur dioxide, the feed flow rate and different membrane materials. As the concentration of absorbent increased, the removal efficiency increased. By increasing the concentration of sulfur dioxide, the removal efficiency decreased. As the feed flow rate increased, it was observed that the removal efficiency decreased. Finally, the effect of the membrane material on separation was found to be negligible.

• Journal of Climate Change Research
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• 제7권3호
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• pp.249-256
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• 2016

Porous $Al_2O_3$ hollow fiber membranes were successfully prepared by dry-wet spinning/sintering method. The SEM image shows that the $Al_2O_3$ hollow fiber membrane consists mostly of sponge pore structure. The contact angle and the breakthrough pressure were $126^{\circ}$ and 1.91 bar, respectively. This results indicate that the $Al_2O_3$ hollow fiber membranes were successfully modified to hydrophobic surface. The hydrophobic modified $Al_2O_3$ hollow fiber membranes were assembled into a membrane contactor system to separate $CO_2$ from a model gas mixture of the flue gas at elevated gas velocity. The $CO_2$ absorption flux was enhanced when the gas velocity increased from $1{\times}10^{-3}$ to $6{\times}10^{-3}$ m/s. Whereas the $CO_2$ absorption flux was decreased with the number of hollow fiber membrane of a module because of the concentration polarization. Furthermore, we developed an lab-scale $Al_2O_3$ hollow fiber membrane contactor modules and their system (i.e., $CO_2$ absorption using the $Al_2O_3$ membrane and monoethanolamine (MEA)) that could dispose of over $0.02Nm^3/h$ mixture gas (15% $CO_2$) with the removal efficiency higher than 95%. The results can be useful in a field of the membrane contactor for $CO_2$ separation, helping to design and extend a equipment.

• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.39-42
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• 1998

1. 서론 : 막을 경계로 접촉한 두 상(phase)간의 물질전달에 의해 물질을 효과적으로 분리해내는 막접촉기(membrane contactor) 방식은 추출이나 흡수에 적용되고 있다. 이것은 고전적인 충전탑이 갖는 접촉면적의 한계, 불안정한 유체유동의 단점을 가급적 극복할 수 있다는 측면에 있다. 막접촉방식의 하나인 막 흡수법의 경우, 흡수제(absorbent)를 정지시킨 contained(혹은, supported) liquid membrane 방식에서 인공폐의 원리를 기초로 독립적으로 분리시킨 흡수와 탈착모듈간의 계속 순환시키는 circulatory membrane absorber방식이 제안되었다.(생략)

• Membrane and Water Treatment
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• 제13권3호
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• pp.147-166
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• 2022

Liquid-liquid membrane contactor (LLMC), a device that exchanges dissolved gas molecules between the two sides of a hydrophobic membrane through membrane pores, can be employed to extract ammoniacal nitrogen from a feed solution, which is transported across the membrane and accumulated in a stripping solution. This LLMC process offers the promise of improving the sustainability of the global nitrogen cycle by cost-effectively recovering ammonia from wastewater. Despite recent technological advances in LLMC processes, a comprehensive review of their feasibility for ammonia recovery is rarely found in the literature. Our paper aims to close this knowledge gap, and in addition to analyze the challenges and provide potential solutions for improvement. We begin with discussions on the operational principles of the LLMC process for ammonia recovery and membrane types and membrane configurations commonly used in the process. We then assess the performance of the process by reviewing publications that demonstrate its practical application. Challenges involved in the implementation of the LLMC process, such as membrane fouling, membrane wetting, and chemical requirements, are presented, along with discussions on potential strategies to address each. These strategies, including membrane modification, hybrid process design, and process optimization based on cost-benefit analysis, guide the reader to identify key areas of future research and development.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.521-528
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• 2008

The micro-porous asymmetric PVDF hollow fiber membranes for gas-liquid contactor were prepared by the dry-jet wet phase inversion process and the characteristics of hollow fiber membranes were evaluated by the gas permeation method and scanning electron microscope. The chemical absorbent for removal of $SO_2$ gas was sodium hydroxide at bench scale hollow fiber membrane contactor. The experiments were performed in a counter-current mode of operation with gas in the shell side and liquid in the fiber lumen of the module to examine the effect of various operating variables such as concentration of absorbent, gas flow rate, L/G ratio and concentration of inlet $SO_2$ gas on the $SO_2$ removal efficiency using PVDF hollow fiber membrane contactor. Membrane mass transfer coefficient($k_m$) was calculated by mathematical modeling. The volumetric overall mass transfer coefficient increased with increasing the concentration of absorbent and L/G ratio. The increase of the absorbent concentration and L/G ratio not only provides more sufficient alkalinity but also decreases liquid phase resistance. The volumetric overall mass transfer coefficient increased with increasing gas flow rate due to decreasing the gas phase resistance.

• Membrane and Water Treatment
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• 제8권1호
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• pp.35-50
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• 2017

The theoretical membrane gas absorption module treatments in a hollow fiber gas-liquid membrane contactor using Happel's free surface model were obtained under countercurrent-flow operations. The analytical solutions were obtained using the separated variable method with an orthogonal expansion technique extended in power series. The $CO_2$ concentration in the liquid absorbent, total absorption rate and absorption efficiency were calculated theoretically and experimentally with the liquid absorbent flow rate, gas feed flow rate and initial $CO_2$ concentration in the gas feed as parameters. The improvements in device performance under countercurrent-flow operations to increase the absorption efficiency in a carbon dioxide and nitrogen gas feed mixture using a pure water liquid absorbent were achieved and compared with those in the concurrent-flow operation. Both good qualitative and quantitative agreements were achieved between the experimental results and theoretical predictions for countercurrent flow in a hollow fiber gas-liquid membrane contactor with accuracy of $6.62{\times}10^{-2}{\leq}E{\leq}8.98{\times}10^{-2}$.