• Membrane Journal
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• v.21 no.2
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• pp.177-192
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• 2011

Hollow fiber membrane using CTA polymers were prepared by the phase separation method for the separation and purification of biogas and the hollow fiber gas separation membrane modules with the effective surface area of 0.17 $m^2$ were prepared. The pure gas permeation properties of membrane modules for methane, oxygen and carbon dioxide were measured. The permeance of $CO_2$ and $CH_4$were 0.46 GPU and 18.52 GPU, respectively, therefore, the high $CO_2$/$CH_4$ selectivity of 40.4 was obtained. The separation and purification test for 4 different simulated mixed gases were carried out after the pure gas test and the gas concentration and flux of the permeate at the various stage-cut were measured from the 1 stage, 2 stage, and 3 stage cascade of membrane modules. In the 1 stage test, the concentration of $CH_4$ increased as the increase of the stage-cut, while the $CH_4$ recovery efficiency ratio decreased. In the 2 stage test, the $CH_4$ recovery efficiency ratio increased compared to the 1 stage. The 3 stage test was employed to reduce the loss of $CH_4$ in biogas and the result showed less than 5% of $CH_4$ recovery loss.

• Membrane Journal
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• v.25 no.1
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• pp.15-26
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• 2015

In this study, porous metal (O.D. = 10 mm, length = 10 mm, 316 L SUS, Mott Corp.) and ${\alpha}$-alumina tube (O.D. = 10 mm, length = 50 mm, Pall, German) support was modified with suspension sols, which were consisted of $3{\sim}4{\mu}m$ and 150 nm size of ${\alpha}$-alumina particle in the water or silica-zirconia colloidal sol. The porous support was fabricated by dip coating method for 5 seconds with suspension of alumina particles. After drying at $100^{\circ}C$ for 1 h, it was calcined at $550^{\circ}C$ for 30 min. It was repeated several times in order to decrease big pore on support. The surface roughness and largest pore size on the porous support was decreased by increasing coating times with $3{\sim}4{\mu}m$ size of ${\alpha}$-alumina particle and alumina coating with 150 nm size of ${\alpha}$-alumina particle served as further smoothening the surface and decreasing the pore size of the substrate. And the silica-zirconia membranes were successfully prepared on the modified porous metal and ${\alpha}$-alumina supports, and showed hydrogen permeance in the range of $1.8-8.4{\times}10^{-4}mol{\cdot}m^{-2}{\cdot}s^{-1}{\cdot}Pa^{-1}$ and $3.3-5.0{\times}10^{-5}mol{\cdot}m^{-2}{\cdot}s^{-1}{\cdot}Pa^{-1}$, respectively.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.250-255
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• 2011

In this study, by using the polymeric membrane separation process, the $CO_{2}/CH_{4}$ separation and $H_{2}S$ removal from biogas were performed in order to $CH_{4}$ purification and enrichment for the fuel cell energy source application. Fibers were spun by dry/wet phase inversion method. The module was manufactured by fabricating fibers after surface coating with silicone elastomer. The scanning electron microscopy(SEM) studies showed that the produced fibers typically had an asymmetric structure; a dense top layer supported by a porous, sponge substructure. The permeance of $CO_{2}$ and $CO_{2}/CH_{4}$ selectivity increased with pressure and temperature. Mixture gas with increasing pressure and temperature, removal efficiency of the $CO_{2}$ and $H_{2}S$ were decreased while concentration of $CH_{4}$ was increased up to 100%. When retentate flow rate was increased with the decreasing of pressure and temperature the $CH_{4}$ recovery ratio in retentate side was increased while the $CH_{4}$ purity in retentate side was decreased.

• Membrane Journal
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• v.22 no.6
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• pp.404-414
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• 2012

In order to investigate $SO_2$ removal, PEI hollow fiber membranes were produced by a dry-wet phase inversion method. The membrane support layer on surface was coated with PEBAX1657$^{(R)}$ and PEG blending materials. Modules were prepared for the single gas permeation characteristics of composite membrane according to temperature and pressure. As a result, $SO_2$ permeance and $SO_2/N_2$ selectivity were 220~1220 GPU and 100~506 through operating condition, respectively. Moreover, $SO_2/CO_2/N_2$ mixture gas was used to compare the performance of separation properties according to temperature, pressure and retentate flow rate difference. $SO_2$ removal efficiency was increased with pressure and temperature.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.4
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• pp.43-52
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• 2020

As the membrane gas separation technology grows, various models were developed by numerous researchers to describe the separation process. In this work, the counter-current model was compared thoroughly with experimental data. Experimentally, hollow fiber membrane using CA module was prepared for the separation of biogas. The pure gas permeation properties of membrane module for methane, nitrogen, oxygen, and carbon dioxide were measured. The permeance of CO2 and CH4 were 25.82 GPU and 0.65 GPU, respectively. The high CO2/CH4 selectivity of 39.7 was obtained. the separation test for three different simulated mixed gases were carried out after pure gas test, and the gas concentration of the permeate at various stage-cut were measured from CA membrane module. Results showed that the experimental data agreed with the numerical simulation. A mathematical model has implemented in this study for the separation of biogas using a membrane module. The finite difference method (FDM) is applied to calculate the membrane biogas separation behaviors. Futhermore, the counter-current model can be considered as a convenient model for biogas separation process.