• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.765-769
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• 2001

The refuse-derived fuel(RDF) is manufactured using waste plastics-based materials and its physical and chemical properties are analyzed. The manufacturing process consists of hand picking, primary magnetic separation, crushing, secondary magnetic separation, feeding and extrusion. The RDF products have a higher calorie content of over 6, 000 ㎉/kg and high stability because the waste plastics and paper are mainly selected. The combustion flue gas of RDF products is satisfied with the emission criteria of incinerator. The heavy metal concentration of combustion byproduct from the RDF boiler is also satisfied with the criteria and appears to be lower concentration than that of a common municipal waste incinerator.

• Journal of Climate Change Research
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• v.7 no.3
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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.

• Membrane Journal
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• v.33 no.3
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• pp.94-109
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• 2023

1,3-Dioxolane is an exciting material that has attracted widespread interest in the chemical, paint, and pharmaceutical industries as a solvent, electrolyte, and reagent because 1,3-dioxolane is not toxic, carcinogenic, explosive, auto-flammable, and multifunctional, and due to their excellent miscibility in most organic and aqueous solvent conditions. Recently, this material has received increasing attention as a CO₂-selective polymer precursor to separating CO₂ from flue gas and natural gas mixtures. Poly(1,3-dioxolane) (PDXL) possesses higher ether oxygen content than polyethylene oxide (PEO), which demonstrates superior membrane CO₂/N₂ separation properties owing to their polar ether oxygen groups exhibiting strong affinity toward CO₂. Thus, PDXL-based membranes displayed an outstanding CO₂ solubility selectivity over non-polar (N₂, H₂, and CH₄) gases. However, the polar groups of PDXL, like PEO, promote chain packing efficiency and cause polymer crystallization, thereby reducing its gas permeability, which should be improved. In this short review, we discuss the recent advancement and limitations of PDXL membranes in gas separation applications. To conclude, we provide future perspectives for inhibiting the limits of 1,3-dioxolane-based polymers in the CO₂ separation process.

• Clean Technology
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• v.18 no.1
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• pp.22-30
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• 2012

Separation of $SO_2$ from the flue gases of fossil fuel power plants are important issue because of its strong environmental impact. Industrially, $SO_2$ is being removed with a slurry of limestone, lime or aqueous caustic soda. However, these scrubbing processes possess several drawbacks such as the generation of huge amount of wastewater and the production of metal salts. Recently, ionic liquids have gained increasing interest as an absorbent for acid gas, $CO_2$ and $SO_2$. In this review, we have introduced the recent progress of ionic liquids as a $SO_2$ absorbent.

• Membrane Journal
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• v.16 no.3
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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.

• Membrane Journal
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• v.15 no.4
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• pp.310-319
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• 2005

This paper describes the preliminary study on the development of multi-stage membrane demonstration plant for removal of carbon dioxide from flue gas stream being emitted from LNG boiler in thermal power generation plant. The prerequisite requirement is to design and develop the membrane process producing a $99\%\;CO_2$ with $90\%$ recovery from LNG flue gas of 1,000 $Nm^3$/day. Asymmetric polyethersulfone hollow fiber membranes and membrane modules developed in this laboratory[1] were used in this study. Using the permeation data for the hollow fiber membranes, modelling on the membrane module and multi-stage membrane process was done to meet the requirement condition of the process design. The effects of the operating pressure of feed and permeate side and feed concentration on $CO_2$ purity and recovery were investigated experimentally with the developed hollow fiber modules. These experimental results matched well with theoretical modelling results.

• Membrane Journal
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• v.5 no.1
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• pp.35-43
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• 1995

For several years lots of attempts have been made to establish the liquid membrane-based techniques for separations of gas mixtures especially containing carbon dioxide. A more effective system to separate $CO_{2}$ from flue gases, a circulatory hollow-fiber membrane absorber(HFMA) consisting of absorption and desorption modules with vacuum mode, has been considered in this study. Gas-liquid mass transfer has been modeled on a membrane module with non-wetted hollow-fibers in the laminar flow regime. The influence of an absorbent flow rate on the separation performance of the circulatory HFMA can be predicted quantitatively by obtaining the $CO_{2}$ concentration profile in a tube side. The system of $CO_{2}/N_{2}$ binary gas mixture has been studied using pure water as an(inert) absorbent. As the absorbent flow rate is increased, the permeation flux(i.e., defined as permeation rate/membrane contact area) also increases. The enhanced selectivity compared to the previous results, on the other hand, shows the decreasing behavior. It has been found obviously that the permeation flux depends on the variations of pressure in gas phase of desorption module. From an accurate comparison with the results of conventional flat sheet membrane module, the advantageous permeability of this circulatory HFMA can be clearly ascertained as expected. Our efforts to the theoretical model will provide the basic analysis on the circulatory HFMA technique for a better design and process.

• Environmental Engineering Research
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• v.19 no.4
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• pp.299-308
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• 2014

This study presents a review on Chemical looping combustion (CLC) development, design aspects and modeling. The CLC is in fact an unmixed combustion based on the transfer of oxygen to the fuel by a solid oxygen carrier material avoiding the direct contact between air and fuel. The CLC process is considered as a very promising combustion technology for power plants and chemical industries due to its inherent capability of $CO_2$ capturing, which avoids extra separation costs of the of $CO_2$ from the rest of flue gases. This review covers the issues related to oxygen carrier materials. The modeling works are reviewed and different aspects of modeling are considered, as well. The main drawbacks and future research and prospects are remarked.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.77-83
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• 2023

Energy consumption is increased by rapid industrialization. As a result, climate change is accelerating due to the increase in CO₂ concentration in the atmosphere. Therefore, a shift in the energy paradigm is required. Hydrogen is in the spotlight as a part of that. Currently 95% of hydrogen is fossil fuel-based reforming hydrogen which is accompanied by CO₂ emissions. This is called gray hydrogen, if the CO₂ is captured and emission of CO₂ is reduced, it can be converted into blue hydrogen. There are 3 technologies to capture CO₂: absorption, adsorption and membrane technology. In order to select CO₂ capture technology, the analysis of the exhaust gas should be carried out. The concentration of CO₂ in the flue gas from the hydrogen production process is higher than 20%if water is removed as well as the emission scale is classified as small and medium. So, the application of the membrane technology is more advantageous than the absorption. In addition, if LNG cold energy can be used for low temperature CO₂ capture system, the CO₂/N₂ selectivity of the membrane is higher than room temperature CO₂ capture and enabling an efficient CO₂ capture process. In this study, we will analyze the flue gas from hydrogen production process and discuss suitable CO₂ capture technology for it.

• Membrane Journal
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• v.16 no.4
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• pp.252-258
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• 2006

A numerical analysis was performed for a separation process of carbon dioxide from a flue gas stream using polyethersulfone hollow fiber membranes. Countercurrent flow governing equations were regarded to be two point boundary-value problem and the nonlinear ordinary differential equation were simultaneously solved using the finite- difference method. A computer program was developed using the Compaq Visual Fortran 6.6 software. The carbon dioxide permeate driving force and the fred gas residence time at the inside of membrane were found to be very important factors affecting the permeation characteristics of carbon dioxide. The carbon dioxide concentration in the permeate and the flow rate of the permeate were found to be slightly larger by a few percent with a countercurrent flow analysis than those with a cocurrent flow analysis.