• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.33-35
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• 2012

본 연구에서는 전이금속 Cu, Mn이 함침된 제올라이트를 사용하여 일산화탄소의 흡착능을 연구하였다. 금속 복합 산화물촉매 제조는 Cu, Mn을 서로 다른 비율로 물리 혼합하여 지지체에 담지하였다. 제올라이트 분자체는 상용 13X를 사용하였다. 함침방법은 과잉용액 함침법을 사용하였고, 건조 후 소성 하여 산화물 형태로 담지하였다. 합성된 개질 흡착제의 표면특성 분석은 $N_2$흡착 및 탈착곡선을 통한 질소흡착 특성 분석으로 기공크기, 기공분포, 비표면적을 구하였으며, FT-IR, X-선 회절분석, 전자주사현미경, $NH_3$-TPD/TPR 으로 특성을 분석하였다. 흡착 실험은 고정층 반응기에서 수행하였으며, 내경 4 mm 석영관에 흡착제를 충진하고 흡착파과곡선을 Gas Chromatograph로 측정하여 Cu-Mn 제올라이트 촉매의 일산화탄소 흡착 성능을 연구하였다. Cu-Mn 함량 비율과 흡착조업조건에 따른 흡착능을 측정하여 최적 흡착조건을 구하였다.

• Membrane Journal
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• v.23 no.6
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• pp.409-417
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• 2013

Adsorptive permeation hollow fiber membrane (APM) has been developed for effectively separating $CO_2$ from gas mixture. Inside the APM, zeolite 13X particles were uniformly dispersed without covering their surfaces by a symmetric porous structure of polypropylene lattice. In this study, $CO_2/N_2$ mixture was used as a simulated gas mixture. Separation was achieved by adsorbing $CO_2$ on the zeolite particles in the APM and then permeating $N_2$ into permeate side in passing all the feed gas through the APM. Adsorptive permeation tests were carried out with a set of APM modules, and the adsorptive permeation performances of the modules were analyzed from the test results. After saturation of the adsorbent with $CO_2$, the APM was regenerated by desorption of $CO_2$ from it through vacuuming both inside of outside of the APM hollow fiber, and the regeneration process of the APM by vacuuming was discussed in terms of regeneration efficiency and energy consumption.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.761-766
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• 2010

This study was aimed to propose La(III)-zeolite composite which can effectively and simultaneously remove ammonia and phosphate in confined water bodies such as lakes and ponds. The optimum ratio of La(III):zeolite for the simultaneous removal of ammonia and phosphate was 0.0048 La(III) g:1 zeolite g. The drying temperature of La(III)-zeolite composite severely affected phosphate adsorption showing optimum condition at room temperature. It was revealed that the optimum dosage of La(III)-zeolite composite was 4.052 g/L at adsorption time of 90 min. The presence of alkalinity in aqueous solution brought positive effect on phosphate adsorption. Detachment of La(III) from La(III)-zeolite composite, which was dried at room temperature, was not observed in aquous solution. It indicates that La(III)-zeolite composite could effectively block phosphate released from sediment.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.515-520
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• 2007

Recently, the treat of sludge is usually progressed by ocean disposal. But it will be totally banned by content of its heavy metal according to London Dumping Convention, gradually. The stable way of treat of sewage sludge should be examined urgently. To solve the problem, recently, there are efficient and environment-oriented method. One of them is to produce absorbent through the activation. This study produces absorbent through steam activation. As basic experiment, optimum activation condition for preparation of good absorbent is researched through study of the fellowing variables : steam flow rate, activated temperature, activation time. As the result of this with standard on iodine adsorptivity, it is chosen, that steam flow rate "30 mL/hr", activation temperature $"500^{\circ}C"$, activation time "60 minutes". At the time, iodine adsorptivity and yield shown that 228.4 mg/g, 77.23%. And also, by using nitrogen adsorption, SEM and EDS are confirmed that pore development, specific surface area, mean pore size, chemical component and content. Pore developed by steam activation is also confirmed that it is micropore.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.604-610
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• 2023

The nitrogen reduction reaction (NRR), which produces NH₃ by reducing N₂ under ambient conditions, is attracting attention as a promising technology that can reduce energy consumption in industrial processes. We investigated the adsorption behaviors at various active sites on the Ni (100) surface, which is widely used among catalytic metal surfaces capable of adsorbing and activating N₂, based on density-functional theory calculations. We also investigated two N₂ adsorption structures, so-called end-on and side-on structures. We find that for the end-on case, N₂ is adsorbed on a top site, and the reaction proceeded in a distal pathway, while for the side-on case, N₂ is adsorbed on a bridge site, and the reaction proceeded with enzymatic pathway. Finally, this study provides insight into the adsorption of metal catalyst surfaces for the NRR reactions based on the calculated Gibbs free energy profiles of the thermodynamically most favorable pathways.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.606-616
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• 2011

The objectives of this study were to evaluate the applicability of adsorption models for adsorption properties of adsorbents. For this study, adsorption experiment of $NO_3^-$ ion using anion exchange resin has been investigated under adsorption equilibrium and kinetic in bach process. Adsorption equilibrium experiment were carried out that two conditions is change of adsorbate concentration and change of adsorbent weight. Experiment results have been analyzed by adsorption isotherm models, energy models and kinetic models. Under the condition of change of adsorbate concentration was best described by Sips and Redlich-Perterson isotherm models. However case of change of adsorbent weight was described by Langmuir isotherm models. It seems reasonable to assume that isotherm model was dominated by multiple mechanism according to experiment condition.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.377-385
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• 2022

Surface morphology and adsorption characteristics of charcoals prepared from Korean traditional kiln were analyzed, and their moisture adsorption capacities were examined with respect to humidity and temperature change. Moisture adsorption capacities of red-clay powder, activated carbon fiber fabric (ACF fabric) and activated carbon fiber paper(ACF paper) were also examined to compare with those of charcoals. Moisture adsorption capacity of charcoal was low less than 45% humidity due to its hydrophobic property, but it slowly and linearly increased as increasing the humidity. Moisture adsorption capacity of red-clay powder was similar to charcoal at low level humidity, it increased exponentially as increasing the humidity showing Type V adsorption isotherm. Therefore, the weather forecast annal prepared by employee of weather centre in Joseon Dynasty is experimentally approved. ACF fabric and ACF paper show excellent moisture adsorption capacities, which can be used to humidity measuring sensor. Adsorption isotherm of charcoal slice was peculear showing the mixed Type I and Type IV due to low-pressure hysteresis that was occurred from embedment of nitrogen in crevice of charcoal. The specific surface area of charcoal increased by grinding charcoal slice to powder, resulted in increasing the desorption amount of adsorbent at low relative pressure.

• Clean Technology
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• v.28 no.3
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• pp.249-257
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• 2022

The adsorption equilibria of nitrogen on a region of nanoporous carbonaceous adsorbent with local molecular orientation (LMO) were calculated by grand canonical Monte Carlo simulation at 77.16 K. Regions of LMO of identical size were arranged on a regular lattice with uniform spacing. Microporosity was predominately introduced to the model by removing successive out-of-plane domains from the regions of LMO and tilting pores were generated by tilting the basic structure units. This pore structure is a more realistic model than slit-shaped pores for studying adsorption in nanoporous carbon adsorbents. Their porosities, surface areas, and pore size distributions according to constrained nonlinear optimization were also reported. The adsorption in slit shaped pores was also reported for reference. In the slit shaped pores, a clear hysteresis loop was observed in pores of greater than 5 times the nitrogen molecule size, and in capillary condensation and reverse condensation, evaporation occurred immediately at one pressure. In the LMO pore model, three series of local condensations at the basal slip plane, armchair slip plane and interconnected channel were observed during adsorption at pore sizes greater than about 6 times the nitrogen molecular size. In the hysteresis loop, on the other hand, evaporation occurred at one or two pressures during desorption.

• Journal of the Korean Vacuum Society
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• v.2 no.1
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• pp.92-98
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• 1993

Si 기판 위에 증착된 Al 박막을 질소 ECR 플라즈마에 노출시켜 시료를 제작하고 분광타원해석법으로 분석한 결과 Al박막에 질화층이 형성되었음을 확인하였다. 사용한 질소 ECR 플라즈마의 전자온도와 전자밀도는 챔버내의 위치에 따라 각각 10~20eV, 0.9~1.2$\times$1011/㎤의 값을 보였다. 질소 ECR 플라즈마에 노출된 기판은 급격한 온도상승을 보였으며 노출시킨 뒤 5~6분이 지나면 $500^{\circ}C$ 근처에서 포화상태를 이루었다. 분광타원해석상수인 $\Delta$와 Ψ를 분석한 결과 증착된 Al의 두께는 시료에 따라 $140~160AA$이었고 표면에 형성된 AIN 층의 두께는 질소 ECR 플라즈마에 노출된 시간이 길수록 그리고 시료의 위치가 공명지점에 가까울수록 증가하였다. AlN층의 두께가 노출시간의 제곱근에 비례하는 것으로부터 AlN층은 Al의 표면에 흡착된 질소가 Al속으로 확산하여 이루어진 것으로 설명하였다.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.105-113
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• 1994

The amount of nitrogen gas adsorbed by Spherocarb and Sucrose Char was measured as a function of the relative pressure with temperature being kept constant at 77 to 184K. Isotherms at different temperatures were obtained by keeping the adsorbent at a constant temperature using liquid nitrogen, iso-pentane, n-pentane, ethyl alcohol, and iso-propyl alcohol slush baths. The objective for this study is to provide information on the specific surface area and pore volume by analyzing the experimental data using adsorption models such as the Brunauer-Emmett-Teller and Dubinin-Radushkevich models.