• 한국안전학회지
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• 제6권3호
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• pp.5-11
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• 1991

To remove NO from flue gas, a direct decomposition method to $N_2$ and $O_2$ was investigated by using copper / zeolite catalyst. The copper ion-exchanged HY type zeolite has high activity on NO decomposition. The decomposition activity was increased with the increase of ion-exchange level, contacting time and reaction temperature in the range of 30$0^{\circ}C$ -50$0^{\circ}C$ , and decreased with the oxygen addition.

• 공업화학
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• 제18권3호
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• pp.273-278
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• 2007

본 논문은 배연가스로부터 이산화탄소를 흡착 회수하기 위한 허니컴 흡착소자 및 공정에 관한 것이다. 세라믹섬유와 Na-X를 주원료로 제올라이트 종이를 제조하였다. 제올라이트 종이의 이산화탄소 흡착능을 향상시키기 위해서 $Li^+$, $Ca^{2+}$, $K^+$ 이온교환 및 추가적인 표면코팅을 실시하여 그 특성을 분석하였다. $Li^+$ 이온교환 방법은 이산화탄소 흡착능을 가장 많이 증가시켰지만 공정적용이 가능할 만큼의 흡착능 변화를 보이지 않았다. 반면 Na-X의 추가적인 표면코팅은 이산화탄소 흡착능을 증가시키는 효율적인 방법이었다. 제올라이트 종이를 성형하여 만든 허니컴형 흡착소자에 대한 이산화탄소 흡착파과 특성을 분석하였으며, 이의 결과로서 회전식 이산화탄소 흡착 농축공정의 적용 예를 보여주었다.

• 공업화학
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• 제34권3호
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• pp.313-317
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• 2023

본 연구에서는 이온교환 공정에서 사용된 제올라이트의 재이용을 위해 물리화학적 특성 분석 및 대기오염물질(VOCs, SO₂, CO₂) 흡착 성능을 평가하였다. SEM 및 XRD 분석을 통해 사용된 제올라이트의 표면 특성을 확인하였으며, XRF 분석을 통해 조성, BET 분석을 통해 비표면적을 측정하였다. 사용된 제올라이트의 표면 특성 변화는 없었지만 칼륨 및 칼슘의 함량이 증가하고 비표면적이 감소하였다. 사용된 제올라이트의 톨루엔, 황산화물, 이산화탄소 흡착 성능 평가를 수행하였으며, 기존 제올라이트 대비 성능이 증진됨을 확인하였다. 특히 톨루엔, 황산화물에 대해서는 흡착량이 각각 2.6배, 2.3배 증가하였다. 이는 사용된 제올라이트 조성 변화에 따라 각각 중합반응 증진, 염기점 증가에 의한 것으로 판단된다.

• 멤브레인
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• 제18권3호
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• pp.250-255
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• 2008

열적, 기계적, 화학적 안정성이 우수한 제올라이트 분리막의 물/에탄올 선택도를 이온교환 실험을 통해 더욱 효과적으로 높이고자 하였다. KA형 제올라이트 분리막을 직접 합성하는 것은 용이하지 않으므로 NaA형 제올라이트 분리막을 합성한 후 이를 다시 이온교환 하여 KA형 제올라이트 분리막을 제조하였다. 공급되는 에탄올의 농도 변화 및 투과 증발실험 온도의 변화가 투과플럭스와 물 선택도에 미치는 영향을 고찰하였다. 이온교환 실험 후 전체 투과플럭스는 감소하였고 물 선택도는 증가함을 관찰할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1814-1818
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• 2003

$Li^+$ and $H^+$ co-exchanged LSXs (Li-H-LSX) with various ratios of $Li^+$ and $H^+$ were prepared, and those adsorption characteristics of nitrogen and oxygen were compared with Li-Na-LSX and Li-Ca-LSX. Li-H-LSX showed higher nitrogen capacity and selectivity than that of Li-Na-LSX in the wide range of Li-exchanged ratio. The nitrogen capacity of Li-Ca-LSX was slightly higher than that of fully Li- or Ca-exchanged LSX (Li- LSX or Ca-LSX). However, Li-Ca-LSX showed low nitrogen/oxygen adsorption selectivity until the Li content reached about 80%, which was a tendency near that of Ca-LSX.

• Bulletin of the Korean Chemical Society
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• 제18권3호
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• pp.291-295
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• 1997

The adsorption of methane in K+ ion exchanged zeolite L has been studied using grand canonical ensemble Monte Carlo simulation. Average number of molecules per unit cell, number density of molecules in zeolite, distribution of molecules per unit cell, average potential per sorbate molecule, and isosteric heats of adsorption were calculated, and these results were compared with experimental results. The simulation results agreed fairly well with experimental ones. All methane molecules were located in the main channel, and the average potential of sorbate molecule was almost constant regardless of average number of molecules per unit cell and the amounts sorbed in zeolite.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.142-145
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• 1999

We confirm that when A-type zeolite supporting silver lone is placed in ion-exchanged distilled water, silver ions is eluted and eluted silver ions generates hydroxyl-radical (.OH) and hydro-radical (.H) continuously, the amount of those is proportion to the silver-ion concentration. Hydroxyl-radical is not generated by super-oxide anion-radical (.O2) but by directly dissolved water. To know such a above discussed mechanism, we prepare A-type zeolite supporting silver ions, and measure the amount of the eluted silver tons by atomic absorption spectroscopy and the generated radical by ESR The radical generated by A-type zeolite supporting silver ions is discussed in the application of elecrical and electronic materials.

• 공업화학
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• 제9권3호
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• pp.317-321
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• 1998

수열 방법으로 합성한 기체 분리용 제올라이트 흡착제의 분자체 및 이온교환 특성을 파악하기 위하여 KCl, $CaCl_2$, $YCl_3$ 그리고 $InCl_3$으로 제올라이트에 함유된 Na 이온을 치환시켰다. 치환시킨 X형 제올라이트를 $25^{\circ}C$에서 $CO_2$가스로 그리고 합성 제올라이트에 대하여 $O_2$, $N_2$가스로 부피법 장치를 통해 평형 흡착 특성을 각각 비교하였다. 측정결과를 Freundlich, Langmuir 그리고 Toth형 model 식을 이용하여 변수를 파악하였으며, 제올라이트의 $CO_2-PSA$ 흡착공정에 적용가능성을 측정하기 위하여 흡착파괴실험을 실시하고, 이를 PSA 공정 simulation에 적용하였다. 여기서 X형 제올라이트는 공정 배가스에서 $CO_2$회수에 적합한 흡착제로 사용할 수 있음을 확인하였다.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.32-44
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• 2002

Selective catalytic reduction of nitric oxide by methane in the presence of excess oxygen was investigated over copper and cobalt ion-exchanged ZSM-5 zeolites. Copper ion-exchanged ZSM-5(Cu-ZSM-5) has the limitations for commercial applications to lean-bum gasoline and diesel engines due to low thermal stability and resistance to water vapor and sulfur dioxide. But cobalt ion-exchanged ESM-5(Co-ZSM-5) is more active at high temperatures and also stable to water vapor and sulfur dioxide for catalytic reduction of nitric oxide by methane. The catalytic activity of Cu-ZSM-5 for NO reduction increases with increasing temperatures, reaches the maximum conversion of 23.0% at 350\"C. and then decreases with higher temperatures. In the meantime catalytic activities of Co-ZSM-5 show the maximum conversion of 25.8% at $500^{\circ}C$ Therefore Co-ZSM-5 catalysts have higher thermal stability at high temperatures. Catalytic activities of both zeolites were remarkably enhanced with the existence of oxygen in the exhaust. It is noted that the catalytic activity of Cu-ZSM-5 decreases with the increasing concentration of methane while the catalytic activity of Co-ZSM-5 decreases with increasing contents of methane in the exhaust. This may imply the existence of different paths of NO reduction by methane in the presence of excess oxygen fur Cu-ZSM-5 and Co-ZSM-5 catalysts. For binary metal ionexchanged ZSM-5, the primary ion-exchanged metal may be masked by secondary ion-exchanged component, which plays the important role for catalytic activities of binary metal ion-exchanged ZSM-5, Therefore CuCo-ZSM-5 catalysts show the similar volcano-shaped curves to Cu-ZSM-5 catalysts between the activity and temperature. It Is interesting that the activities of CoCu-ZSM-5 catalysts indicate almost no dependence on the concentration of methane in the exhaust.aust.

• 환경위생공학
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• 제14권4호
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• pp.165-171
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• 1999

A study on the synthesis of zeolite 4A using the bituminous coal fly ash from power plant was carried out. This study aims to investigate possibility for detergent builder with synthesized zeolite. It was examined at the crystallization conditions of atmospheric pressure and that of pressurization. The synthesized zeolite was proved to be Zeolite 4A type by means of the XRD and SEM analysis, and then the synthesized zeolite was used as an absorbent the remove the $Ca^{2+}$ ions in the water. In this study, commercial zeolite and synthesized zeolite reached equilibrium within 10 and 30 minutes respectively. The amount of $Ca^{2+}$ ions exchanged by the commercial zeolite, atmospheric pressure zeolite (zeolite A) and pressurized zeolite(zeolite PA) were 391mg/L(as $CaCO_3$), 323mg/L(as $CaCO_3$) and 355mg/L(as $CaCO_3$) respectively.