• Korean Chemical Engineering Research
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• 제43권5호
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• pp.588-594
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• 2005

흡착식 경유 탈황을 위하여 Y 제올라이트와 활성탄에서의 황화합물 흡착특성을 분석하였다. n-옥탄에 BT, DBT, 4,6-DMDBT가 각각 50 ppmw씩 포함된 모사경유와 상용경유를 이용한 회분식 흡착에서 금속이온($Cu^{2+}$, $Ni^{2+}$)이 교환된 제올라이트 흡착제들이 모사경유에서는 우수한 황화합물 흡착성을 보였으나 상용경유에서는 활성탄이 더 우수한 흡착능력을 나타냈다. 모사경유에 벤젠을 첨가하였을 때, 벤젠의 함량이 증가할수록 Ni-Y 제올라이트에서의 황흡착량은 급감하였는데, 활성탄에서는 황흡착량에 큰 영향을 받지 않았다. 활성탄에서의 파과실험에서 황화합물의 평형흡착이 일어나도록 상용경유를 최적 조건의 유속으로 주입하였을 때에 활성탄 1g은 황농도 186 ppmw인 상용경유를 15 ml까지 처리할 수 있었다. 다양한 용매를 이용한 활성탄 재생실험에서 톨루엔이 가장 우수한 재생능력을 나타냈다.

• Carbon letters
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• 제8권1호
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• pp.37-42
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• 2007

Carbon nanofiber (CNF) grown catalytically was chemically activated with KOH to attain structural change of CNF. The structural changes of CNF through KOH activation were investigated by using BET and SEM. From the results of BET, it was found that KOH activation was effective to develop particular sizes of pores on the CNF surface, increasing the surface area of CNF. Activated CNF was applied as an anode catalyst support of fuel cell. The effects of different activation conditions including the activation temperature and the activation time on the specific surface area of the CNF activated with KOH were investigated to obtain appropriate structure as a catalyst support. The 60 wt% Pt-Ru catalyst prepared was observed by using TEM and XRD.

• 임산에너지
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• 제21권2호
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• pp.17-24
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• 2002

소나무 수피로 부터 수증기 활성화 의하여 활성탄을 제조하였으며, 제조된 활성탄은 세공 구조 및 표면적에 대한 검토를 행하였다. 활성화를 위하여 3종류의 서로 다른 형태의 로(정치식 수직, 수평로 및 회전식 수평로)가 본 실험에 사용되었다. 정치식 수직 및 수평로를 이용하여 수피를 탄화시키고 이를 수증기 활성화시키면, 1,000 ㎡／g이상의 높은 비표면적을 얻기는 어려웠다. 분말상태의 시료를 사용하면 비표면적이 약간 향상되었지만, 여전히 정치식 로의 경우 높은 비표면적의 결과를 얻기는 어려웠다. 로타리식 수평로에서 수피를 수증기 활성화시키면, 시판 1급 활성탄과 유사한 1,000 ㎡／g 이상의 비표면적을 나타내는 활성탄을 제조할 수 있었다. 로타리식 수평로에서 제조된 활성탄은 미세공에서 중세공까지 다양한 공극 분포를 나타내었다.

• 한국수소및신에너지학회논문집
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• 제17권3호
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• pp.301-308
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• 2006

The present work explores the effect of carbon-supported platinum catalyst on the HI decomposition using gas adsorption analyzer, thermogravimetry, X-ray diffractometry, scanning electron microscopy, and gas chromatography. For this purpose, three types of activated carbon (C), Pt/C-1 wt.%, and Pt/C-5 wt.% were prepared. The HI gas conversion is crucially influenced by the amount of Pt on the carbon support. The more the amount of Pt was, the higher results in the HI gas conversion. For three types of catalysts, HI conversion increased with increasing the decomposition temperature but with decreasing the space velocity. The increase of HI conversion with temperature was more pronounced in activated carbon than that in Pt/C. From EDX result, it was found that the activated carbon comprised higher amount of iodine than the Pt/C after the decomposition reaction. This implies that the HI conversion is closely related to the amount of Iodine.

• 한국수소및신에너지학회논문집
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• 제14권4호
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• pp.305-312
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• 2003

A study is presented of the adsorption capacity of a number of different activated carbons for hydrogen at 100 bar aad 298 K. The hydrogen adsorption isotherm was measured by isothermal gravimetric analysis, using a microbalance. The effect of activated carbon's porosity on hydrogen adsorption capacity is surveyed. It is concluded that hydrogen adsorption capacity of activated carbon is lineally increased according to the increase of specific surface area and total pore volume, It seems that microporosity is more contributive than mesoporosity. Most of the adsorbed quantity is due to physical adsorption and chemisorption is negligible, In this work, 0.79 wt.% of hydrogen adsorption capacity is reached.

• Bulletin of the Korean Chemical Society
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• 제20권12호
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• pp.1447-1450
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• 1999

Countercurrent oxygen reaction (COR) was developed and evaluated for regeneration of exhausted activated carbon. Whether the regeneration technique is feasible or not is affected strongly by gradual loss and physical changes of activated carbon, energy consumption, and effective removal of adsorbed materials during the process. Various parameters such as reaction temperature, the loss of activated carbon, surface area, pore volume, surface structure, adsorptive property, etc. were examined to determine the effectiveness of COR. The results of these tests showed that the parameters were strongly dependent on oxidant flow rate, and suggest that the newly developed COR is comparable and, in some ways, possibly superior to conventional regeneration techniques because the overall process runs in a single step and is less energy intensive, and also because the adsorptive capacity of exhausted activated carbon was completely recovered.

• Korean Chemical Engineering Research
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• 제45권3호
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• pp.277-285
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• 2007

실제 공정에서 사용빈도가 높은 비흡착성 화합물을 포함하고 있는 다성분계 가스상 휘발성유기화합물의 제거 및 회수의 최적설계 도출을 위하여 직경 10.2 cm ${\times}$ 높이 50 cm의 고정층 흡착탑에서 다성분계 휘발성유기화합물(toluene-xylene-MEK, toluene-MEK-IPA)의 탄소흡착제에 대한 흡착실험을 수행하였다. 탄소흡착제로는 펠렛형 입상활성탄과 활성탄소섬유를 사용하였으며, 흡착실험을 통하여 흡착파과곡선을 구할 수 있었으며 이로부터 흡착제별 흡착특성을 고찰하였다. 흡착제별 흡착성능은 활성탄소섬유, 활성탄소섬유 + 활성탄 조합흡착제, 활성탄 + 활성탄 조합흡착제, 단독 활성탄 순으로 나타났으며, 탄소흡착제에 대한 휘발성유기화합물의 흡착은 분자량이 크고 비극성인 화합물이 저분자량이면서 극성의 정도가 강한 화합물에 비하여 흡착성능이 우수하였다. 특히, 다성분계 휘발성유기화합물의 흡착에서 알콜류 및 케톤류의 화합물은 흡착성능이 우수한 방향족류 흡착질의 경쟁흡착으로부터 밀리어 저조한 흡착성능을 나타내었으나, 기공들의 크기분포가 다른 탄소흡착제의 적절한 조합으로부터 현장 적용이 가능할 정도로 비흡착성 화합물의 배출문제를 억제할 수 있었다.

• 전기학회논문지
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• 제67권11호
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• pp.1477-1485
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• 2018

There are two major issues for activated sludge process in sewage treatment plant. One is how to make sewage be more clean and the other is the energy saving in sewage treatment process. The major monitoring sewage qualities are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent. These are transmitted to the national TMS(Telemetry Monitoring System) at every hour. If these exceed the environmental standard, the environmental charges imposed. So, these water qualities are to be controlled below the environmental standard in operation of sewage treatment plant. And recently, the energy saving is also important in process operation. Over 50% energy is consumed in blowers and motors for injection oxygen into aeration tank. So, with the water qualities to be controlled below the environmental standard, the energy saving also is to be accomplished for efficient plant management. Almost researches are aimed to control water quality without considering energy saving. AI techniques have been used for control water quality. AI modeling simulator provided the optimal control inputs(blower speed, waste sludge, return sludge) for control water quality. Blower speed is the main control input for activated sludge process. To make sewage be more clean, the excessive blower speed is supplied, but water quality is not better than the previous. In results, non necessary energy is consumed. In this paper we propose a new method that the energy saving also is to be accomplished with the water qualities to be controlled below the environmental standard for efficient plant management. Water qualities in only aeration tank are used the inputs of fuzzy models. Outputs of these models are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent and have the environmental standards. In test, we found this method could save 10% energy than the previous methods.

• Korean Chemical Engineering Research
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• 제43권3호
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• pp.432-437
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• 2005

혼합가스로부터 $CO_2$를 분리, 회수하기 위하여 활성탄소섬유를 흡착제로 사용한 전기변동흡착(electric swing adsorption, ESA) 공정의 타당성을 검토하였다. 활성탄소 섬유는 상압에서도 $CO_2$에 대해 빠른 흡착 속도를 보였으며, 비교적 짧은 흡착대와 긴 파과시간, 흡착제의 단위무게당 높은 흡착량을 나타내었다. 포화흡착된 흡착탑의 재생에서 비표면적이 큰 활성탄소섬유일수록 일정한 모양의 파과곡선을 유지하여 흡착-탈착의 재생사이클에 유리하였다. 진공탈착에 의한 흡착탑의 재생률은 64 cmHg의 압력에서도 64％ 이상이었고, 전기탈착을 병행한 hybrid 재생단계에서는 17％의 추가적인 재생률을 보이며 7-8 Wh의 낮은 재생에너지에서도 높은 재생률을 보였다.

• Nuclear Engineering and Technology
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• 제28권5호
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• pp.482-487
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• 1996

The dissolved oxygen removal by H$_2$-O$_2$ reaction in column packed with various catalysts wes examined. The catalysts employed were the prepared polymeric catalyst platinum on activated carbon, and Lewatit OC-1045 which is available commercially. The column experiments with the prepared polymeric catalyst showed the dissolved oxygen reduced to 35 ppb which is below the limit in feed water of power plants. This implies the likely application of the prepared catalyst for practical use. The activated carbon required the pre-treatment for the removal of dissolved oxygen, since the surface of activated carbon contains much oxygen adsorbed initially. The Lewatit catalyst exposed the best performance, however, the aged one showed the gradual loss of catalytic activity due to degradation of resin catalyst.