• 대한기계학회논문집B
• /
• 제37권11호
• /
• pp.977-984
• /
• 2013

흡착식 제습기에 적용되는 제습 로터는 높은 제습 성능을 달성키 위해, 흡수율이 높은 재질로 구성된 수많은 미세 채널을 포함하고 있다. 본 연구에서는 습공기 흐름에 의해 나타나는 제습 로터 내부의 반복적인 흡착/탈착 과정에 대한 수치해석 결과를 소개한다. 수치해석의 정확도와 효율성을 고려하여 흡습층 내부에서는 표면 확산(surface diffusion)만을 고려하여 해석을 수행하였다. 해석결과는 이전의 연구와 비교하였고, 온도에 대한 비교 오차는 약 2%이하인 점을 감안하여 해석결과가 매우 잘 일치하는 것을 확인하였다. 단일 채널 내부에서 유동층 (flow layer)과 흡습층 (desiccant layer) 간 열/물질전달 연계 해석을 통하여 채널 내부의 수증기 분율, 흡수된 물 분율과 온도 등에 대한 시간 및 공간적 변화를 나타내었다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.77-80
• /
• 2007

To increase the capacity of hydrogen adsorption, transition metals were adopted as catalyst. The PAN-based CNFs involving transition metal were obtained by electrospinning method and heat treatment. To study the surface of carbon fibers, SEM analysis was conducted. The mass of transition metals were spreaded or covered among CNFs. XRD and EDX analysis were used to confirm transition metals on the surface of carbon fibers. Volumetric method was used for studying the capacity of hydrogen adsorption on the carbon fibers involving transition metals. In this study. vanadium has the best characteristics among chromium, titanium, and copper for hydrogen adsorption.

• Preventive Nutrition and Food Science
• /
• 제12권2호
• /
• pp.111-114
• /
• 2007

Water vapor adsorption kinetics of Inonotus mushroom powders were investigated in temperature and water activity ranges of 20 to 40$^{\circ}C$ and 0.30 to 0.81, respectively. Initial water vapor adsorption rate of mushroom powders increased with increases in temperature and water activity. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Water vapor adsorption kinetics of the mushroom powders can be well described by a simple empirical model. Temperature dependency of the reaction rate constant followed the Arrhenius relationship. The activation energy ranged from 56.86 to 91.35 kJ/mol depending on water activity. Kinetic compensation relationship was observed between k$_o$ and E$_a$ with the isokinetic temperature of 790.27 K.

• 한국산업융합학회 논문집
• /
• 제8권1호
• /
• pp.37-45
• /
• 2005

Adsorption equilibrium data of pure solvent vapors (n-Hexane, Toluene, MEK) as well as their binary mixtures on activated carbon (sorbonorit $B_4$) were experimentally determined in the range of 293.2~323.2 K and beyond saturated vapor pressure corresponding to experimental temperature. Langmuir, Freundlich, LRC, W-VSM, FH-VSM were estimated for the predication of single component as well as binary mixtuer systems. The isosteric heat of adsorption at infinite dilution of pure n-hexane, toluene, MEK on activated carbon were 45.18, 25.85, 34.62 Kcal/mol, respectively, also, n-hexane-toluene binary adsorption of activated carbon formed an azeotrope at 293.2 K and total pressure 5.1~10.3 mmHg.

• Membrane and Water Treatment
• /
• 제15권3호
• /
• pp.107-115
• /
• 2024

This study proposes the recycling of MVS as a value-added product for the removal of phosphate from aqueous solutions. By comparing the phosphate adsorption capacity of each calcined adsorbent at each temperature of MVS, it was determined that the optimal heat treatment temperature of MVS to improve the phosphate adsorption capacity was 800 ℃. MVS-800 suggests an adsorption mechanism through calcium phosphate precipitation. Subsequent kinetic studies with MVS-800 showed that the PFO model was more appropriate than the PSO model. In the equilibrium adsorption experiment, through the analysis of Langmuir and Freundlich models, Langmuir can provide a more appropriate explanation for the phosphate adsorption of MVS-800. This means that the adsorption of phosphate by MVS-800 is uniform over all surfaces and the adsorption consists of a single layer. Thermodynamic analysis of thermally activated MVS-800 shows that phosphate adsorption is an endothermic and involuntary reaction. MVS-800 has the highest phosphate adsorption capacity under low pH conditions. The presence of anions in phosphate adsorption reduces the phosphate adsorption capacity of MVS-800 in the order of CO 3 2-, SO 4 2-, NO 3- and Cl-. Based on experimental data to date, MVS-800 is an environmentally friendly adsorbent for recycling waste resources and is considered to be an adsorbent with high adsorption capacity for removing phosphates from aqueous solutions. This paper combines the advantages of gray predictor and AI fuzzy. The gray predictor can be used to predict whether the bear point exceeds the allowable deviation range, and then perform appropriate control corrections to accelerate the bear point to return to the boundary layer and achieve.

• 한국토양환경학회지
• /
• 제2권2호
• /
• pp.61-72
• /
• 1997

본 연구에서는 산과 계곡에 폐기물로 방치되어 있는 석탄폐석의 재활용 및 자원화의 측면에서 수처리에 이용될 수 있는 흡착제의 개발을 위한 기초실험이 수행되었다. 석탄폐석으로는 굴진폐석과 선탄폐석이 이용되었으며, 석탄폐석 자체가 지니고 있는 흡착능 실험과 열처리로 인한 흡착능 개선 여부를 검토하였다. 처리 대상물질은 중금속, 색도, 그리고 COD등을 선정하였다. 실험조건은 회분식과 컬럼식으로 구분하여 각각 이루어졌으며, 실험결과 다음과 같은 결론을 얻을 수 있었다. 1) 천연상태의 석탄폐석은 약 20~30%의 중금속 흡착능을 지니고 있는 것으로 나타났으며, 탄화 공정인 간단한 열처리만으로도 약 2~5배의 흡착능 향상이 이루어졌다. 2)석탄폐석의 열처리 조건 변화에 따른 중금속 흡착능을 비교한 결과, 50$0^{\circ}C$에서 6시간 반응시킨 것이 가장 우수하였다. 3)칼럼실험에 있어 기존의 입상활성탄 보다 처리효율이 저조하나 석탄폐석은 무가공 상태로도 약 20~60%의 COD 및 색도를 제거할 수 있었다. 4) $500^{\circ}C$, 에서 6시간 열처리된 폐석의 컬럼실험에서 생물학적 유출수의 색도 제거에 우수함을 알 수 있었으며, 중금속 및 COD제거에 있어서는 여과 속도에 따라 많은 차이를 보였다. 따라서 석탄폐석을 흡착제로의 활용이 가능할 것으로 판단되며, 본 연구 이외에 활성화 공정을 적용할 경우 흡착정도는 더 향상 될 것으로 판단된다.

• 한국대기환경학회지
• /
• 제26권3호
• /
• pp.286-297
• /
• 2010

This study deals with the effect of pretreatment on the $CO_2$ adsorption capacity of zeolitic adsorbents including a commercial A-type zeolite and cation exchanged adsorbents. The pre-heating could change the intrinsic properties such as specific surface area and adsorption capacity of the adsorbent. As a result of the experiment, the moisture previously filled inside might affect the potential adsorption capacity of the adsorbent, and could be disappeared throughout the heat treatment. An optimum pretreatment temperature for the test adsorbent was found to be $400^{\circ}C$, at which temperature enabled more than 90% refreshment. Precise examination through the TPD test showed that the TSA (Temperature Swing Adsorption) process would be desirable in dry adsorption of $CO_2$.

• 한국식품저장유통학회지
• /
• 제24권4호
• /
• pp.505-509
• /
• 2017

Water vapor adsorption kinetics of vacuum-dried jujube powder were investigated in temperature and relative humidity ranges of 10 to $40^{\circ}C$ and 32 to 75%, respectively. Water vapor was initially adsorbed rapidly and then reached equilibrium condition slowly. Reaction rate constant for water vapor adsorption of vacuum-dried jujube powder increased with an increase in temperature. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Good straight lines were obtained with plotting of $1/(m-m_0)$ vs. 1/t. It was found that water vapor adsorption kinetics of vacuum-dried jujube powder was accurately described by a simple empirical model, and temperature dependency of the reaction rate constant followed the Arrhenius-type equation. The activation energy ranged from 50.90 to 56.00 kJ/mol depending on relative humidity. Arrhenius kinetic parameters ($E_a$ and $k_0$) for water vapor adsorption by vacuum-dried jujube powder showed an effect between the parameters with the isokinetic temperature of 302.51 K. The information on water vapor adsorption kinetics of vacuum-dried jujube powder can be used to establish the optimum condition for storage and processing of jujube.

• 한국연초학회지
• /
• 제18권2호
• /
• pp.150-159
• /
• 1996

In this study, to obtain the basic data for the optimum moisture control system, moisture adsorption characteristics, adsorption isotherms models for water and surface physical characteristics of burley and flue-cured tobacco were investigated. By the hypothesis' the phenomenon of moisture adsorption of tobacco is the same as the first order reaction, the wetting constant (k) and equilibrium moisture content were obtained. And activation energy, frequency factors were also calculated by applying its data to Arrhenius equation. The Kamei's empirical formula of moisture adsorption isotherms showed the best agreement with the experimental data and its correlation coefficient (r) was 0.997. It can be seen that specific surface area of burley is 157 m2/g, that of flue-cured is 152 m2/g, -△H1 of adsorbed monolayer is 45,972 J/mol, 45,486 J/mol, respectively, and the condensation heat (40,595 J/mol) being caught in adsorbed multilayer is less than that of monolayer.

• 청정기술
• /
• 제9권4호
• /
• pp.153-161
• /
• 2003

벤젠과 톨루엔을 활성탄에 흡착하는 공정을 개발하기 위한 기초 실험을 수행하였다. 정적흡착실험은 온도와 압력의 변화에 따른 벤젠과 톨루엔의 흡착특성을 연구하였다. 흡착제로는 활성탄 12~20mesh와 20~40mesh를 사용하였으며 흡착질로는 벤젠, 톨루엔, 질소를 사용하였다. 실험결과는 Langmuir isotherm으로 fittimg하였고, 온도의존성을 계산하였고, 흡착열과 흡착상수를 얻었다. 이성분 정적흡착실험에서는 Langmuir isotherm parameter들이 Extended Langmuir isotherm에 일반적으로 적용할 수 있는 지를 확인하였다. 이때 사용한 실험기법은 기존의 방법에서처럼 흡착 전후의 기상의 몰분율을 측정하여 실험하는 방법이 아닌 압력변화반을 측정하는 정용적법에 기초한 방법을 사용하였다. 동적흡착실험올 수행하여 실험결과를 전사모사로부터 얻어진 결과와 비교하였다. 본 연구에서는 공정에서 흡착조건을 결정할 수 있는 기본 데이터를 획득할 수 있었다.