• Environmental Engineering Research
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• 제22권2호
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• pp.169-174
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• 2017

Vacuum swing adsorption (VSA) is a promising treatment method for volatile organic compounds (VOCs). This study focuses on a VSA process for regenerating activated carbon spent with VOCs, and then investigates its adsorption capacities. Toluene was selected as the test VOC molecule, and the VSA regeneration experiments results were compared to the thermal swing adsorption process. Cyclic adsorption-desorption experiments were performed using a lab-scale apparatus with commercial activated carbon (Samchully Co.). The VSA regeneration was performed in air (0.5 L/min) at 363.15 K and 13,332 Pa. The comparative results depicted that in terms of VSA regeneration, it was found that after the fifth regeneration, about a 90% regeneration ratio was maintained. These experiments thus confirm that the VSA regeneration process has good recovery while operating at low temperatures (363.15 K) and 13,332 Pa.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.218-222
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• 1998

Removal of Cd(Ⅱ), Zn(Ⅱ) and Cu(Ⅱ) from aqueous solutions using the adsorption process on magadiite has been investigated. It was found that the removal percentage of metal cations at equilibrium increases with increasing temperature, and follows the order of Cd(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ). Equilibrium modeling of adsorption showed that the adsorptions of Cd(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) were fitted to Langmuir isotherm. Kinetic modeling of the adsorption showed that first order reversible kinetic model fitted to experimental data. From kinetic model and equilibrium data, the overall rate constant (k) and the equilibrium constant (K) for the adsorption process were calculated. The overall rates of adsorption of metal ions follow the order of Cd(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ). From the results of thermodynamic analysis, standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°) of adsorption process were calculated.

• Carbon letters
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• 제12권3호
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• pp.152-161
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• 2011

Activated carbon was prepared from pre-carbonized petroleum coke. Textural properties were determined from studies of the adsorption of nitrogen at 77 K and the surface chemistry was obtained using the Fourier-transform infrared spectrometer technique and the Boehm titration process. The adsorption of three aromatic compounds, namely phenol (P), p-nitrophenol (PNP) and benzoic acid (BA) onto APC in aqueous solution was studied in a batch system with respect to contact time, pH, initial concentration of solutes and temperature. Active carbon APC obtained was found to possess a high surface area and a predominantly microporous structure; it also had an acidic surface character. The experimental data fitted the pseudo-second-order kinetic model well; also, the intraparticle diffusion was the only controlling process in determining the adsorption of the three pollutants investigated. The adsorption data fit well with the Langmuir and Freundlich models. The uptake of the three pollutants was found to be strongly dependent on the pH value and the temperature of the solution. Most of the experiments were conducted at pH 7; the $pH_{(PZC)}$ of the active carbon under study was 5.0; the surface of the active carbon was negatively charged. The thermodynamic parameters evaluated for APC revealed that the adsorption of P was spontaneous and exothermic in nature, while PNP and BA showed no-spontaneity of the adsorption process and that process was endothermic in nature.

• Elastomers and Composites
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• 제50권1호
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• pp.55-61
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• 2015

Manufacturing process of OLED contains adsorption-desorption process of glass substrate. There are several adsorption methods of glass substrate such as atmospheric pressure, vacuum and electrostatic adsorption. However, these methods are very complex to connect system. Therefore, the adsorption method using silicone rubber based sticking chuck was proposed in this study. Three types of silicone rubbers having 0, 19.3 and 32.2 wt% of fluorine were used and their mechanical properties, surface energies and adsorption properties were examined. According to the results ${\sigma}_{300}$ and hardness increased with increasing fluorine contents, but elongation was decreased. Also, fluorosilicone rubber containing 32.2 wt% of fluorine showed the lowest surface tension, among three types of rubber and resulted in the highest initial tack with glass substrate. After the adsorption-desorption test of 300,000 cycles was performed, the adsorption force of S-1 (silicone rubber) decreased largely from 2.34 to 0.73 MPa. However, the S-3 (fluorosilicone rubber having 32.2 wt%. of fluorine) decreased only from 3.15 to 2.24 MPa. From this study, we obtained the valuable equations related to long term durability of silicone based sticking chuck. Finally the transfer of silicone rubber to glass substrate with the adsorption-desorption process was not occurred and this phenomenon was examined by UV-Visible spectroscopy.

• 폴리머
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• 제26권4호
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• pp.516-522
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• 2002

4급 암모늄기를 관능기로 갖는 아민화 아크릴계 이온교환섬유를 이용하여 연속식 흡착공정 중 linear alkylbenzene sulfonate(LAS)의 흡착특성을 확인하였다. 아민화 아크릴계 이온교환섬유의 LAS흡착성능은 온도가 증가함에 따라 증가하였으며 $40^{\circ}C$에서 최적 흡착성능을 나타내었다. 또한 컬럼 베드 충진비(L/D)의 변화에 따른 LAS 이온의 흡착능은 L/D>2에서 최대 흡착능을 나타내었다. pH 변화에 따른 LAS이온 흡착능은 pH가 증가함에 따라 증가하는 경향을 나타내었고, pH 7에서 최대 흡착능을 나타내었다. 유속변화에 따른 LAS 흡착능은 유속이 증가할수록 낮아졌으며 농도가 높을수록 떨어졌다.

• Korean Chemical Engineering Research
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• 제46권6호
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• pp.1087-1094
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• 2008

본 연구는 활성탄을 사용한 n-hexane의 흡착공정에 있어서 분자수준에서 시작하여 공정단계에 이르는 다중규모 모사에 관하여 기술한다. 분자모사에서는 GCMC(Grand Canonical Monte Carlo) 방법을 이용하여 활성탄에서 n-hexane의 등온흡착식을 예측하고, 2차원 전산유체역학(CFD; Computational fluid dynamics) 모사를 통하여 흡착컬럼 내 유체흐름에 대한 수력학적 특성을 파악한다. 공정모사단계에서는 분자모사 및 유체역학 모사에서 각각 얻은 등온흡착식과 축방향 확산계수값을 이용하여 n-hexane의 용출곡선을 얻는다. 이러한 3단계 다중규모 모사기법을 활용하여 얻은 공정모사 결과는 펄스응답의 실험결과와 비교해볼 때, 온도와 유량변화에 따른 1차 모멘트(평균 체류시간)에 관하여 약 20% 미만의 오차범위에서 일치함을 확인할 수 있다. 이 결과로부터 분자수준에서 시작하는 다중규모 모사는 필요한 실험횟수를 줄이면서 흡착공정 개발을 가속화할 수 있는 가능성을 보여준다.

• 상하수도학회지
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• 제11권4호
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• pp.110-117
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• 1997

Performances of combined adsorption and coagulation were evaluated as one of the options for pre-treatment or post-treatment of MSW landfills leachate and industrial landfill leachate. The COD and color removals of leachate from an old MSW landfill were 35% and 33% at an alum dose of 300mg/L with preceding PAC(powdered activated carbon) dose of 200mg/L, respectively. The COD and color removals of leachate from an young MSW landfill were 58% and 25% at an alum dose of 700mg/L and PAC dose of 500mg/L, respectively. The COD and color of biologically treated leachate from an industrial waste landfill were removed up to 32% and 68%, respectively, with pH control at addition of 500mgAlum/L and 1,000mgPAC/L. Adsorption and coagulation process with pH control showed better COD and color removals than the process without pH control for biologically treated leachate from an industrial waste landfill. The color removal was influenced greatly by pH control, while COD removal was not significant. No difference in removal efficiency was observed between adsorption-coagulation and coagulation-adsorption process. The COD removal was accomplished mainly by adsorption, while coagulation was a key mechanism of color removal. However, the mechanism of COD removal was obscure, when BOD/COD ratio was high. Maximum net increases in COD and color removals by the adsorption-coagulation process were respectively 45% and 46% compared with the unit process of adsorption or coagulation, although those removals depended on leachate characteristics. Thus, adsorption-coagulation process was considered to be effective for pre- and post-treatment of landfill leachate, and has distinct features of simple, flexible, stable and reliable operation against fluctuation leachate quality and flowrate.

• 공업화학
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• 제22권2호
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• pp.224-229
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• 2011

입상활성탄에 대한 erythrosine의 흡착특성을 초기농도, 접촉시간 및 흡착온도를 변수로 하여 회분식실험을 통하여 조사하였다. Erythrosine에 대한 흡착동력학적 연구는 298 K에서 초기농도가 100, 250, 500 mg/L인 에리스로신 수용액에 대해 수행하였다. 흡착공정은 유사이차속도식에 잘 맞았으며 유사이차속도상수(k2)는 에리스로신의 초기농도가 높을수록 감소하였다. 에리스로신의 평형흡착관계는 298~318 K의 온도범위에서 Freundlich 등온식이 잘 적용되었다. 흡착자유에너지변화(${\Delta}G^o$), 엔탈피변화(${\Delta}H^o$), 엔트로피변화(${\Delta}S^o$)를 계산하여 본 결과, 표준자유에너지 변화량이 -3.72~-9.62 kJ/mol로 자발적인 공정임을 알았다. 엔탈피변화량이 양의 값을 나타내어 활성탄에 대한 에리스로신 염료의 흡착이 흡열반응임을 알 수 있었다.

• 한국정보통신학회논문지
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• 제17권7호
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• pp.1709-1714
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• 2013

생물 및 화학공정의 정제과정은 여러 단계의 크로마토그래프 분리공정을 포함할 수 있다. 최근 생명공학의 발전과 더불어 중요시되는 단백질과 같은 생물 분자의 분리를 위하여 크로마토그래피 흡착공정에 많은 관심이 집중되고 있다. 따라서 본 논문에서는 흡착공정 모델링을 위한 시뮬레이션 시스템을 설계 및 구현하였다. 본 시스템은 흡착공정 모델링에 따른 시뮬레이션 결과 값을 시각화하거나 곡선 그래프로 나타나도록 하였다. 본 시스템의 개발은 회분식 흡착공정 모사프로그램에 중점을 두어 국한되어 개발하였다.

• 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.