정상상태하에서 다공성 필터 내의 유체 흐름에 대한 전산모사

서양곤,최주홍,정진도 ( Yang Gon Seo,Joo Hong Choi,Jin Do Chung ) 한국화학공학회 1995 화학공학의이론과응용 Vol.1 No.2

수산화인회석에 의한 수용액으로부터 중금속 이온의 제거에 관한 연구

서양곤,이동근 한국화학공학회 1995 화학공업과 기술 Vol.13 No.4

수산화인회석에 의한 수용액으로부터 중금속 이온의 제거에 관한 연구

서양곤,이동근 ( Yang Gon Seo,Dong Keun Lee ) 한국화학공학회 1995 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.33 No.3

Removal of divalent heavy metal ions, i.e., Pb^(2+), Cu^(2+), Zn^(2+) and Cd^(2+), respectively, from their chloride or nitrate aqueous solutions was studied by the addition of hydroxyapatite in a batch system. The isotherms for heavy metal ions were of the rectangular type so that the amounts removed from aqueous phase were constant irrespective of the concentration of solutions. The selectivity for the cations on hydroxyapatite can be explained in terms of the ionic radii and the its electronegativities. Kinetic experiments were carried out in an agitated tank adsorber. Effective diffusivities of cupric chloride, zinc chloride and cadmium chloride inside hydroxyapatite were 2.88×10^(-10)㎡/s , 2.77×10^(-10) ㎡/s 그리고 2.95×10^(-10)㎡/s, respectively. Pb^(2+) was also exchanged very quickly with Ca^(2+) and easily removed by hydoxyapatite.

무작위 에칭 흑연 기공을 가지는 탄소기반 흡착제에 의한산소, 질소 및 아르곤의 흡착 계산

서양곤 한국청정기술학회 2018 청정기술 Vol.24 No.4

The adsorption equilibria of oxygen, nitrogen and argon on carbonaceous adsorbent with slit-shaped and randomly etched graphite (REG) pores were calculated by molecular simulation method. Reliable models of adsorbents and adsorbates for adsorption equilibria are important for the correct design of industrial adsorptive separation processes. At the smallest physical pore of 5.6 Å, only oxygen molecules were accommodated at the center of the slit-shaped pore, and from 5.9 Å nitrogen and argon molecules could be accommodated in the pores. Slit pores showed higher adsorption capacity compared with REG pores with same averaged reenterance pore size due to dead volume and inaccessible volume in defected pores. And it was shown the adsorption capacities of oxygen and argon was same in larger pore size. From calculated adsorption isotherms at 298 K it showed that the adsorption capacity ratio of oxygen to nitrogen is increased as pressure is increased. 분자전산 모사 방법에 의하여 슬릿 기공과 무작위 에칭 흑연(randomly etched graphite, REG) 기공을 가지는 탄소계 흡착제에서 산소, 질소 그리고 아르곤에 대한 흡착 평형을 계산 하였다. 흡착량 계산에서 흡착제와 흡착질의 신뢰할 만한 모델은공업적 흡착 분리 공정의 정확한 설계에 매우 중요하다. 5.6 Å의 가장 작은 물리적 기공 크기에서 오직 산소만이 기공의 중심에 흡착하였으며, 5.9 Å부터 질소와 아르곤이 흡착을 시작하였다. 균일한 표면을 가지는 슬릿기공이 결함 기공의 불용 부피와 접근이 불가능한 부피로 인하여 표면에 이질성을 가지는 REG 기공보다 더 높은 흡착 능력을 보였다. 탄소계 흡착제의경우 질소보다 산소가 높은 흡착량을 보였으며, 기공이 큰 경우 산소와 아르곤의 흡착량은 동일함을 보였다. 298 K에서 흡착 등온선 계산으로부터 압력이 증가할수록 질소에 대한 산소의 흡착량의 비율이 높아짐을 보였다.

국부분자배향의 탄소 미세기공 구조에 대한 질소의 흡착 특성

서양곤,Seo, Yang Gon 한국청정기술학회 2022 청정기술 Vol.28 No.3

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.

저온에서 규칙적인 단일벽 탄소나노튜브 배열의 수소 흡착 특성

서양곤 한국청정기술학회 2023 청정기술 Vol.29 No.3

본 연구에서는 grand canonical 몬테카를로 전산모사 방법을 이용하여 정사각형 배열을 가지는 단일벽나노튜브에서 나노튜브의 직경과 가장 가까운 튜브들 사이의 거리의 함수로써 수소의 흡착특성을 연구하였다. 그리고 동일한 직경과 간격을 가지는 삼각형 배열을 이용하여 기하학에 대한 영향도 연구하였다. 수소-탄소 그리고 수소-수소의 인력은 단거리 인력의 경우Lennard-Jones 포텐셜을 사용하였고, 수소-수소의 경우는 정전기적 인력을 저온에서의 양자효과를 고려하기 위해 추가하였다. 194.5 K에서 큰 직경을 가지는 단일벽나노튜브의 경우 Typ e I과 넓은 간격을 가지는 나노튜브의 경우 흡착과 탈착과정에서 Typ e IV의 흡착 등온선이 관찰되었다. 200 bar에서 단일벽나노튜브의 중량 수소저장 능력은 미국 에너지부의 목표치에 도달하거나 초과하였다. 그러나 부피 수소저장 능력은 목표치의 약 70%에 해당하였다. 77 K에서는 단일층 형성과 이후 응축 단계가 따르는 두 단계의 흡착이 관찰되었다. 수소는 나노튜브의 내부 표면, 외부 표면, 관 내부의 공간 그리고 나노튜브 다발 사이의 틈새 채널의 순서로 흡착하였다. 1 bar 이하에서도 여러 가지 직경과 간격을 가지는 탄소나노튜브는 중량 그리고 부피 저장 능력이 모두 목표치를 초과하였다. The amount of hydrogen adsorbed in arrays of single walled carbon nanotubes (SWNTs) was studied as a function of nanotube diameter and distance between the nearest-neighbor nanotubes on square arrangements using a grand canonical Monte Carlo simulation. The influence of the geometry of a triangle array with the same diameters and distances was also studied. Hydrogen-carbon and hydrogen-hydrogen interactions were modeled with Lennard-Jones potentials for short range interactions and electrostatic interactions were added for hydrogen-hydrogen pairs to consider quantum contributions at low temperatures. At 194.5 K, Type I isotherms for large-diameter SWNTs and Type IV isotherms without hysteresis between adsorption and desorption processes for wider tube separations were observed. At 200 bars, the gravimetric hydrogen storage capacity of the SWNTs was reached or exceeded the US Department of Energy (DOE) target, but the volumetric capacity was about 70% of the DOE target. At 77 K, a two-step adsorption was observed, corresponding to a monolayer formation step followed by a condensation step. Hydrogen was adsorbed first to the inner surface of the nanotubes, then to the outer surface, intratubular space and the interstitial channels between the nanotube bundles. The simulation indicated that SWNTs of various diameters and distances in a wide range of configurations exceeded the DOE gravimetric and volumetric targets at under 1 bar.

유연한 구조체를 가지는 제올라이트에서 메탄과 이산화탄소의 흡착 특성

서양곤 한국청정기술학회 2024 청정기술 Vol.30 No.3

제올라이트는 기체 혼합물로부터 흡착을 기반으로 하는 이산화탄소 분리에 흡착제로써 사용할 수 있는 미세기공 재료 중 하나이다. 본 연구에서는 LTA-4A, FAU-13X 그리고 FAU-NaY에 대해 273, 298 그리고 323 K에서 30 bar까지 몬테 카를로 방법을 이용하여 메탄과 이산화탄소의 순수한 기체의 흡착 등온선과 혼합물의 선택도를 계산하였다. 또한 제올 라이트에서 메탄과 이산화탄소의 분리에 구조체의 유연성에 대한 연구를 수행하였다. 본 연구에서 사용한 제올라이트 에는 메탄보다 이산화탄소가 유리하게 흡착하였다. FAU-13X가 가장 높은 흡착 능력을 나타내었다. 그러나 메탄에 대한 이산화탄소의 선택도는 LTA-4A가 보다 높았다. 견고한 구조체가 유연한 구조체 보다 흡착능력이 높았다. 구조체 유연성 의 영향은 FA U 제올라이트는 적었으나 선택도에 대한 영향은 큰 것으로 나타났다. Carbon dioxide is an undesired component of biogas and landfill gas. As a result, it needs to be removed from these mixtures in order to increase their heating value and reduce corrosion during treatment. Zeolites are a class of microporous materials that can be used as adsorbents for the separation of carbon dioxide from gas mixtures. In this work, the pure gas adsorption isotherms of methane and carbon dioxide and the selectivity of their mixture onto LTA-4A, FAU-13X and FAU-NaY adsorbents at temperatures of 273, 298 and 323 K and pressures up to 30 bars were calculated by the Monte Carlo method. Also, the influence of a flexible framework in a set of zeolites on the separation of methane and carbon dioxide was studied. Carbon dioxide adsorption onto the zeolites used in this work was more favorable than methane adsorption. The FAU-13X adsorbent had the highest adsorption capacity among the studied adsorbents. However, the selectivity of carbon dioxide over methane for LTA-4A was the highest. The adsorption capacities of a rigid framework were higher than those of a flexible framework. The influence of the framework flexibility in FAU on adsorption capacity was small. In contrast, its influence on selectivity seemed to be much larger.

행사보고 : 2011년 봄 총회 및 학술대회를 마치며

서양곤 한국화학공학회 2011 NICE Vol.29 No.3

비이온성 수지를 이용한 음이온 계면활성제의 흡착에 관한 연구

서양곤,안주현,허병용 한국환경과학회 1996 한국환경과학회지 Vol.5 No.3

The adsorption of the anionic surfactants, sodium lauryl sulfate (SLS) and sodium dodecylbenzene sulfonate (SDBS) anion surfactants from aqueous solutions with nonionic resins, Amberlite XAD-2, XAD-4 and XAD-7 at temperatures in 15∼45℃ range was studied. Several adsorption isotherm models were used to fit the experimental data. The best results were obtained with the Redlich-Peterson equation and the Freundlich model provided remarkably good fits. For a particular resin at a particular temperature, SDBS was more extensively adsorbed than SLS. The highest adsorption were obtained with XAD-4 resin and the specific surface area of the resins plays a major role in adsorption of the surfactants. Estimations of the isosteric heat of adsorption were indicative of an exothermic process, and their magnitudes manifested a physisorption process.

폐수 중 유해 유기물의 화학적 산화

서양곤,허병용 경상대학교 환경보전연구소 1995 環境保全硏究所報 Vol.3 No.1

In the last 20 years or so has been as increasing concern about the contamination of drinking water supplies with organic compounds used as solvents in industry. The widely adopted chlorination of potable water has also been shown to have led to the formation of halogenated organic compounds. The removal of low levels of organics is an important problem in drinking-water and wastewater treatment. In this paper, ultraviolet(UV) light irradiation is combined with hydrogen peroxide(H₂O₂) or ozone(O₃) and ferrous ion-hydrogen peroxide system (Fenton's reagent) are reviewed. The processes exhibit a synergistic effect leading to the formation of reactive hydroxyl radicals which can bring about more complete oxidation as well as react with a wider range of organics. New designs that combine hydroxyl radical generation system with ozone, hydrogen peroxide, and UV may emerge as the best commercial prospects for advanced oxidation processes in water and wastewater treatment.