진공승화법에 의한 몇가지 방향족 화합물의 분리거동 및 물질전달(Ⅲ)

崔大雄,金住奉 東亞大學校 大學院 1984 大學院論文集 Vol.9 No.-

The heating temperature, vacuum condensing point, velocity of sublimation and distance of diffusion were measured according to the change of vacuum degree of aromatic compounds by vacuum sublimation method. Their correlation and separation were experimented. Results obtained on the sublimatographic character of aromatic compounds are as follows; (1) Vacuum condensing point of aromatic compounds at different heating temperature and vacuum degree is obtained. (2) Pyrocatechol and resorcinol, pyrocatechol and hydroquinone, resorcinol and hydroquinone, pyrogallol and pyloroglucinol were easily separated from each of its mixtures. The results were in good agreement with those expected from the tn-V.C.P curves. (3) The vapor pressure, molar velocity of sublimation, mass transfer coefficient and diffusion coefficient of aromatic compound are calculated by experimental data'. Pn/Ps=r (r=1, 0.006∼1.123) Ps=KGn (K=0.154, n=0.996), KG=(2.350∼9.667)10-3

제올라이트 A, X 및 L부터 알칸들의 승온탈착(Ⅰ)

최대웅 東義大學校産業技術開發硏究所 1994 産業技術硏究誌 Vol.8 No.-

Thermal gravimetric desorption of n-hexane, n-octane, and n-decane on zeolite A, X, and L in a nitrogen stream at single heating rate was studied. The activiaton energy of desorption (??) and entropy (??) were evaluted from the method proposed by L.V.C.Rees. ?? increased with decreasing the coverage of hydrocarbon, and was dependent on the aperture of main channel, cage volume of zeolite, and the size of adsorbate molecule. Εd was considerably larger than isosteric heat obtained from adsorption isotherms, which suggests that in case of large molcecule ?? obtained by temperature programmed desorption contained contributions from the activation energy of diffusion of the desorbed molecules.

합성 제올라이트X의 이온교환 반응에 관한 연구

최대웅,문성두,김영미 東義大學校産業技術開發硏究所 1989 産業技術硏究誌 Vol.3 No.-

A study have been made of the exchange of ??, ??, and ?? ion by synthetic zeolite X. The zeolite used in this work was supplied as powder by Union Carbide Corp., and unit cell content is ?? ·264H₂O. X-ray diffractometry and infrared spectroscopy indicated the cation exchanged zeolites retained crystallinities. The number of H₂O molecules per unit cell was measured by thermal analyzer, and the extent of ion exchange was measured by the determining of the amount of cation remained in solution by atomic absorption spectrophotometer. The equilibrium constant (Ka) and the standard free energy(△G˚)were obtained at 25℃ using Kielland plots. The values of Ka and △G˚in ion exchange reaction of ?? with ??-X are 1.436 and -10410J/mol, respectively. The values of the reaction of ?? with ?? are 1.764 and -7228.3J/mol respectively.

진공승화법에 의한 몇가지 아미노산의 분리거동과 물질전달

김주봉,손진언,김상열,최대웅 한국화학공학회 1985 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.23 No.1

진공승화법에 의하여 몇가지 아미노산의 가열승화 온도와 진공도 변화에 따른 진공응축점, 승화량 및 확산거리를 실험측정하여 분리성을 조사한 결과 10^(-2)㎜Hg에서 이들 이성체 및 혼합물의 분리성이 우수하였으며 또한 t_h-V.C.P.선도 관계는 양호한 일치를 보였으며 아울러 이들 데이타로부터 계산된 증기압, 승화량 및 물질전달계수는 P_h/P_S=r(r=1.109∼1.195), P_S=kG^n(k=0.162, n=1.58), K_G=1.375∼2.159 × 10^(-3)임을 알았다. The vacuum condensing point, velocity of sublimation and distance of diffusion were measured according to the heating sublimation temperature and vacuum degree of some ℓ-amino acids by a vacuum sublimation method. Their correlation and separation were investigated experimentally. Results obtained on the sublimato-graphic character of ℓ-amino acids are as follows; (1) Vacuum condensing point of ℓ-amino acids at different heating sublimation temperature and vacuum degree are obtained. (2)The isomers and mixtures of ℓ-amino acids are sepatated completely from each other under vacuum of 10^(-2) ㎜Hg. The results are in good agreement with those expected from the t_h-V.C.P. curves. (3) The ratio of vapour pressure, molar velocity of sublimation and mass transfer coefficient of ℓ-amino acids are calculated by experimented data; P_h/P_S=r(r=1.109∼1.195), P_S=kG^n(k=0.162, n=1.58), K_G=1.375∼2.159 × 10^(-3)

실관막관에서 Lix84 에 의한 중금속 추출

박동원,이성식,최대웅,신군섭 한국공업화학회 1998 응용화학 Vol.2 No.1

Extraction by hollow fibers are fast compared with conventional extractional equipment because of the large surface area per volume, and the feeds can be contacted at high speed and two flows are completely independent, so there no problems withlaoding, flooding and channeling. In this paper, it was investigated the flow rate of aqueous and organic solution by using the hollow fiber membrane. It is known that the mass transfer is done as the flow rate of aqueous phase increase. For the system with high distribution ratio, effect of the distribution ratio on mass transfer was weak in system in the hollow fiber membrane.

제올라이트 L 중 에탄과 프로판의 흡착성질에 대한 몬테칼로 시뮬레이션

문성두,최대웅,김양,Moon, Sung Doo,Choi, Dai Ung,Kim, Yang 대한화학회 1998 대한화학회지 Vol.42 No.1

칼륨이온이 교환된 제올라이트 L중 에탄과 프로판의 흡착 성질을 그랜드 카노니칼 앙상블 몬테칼로 시뮬레이션을 이용하여 연구하였다. 퍼텐셜 계산에서 흡착분자의 $CH_3\;와\; CH_2$그룹을 하나의 유사원자로 고려하였으며, 분자 내의 결합길이와 결합각도는 시뮬레이션 과정에서 고정시켰다. 단위세포당 평균 분자수, 단위세포당 분자들의 분포, 제올라이트 중 분자의 수밀도, 흡착 분자의 평균 퍼텐셜, 그리고 등량흡착열을 계산하였고, 이들을 실험 결과와 비교하였다. 에탄의 시뮬레이션 결과는 넓은 온도 범위에서 실험값과 상당히 잘 일치하였다. 에탄과 프로판 분자의 퍼텐셜은 흡착량의 증가에 따라 천천히 감소하였다. The adsorption of ethane and propane in $K^{+}$ ion exchanged zeolite L has been studied using grand canonical ensemble Monte Carlo simulation. $CH_3$ and $CH_2$ groups of sorbate molecule were considered as pseudoatoms in calculation of potential, and the bond lengths and bond angles within a molecule were fixed during 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. For ethane the simulation results agreed considerably well with experimental ones over a wide range of temperature. The average potential of sorbate molecule decreased slowly with the increase of amounts sorbed in zeolite.

칼륨 이온 치환 제올라이트-L 에서 물, 암모니아 및 메틸아민류의 탈착

문성두,최대웅,김은식,김양,Sung-Doo Moon,Dai-Ung Choi,Un-Sik Kim,Yang Kim 대한화학회 1988 대한화학회지 Vol.32 No.3

$K^+$이온 치환 제올라이트-L(K-L)의 main channel에 있는 흡착 분자의 퍼텐셜 에너지를 계산하였다. 단위 세포에 3분자가 흡착된 K-L에서 제올라이트 격자와 $H_2O,\;NH_3,\;CH_3NH_2,\;(CH_3)_2NH$ 및 $(CH_3)_3NR 분자와의 상호작용 에너지는 각각 61.11, 62.31, 65.68, 74.65, 79.88 kJ/mol이다. 이들 값은 $K^+$이온과의 친화력보다 $3.7{\sim}12.6kJ/mol$이 작다. 이들 결과는 골조 산소의 음전하에 의해서 정전기적 에너지가 감소되기 때문일 것이다. K-L에 관해서 $NH_3$와 $CH_3NH_2$의 흡착자리 분포를 승온탈착법에 의하여 연구하였다. K-L에서 NH3와 CH3NH2의 실험적 탈착에너지는 이론적 값과 잘 일치하였다. $NH_3$와 $CH_3NH_2$의 탈착은 재흡착이 일어나는 1차 탈착반응이다. The potential energy of adsorbate molecules in the main channel of $K^+$ ion exchanged zeolite L(K-L) was calculated. In K-L which adsorbs three molecules per unit cell, the interaction energies of $H_2O,\;NH_3,\;CH_3NH_2,\;(CH_3)_2NH,\;and\;(CH_3)_3N$ molecules with zeolite lattice are 61.11, 62.31, 65.68, 74.65, and 79.88kJ/mol, respectively. These values are less by 3.7∼12.6kJ/mol than $K^+$ ion affinities with adsorbing molecules. These results may be due to the facts that the electrostatic energies are reduced by the negative charge of the lattice oxygens. The distribution of adsorption sites of $NH_3$ and $CH_3NH_2$ in K-L was investigated by a technique of temperature programmed desorption. The experimental value of desorption energies of $NH_3$ and $CH_3NH_2$ on K-L are in good agreement with the theoritical values. It is concluded that the desorption of $NH_3$ and $CH_3NH_2$ on K-L is the first-order desorption with free readsorption.

제올라이트 X에서 알칼리토류 금속이온의 교환

문성두,김영미,최대웅 東義大學校産業技術開發硏究所 1990 産業技術硏究誌 Vol.4 No.-

A study have been made of the exchange of alkaline earth metal ions by synthetic zeolite-x at room temperature. The extent of ion exchange was measured by the determining of the amount of divalent ion remained in solution by atomic absorption spectrophotometer. From the ion exchange isotherm and standard Gibbs free energy of ion exchange, the ion exchange selectivity was in the order ?? for alkaline earth metal ion. The maximum extent of ion exchange of zeolite-x increases with decrease in the cation size. When zealite-x was heated from 30℃ to 90℃ the ion exchange properties were increased.

미세공 실관막을 이용한 카드뮴이온의 투과추출

박승현,최대웅 ( Seung Hyun Park,Dai Ung Choi ) 한국공업화학회 1997 응용화학 Vol.1 No.1

Extraction by hollow fibers are fast compared with conventional extractional equipment because of the large surface area per volume, and the feeds can be contacted at high speed and two flows are completely independent, so there no problems with laoding, flooding and channeling. In this paper, it was investigated the flow rate of aqueous and organic solution by using the hollow fiber membrane. It is known that the mass transfer is done as the flow rate of aqueous phase increase. For the system with high distribution ratio, effect of the distribution ratio on mass transfer was weak in system in the hollow fiber membrane.

킬레이트수지 흡착에 의한 구리프탈로시아닌 염료수용액중 구리의 제거

이성식(Sung Sik Lee),유명호(Myung Ho Yu),최금찬(Kum Chan Choi),최대웅(Dai Ung Choi) 大韓環境工學會 1997 대한환경공학회지 Vol.19 No.12