CXTFIT기법을 이용한 오염토양의 중금속 이동특성에 관한 연구

오광중,김효진,박창웅,오방일 부산대학교 환경문제연구소 2002 環境硏究報 Vol.20 No.-

The sorption and transport characteristics of Cd and Pb is founded by changing of soil concentration and velocity of injected Cd and Pb solution. The results of batch-type experiment indicated that sorption capacity of Pb was stronger than sorption capacity of Cd. Batch-type experiment indicated that the results of Cd and Pb adsorption experiment fitted in the Freundlich isotherm equation well and were highly nonlinear. Results from column experiment showed the retention of the transport of heavy metals at low concentration, low velocity and high pH in soil of different characteristics. The BTCs of the heavy metals were analysed by using a two-site model, and transport parameters were derived by using the CXTFIT curve-fitting program. The model results indicated that the partitoning coefficient(β), forward rate coefficient(Ks) and backward rate coefficient(kd) were in proportion to the concentration, velocity and pH.

Simultaneous absorption of carbon dioxide, sulfur dioxide, and nitrogen dioxide into aqueous 1, 8_diamino-p-menthane

오광중,박상욱,민병무,김성수 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.8

3 Gaseous mixtures of CO_2, SO_2, and NO_2 were simultaneously absorbed into 1, 8-diamino-p-menthane (DAM) in a stirred, semi-batch tank with a planar, gas-liquid interface within a range of 0-2.0 kmol/m3 of DAM, 0.05-0.3 atm of CO_2, 0.0025-0.04 atm of SO_2, and 298.15-323.15 K at a fixed NO_2 of 0.001 atm to measure their total molar fluxes. Diffusivity and Henry constants of CO_2, SO_2, and NO_2 were obtained using the reference data, measured by N_2O analogy. The mass transfer coefficient of each gas, needed to obtain the absorption rate without a chemical reaction,was modified with viscosity of aqueous DAM solution. In CO_2-SO_2-NO_2-DAM system accompanied by firstorder reaction with respect to CO_2 and instantaneous reactions with respect to SO_2 and NO_2, the enhancement factors of CO_2 and SO_2 were obtained by using an approximate solution of mass balances consisting of reaction regimes of two gases, one of which reacts instantaneously, and then, the enhancement factor of NO_2 by comparing the instantaneous rates of SO_2 and NO_2. The observed values of the molar flux approached to the calculated values very well.

Improvement in CO2 absorption and reduction of absorbent loss in aqueous NH3/triethanolamine/2-amino-2-methyl-1-propanol blends

오광중,강민경,전수빈,이민호 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.6

Changes in the CO2 absorption rates and capacities of the absorbent 2-amino-2-methyl-1-propanol (AMP),blended with NH3 and other additives, were investigated toward performance improvement. The NH3-blended absorbent removed CO2 more efficiently than the AMP absorbent alone. However, absorbent loss through NH3 evaporation was observed under these conditions. A second absorbent, the tertiary amine triethanolamine (TEA), which has a low vapor pressure, was selected and blended with the NH3/AMP system to reduce NH3 evaporation. Its effects on NH3loss and the absorption rate and capacity of the NH3/AMP system were investigated, and the optimum blending ratios were determined. In addition, the absorbent blend at the optimum blending ratio was compared to AMP alone and the commercially available absorbent monoethanolamine at the same weight ratio. The thermal stabilities of the absorbents,under conditions used in the CO2 absorption process, were compared by thermogravimetric analysis.

알카리금속염을 첨착시킨 활성탄을 이용한 CO_2 제어에 관한 흡착특성

오광중,심언봉,최원준,조기철 부산대학교 환경문제연구소 2001 環境硏究報 Vol.19 No.-

Na_2CO_3,K_2CO_3, Li_2CO_3-impregnated activated carbon which had a longer breakthrough time and more enhanced adsorption capacity than the activated carbon was tested with isothermal adsorption and tested for the CO_2 adsorption amount varied with temperature, CO_2 inlet concentration, flow rate, aspect ratio. As a result, when Langmuir, Freundlich and Dubinin-Polanyi adsorption isotherms were used for linear regression of isothermal adsorption data, Langmuir adsorption isothermal was the most suitable. And, The optical condition for Na_2CO_3 and K_2CO_3 impregnated activated carbon make-up was 1N and Li_2CO_3 was 0.1N. It could be concluded that adsorption capacity was decreased with adsorption temperature and increased gas concentration. When the aspect ratio(L/D) was varied 0.5, 1.0, and 2.0, the significant drop of adsorption amount was observed below 1.0 and breakthrough time was shortened with gas flow rate.

CO₂ 용접에서 용접변수의 변화에 따른 용접흄 제어방법에 관한 연구

오광중,김현수,손병현,지해성,Oh, Kwang-Joong,Kim, Hyun-Soo,Shon, Byung-Hyun,Jee, Hae-Sung 한국산업보건학회 1998 한국산업보건학회지 Vol.8 No.1

The concentration of welding fume was measured by 221 welders themselves in chassis frame workplace of the manufactory from February, 1, 1996 to May, 31, 1997. Welding parameters were the welding current and the distance between helmet and arc. Those two optimum conditions were proposed by excess probability analysis using logistic regression, so the best position in the workplace was proposed considering two factors to control the welding fume. The results are as followings; 1) The excess proability of welding fume TLV was over 99% in above 260 Amperes of welding current and also in below 30cm of distanced between helmet and arc. 2) The equation from logistic regression analysis using SPSS/PC+5.02 had the welding current as a independent variable and the excess of welding fume TLV as a dependent variable (p<0.05). Logit(welding fume TLV) = 0.1296 ${\times}$ wlding currnet - 28.8750 3) The equation from logistic regression analysis using SPSS/PC+5.02 had the distance between helmet and arc as a independent variable and the excess of welding fume threshold limit value a, a dependent variable (p<0.05). Logit (welding fume TLV) = -0.6809 ${\times}$ distance between helmet and arc +25.1665 4) Considering both cases or 2) and 3). the result equation is following. (p<0.05). Logit (welding fume TLV) = 0.1346 ${\times}$ welding current -0.3859 ${\times}$ distance between helmet and arc -15.7382 5) The excess probability of welding fume threshold limit value was 100% in above 240 Ampere of welding current. Thus, below 220 Ampere can be suggested to reduce the 40% number of welders who have a excess welding fume threshold limit value. 6) The excess probability of welding fume TLV was 100% in below 34cm of distance between helmet and arc. Thus, over 38cm can be suggested to reduce the 33% number of welders who have a excess welding fume TLV. 7) Considering both 5) and 6) cases, first of all, the best welding current can be 200 Ampere to have a below 15% of welding fume excess probability for the welders who works in distance of 34-37cm. Secondly, to have a below 30% excess probability of welding fume TLV, the working distance must be over 38cm in 220 Ampere and 32cm in 200 Ampere. 8) To reduce the average exposure concentration of welding fume ($8.21{\pm}5.83mg/m^3$), the movable local exhaust system equipped with flexible hoods can be used.

기 - 고 유동층에서 입자크기가 축방향 압력요동에 미치는 영향

오광중,홍성창,도동섭,최청송 한국화학공학회 1991 NICE Vol.9 No.3

Chemical absorption of carbon dioxide into oxirane solution containing ID-CP-MS41 catalyst

오광중,박상욱,Seong-Man Mun,김성수 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.2

CP-MS41 was synthesized by hydrolysis of tetraorthosilicate, as a silicon source, with 3-chloropropyltriethoxysilane as an organosilane using cetyltrimethylammonium bromide as a template. ID-CP-MS41 was synthesized by immobilization of imidazole on the CP-MS41 and was dispersed in organic liquid as a mesoporous catalyst for the reaction between carbon dioxide and oxirane. Phenyl glycidyl ether and glycidyl methacrylate were used as oxiranes. Carbon dioxide was absorbed into the oxirane solution in a stirred batch tank with a planar gas-liquid interface within a range of 0-2.0 kmol/m^3 of oxirane and 333-363 K at 101.3 kPa. The measured values of absorption rate were analyzed to obtain the reaction kinetics using the mass transfer mechanism associated with the chemical reactions based on the film theory. The overall reaction of CO_2 with oxirane, which is assumed to consist of two steps--i) a reversible reaction between oxirane (B) and catalyst of ID-CP-MS41 (QX) to form an intermediate complex (C_1), and ii) irreversible reaction between C_1 and CO_2 to form QX and five-membered cyclic carbonate (C)--was used to obtain the reaction kinetics through the pseudo-first-order reaction model. Polar solvents such as N, N-dimethylacetamide, Nmethyl-2-pyrrolidinone, and dimethyl sulfoxide affected the reaction rate constants.

연료용 알코올 연구현황 및 향후 전망

오광중 한국주류산업협회 2005 주류산업 Vol.25 No.2

기 -고 유동층에서 입자크기가 축방향 압력요동에 미치는 영향

오광중,홍성창,도동섭,최청송 한국화학공학회 1991 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.29 No.2

내경이 0.109m인 기-고 유동층에서 입자크기가 각각 0.715, 0.359 및 0.194㎜인 세종류의 균일 크기의 모래입자를 사용하여 축방향에 따른 압력요동을 차압전달기로 측정하여 통계학적 특성치의 하나인 표준편차와 power spectrum의 분포를 이용하여 분석하였다. 입자크기가 압력요동에 미치는 영향을 유속과 초기층높이에 따라 규명하고 이를 이용하여 기포의 운동과 입자 혼합 등의 유동층 내부의 거동을 예측하였다. 실험결과 입자의 크기가 압력요동에 큰 영향을 미쳤으며 일정 유속에서 압력요동의 크기가 최대값을 갖는 위치에서 spectrum의 분포가 가장 넓고 복잡하게 나타났으며 이것으로부터 이 지점에서 기포가 가장 격렬한운동을 하며 입자의 혼합이 가장 좋음을 알았다. The pressure fluctuations along the axial distance above the distributor were measured by a differential pressure transducer in a 0.109 m ID fluidized bed of sand particles(0.715, 0.359 and 0.194 mm). The pressure fluctuations were analyzed by the standard deviation and the distribution of power spectrum. The effect of particle size on the pressure fluctuations was investigated with different gas velocities and static bed heights to interpret the fluidized bed behavior such as bubble motion and particle mixing. The amplitude of pressure fluctuation was greatly affected by the particle size and exhibited a maximum value at which the distribution ◎ power spectrum has the most wide and complicate peaks, thus, the most vigorous bubble motion and particle mixing took place at that position in a fluidized bed.

Characteristics of absorption and regeneration of carbon dioxide in aqueous 2-amino-2-methyl-1-propanol/ammonia solutions

오광중,Dong-Hyeon Lee,Won-Joon Choi,Seung-Jae Moon,Soo-Ho Ha,Im-Gyung Kim 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.2

In this study, the removal efficiency, absorption amount, and loading value of CO2 into aqueous blended 2-amino-2-methyl-1-propanol (AMP)/ammonia (NH3) solutions were measured by using the absorption and regeneration continual process. The effect of adding NH3 to enhance absorption characteristics of AMP was investigated. The performance was evaluated under various operating conditions. As a result, the method of blending AMP and NH3 was not adequate because of a problem with scale formation. Consequently, NH3 of 1, 3, 5, and 7 wt% was added to 30 wt% AMP. Of these additions, 5 wt% NH3 was the optimum concentration because the CO2 removal efficiency and absorption amount were almost 100% and 2.17 kg CO2/kg absorbent, respectively. Also, the scale problem was almost absent. As the regenerator temperature varied from 80-110 oC, the loading of rich amine was almost constant, but the loading of lean amine was decreased as the regenerator temperature increased. Thus, the optimum regenerator temperature was 110 oC in this experiment.