• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.11a
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• pp.129-134
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.377.2-377
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• 2001

• Membrane Journal
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• v.20 no.4
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• pp.342-350
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• 2010

Membrane distillation (MD) is a separation process which higher vapor pressure components are evaporated in mixed liquid solution through hydrophobic membrane with 0.1 or $0.5{\mu}m$ pore size. In this study, direct contact membrane distillation process for hollow fiber module were interpreted numerically using the "COMSOL Multiphysics" software. The variables for the system were temperatures and flow rates of lumen and shell side solutions. The permeate flux increased from 1.0 to $3.8L/m^2{\cdot}hr$ as temperature of the feed solution for lumen increased from 30 to $50^{\circ}C$. However the effect of shell solution temperature on permeate flux was relatively low. Also, the optimum velocity of lumen feed was obtained at 0.15 m/s ($Re_L=135$) by considering MD permeate flux as well as operating pressure loss.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.191-199
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• 2021

A distillation column, which is a main facility of the chemical process, separates the desired product from a mixture by using the difference of boiling points. The distillation process requires the optimization and the prediction of operation because it consumes much energy. The target process of this study is difficult to operate efficiently because the composition of feed flow is not steady according to the supplier. To deal with this problem, we could develop a data-driven model to predict operating conditions. However, data preprocessing is essential to improve the predictive performance of the model because the raw data contains outlier and noise. In this study, after optimizing the predictive model based long-short term memory (LSTM) and Random forest (RF), we used a low-pass filter and one-class support vector machine for data preprocessing and compared predictive performance according to the method and range of the preprocessing. The performance of the predictive model and the effect of the preprocessing is compared by using R2 and RMSE. In the case of LSTM, R2 increased from 0.791 to 0.977 by 23.5%, and RMSE decreased from 0.132 to 0.029 by 78.0%. In the case of RF, R2 increased from 0.767 to 0.938 by 22.3%, and RMSE decreased from 0.140 to 0.050 by 64.3%.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.06a
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• pp.59-92
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• 1994

식품가공공장은 제품의 특성에 따라 필요로되는 여러가지의 단위공정이 조합되어 가동되고 있다. 식품제조 공정중 분리, 분획 및 농축은 매우 중요한 처리로 이를 위해서 증류, 증발, 원심분리, 여과 등의 조작이 절대적으로 필요하고, 최종제품이 액상일 경우 유통중 변질발생을 방지키 위해 살균 공정을 반드시 거치도록 되어있다. 또한 제품의 생산과정중 사용되는 폐수에 의한 환경오명을 막기위해서 폐수정화시설이 필수적으로 되어있다. 이러한 대부분의 조작과정중에서는 열처리가 반드시 수반됨에 따라 가공원료중에 함유된 각종 영양성분이 부분적으로 열레 의해 파괴되고 냄새나 색등이 변함에 따라 제품의 품질이 열화됨은 물론, 에너지비용, 관련시설의 설치에 소요되는 부지, 시설비 및 운영비 등이 많이 필요로 한다.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.3-15
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• 2001

The ozone kinetics including ozone auto-decomposition. effect of pH, and solubility were investigated. Diesel decomposition process including TCE & PCE decomposition. effect of hydroxyl radical scavenger, effect of pH, and ozone/$H_2O$$_2$by ozonation process were also examined using deionized water, simulated groundwater. and actual groundwater. Reactions with deionized water and groundwater both stowed the second-order reaction rates, and the reaction rate was much higher in groundwater (half-life of 14.7 min) than in deionized water (hal(half-life of 37.5 min). The reaction rate was accelerated at high pH values in both waters. The use of ozone showed high oxidation rates of TCE. PCE and diesel. Though hydroxyl radical scavengers existing in groundwater were inhibitors for treating diesel, high pH condition and addition of hydrogen peroxide could accelerate to degrade diesel in groundwater, indicating ozone oxidation process could be applied to treating diesel contaminated-groundwater.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.351-355
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• 2007

It is necessary to convert butene-2 into butene-1 with higher added-values through positional isomerization. In this study, hydro-isomerization of butene-2 with hydrogen over Pd/alumina catalysts was investigated in a fixed bed reactor. The yield of butene-1 over Ld-265 catalyst was higher than that over other catalysts. The yield of butene-1 was highest (5.3%) under the conditions of reaction temperature of $75^{\circ}C$, reaction pressure of 150 psig, 2-butene flow rate of 48 cc/h and hydrogen flow rate of 3 cc/min. We conducted simulation for the process composed of a hydro-isomerization reactor and a distillation tower. In the case of 78% of tray efficiency, we obtained over 99% pure butene-1 through a distillation tower with 171 steps (R=120).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4643-4651
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• 2013

In this study, we have surveyed the new technologies in the cryogenic distillation of ITER, equilibrium reactors and helium refrigeration cycle contained in the isotope separation system (ISS). We also have collected thermodynamic and transport properties for $H_2$, HD, $D_2$, HT, DT and $T_2$ components of which properties are not built in a general purpose chemical process simulators such as Aspen Plus and PRO/II with PROVISION. Verification works have been performed to compare between literature data and simulation results. For the simulation of ISS involving six hydrogen isotope components, four distillation columns and two equilibrium reactors are used for the separation of $D_2$ and DT from $T_2$.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.335-338
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• 2003

최근의 통계에 따르면 국내의 인터넷 인용율은 2000년도에 44.7%, 2001년도에 56.6%, 2002년도에는 55.2%로 아이슬랜드(60.8%), 스웨덴(57.3%)에 이어 세계에서 세번째로 높은 것으로 나타났다. 또한 인구 100명당 PC보급율 또한 미국(62.5대), 덴마크(57.68대)에 이어 한국(55.58대)이 세계3위를 기록해 명실상부한 정보화 선진국임이 입증되고 있다. 따라서 잘 발달된 infrastructure을 이용하는 기술개발은 초고속정보이용을 가능케하고 있다. 근래에 들어 인터넷을 기반으로 기본적인 활용인 문자, 음성 및 영상 전송 등의 데이터 전송뿐만 아니라, 근래에는 인터넷을 통한 remote control 및 monitoring system에 대한 연구가 활발히 진행되고 있다. 기존의 증류공정은 DCS(Dispersion Control System)로써 공정상태(온도, 압력, 유량, 레벨, 순도등)를 Control room까지 선로를 통하여 신호전달이 이루어지고 있다. 따라서, 제한된 지역에서만 I/O(Input/output)이 이루어지고 있다. 이로 인해 안전감시시스템의 효율성이 떨어지고 있는 게 사실이다. 본 연구에서는 PC기반의 프로그램을 바탕으로 인터넷을 이용한 remote control 및 monitoring system을 개발함으로써 close Network에서 Open Network으로 발전시켰다. 여기서 local plant의 안전시스템 알고리즘은 그대로 Server system에 도입하였으며 사용자의 실정에 맞게 손쉽게 설정을 할 수 있도록 확장성을 높였다. 이는 PC기반의 시스템을 구축함으로써 가능하게 된 것이다. 또한, 웹 상에서의 무차별적 접근으로부터 보호하기 위하여 감시 대상의 성질에 따라 프로그램상에서 차별적 접근형식을 택할 수 있으며, control room의 indicator들과 controller를 프로그램상에 그대로 이식시킴으로써 감시자에게 충분한 정보제공 및 원격제어가 가능하도록 하고있다.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.458-466
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• 2005

Full-scale utilizations of batch separation process often require knowledge about thermodynamics and correlation techniques of physical properties of complex mixture consisting of a great number of many unknown components. Various empirical correlations have been proposed to predict the physical properties mostly about the pseudocomponent of petroleum. In this study, one parameter correlations are developed for the calculations of the critical physical properties and ideal heat capacity of the pseudo-component of coal tar fractions. Developed model can provide a tool for the design and operations for the batch distillation of coal tar mixture.