• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.668-671
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• 2010

A lab scale distillation experiment is conducted with small size packing used in lab scale multi-tray distillation equipment for the performance evaluation of distillation system. A sufficient surface are yielded with 6.7 mm cylindrical packings made of stainless steel, and a good liquid holdup and residence time are resulted. The comparison between the theoretical tray from the HYSYS and the experimental distillation outcome indicates that a 7 cm HETP from 27 cm packing height and a 8 cm HETP from 45 cm packing height are obtained. Comparing with the 8 cm HETP of commercial structured packing shows a similar experimental results obtained here. The 7 cm HETP is available with a complete insulation, and the importance of the insulation is proved. The results of this study indicates that a practical distillation column used in field can be tested in lab.

• Clean Technology
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• v.17 no.1
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• pp.56-61
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• 2011

In this study, hydrocarcking of vacuum residue was carried out in an autoclave reactor at $450^{\circ}C$ and $500^{\circ}C$ with a commercial catalyst (HDM) and the quantitative product distributions were analyzed by GC-SIMDIS method or simple distillation. During catalytic hydrocracking, thermal cracking also occurred together with catalytic cracking and the higher conversion and selectivity of gasoline and naphtha were obtained at high reaction temperature. GC-SIMDIS and simple distillation revealed different results for the analysis of products produced at different hydrocracking temperatures; almost same results were obtained for the product produced at $500^{\circ}C$ but different ones for the product produced at $450^{\circ}C$. In the analysis of product produced at $450^{\circ}C$, the GC-SIMDIS showed that a main product was VGO while a main product in the simple distillation was diesel, which implies that the simple distillation for the $450^{\circ}C$ reaction was not accurate due to thermal cracking of the product by the simple distillation.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.356-358
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• 2022

추천 시스템에서 사용되는 피드백은 단일 클래스와 다중 클래스 피드백으로 구분할 수 있다. 추천 시스템을 위한 지식 증류 기법들은 단일 클래스 환경에서 주로 연구되어 왔다. 우리는 다중 클래스 환경에서 또한 추천 시스템을 위한 최신 지식 증류 기법들이 효과적인지에 대해 알아보고자 하며, 해당 방법들 간의 추천 정확도를 비교해보고자 한다. 추천 시스템에서 보편적으로 사용되는 데이터 셋들을 기반으로 한 실험들을 통해 추천 시스템을 위한 지식 증류 기법들은 같은 조건의 기본적인 추천 시스템에 비해 정확도가 최대 193%까지 개선되는 것을 확인했다.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.39-45
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• 2007

This paper proposed a shortcut method for the structure design of dividing wall column based on the Fen-ske-Underwood equation by applying it on three conventional simple column configuration. It is shown that the proposed shortcut method can design the column structure including the feed tray, dividing wall section, and side-stream tray in a simple and efficient way in the initial design stage. Simulation study using HYSYS to compare the energy saving performance between the conventional sequential two column system and the dividing wall column designed by the proposed method shows that the proposed dividing wall column system saves from 16% to 65% more over the condepends on the composition of intermediate component while the optimal energy consumption pattern to internal flow distribution on the dividing wall section is characterized by the ESI factor of the feed mixture.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.93-97
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• 2013

A lab-sized distillation experiment was conducted using small-size packings and a horizontal distillation column. The 6.7 mm Raschig ring type packings of stainless steel and a 40 mm glass column were used, and five independent electric heaters were installed in the axial direction to adjust the column inside temperature separately. The temperature was continuously distributed along the column length to provide equivalent equilibrium to the temperature for the separation. From the experimental results, a larger HETP of the column than the vertical distillation column was obtained, but it was found that the practical separation with proper processing capacity and separation efficiency was available.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.520-525
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• 2020

In this study, we developed a machine learning-based model for predicting the production stage temperature of distillation process. It is necessary to predict an accurate temperature for control because the control of the distillation process is done through the production stage temperature. The temperature in distillation process has a nonlinear complex relationship with other variables and time series data, so we used the recurrent neural network algorithms to predict temperature. In the model development process, by adjusting three recurrent neural network based algorithms, and batch size, we selected the most appropriate model for predicting the production stage temperature. LSTM₁₂₈ was selected as the most appropriate model for predicting the production stage temperature. The prediction performance of selected model for the actual temperature is RMSE of 0.0791 and R² of 0.924.

• ICROS
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• v.3 no.5
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• pp.43-50
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• 1997

이 글에서는 이진 증류탑을 위한 적응 제어 기법에 대해 소개하였다. 제안된 방법은 최근 개발된 다변수 예측 제어 알고리즘과 공분산 행렬 정규화 기능을 갖는 추정 알고리즘에 기초하고 있다. 이러한 적응 시스템은 그 설계과정이 복잡하지 않아 실저적 적용 가능성이 높다는 점에서 가치가 있다. 필터를 제외하면 단 두 개의 제어기 상수만이 결정되면 되고, 더욱이 이들이 공정의 상승 및 정정 시간과 관련되어 그 설정이 쉽다는 중요한 특징을 갖는다. 이와 같은 제어기 설계의 간소화에도 불구하고 증류탑의 설정값 추종 성능 및 Feed 변화에 대한 제어 성능의 우수함을 공정 모사를 통해 확인하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.539-544
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• 1998

MEO 공정에서 발생하는 질산폐액으로 부터 고농도 질산을 회수하기 위한 증발및 증류 공정특성을 연구하였다. 증발율이 20 이상인 경우 질산회수가 최대가 되는 특정 염농도가 존재함을 알 수 있었다. 증발율이 25인 경우 증발공정에서 발생한 묽은 질산용액을 12 M의 고농도 질산용액으로 농축하기 위한 증류탑을 계산하였다. 그 결과 증류탑은 효을이 70%인 9개의 단으로 구성되고, 환류비 0.25, 재비기 열량 2.7 kW, 응축기 열량 0.4 kW의 운전조건을 도출하였다.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.713-719
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• 2014

When multiple reactions of quaternary mixtures take place in a reactive distillation column, the behavior of composition trajectory is analyzed by a visual-aided method. By adding additional vectors of multiple reactions and visualizing them in composition space, the composition of each component and extent of each reaction on an arbitrary stage can be easily estimated in terms of the composition trajectory and reaction cascade difference points. Moreover, for a given operating conditions, the number of total stages and position of optimum reaction zone can be determined by the visual-aided method. In this study, ethylene glycol synthesis with a side reaction is taken as an example and analyzed by the proposed graphical method. Through this method, the quaternary reactive distillation with multiple reactions can be analyzed without numerous experiments and simulations.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.52-56
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• 2007

Though a reactive distillation column reduces energy requirement and gives easy separation of azeotropic mixture to result in wide practical applications in field, its design is difficult. On the other hand, a commercial design software used largely in chemical process design and performance evaluation can solve the problem, but the addition of reaction into the tray is not simple. In this study the addition is implemented to make the process simulation available, and it is utilized in the design of a TAME process to find the following design guidelines. The addition of reactive trays gives more composition elevation than the composition decrease from the reduction of the trays, and the increase of non-reactive trays does not improve product quality. The elevation of reboiler heat duty lowers the product quality by the reduction of residence time in reactive tray and conversion.