• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1197-1201
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• 2006

In order to improve the operability in a fully thermally coupled distillation column the main column is separated into an upper and a lower column, and its design method is explained. With a distillation experiment using a two-inch column the operability of the proposed column is examined. Readily available methanol, ethanol and propanol are used as the feed, and the experimental result is compared with that of the HYSYS simulation. It is found from the experiment that the recovery ranges between 58.8% and 68% and the distillation efficiency is lower than that of the simulation. consumes less energy than an original column, it is not widely implemented in practice due to its operational difficulty. However, it is proved that the proposed distillation column can be operated without compressors and it can be practically utilized.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.50.3-50
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• 2001

Nonlinear feedback control scheme for reactive distillation column has been proposed. The proposed control scheme is derived in the framework of Nonlinear Internal Model Control. The product compositions and liquid and vapor flow rates in sections of the reactive distillation column are estimated from selected tray temperature measurements by an observer. The control scheme is applied to example reactive distillation column in which two products are produced in a single column and the reversible reaction A + B = C + D occurs. The relative volatilities are favorable for reactive distillation so that the reactants are intermediated boilers between the light product C and the heavy product D. Ideal physical properties, kinetics and ...

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.9
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• pp.945-953
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• 2006

Though a fully thermally coupled distillation column consumes less energy than an original column, it is not widely implemented in practice due to its operational difficulty. A new fully thermally coupled distillation column is proposed for the operability improvement, and its performance is investigated. The main improvement is the separation of a main column to give an upper and lower columns and the installation of an intermediate heat exchanger between them to regulate the fluctuation of product compositions. A proper manipulation of column pressure in the separated main columns made easy vapor flow without a compressor. The operability improvement is examined in a hexane process from the dynamic simulation using a commercial design software HYSYS. The simulation results indicate that the coupling among inputs and outputs is loosened to make easy manipulation of product compositions in the proposed distillation system.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.892-897
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• 2008

A new ethanol dehydration process utilizing a thermally coupled distillation column is proposed to reduce the energy requirement of the existing dehydration processes. An entrainer of benzene is used in the proposed system having the column profile similar to the equilibrium composition profile for the maximum distillation column efficiency, and the feed composition is arranged to close to the boundary of different distillation regions. It is found that the proposed distillation system gives some 18% of energy saving over the existing process. In addition, design guidelines are suggested for other azeotropic distillation process.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.742-748
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• 1993

The dynamics and control of two complex column configurations (sidestream column with stripper; prcfractionater/sidestream column configuration), which are multivariable interacting and nonlinear, have been studied. A new control scheme developed by Hanand Park(1993) to deal with the nonlinear and multivariable nature of distillation processes has been applied to these complex distillation configurations. The control scheme incorporates a nonlinear wave model into a generic model control framework. An observer based on the nonlinear wave model is used to determine the profile positions of distillation column sections. The control scheme enables tight control of the profile position of each column section that leads to fast stabilization of product compositions.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.145-150
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• 2002

The distillation column is one of large energy consumable units in the cryogenic air separation process and the accurate energy analysis of this unit is necessary for choice of energy saving process. In this work, the energy method was adopted for energy analysis of a cryogenic nitrogen distillation column. In order to designing the energy saving distillation column, the exergy distribution of feed air, exergy efficiency and exergy loss for process condition was investigated and the optimal process condition to minimize the exergy loss was found. The result from this work can be used as a guideline for the choice of the process design conditions and efficiency improvement of cryogenic distillation column.

• 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.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.1017-1022
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• 2008

Though many divided wall columns are implemented in field as energy-efficient distillation columns, its application is limited due to the difficulty of building a new column. A novel energy-efficient distillation system utilizing the existing columns is proposed here. The proposed can reduce the energy consumption by about 39% comparing with the existing system. And it is shown that the proposed improves the column operability over the existing. The tray numbers of the added columns have no significant influence on the composition of a side draw.

• Clean Technology
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• v.16 no.1
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• pp.59-63
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• 2010

The concentration process of 2-ethyl hexanol used for the intermediate material in the production of plasticizer is examined for the energy conservation of energy-efficient distillation system instead of the conventional two column system through numerical simulation. Some 41 % of energy conservation is expected from the proposed system, and its conservation principle is explained with column profiles. In addition, not only the operating cost but also investment cost can be reduced for the additional benefit of the column application when the thermally coupled distillation is implemented.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.55-60
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• 2012

The energy conservation and exergy loss of a fully thermally coupled distillation commercialized as the divided wall column are compared with those of a conventional two-column system for ternary separation. The used example for the comparison is the benzene-toluene-m-xylene separation process widely used in a petrochemical plant. The design procedure of the fully thermally coupled distillation column is explained, and the energy requirement is compared using the HYSYS. When the same numbers of trays are utilized, the fully thermally coupled distillation column uses 28.2% less energy and 10.4% more exergy loss. The increase of the exergy loss is due to the additional mixing from the bidirectional inter-linking and the temperature elevation in the reboiler from the increased pressure at the bottom of the main column.