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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
KIM JAE JEONG
Volume & Issues
Volume 40, Issue 5 - Oct 2002
Volume 40, Issue 4 - Aug 2002
Volume 40, Issue 3 - Jun 2002
Volume 40, Issue 2 - Apr 2002
Volume 40, Issue 6 - 00 2002
Volume 40, Issue 1 - 00 2002
Selecting the target year
The Optimal Scheduling of Paper Mill Process Considering Width-Pattern Change
Kim, Dong-Hoon ; Chung, Yon-Soo ; Yeo, Yeong-Koo ; Moon, Il ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 535~543
This paper focuses on the new developed MILP model for the optimal scheduling of the sheet cutting process considering the width-pattern change. This study uses a mathematical model in scheduling a paper mill process, differing from generally used heuristic methods. This method minimizes the amount of trim loss produced during the processing and produces optimal paper mill processing schedules to meet user's demands. First, mathematical modelling considering trim loss is carried out. Next, using the formula, reformulation is done by introducing methods to patternize maximum width of raw paper reel to reduce trim loss effectively. After the mathematical formulation of this concept in the form of MINLP, the parameterization method is applied to simplify the complex form of MINLP to MILP in order to solve the bilinearity created in this model. This study introduces an effective method to reduce trim loss in paper mill processing and to set an optimal scheduling which meet user’s demands by using a mathematical model considering the width-pattern change in the cutting process.
The Optimal Scheduling Using Parameterization in Paper Mill Process
Kim, Dong-Hoon ; Na, Seong-Hoon ; Yeo, Yeong-Koo ; Moon, Il ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 544~549
This study focuses on the optimal scheduling of the paper mill process using MINLP(Mixed-Intger Non-Linear Programming) considering the trim loss in the sheet cutting process. The mathematical modeling of the sheet cutting processs in the form of MINLP is developed and minimizing total cost is performed in this study. To eliminate bilinearity appeared in this model, a two-step optimization strategy is proposed. The proposed parameterization algorithm converts one of the two integer variables in the product form to a parameter, and the model optimization is solved using a set of parameters made by the parameterization method. The main contribution of this study is that a model for the optimal scheduling of the paper mill process is developed considering the minimization of trim loss and a two-step strategy is proposed to solve complex problems.
Process Simulation for Hybrid System Consisting of Membrane Steam Reformers and a Layered PSA
Choi, Young-Jae ; Lee, Uk-June ; Oh, Min ; Chung, Sung-Taik ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 550~557
In this study we propose hybrid system consisting of membrane steam reactors and a layered PSA process, and carry out theoretical analysis by means of modelling and process simulation. The proposed system is comprised of the reaction part including membrane reactors and separation part including a layer PSA column. Detailed mathematical description for each process is developed and dynamic simulation for the combined process is performed. The reaction part contains two membrane reactors and the methane conversion of the system is improved more than 1% comparing with the conventional one membrane reactor system. The hydrogen mole fraction at the exit of the membrane reactor is approximately 0.31 but in order to use it for a commercial purpose, layered PSA process, which includes two adsorbents, is employed. The purity of hydrogen gas at the exit of the layered PSA is 99.999%. By recycling all useful gases from the layered PSA except hydrogen to the membrane reactor as a feedstock, the process efficiency is highly improved. In particular, the hydrogen recovery is improved as much as 9% comparing with the non-recycle system. It is, therefore, concluded that the proposed hybrid system contributes to the efficient production of high purity hydrogen.
Study on Microstructural Properties of Polyelectrolyte Complex Fluids by Employing Hybrid Molecular Simulations of Molecular Dynamics and Monte Carlo Scheme
Lee, Hyun-Su ; Chun, Myung-Suk ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 558~564
The microstructural properties of charged polyelectrolytes described by a potential model regarding both the harmonic springs and
interaction were investigated by employing a hybrid scheme of molecular dynamics(MD) and Monte Carlo(MC) simulations. Based on the previous hybrid scheme, a novel hybrid scheme has been developed in the present study, with which computational efforts are effectively reduced. We present the conformational properties such as end-to-end distance, radius of gyration and structure factor. It is evident that the simulation results of the present study agree well with the previously reported results. The elongation behavior of the polyelectrolyte chain can successfully be observed by the calculations of the characteristic mean square ratio of end-to-end distance to radius of gyration as well as the structure factor. As the Bjerrum length
and the Debye length
increase, the polyelectrolyte chain becomes elongated.
Preparation of p-Toluene Sulfonic acid Using Reactive Distillation
Kim, Joo-Hyoung ; Lim, Chae-Yong ; Han, Myung-Wan ; Kim, Beom-Sik ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 565~571
The sulfonation of toluene to produce p-toluene sulfonic acid (p-TSA) is strongly limited by chemical equilibrium. Therefore, in chemical process industry, excess sulfonic acid is used in order to increase the reaction yield. However, this causes an environmental problem. We propose a new process using reactive distillation to increase the reaction yield and get pure p-TSA. The first step was to study the reaction kinetics and chemical equilibrium. In this work, we explored the feasibility of using a reactive distillation column for the preparation of p-TSA based on the simulation of the new column and kinetic data obtained by experiments.
Adsorption and Desorption Characteristics of Maltooligosaccharides for Activated Carbons
Kim, Seung-Jai ; Yoo, Jung-Wook ; Cho, Yong-Ick ; Cho, Sung-Yong ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 572~581
The adsorption and desorption characteristics of maltooligosaccharides on two commercial activated carbons were studied experimentally in a batch reactor to obtain basic data for the separation of a sugar from oligosaccharides solution. Adsorption rates of larger molecules such as maltopentaose (G5) and maltoheptaose (G7) for a pitch coal base activated carbon, F400 with relatively uniform pore size distribution of
, were faster than those of smaller molecules. On the other hand, the adsorption rates of smaller molecules such as glucose(G1) and maltose (G2) for a coconut shell base activated carbon, SLS103 with smaller pore size in the range of
, were faster than those of larger molecules. With pH adjustment using acetic acid, both adsorbents adsorbed almost all of the saccharides except for G1 at pH>4.1, but all saccharides are not adsorbed at pH<2.2 For 2.2
Reaction Characteristics of
Separation from a Syngas Using CaO
Kim, Jae-Kwon ; Yoo, Kyung-Seun ; Park, Tae-Jin ; Song, Byung-Ho ; Lee, Jae-Goo ; Kim, Jae-Ho ; Han, Choon ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 582~587
Reaction characteristics of
separation have been investigated in a thermogravimetric analyzer and packed bed reactor using CaO for the removal of
in a syngas produced from the gasification of combustible wastes. Reactions of CaO with
were fitted well by the rate equation of shrinking core model at the product layer diffusion control regime. Furthermore, the reaction order and the activation energy were found as 1.95 and 104 kJ/mol, respectively. Reaction rates of CaO does not increases with the increase of operating pressures, which might be because CaO has macropores in the particle inside and reaction is carried out by the surface solid diffusion. The presence of
and CO inhibits the
removal reaction by the water gas shift reaction and reduction of CaO above the temperature of
. On the other hand, the
removal reaction was not affected below
Population Density in Calcium Carbonate Precipitation with Agglomeration and Breakage
Lee, Sae-Ill ; Han, Hyun-Kak ; Lee, Chul-Soo ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 588~591
Changes of particle size distribution with agglomeration and breakage were experimentally studied in calcium carbonate precipitation. The particle size distribution using population balance equation were calculated. The calculated population density agrees with the experimental data which are agglomeraive and breakable.
Generation of Non-Equilibrium Plasma Under Atmospheric Pressure and Its Application to Etching Processes of Zinc Oxide Films
Lee, Bong-Ju ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 592~595
Under atmospheric pressure, an apparently homogeneous and stable plasma can be generated from an insulator barrier rf plasma generator of which contains an rf powered cathode and a grounded anode covered with a dielectric insulating material. This is a structure in which the dielectric materials are covered and arranged in parallel in the one side of electrode. In order to characterize the generating plasma under atmospheric pressure, some basic characteristics have been evaluated by the Langmuir probe method as well as by optical emission spectroscopy. From the result of plasma characteristics, the generated plasma was verified to be non-equilibrium; T(electron)>T(excitation)>T(vibration)>T(gas). We tried to apply this to etching of an Zinc oxide(ZnO) films also.
A Study on Preparation and Characteristics of Acrylic Superabsorbent Polymers for Magnetic Beam Gate
Shin, Yeon-Soon ; Chen, Swung-Whan ; Park, Sang-Soon ; Choi, Joong-So ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 596~601
Superabsorbent polymers were composed of acrylic acid, acrylamide, sodium allysulfonate and sodium acrylate as a starting materials, N,N,N'N'-tetramethylenediamine and N,N'-methylenebisacrylamide as a cross-linker, potassium persulfate as a initiator. The solution polymerization on the formation of superabsorbent polymers were prepared in pH range 5 to 7. It can be seen that the water absorption capacities of poly(acrylamide-sodiumallysulfonate), poly(AM-SAS) depends on the pH. The maximum water absorption capacity of poly(AM-SAS-AA) shown at the condition of pH 7. The prepared poly(acrylamide- sodiumallysulfonate-acrylicacid), poly(AM-SAS-AA) were used to measure the absorption capacity at the temperature range
. The water absorption capacities increased with the increase of water temperature independent. The synthesized magnetic beam gate which were prepared MnZn ferrite was dispersed by weighing based on the optimal reaction condition of poly(AM-SAS-AA). The water absorption capacities decreased with the increase of MnZn ferrite contents.
Observation of Inner Surface Change in Plasma Display Panel (PDP)
Soh, Hyun ; Lee, Ki-Hyung ; Kim, Young-Chai ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 602~606
Aging process for the surface stabilization is the final step in plasma display panel(PDP) fabrication. We designed and installed a in-situ analysis system to investigate the change of interior surface of 7-inch test panel. PDP was disassembled in the system and transferred to the in-situ electron spectroscopy for chemical analysis(ESCA) chamber without exposure. MgO protection layer on the front panel indicated the presence of
compounds due to the hydration and carbon incorporation on the panel. These compounds were converted to the MgO with increasing time of the plasma aging. Carbon impurity in phosphor on the rear panel was reduced to the level lower than detection limits of ESCA by sputtering of the radicals in the plasma after 12 hours of aging. ESCA analysis revealed that 12 hours of aging time is consistent with the time to stabilize the change interior surface.
Nanoparticles for Supercapacitor by Liquid Phase Synthesis Method
Kim, Du-Hyun ; Seo, Won-Sik ; Song, Ki-Chang ; Shin, Kyung-Hee ; Kim, Jong-Huy ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 607~612
nano powders used for supercapacitor were synthesized by precipitation and microemulsion method, respectively and properties of powders were compared. The hydroxide powders prepared by the precipitation method were found to be more than above 30 nm in particle diameter and to have a highly aggregated microstructure. The specific surface area(SSA) of the powders, depended on the pH conditions during precipitation, decreased with increasing calcination temperature and showed
. On the other hand, the hydroxide powders prepared by the microemulsion method were found to be 15-20 nm in particle diameter and to have a non-aggregated microstructure. The SSA depended on calcination temperature and showed
Surface and Adhesion Characteristics of Polyimide Film Treated by Corona Discharge
Park, Soo-Jin ; Cho, Ki-Sook ; Kim, Sung-Hyun ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 613~617
In this work, the effect of corona discharge treatment on surface properties of polyimide film was investigated in terms of FT-IR(Fourier Transform-IR), XPS(X-ray Photoelectron Spectroscopy) and contact angles. And the adhesion characteristics of the film were studied in peel strengths of polyimide coatings. As a result, polyimide surfaces treated by corona discharge led to an increase of oxygen-containing functional groups or polar component of the surface free energy, resulting in improving the adhesion characteristics of the polyimide/copper foil. However, the surface energy of the film was decreased as the aging time increased. These results could be discussed in the formation of surface functional groups or deterioration of reactive sites of polyimde film in the presence of corona treatment with aging time.
Chemical Modification of Singlewall Carbon Nanotubes with Octadecylamine and Amino-terminated Polystyrene
Ham, Hyeong-Taek ; Koo, Chong-Min ; Kim, Sang-Ouk ; Choi, Yeong-Suk ; Chung, In-Jae ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 618~623
The solubility enhancements of singlewall carbon nanotubes(SWNTs) in various organic solvents were investigated by chemical modification of SWNTs. Carboxylic acids were attached to the open ends of SWNTs during purification and cutting. Octadecylamine and amino-terminated polystyrene were grafted to cut SWNTs via the formation of amide functionality. SWNTs with carboxylic acid bond were not dispersed well in organic solvents. But, polystyrene-grafted SWNTs and octadecylamine-grafted SWNTs were dispersed well in some organic solvents.
Kinetics for the Photocatalytic Degradation of Acetaldehyde
Park, Sang-Eun ; Joo, Hyun-Ku ; Jeong, Hee-Rok ; Jeon, Myung-Seok ; Auh, Chung-Moo ; Kang, Joon-Wun ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 624~627
In this study, the photocatalytic degradation of acetaldehyde into
with coated photocatalyst on the flat substrate was conducted. To obtain the detailed characteristics of the reaction the Lanmuir-Hinshelwood kinetics was applied. Modelling of the reaction was successfully achieved with the aid of constants(
) extrapolated from the experiments. Reaction rates increased with increased coated area under the same initial concentrations and light intensities. The order of rate, however, changed first to zero with increased light intensity and the same coated area. Those two results brought an issue that at certain light intensity a less-coated area may result in a higher rate, which was finally identified experimentally in this study. The light intensity and the coated area are the most critical factors in photocatalysis, the optimal combination of which can show the synergy.
Numerical Simulation for the Development of Waste Oil Cavity Incinerator
Chun, Young-Nam ; Lee, Kwy-Joo ; Kim, Mi-Hwan ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 628~634
We proposed advanced cavity incinerator to incinerate waste oil which is contained water. The cavity incinerator has heat recirculation region in the cavity to be burnt out completely in high temperature zone. And heat recuper, being left side of cavity, plays a role in the flame stabilization of auxiliary burner flame by heat recovery of exhaust gas. The results in standard incinerator, which was selected by iterative calculation, showed that the combustion and emission characteristics of cavity incinerator are excellent. And operating conditions were proposed by parametric screening studies about injection velocity, injection temperature and injection point of waste oil and air.
Removal of Anionic Dyes by Acid-Treated Chitin
Kim, Sung-Bae ; Lee, Jae-Hwan ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 635~639
Dye removal by acid-treated chitin was investigated and compared with results from chitosan. Dyes used were Acid Blue 25, Direct Red 81 and Mordant Yellow 10 which were all anionic dyes. When the pH of initial dye solution was 6, the dye removal of the acid treated chitin was superior to those of untreated chitin and chitosan. Dye removal was varied with the moisture content of the acid treated chitin and increased as the moisture content was increased. Also, dye removal was varied very sensitively with the pH of dye solution and increased as pH was decreased. When the pH of initial dye solution was 6, the dye removals of acid-treated chitins were significantly higher than those of untreated chitin and chitosan. But, at pH 3, the dye removal of chitosan was the highest among them.
Heat Transfer Coefficient in a Three-Phase Circulating Fluidized-Bed Bioreactor
Kang, Tae-Gyu ; Song, Pyung-Seob ; Choi, Gill-Soo ; Cho, Yong-Jun ; Kang, Yong ; Choi, Ho-Suk ; Kim, Sang-Done ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 640~645
Heat transfer characteristics have been investigated in the riser of gas-liquid circulation and three-phase circulating fluidized-bed bioreactors whose diameter and height are 0.102 m and 1.0 m, respectively. Effects of gas and liquid velocities and holdup of fluidized biofilm media on the heat transfer coefficient between the immersed vertical heater and the bed have been determined. The heat transfer coefficient in the gas-liquid circulation reactor increases with increasing gas velocity, but increases only slightly with increasing liquid velocity. The h(heat transfer coefficient) value in the three-phase circulating fluidized-bed bioreactor also increases with increasing gas velocity or holdup of fluidized biofilm media, but it increases only slightly with liquid velocity. The value of heat transfer coefficient has been well correlated in terms of operating variables.
in a Fixed Bed Recycle Reactor
Kim, Jun-Sik ; Kang, Yong ; Lee, Sang-Bong ; Choi, Myoung-Jae ; Lee, Kyu-Wan ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 646~650
A catalytic fixed-bed recycle reactor was proposed to increase the level of reaction conversion in conducting the hydrogenation of
$CO_2$. The hydrogenation of
$CO_2$ was carried out over
catalyst. The conversion of carbon dioxide (
) increased with increasing reaction temperature and modified residence time (
) in the fixed bed single reactor. In series reactors, the
increased up to the level of 68.5% (
) in comparison with the level of 40.8% in the fixed bed single reactor at the same conditions. The
increased with increasing recycle ratio(R) and exhibited a maximum value with increasing total space velocity (
). The maximum
was the level of 75.6% (
) in the recycle reactor when the
. From the results of this study, it was found that the recycle ratio of reactant gas, effective separation of water vapor and liquid hydrocarbon, modified residence time and equilibrium conversion level of the reaction were important factors to determine the conversion level of the hydrogenation of carbon dioxide.
Effects of the Addition of NaOH on the Decomposition of Dihydrobenzenes under Supercritical Water Oxidation Conditions
Lee, Geun-Hee ; Kim, Jong-Guk ;
Korean Chemical Engineering Research, volume 40, issue 5, 2002, Pages 651~657
The aim of this study is to compare the effects of NaOH addition in the decomposition of dihydrobenzenes(catechol and hydroquinone) using supercritical water(SCW) and supercritical water oxidation(SCWO) conditions. Experiments were performed using four sets of conditions, which were in the presence and absence of NaOH in both SCW and SCWO conditions. Under the experimental conditions, the addition of NaOH accelerated the decomposition of catechol and hydroquinone in both the conditions. Several intermediates were identified by performing GC/MS analysis from SCWO of catechol and hydroquinone, and in particular, a large quantity of 1,4-benzoquinone were detected from SCWO of hydroquinone, which is known as an probable inhibitor to hinder the production of
after hydroquinone oxidation. The addition of NaOH to catechol and hydroquinone oxidation reduced the generation of these intermediates including 1,4-benzoquinone, however the effects of the NaOH addition in SCW were the similar as compare to those of SCWO. Further, the addition of NaOH increased the production of
in both the conditions. These results revealed that the effects of NaOH on the decomposition of catechol and hydroquinone using SCWO are not negligible. Therefore, its effects on the decomposition of other organic compounds under SCWO conditions should be estimated for determining optimized operating conditions and reactor designs.