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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 :
Volume & Issues
Volume 31, Issue 6 - Dec 1993
Volume 31, Issue 5 - Oct 1993
Volume 31, Issue 4 - Aug 1993
Volume 31, Issue 3 - Jun 1993
Volume 31, Issue 2 - Apr 1993
Volume 31, Issue 1 - Feb 1993
Selecting the target year
An Analysis of Heat Transfer in Optical Recording Media
Lee, Jong-Dae ; Shin, Chee-Burm ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 493~493
Thermal characteristics of optical recording media were investigated using the finite element method when a laser beam with a Gaussian distribution was incident on it. For a stationary media, it was found that the maximum temperature increased with increasing laser power and decreasing film thickness. thermal equilibrium state was reached in 100 ns after the laser was turned on. In addition, in the recording media moving with a constant linear velocity, it was possible to predict the formation of teardrop-shaped pit.
Swelling Phenomena and Enrichment Effect of L-Phenylalanine Utilizing (W/O)/W Liquid Emulsion Membrane
Kim, Jong-Kuk ; Kim, Woo-Sik ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 502~502
The enrichment of L-phenylalanine and swelling of liquid membrane were investigated quantitatively in the (W/O)/W liquid emulsion membrane. The swelling of liquid membrane is affected by the viscosity and the non-polar characteristics of oil phase, the content of surfactant and the concentration difference of counter ion. In case of system using chloroform as a membrane phase and Adogen 464 as a carrier, the maximum enriched concentration was 5.2times(20.8g/l) higher than the feed concentration(4g/l) and the swelling ratio showed 2.3. And in case of dodecane(membrane phase)and D2EHPA(carrier) system, the maximum enrichment and swelling ratio were 6.78 and 1.5, respectively.
, CO and Hydrocarbon Gases Contained in Hydrogen Gas and Its Regeneration
Nahm, Kee-Suk ; Moon, Seong-Sik ; Lee, Wha-Young ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 513~513
The deactivation of
and hydrocarbon gases contained in hydrogen gas, and the regeneration of the deactivated
were studied. The pressure-concentration- temperature curves for pure and microencapsulated
were shown to be almost the same. In the mixed gases, the hydrogenating reaction rates of microencapsulated
were higher than of pure
. Independent of the sample, in the hydrogen gas containing oxygen, the reacted fraction of
maintained constant at nearly 100%. In the hydrogen gas containing carbon monoxide, on the contrary, the reacted fractions decreased with the increase of the reaction cycle although the magnitudes of them were slightly different according to the samples. The deactivated
was regenerated by the formation of
from the reaction of CO and
at 423K, and the regenerated
showed a fraction higher than 90%.
Mass Transfer between Gas and Liquid through CMC Solutions in a Bubble Column with a Draught Tube
Han, Seung-Wan ; Choi, Il-Gon ; Yun, Young-Woung ; Kim, Sang-Yeul ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 521~521
The gas holdup
and volumetric liquid-phase mass transfer coefficient
in a bubble column with a draught tube were studied experimentally with variation of the concentration of CMC solutions, gas velcoity and diameter and height of the draught tube. The gas holdup
increased with decreasing concentration of CMC solutions and increasing the diameter ratio of the draught tube to column diameter but was not affected by H/HT. The volumetric liquid-phase mass transfer coefficient
decreased with increasing concentration of CMC solutions and the height ratio of the draught tube to column height but was not affected by the diameter ratio of the draught tube to column diameter. Dimensionless equations of the gas holdup
and the volumetric liquid-phase mass transfer coefficient
were proposed from the experimental results.
Dynamic Characteristics and Modeling of Rotating Packed Disk Reactor
Han, Jae-Sung ; Song, Kyu-Min ; Hong, Won-Hi ; Chang, Ho-Nam ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 529~529
The flow pattern in a rotating packed disk reactor was studied by using dye tracers in 50% glycerin solution. Based on the observation it was postulated that the fluid can be divided into two regions of mixing one region where fluid rotates in the same direction of the disk, and the other region where fluid rotates in the opposite direction. The fluids in the two regions were highly turbulent and perfectly mixed. A three-parameter multi-step model was adopted, with each step composed of two perfect mixing regions and a bypassing to illustrate the residence time distribution of fluid in the reactor. The parameters of the model were obtained from the experimental data, using Marquardt？s optimization algorithm. The model was in good agreement with the experimental data. Correlations were proposed for the analysis of residence time distribution.
A Study on Spontaneous Ignition Estimation of Granulated Activated Carbon
Choi, Jae-Wook ; Mok, Yun-Soo ; Kim, Sang-Yeul ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 538~538
The characteristics of critical spontaneous ignition of granulated activated carbon were investigated at a constant ambient temperature and sinusoidally varying ambient temperatures. At a constant ambient temperature, but larger vessels yielded the lower critical spontaneous ignition temperature. The apparent activation energy calculated by the Frank-Kamenetskii's thermal ignition theory was 38.82(kcal/mol). At sinusoidally varying ambient temperatures, the critical spontaneous ignition temperature was generally lower than that measured at the constant ambient temperature. For the amplitudes
, a period of 1hour showed the minimum the of the critical spontaneous ignition temperature, and for the amplitude of
, a period of 2 hours showed the minimum value of the critical spontaneous ignition temperature. The Frank-Kamenetskii's
was determined from the results.
Analysis of Three-Phase Hollow Fiber Bioreactor Using Enzymatic Glucose Oxidation
Chang, Ho-Nam ; Choi, Sang-Kyo ; Kim, Gyeong-Won ; Lee, Chang-Woo ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 547~547
Experimental and theoretical studies on three-phase hollow fiber bioreactor were performed using an asymmetric hollow fiber in which glucose oxidase was entrapped in the porous sponge region and silicone coating was applied on top of that. Oxygen limitation has been confirmed by theory and experiment when the glucose concentration was above 75mM. The measured effectiveness factor was lower by 15-25% than the predicted one, which may be attributed to the deactivation of the enzyme upon immobilization. The theoretical and experimental values were in good agreement within error limits of 15-25%.
A Study on Propylene Polymerization with
Jeong, Dong-Wook ; Choi, Hong-Ki ; Han, Taek-Kyu ; Woo, Seong-Ihl ; Seong, Jun-Yong ; Ro, Jung-Seok ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 556~556
catalysts need for propylene polymerization were prepared by using silica(Davison-952) as a support, which is known to produce polypropylene with spherical shape and narrow particle size distribution. Propylene polymerization was carried out with the silica supported catalyst cocatalyzed with triethylaluminum(TEA) in the presence of an external electron donor(EED), p-ethoxy ethyl benzoate(PEEB) at 8atm. The effect of TEA, PEEB concentration and polymerization temperature on activity as well as stereospecificity was investigated. The maximum average polymerization rate during the initial first hour of polymerization was obtained at the mole ratio of [TEA]/[Ti]=200 and
. The increase of TEA concentration decreased stereospecificity. As the polymerization temperature increased, the stereo-specificity did not change. The polymerization activity in the absence of PEEB was 16.2kg-PP/g Ti-hr atm and the isotactic index was 84% at the molar ratio of TEA to Ti of 200 and
. However, the activity decreased to 12.4kg-PP/g-Ti hr atm and isotactic index increased to 93% at the same polymerization condition except for the addition of PEEB of which amount is 17% of [TEA]. Further addition of PEEB([PEEB]/[Al]=0.25) decreased the activity to 5.2kg-PP/g-Ti hr atm and increased isotactic index to 96%.
Hydrodynamic Characteristics in Inverse Fluidized Bed
Kim, Dong-Seog ; Sea, Bong-Kuk ; Lee, Min-Gyu ; Song, Seung-Koo ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 563~563
The variation of gas holdup, the liquid circulation velocity and fluidization characteristics of poly-styrene particles in inverse fluidized bed were observed by varying the gas flow rate. The relationship between the superficial gas velocity and the gas holdup was found as
which showed similar to the Chisti model. The liquid circulation velocity was measured directly and gave good relationship with those physical properties of particle and circulating fluid. Since Archimedes number, Ar, and Reynolds number at the mini-mum fluidization velocity could be predicted with the informations of physical properties of particle and fluid involved in the bed.
Kinetics of Methanol Decomposition over
Yoon, Ki-June ; Jeong, Kyeong-Sug ; Yie, Jae-Eui ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 569~569
Decomposition of methanol over a
catalyst was carried out using a tubular flow reactor in a temperature range between 473 and 533K. The partial pressure of methanol was below 0.141 atm.
and CO were the major decomposition products, and a small amount of
was produced. Although the amount of
formed increased with temperature, the selectivity to CO was greater than 95%. The following rate equation was proposed and the kinetic parameter values were evaluated.
Preparation of Mesophase Pitch by Supercritical Fluid Extraction -Properties of Insoluble Coal Tar Pitch in Supercritical Toluene-
Kim, Cheol-Joong ; Ryu, Seung-Kon ; Rhee, Bo-Sung ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 577~577
Supercritical toluene solubles in isotropic coal tar pitch is extracted at conditions of
, and 50 bar, 70 bar, and 90 bar, respectively. Benzene and quinoline insoluble contents, C/H atomic ratio, and softening point of extraction residues were increased by the extraction residues were increased by the extraction of supercritical toluene solubles.
content in extraction residues increased as extraction and the maximum value is reached at about 10wt% in the experiment conditions. Mesophase formation rate in thermal treatment of extraction residues is in parallel with extraction amount, and it shows the modification of carbonization properties of isotropic coal tar pitch by extraction of solubles with supercritical toluene.
Dynamic Characteristics of the Melt Spinning of Viscoelastic Fluids I. Steady State Behavior of the Spinline
Kim, Joo-Hwan ; Kim, Byung-Min ; Lee, Sang-Heon ; Yoo, Byung-Kyu ; Hyun, Jae-Chun ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 584~584
Dynamic characteristics of melt spinning, the most important process in synthetic fibers manufacturing has been investigated by conducting a simulation. The governing equations of one-dimensional model comprising the continuity equation, the equation of motion, the energy equation, and the constitutive equation of the materials, have been solved for different material constants and different operating conditions to find out the effect of the industrially important operating variables on the spinline dynamics. This kind of prediction through a simulation provides valuable information to the productivity improvement of melt spinning, i.e., process stability and product quality. Specifically, in this study we evaluated how the spinning process is influenced by the characteristics of viscoelastic fluids and the operating conditions such as spinning velocity, cooling conditions, spinning distance, and so forth.
CO Hydrogenation over Supported Iridium Catalysts Derived from Iridium Carbonyls
Lee, Tae-Jin ; Kim, Jang-Hee ; Chang, Won-Chul ; Lee, Dong-Jo ; Kim, Yoon-Kap ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 593~593
Iridium catalysts were prepared by converting
on acidic supports
and basic supports(MgO, Basic Zeolite). The samples were used as catalysts for CO hydrogenation at 1-20atm,
feed molar ratios of 0.5-3.0. Ir catalysts supported on acidic support and on basic support showed markedly different catalytic performance in activity maintenance, olefin/paraffin product ratio, hydrocarbon distribution, and by-product species. These unique results are believed to be due to the presence of different active species on both catalysts. The IR spectra suggested that predominant iridium species in the catalysts supported by the acidic supports were metallic or carbonyl clusters, whereas those of the catalysts supported by the basic supports were carbonyl cluster anions.
Loop Control Method for Processes with Input Redundancy
Lee, Ki-Hyoung ; Lee, Dae-Wook ; Lee, Kwang-Soon ; Jeoung, Sang-Tae ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 602~602
A loop control method, where all potential manipulated variables are actively utilized, is proposed for a process which has redundant manipulated inputs. Through analyses in the frequency domain, it was shown that the performance and stability of the proposed method are improved in comparison with those of the conventional method where extra manipulated variables are fixed at constant values. For experimental evaluation, the proposed method was applied to temperature control of a batch reaction calorimeter. As a result, tracking as well as regulation performances were found to be greatly improved compared to the conventional approach.
Removal of Cr(VI) from Aqueous Solution by Adsorbing Colloid Flotation
Kang, Sung-Gil ; Choi, Sang-June ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 611~611
Experimental investigations on the removal of Cr(VI) from aqueous solution were carried out by adsorbing colloid flotation using sodium lauryl sulfate as a collector. The optimum pH for the removal of Cr(VI) was found to be about 4.0-4.5 using
as an adsorbing colloid and about pH4.0-6.5 using
as a reduction agent. The effects of surfactant(sodium lauryl sulfate), foreign ions
, and Al(III) on the removal efficiency were investigated. The adsorption and separation mechanism on the removal of Cu(II) ion by the foam separation techniques were observed.
Feeding Rate Control Using Weight Measurement in a Weighing Tank
Kwon, O-Jeoung ; Lee, Kwang-Soon ; Son, Jong-Sung ; Yoon, Sang-Chul ; Lee, Suk-Ho ;
Korean Chemical Engineering Research, volume 31, issue 5, 1993, Pages 618~618
A novel method for flow rate control in a batch feeding system was proposed through transformation of the conventional flow rate control loop. The proposed method does not need a flow rate measuring device, and directly utilizes the weight measurement in the weighing tank. Performance of the proposed control method was analyzed in the viewpoints of set point tracking as well as sensitivity to measurement noise, and was compared with those of other conceivable control methods which directly use the weight measurement. As a consequence, the proposed method was analyzed to be superior to the other flow rate control methods, which was again confirmed through experiments.