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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
Volume & Issues
Volume 50, Issue 6 - Dec 2012
Volume 50, Issue 5 - Oct 2012
Volume 50, Issue 4 - Aug 2012
Volume 50, Issue 3 - Jun 2012
Volume 50, Issue 2 - Apr 2012
Volume 50, Issue 1 - Feb 2012
Selecting the target year
Study on the Pyrolysis Kinetics of Deasphalted Oil Using Thermogravimetric Analysis
Shin, Sang Cheol ; Lee, Jung Moo ; Lee, Ki Bong ; Jeon, Sang Goo ; Na, Jeong Geol ; Nho, Nam Sun ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 391~397
DOI : 10.9713/kcer.2012.50.3.391
The depletion of conventional oil reserves and the increasing energy need in developing countries such as China and India result in exceeding oil demand over supply. As a solution of the problem, the efficient utilization of heavy oil has been receiving more and more interest. In order to utilize heavy oil, upgrading processes are required. Among the upgrading processes, thermal decomposition is thought to be relatively simple and economical. In this study, to understand basic characteristics of thermal decomposition of heavy oil, we conducted pyrolysis experiments of deasphalted oil (DAO) produced by a solvent deasphalting process. DAO is a mixture of many components and consists mainly of materials of carbon number 20~40. For the comparison with results of DAO pyrolysis, additional pyrolysis experiments with single materials of carbon number 30 (
) were conducted. Pyrolysis experiments were carried out non-isothermally with variation of heating rate (10, 50,
/min) in a thermogravimetric analyzer. Average pyrolysis activation energy determined by using Arrhenius method, Ingraham and Marrier method, and Coats and Redfern method was 72~99 kJ/mol. In the activation energy calculated by Ozawa-Flynn-Wall method, DAO had wider variation than other single materials.
Selective Oxidation of Hydrogen Sulfide Containing Ammonia and Water Using Fe
Kim, Moon-Il ; Lee, Gu-Hwa ; Chun, Sung-Woo ; Park, Dae-Won ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 398~402
DOI : 10.9713/kcer.2012.50.3.398
The catalytic performance of some metal oxides in the vapor phase selective oxidation of
in the stream containing ammonia and water was investigated. Among the catalysts tested
was the most promising catalyst for practical application. It showed higher than 90%
conversion and very small amount of
emission over a temperature range of
. The effects of reaction temperature,
ratio, amount of ammonia and water vapor on the catalytic activity of
were discussed to better understand the reaction mechanism. The
conversion showed a maximum at
and it decreased with increasing temperature over
. With an increase of
ratio from 0.5 to 4, the conversion was slightly increased, but the selectivity to elemental sulfur was remarkably decreased. The increase of ammonia amount favored the conversion and the selectivity to elemental sulfur with a decrease in
production. The presence of water vapor decreased both the activity and the selectivity to sulfur, but increased the ATS selectivity.
Preparation and Properties of Aniline Terminated Waterborne Polyurethane/Multi-walled Carbon Nanotube Composite Coating Solutions
Hong, Min Gi ; Kim, Byung Suk ; Song, Ki Chang ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 403~409
DOI : 10.9713/kcer.2012.50.3.403
Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate, and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATWPUD) was synthesized by capping aniline on the NCO group of the prepolymer. Subsequently, ATWPUD was mixed with multi-walled carbon nanotube (MWCNT) to yield coating solutions, and the mixture was coated on the polycarbonate substrate. The surface resistance (
) of coating films from ATWPUD showed better conducting properties than that (
) from pure waterborne polyurethane dispersion (WPUD) when MWCNT was mixed. Also, the surface resistance of coating films was increased, but the pencil hardness and adhesion were decreased with increasing the amount of MWCNT added in the ATWPUD.
Preparation of Waterborne Polyurethane-Acrylic Hybrid Solutions from Different Types of Acrylate Monomers
Kim, Byung Suk ; Hong, Min Gi ; Yoo, Byung Won ; Lee, Myung Goo ; Lee, Woo Il ; Song, Ki Chang ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 410~416
DOI : 10.9713/kcer.2012.50.3.410
Waterborne polyurethane dispersions (PUD) were synthesized from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA) as starting materials. Subsequently, polyurethane-acrylic hybrid solutions were prepared by reacting the PUD with different types of acrylate monomers, such as HEMA (2-hydroxyethyl methacrylate):MMA (methyl methacrylate), HEMA:BA (butylacrylate), HEMA:BMA (butyl methacrylate), HEMA:HEA (2-hydroxyethyl acrylate), HEMA:PETA (pentaerytritol triacrylate) mixture. Also, the effects of acrylate types on the chemical resistance and the abrasion resistance of polyurethane-acrylic hybrid solutions were investigated. The test results showed that the HEMA:MMA mixture had the strongest chemical resistance, while the HEMA:PETA mixture had the strongest abrasion resistance among several types of acrylate mixtures.
Effect of Pyridine on Toluene Diisocyanate (TDI) Synthesis Using Direct Carbonylation over Pd/SiO
Seo, Myung-Gi ; Kim, Seongmin ; Lee, Dae-Won ; Lee, Kwan-Young ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 417~420
DOI : 10.9713/kcer.2012.50.3.417
This study is about reduction reaction making 2, 4-dinitrotoluene (2, 4-DNT) to 2, 4-toluene diisocyanate (2,4-TDI) with Pd/
. Catalytic systems based on Pd/
and under 100 bars of carbon monoxide. We studied the effect of pyridine on the yield of the TDI. TDI was not created without pyridine, but created with pyridine, at the reaction result. According to research, homogeneous synthesis of TDI with direct carbonylation, palladium and pyridine complexion is known to catalyze. When adding pyridine the reason of TDI synthesis is palladium leaching, ICP-AES was performed to confirm it. As a result, the proportion of Pd loaded in
was decreased 52% than before, after the reaction by adding 20 vol% pyridine. Generating TDI by adding pyridine might be the effect of the complex ion, which is composed of leached palladium and pyridine.
Preparation of UV-curable Ozone Resistance Coating Solutions using Fluoromonomer
Lee, Chang Ho ; Lee, Sang Goo ; Kim, Sung Rae ; Lee, Jong Dae ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 421~426
DOI : 10.9713/kcer.2012.50.3.421
The effect of synthesis conditions such as various organic material and composition of organic-inorganic material in ozone resistance and surface characteristic of ultraviolet cured organic-inorganic hybrid coating film has been investigated. Organic-inorganic hybrid coating solution was prepared using tetraethoxysilane (TEOS), silane coupling agent methacryloyloxypropyltrimethoxysilane (MPTMS), 2,2,2-trifluoroethylmethacrylate, and various organic materials with acrylate group, bar-coated on substrates using applicator and densified by UV-curing. It was found that ozone resistance and surface hardness of the coating film was increased with contents of TEOS. It was also found that ozone resistance of coating film was increased with contents of 2,2,2-trifluoroethylmethacrylate. On the other hand, surface hardness was decreased with increase of 2,2,2-trifluoroethylmethacrylate. In addition, Surface hardness of coating film was increased with the addition of aliphatic urethane acrylate. It was also found that the transmittance of coating films was not influenced by content of TEOS and 2,2,2-trifluoroethylmethacrylate. In addition, the coating film exhibited high transmittance of above 90%.
Preparation of Waterborne Polyurethane Coating Solutions with Antistatic Property from Alkali Metal Salts
Hong, Min Gi ; Kim, Byung Suk ; Lee, Yong Woon ; Song, Ki Chang ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 427~434
DOI : 10.9713/kcer.2012.50.3.427
Waterborne polyurethane dispersions (PUD) were synthesized from poly (carbonate diol), isophrone diisocyanate and dimethylol propionic acid at different NCO/OH molar ratios. Subsequently, the PUD was mixed with different types of alkali metal salts (
) to prepare antistatic waterborne polyurethane coating solutions. Effects of the types and amounts of alkali metal salts were investigated on the surface resistances of the resulting coating films. The surface resistances of coating films were decreased with increasing the amounts of alkali metal salts added in the PUD. The coating films prepared with the same amount of alkali metal salts showed increased ionic conductivity with the order of
. Also, the surface resistances of coating films were increased with increasing the molar ratios of NCO/OH in the PUD.
Direct Conversion of Cellulose into Polyols over Pt Catalysts Supported on Zeolites
You, Su Jin ; Baek, In Gu ; Park, Eun Duck ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 435~441
DOI : 10.9713/kcer.2012.50.3.435
The direct conversion of cellulose into polyols in
was examined over Pt catalysts supported on various zeolites, viz., mordenite, Y, ferrierite, and
. For comparison, Pt catalysts supported on
were also tested. The physical properties of the catalysts were probed with
physisorption. The surface acidity was measured with temperature programmed desorption of ammonia (
-TPD). The Pt content was quantified with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The Pt dispersion was determined with CO chemisorptions and transmission electron microscopy (TEM). The conversion of cellulose appeared to be mainly dependent on the reaction temperature and reaction time because it depends on the concentration of
ions reversibly formed in hot water. Pt/H-mordenite (20) showed the highest yield to polyols among the tested catalysts. Pt/H-zeolite was superior to Pt/Na-zeolite for this reaction. The polyol yield was dependent on the surface acid density and the external surface area.
The Effects of Zeolite-Type Catalysts on the Pyrolysis Reaction of PP to Produce Fuel-oil
Bak, Young-Cheol ; Choi, Joo-Hong ; Oh, Se-Hui ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 442~448
DOI : 10.9713/kcer.2012.50.3.442
The effects of zeolite-type catalysts addition on the thermal decomposition of the PP resin have been studied in a thermal analyzer, a Pyrolyser GC-mass, and a small batch reactor. The zeolite type catalysts tested were natural zeolite, used FCC catalyst, and ZSM-5. As the results of TGA experiments, the pyrolysis starting temperature for PP varied in the range of
according to the heating rate. Addition of the zeolite type catalysts in the PP resin increased the pyrolysis rate in the order of used FCC catalyst> natural zeolite> ZSM-5 > PP resin. Adding the used FCC catalyst in the PP reduced most effectively the pyrolysis finishing temperature. In the PY-G.C. mass experiments, addition of zeolite type catalysts decreased the molecular weight of pyrolyzed product. In the batch system experiments, the mixing of used FCC catalyst enhanced best the initial yield of fuel oil, but the final yield of fuel oil was 2% higher in the case of mixing of natural zeolite. Also in the carbon number analysis, used FCC catalyst was the most useful one in this experiments for fuel oil.
An Economic Analysis of Solvent Extraction Process under Mild Condition for Production of Ash-Free Coal
Choi, Ho-Kyung ; Kim, Sang-Do ; Yoo, Ji-Ho ; Chun, Dong-Hyuk ; Lim, Jeong-Hwan ; Rhim, Young-Joon ; Lee, Si-Hyun ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 449~454
DOI : 10.9713/kcer.2012.50.3.449
Economic feasibility of the process for a coal extraction under mild condition, which will produce ash-free coal at a temperature lower than that of coal softening, was analyzed. To this end, the plant of 6000 t/d in capacity was assumed to be constructed near a coal mine in Indonesia, and the IRR, NPV, B/C ratio, and DPP of the plant were calculated based on $96 million investment cost and 15 years service life. The IRR, NPV, B/C ratio, and DPP of the plant were calculated to be 31%, $87 million, 1.08, and 3.9 years, respectively, and which satisfied the evaluation criteria of investment. The economic feasibility of the plant was mainly dependent on the price of the coal initially fed and the residue coal remaining after the extraction, according to sensitivity analysis.
Measurement of an Isoelectric Point and Softness of a EO-PO Adducted Zwitterionic Surfactant
Lim, JongChoo ; Mo, DaHee ; Lee, JinSun ; Park, JunSeok ; Han, DongSung ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 455~463
DOI : 10.9713/kcer.2012.50.3.455
In this study, the measurement of physical properties of ethylene oxide-propylene oxide adducted zwitterionic surfactants were measured such as critical micelle concentration, surface tension, interfacial tension, contact angle, viscosity and foam stability. Also, the dual function characteristics of a zwitterionic surfactant were investigated by determining an isoelectric point, which were obtained using zeta potential measurement and QCM (quartz crystal microbalance) experiments. The isoelectric point of DEP-OSA82-AO zwitterionic surfactant determined by zeta potential measurement was close to that obtained by QCM experiment and both results have shown almost the same trend as that determined by the frictional property measured using an automated mildness tester. In particular, it has been observed that DEP32-OSA82-AO and DEP34-OSA82-AO surfactants provide better softening effect at a pH of acidic or neutral condition than at an alkaline condition. This result indicates that both surfactants act as a cationic surfactant at a pH of acidic or neutral condition and thus provide good softening effect during a rinsing cycle in the detergency process.
Mixing Characteristics of Sequential Blending with DME and LPG in Mixing Drum
Cheon, Suk Hoon ; Kim, Cha Hwan ; Shin, Dong Woo ; Kim, Lae Hyun ; Lee, Hyun Chan ; Baek, Young Soon ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 464~470
DOI : 10.9713/kcer.2012.50.3.464
To study characteristics of DME and Propane blended fuel in mixing drum as time passed, mixing experiment of two components was performed. After 20 wt% of DME and 80 wt% of Propane were injected into mixing drum sequentially, and the mixture ratio of blended fuel was analyzed at several sampling ports. Consequently, DME and Propane were not easily mixed and DME was sunk to the bottom of the mixing drum by the density difference. The daily rate of DME ingredient increase was 0.2-0.3 wt%, and it took over 500 hours until two of them were mixed uniformly. And after recirculation of blended fuel in mixing drum, DME and Propane were mixed immediately and uniformly.
Strategic Planning of Carbon Capture & Storage (CCS) Infrastructure Considering the Uncertainty in the Operating Cost and Carbon Tax
Han, Jee-Hoon ; Lee, In-Beum ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 471~478
DOI : 10.9713/kcer.2012.50.3.471
A carbon capture and storage (CCS) plays a very important role to reduce
emission sources which are distributed throughout various areas. Numerous research works have been undertaken to analyze the techno-economic feasibility of planning the CCS infrastructure. However, uncertainties such as
reduction costs, and carbon taxes may exist in various impact factors of the CCS infrastructure. However, few research works have adopted these uncertainties in designing the CCS infrastructure. In this study, a two-stage stochastic programming model is developed for planning the CCS infrastructure under uncertain operating costs and carbon taxes. It can help determine where and how much
to capture, store or transport for the purpose of minimizing the total annual
reduction cost in handling the uncertainties while meeting the
mitigation target. The capability of the proposed model to provide correct decisions despite changing the operating costs and carbon taxes is tested by applying it to a real case study based on Korea. The results will help to determine planning of a CCS infrastructure under uncertain environments.
Optimization of Integrated District Heating System (IDHS) Based on the Forecasting Model for System Marginal Prices (SMP)
Lee, Ki-Jun ; Kim, Lae-Hyun ; Yeo, Yeong-Koo ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 479~491
DOI : 10.9713/kcer.2012.50.3.479
In this paper we performed evaluation of the economics of a district heating system (DHS) consisting of energy suppliers and consumers, heat generation and storage facilities and power transmission lines in the capital region, as well as identification of optimal operating conditions. The optimization problem is formulated as a mixed integer linear programming (MILP) problem where the objective is to minimize the overall operating cost of DHS while satisfying heat demand during 1 week and operating limits on DHS facilities. This paper also propose a new forecasting model of the system marginal price (SMP) using past data on power supply and demand as well as past cost data. In the optimization, both the forecasted SMP and actual SMP are used and the results are analyzed. The salient feature of the proposed approach is that it exhibits excellent predicting performance to give improved energy efficiency in the integrated DHS.
A Study of Hydrodynamics and Reaction Characteristics in Relation to the Desulfurization Temperatures of Zn-Based Solid Sorbent in the Lab-scale High Pressure and High Temperature Desulfurization Process
Kyung, Dae-Hyun ; Kim, Jae-Young ; Jo, Sung-Ho ; Park, Young Cheol ; Moon, Jong-Ho ; Yi, Chang-Keun ; Baek, Jeom-In ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 492~498
DOI : 10.9713/kcer.2012.50.3.492
In this study, hydrodynamics such as solid circulation rate and voidage in the desulfurizer and the reaction characteristics of Zn-based solid sorbents were investigated using lab-scale high pressure and high temperature desulfurization process. The continuous HGD (Hot Gas Desulfurization) process consist of a fast fluidized bed type desulfurizer (6.2 m tall pipe of 0.015 m i.d), a bubbling fluidized bed type regenerator (1.6 m tall bed of 0.053 m i.d), a loop-seal and the pressure control valves. The solid circulation rate was measured by varying the slide-gate opening positions, the gas velocities and temperatures of the desulfurizer and the voidage in the desulfurizer was derived by the same way. At the same gas velocities and the same opening positions of the slide gate, the solid circulation rate, which was similar at the temperature of
, was low at those temperatures compared with a room temperature. The voidage in the desulfurizer showed a fast fluidized bed type when the opening positions of the slide gate were 10~20% while that showed a turbulent fluidized bed type when those of slide gate were 30~40%. The reaction characteristics of Zn-based solid sorbent were investigated by different desulfurization temperatures at 20 atm in the continuous operation. The
removal efficiency tended to decrease below the desulfurization temperature of
. Thus, the 10 hour continuous operation has been performed at the desulfurization temperature of
in order to maintain the high
removal efficiency. During 10 hour continuous operation, the
removal efficiency was above 99.99% because the
concentration after desulfurization was not detected at the inlet
concentration of 5,000 ppmv condition using UV analyzers (Radas2) and the detector tube (GASTEC) which lower detection limit is 1 ppmv.
Effects of Liquid Surface Tension on the Heat Transfer Coefficient in a Three-Phase Slurry Bubble Column
Lim, Ho ; Lim, Dae Ho ; Jin, Hae-Ryong ; Kang, Yong ; Jung, Heon ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 499~504
DOI : 10.9713/kcer.2012.50.3.499
Characteristics of overall heat transfer were investigated in a three-phase slurry bubble column with relatively low surface tension media, which has been frequently encountered in the fields of industry. The heat transfer phenomena was examined in the system which was composed of a coaxial vertical heater and a proper of bubble column. The heat transfer coefficient was estimated from the measured mean value of temperature difference between the heater surface and the column proper at the steady state condition. Effects of gas velocity (
), solid fraction in the slurry phase (
) and surface tension (
) of continuous liquid media on the overall heat transfer coefficient (h) in the bubble column were determined. The mean value of temperature difference was estimated from the data of temperature difference fluctuations with a variation of time. The amplitude and mean value of temperature difference fluctuations with respect to the elasped time appeared to decrease with decreasing the surface tension of liquid phase. The overall heat transfer coefficient between the immersed heated and the bubble column increased with an increase in the gas velocity or solid fraction in the slurry phase, but it decreased with an increase in the surface tension of continuous liquid media. The overall heat coefficient in the slurry bubble column with relatively low surface tension media was well correlated in term of operating variables and dimensionless groups within this experimental conditions.
The Effect of Partitioning Porous Plate on Bubble Behavior and Gas Hold-up in a Bench Scale (0.36 m × 22 m) Trayed Bubble Column
Yang, Jung Hoon ; Hur, Young Gul ; Lee, Ho-Tae ; Yang, Jung-Il ; Kim, Hak-Joo ; Chun, Dong Hyun ; Park, Ji Chan ; Jung, Heon ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 505~510
DOI : 10.9713/kcer.2012.50.3.505
The gas hold-up has a strong relationship with the size distribution and rising velocities of bubbles in a bubble column. Therefore, many previous researchers have studied on the hydrodynamics focusing on the bubble size variation in bubble column. In this study, the bubble behavior was influenced by partitioning porous plates installed at a certain height in a trayed bubble column. The gas hold-up was increased in non-sparging region (H/D > 5) as well as sparging region. We identified the effect of the partitioning porous plate using three trayed bubble columns with different reactor geometries. Furthermore, the bubble break-up frequency and size distribution were observed before and after individual bubbles penetrated through the plate. The arrangement of the plates was also investigated using a 0.15-m-in-diameter bubble column. Based on the result, we applied this design concept to a 0.36-m-in-diameter, 22 m tall trayed bubble column and identified the effect of the partitioning porous plate on the gas hold-up increase.
The Computer-Aided Simulation Study on the Gasification Characteristics of the Roto Coal in the Partitioned Fluidized-Bed Gasifier
Park, Young Cheol ; Moon, Jong-Ho ; Lee, Seung-Yong ; Lee, Dong-Ho ; Jin, Gyoung Tae ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 511~515
DOI : 10.9713/kcer.2012.50.3.511
In this study, we used a commercial simulator to investigate the gasification characteristics of Roto coal in the partitioned fluidized-bed gasifier, which consists of 4 parts such as coal pyrolysis, char gasification, tar/oil gasification and char combustion. The heating medium was exchanged between the combustion part and the gasification part in order to supply the energy needed for pyrolysis and gasification. The correlation model from experimental data in relation to the reaction temperatures, the reaction gases and the coal feed rates was derived for the coal pyrolysis. The equilibrium model was used for the gasification and the combustion model for the char combustion. In order to compare the reaction behavior of the partitioned fluidized-bed gasifier, the single-bed gasifier was also simulated. The cold gas efficiency of both partitioned fluidized-bed gasifier and single-bed gasifier was almost the same. The
contents of the syngas in the partitioned fluidized-bed gasifier slightly increased and the CO and
contents slightly decreased, compared with the singlebed gasifier. In order to verify the model, ten cases of the single-bed gasification experiment have been simulated. The contents of CO,
in the syngas from the simulation corresponded with the experimental data while those of
was slightly higher than experimental data, but the tendency of
content in the syngas was similar to the experiments. In the coal conversion, the simulation results were higher than the experiments since equilibrium model was used for the gasification so that the residence time and contact time in the model is different from the experiments.
A Model on a Bubbling Fluidized Bed Process for CO
Capture from Flue Gas
Choi, Jeong-Hoo ; Youn, Pil-Sang ; Kim, Ki-Chan ; Yi, Chang-Keun ; Jo, Sung-Ho ; Ryu, Ho-Jung ; Park, Young-Cheol ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 516~521
DOI : 10.9713/kcer.2012.50.3.516
This study developed a simple model to investigate effects of important operating parameters on performance of a bubbling-bed adsorber and regenerator system collecting
from flue gas. The chemical reaction rate was used with mean particles residence time of a reactor to determine the extent of conversion in both adsorber and regenerator reactors. Effects of process parameters - temperature, gas velocity, solid circulation rate, moisture content of feed gas - on
capture efficiency were investigated in a laboratory scale process. The
capture efficiency decreased with increasing temperature or gas velocity of the adsorber. However, it increased with increasing the moisture content of the flue gas or the regenerator temperature. The calculated
capture efficiency agreed to the measured value reasonably well. However the present model did not agree well to the effect of the solid circulation rate on
capture efficiency. Better understanding on contact efficiency between gas and particles was needed to interpret the effect properly.
Solid Descending Velocity by Gravity in a Vertical Downcomer
Ryu, Ho-Jung ; Park, Jaehyeon ; Shun, Do-Won ; Lee, Seung-Yong ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 522~526
DOI : 10.9713/kcer.2012.50.3.522
New experimental method to measure solid descending velocity in a vertical downcomer was presented and effects of downcomer diameter and particle properties on descending velocities for Geldart group A, B, and D particle have been measured and investigated. The effect of initial solid inventory on solid descending velocity was negligible. However, solid flow rate, solid circulation rate and solid descending velocity increased as the downcomer diameter increased. Moreover, solid descending velocity increased linearly as the downcomer diameter increased and showed distinguishable trend for Geldart group D particle from Geldart group A and B particles. Empirical correlations of solid descending velocity for Geldart group D and Geldart group A and B particles have been derived based on the measured values. The correlations could predict well the solid descending velocities.
Adsorption Dynamics of Activated Carbon and Carbon Molecular Sieve Beds for Ethylene Recovery
Yoon, Ki-Yong ; Jun, Phillip ; Woo, En-Ji ; Ahn, Hyungwoong ; Lee, Chang-Ha ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 527~534
DOI : 10.9713/kcer.2012.50.3.527
The adsorption dynamics of activated carbon (AC) and carbon molecular sieve (CMS) beds were studied to recover ethylene from FCC fuel gas. In this study, the FCC fuel gas used consisted of six-component mixture (
,32:15:14:2:12:25 vol.%). And the breakthrough experiments of adsorption and desorption were carried out. The breakthrough sequence in the AC bed was
while the sequence in the CMS bed was
. The separation performance of the CMS bed during the adsorption step was lower than that of the AC bed. However, due to the characteristics of kinetic separation, the CMS bed could remove
as well asthe molecules that are larger than
, which was not easy to be done by the AC bed. Since it was hard to regenerate the adsorption bed by simple depressurization, vacuum regeneration should be adopted. As a result, the pressure vacuum swing adsorption (PVSA) process, consisting of CMS pretreatment process and AC main process, was suggested to recover ethylene efficiently.
Filtration with Sedimentation II: New Analysis and Solid Mass Fraction of Suspension Entering Cake
Yim, Sung Sam ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 535~544
DOI : 10.9713/kcer.2012.50.3.535
Filtration on horizontal filter medium facing upward is accompanied by sedimentation. When sedimentation phenomenon is not considered, the average specific cake resistance by filtration could be in error more than two times. In the previous paper on this subject, it was insisted that the solid mass fraction of suspension changes in filtration period by sedimentation. But we could not find out the degree of change. At the first half of this paper, the average specific cake resistance measured by permeation will be proved to be exact in several means. The average specific cake resistance conventionally measured by filtration does not give correct results because it uses initial solid mass fraction of suspension. Then we calculated the changed solid mass fraction of suspension due to sedimentation during filtration by the experimental values obtained "filtration-permeation" method. We also determined the solid mass fraction at a certain moment of filtration from the suspension height and a new equation derived in this study. The two results were compared and proven that they almost matched.
Optimization Condition of Astaxanthin Extract from Shrimp Waste Using Response Surface Methodology
Yoon, Chang Hwan ; Bok, Hee Sung ; Choi, Dae Ki ; Row, Kyung Ho ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 545~550
DOI : 10.9713/kcer.2012.50.3.545
A 17-run Box-Behnken design (BBD) was used to optimize the extraction conditions of astaxanthin from shrimp waste. Three factors such as ratio of ethanol to raw material, extraction temperature (
) and extraction time (min) were investigated. The adjusted coefficient of determination (
) for the model was 0.9218, and the probability value (p=0.0003) demonstrated a high significance for the regression model. The optimum extraction conditions were found to be: optimized ratio of ethanol to raw material 29.7, extraction temperature
and extraction time 59.9 min. Under these conditions, the mean extraction yield of astaxanthin was
, which was in good agreement with the predicted model value. Under these conditions, validation experiments were done and the mean extraction yield of astaxanthin was
, which is in good agreement with the predicted model value.
A Study on the Thermal Adsorption and Desorption Characteristics of Industrial Odorants using Activated Carbon
Kim, Joo Yeon ; Rhee, Young Woo ; Han, Mun Hee ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 551~555
DOI : 10.9713/kcer.2012.50.3.551
Desorption reaction characteristics of the commercial activated carbons which were used for the removal of industrial odorants were investigated. BET specific surface area was analyzed to investigate the chemicophysical property of activated carbon. Adsorptivity of activated carbon was estimated by iodine number. Thermogravimetric analyzer (TGA) was used to investigate the desorption characteristics. Activation energies and reaction orders for reaction characteristics according to adsorption and desorption of activated carbons were estimated by employing the Friedman method and Freeman-Carroll method. Adsorptivity of reprocessed activated carbons were significantly lower than that of fresh activated carbons. In this study, it was found that the activation energies were 15.9~23.4 kJ/mol in Friedman method and 22.7~33.8 kJ/mol in Freeman-Carroll method.
Numerical Study on the Effect of Gas Diffusion Layer (GDL) Properties in Cathode on the Performance of Polymer Electrolyte Membrane Fuel Cell (PEMFC)
Chun, Jeong Hwan ; Jo, Dong Hyun ; Lee, Ji Young ; Kim, Sung Hyun ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 556~561
DOI : 10.9713/kcer.2012.50.3.556
In this study, the effect of properties of gas diffusion layer (GDL) on the performance of polymer electrolyte membrane fuel cell (PEMFC) was investigated using the numerical simulation. The multi-phase mixture (
) model was used to calculate liquid water saturation and oxygen concentration in GDL. GDL properties, which were contact angle, porosity, gas permeability and thickness, were changed to investigate the effect of GDL properties on the performance of PEMFC. The results demonstrated that performance of PEMFC was increased with increasing contact angle and porosity of GDL, but decreased with increasing thickness of GDL. The liquid water saturation was decreased but oxygen concentration was increased at the GDL-catalyst layer interface, because the mass transfer resistance decreased as the porosity and contact angle increased. On the other hands, as the thickness of GDL increased, pathway for liquid water and oxygen gas became longer, and then mass transfer resistance increased. For this reason, performance of PEMFC decreased with increasing thickness of GDL.
Fabrication and Property Evaluation of Tubular Segmented-in-Series Solid Oxide Fuel Cell (SOFC)
Yun, Ui-Jin ; Lee, Jong-Won ; Lee, Seung-Bok ; Lim, Tak-Hyoung ; Park, Seok-Joo ; Song, Rak-Hyun ; Shin, Dong-Ryul ; Han, Kyoo-Seung ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 562~566
DOI : 10.9713/kcer.2012.50.3.562
A novel design of tubular segmented-in-series(SIS) solid oxide fuel cell (SOFC) sub module was presented in this paper. The tubular ceramic support was fabricated by the extrusion technique. The NiO-YSZ anode and the yttria-stabilized zirconia (YSZ) electrolyte were deposited onto the ceramic support by dip coating method. After sintering at
for 5 h, a dense and crack-free YSZ film was successfully fabricated. Also, the multi-layered cathode composed of LSM-YSZ composite, LSM and LSCF were coated onto the sintered ceramic support by dip coating method and sintered at
. The performance of the tubular SIS SOFC cell and sub module electrically connected by the Ag-glass interconnect was measured and analysed with different fuel flow and operating temperature.
A Study on Recovery of Aluminum Oxide from Artificial Marble Waste by Pyrolysis
Kim, Bok Roen ; Kim, Chang Woo ; Seo, Yang Gon ; Lee, Young Soon ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 567~573
DOI : 10.9713/kcer.2012.50.3.567
Compared with the natural marble, the artificial marble has the advantages of excellent appearance, high degree of finish, even color, fine pressure and wear resistance, bear erosion and weathering, etc. It can be widely used in kitchen countertops, bath vanity tops, table tops, furniture, reception desks, etc. However, large amounts of artificial marble waste such as scraps or dust have been generated from sawing and polishing processes in artificial marble industry. Waste from artificial marble industry is increasing according to demand magnification of luxurious interior material. Artificial marble wastes can be recycled as aluminum oxide used as raw materials in electronic materials, ceramics production, etc., and methyl methacrylate(MMA) which become a raw material of artificial marble by pulverization, pyrolysis and distillation processes. The characteristics of artificial marble wastes was analyzed by using TGA/DSC and element analysis. Crude aluminum oxide was obtained from artificial marble waste by pulverization and thermal decomposition under nitrogen atmosphere. In this work, Box-Behnken design was used to optimize the pyrolysis process. The characteristics of crude aluminum oxide was evaluated by chromaticity analysis, element analysis, and surface area.
Characterization of Thin Film Passivation for OLED by PECVD
Kim, KwanDo ; Jang, SeokHee ; Kim, JongMin ; Chang, SangMok ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 574~581
DOI : 10.9713/kcer.2012.50.3.574
The relatively short lifetime is a major obstruction for the commercial applications of OLED. One of the reason for the short lifetime is that the organic materials are interacted with water or oxygen in the atmosphere. Protection of water or oxygen from diffusing into the organic material layers are necessary to increase the lifetime of OLED. Although encapsulation of OLED with glass or metal cans has been established, passivation methods of OLED by organic/inorganic thin films are still being developed. In this paper we have developed in-situ passivation system and thin film passivation method using PECVD by which deposition can be performed at room temperature. We have analyzed the characteristics of the passivated OLED device also. The WVTR (Water Vapor Transmission Rate) for the inorganic thin film mono-layer can be reached down to
and improved lifetime can be obtained. Thin film passivation methods are expected to be applied to flexible display.
Study on Isothermal Crystallization Characteristics of PLA Film by Adding APP as a Nucleation Agent
Kim, Gyu-Sun ; Kim, Moon-Sun ; Kim, Byung-Woo ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 582~587
DOI : 10.9713/kcer.2012.50.3.582
In this paper, it was studied on the crystallization characteristics of PLA film by adding ammonium phosphate (APP) as a nucleation agent. Crystallinity and crystallite size of PLA film were determined by Scherrer equation. Crystallization rate constant of PLA film was calculated through Avrami equation. Film samples in the study were prepared by two steps. PLA films were prepared by adding 1, 5, and 10 wt%, respectively, at first and was secondly annealed at 130, 140, and
. Crystallinity of pure PLA film was average 4.6% and those of PLA film with adding 1, 5, and 10 wt% APP were 12.2, 47.7, and 50.0%, respectively. Crystallite size of PLA film was average 28.0 nm and those of PLA film with adding 1, 5, and 10 wt% APP were 26.8, 24.0, and 19.0 nm, respectively. Crystallization rate constants of PLA film with 1 wt% APP were 2.12, 3.86, and 0.27 by annealing at 130, 140, and
, respectively, where was higher than pure PLA film and those with adding 5 and 10 wt% APP, respectively.
Preparation and Characteristic of Sheet Molding Compound using Unsaturated Polyester Resin with Low Profile Agent of Polystyrene
Bae, Gi Boong ; Lee, Sang Goo ; Yoon, Hong Jin ; Lee, Jong Dae ;
Korean Chemical Engineering Research, volume 50, issue 3, 2012, Pages 588~593
DOI : 10.9713/kcer.2012.50.3.588
Compatibility of unsaturated polyester (UP) and low profile agent (LPA) of polystyrene (PS) have been investigated under various mixing conditions such as the ratio of UP and LPA, mixing time, mixing temperature, and input amount of 2nd UP. It was possible to obtain mixture with small particle size and low phase separation in condition of 35 g of LPA, 25 g of 1st UP input, 5 min of mixing time, 1700 rpm of mixing speed, and 45 g of 2nd UP input. It was found that compatibility of UP and LPA was very sensitive to mixing conditions. In addition, molded sample using sheet molding compound prepared by stable mixing condition appeared good properties such as low water adsorption, low shrinkage, and high gloss.