Go to the main menu
Skip to content
Go to bottom
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 51, Issue 6 - Dec 2013
Volume 51, Issue 5 - Oct 2013
Volume 51, Issue 4 - Aug 2013
Volume 51, Issue 3 - Jun 2013
Volume 51, Issue 2 - Apr 2013
Volume 51, Issue 1 - Feb 2013
Selecting the target year
Recent Advances in the Mechanistic Studies of Alkylaromatic Conversions over Zeolite Catalysts
Min, Hyung-Ki ; Hong, Suk Bong ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 1~9
DOI : 10.9713/kcer.2013.51.1.1
The transformation of alkylaromatic hydrocarbons using zeolite catalysts play big part in the current petrochemical industry. Here we review recent advances in the understanding of the reaction mechanisms of various alkylaromatic conversions with respect to the structural and physicochemical properties of zeolite catalysts employed. Indeed, the shape-selective nature of zeolite catalysts determines the type of reaction intermediates and hence the prevailing reaction mechanism together with the product distribution. The prospect of zeolite catalysis in the developement of more efficient petrochemical processes is also described.
State-of-arts in Multiscale Simulation for Process Development
Lim, Young-Il ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 10~24
DOI : 10.9713/kcer.2013.51.1.10
The state-of-arts of multiscale simulation (MSS) in science and engineering is briefly presented and MSS for process development (PD-MSS) is proposed to effectively apply the MSS to the process development. The four-level PD-MSS is composed of PLS (process-level simulation), FLS (fluid-level simulation), mFLS (microfluid-level simulation) and MLS (molecular-level simulation). Characteristics and methods of each level, as well as connectivity between the four levels are described. For example in PD-MSS, absorption column, fluidized-bed reactor, and adsorption process are introduced. For successful MSS, it is necessary to understand the multiscale nature in chemical engineering problems, to develop models representing physical phenomena at each scale and between scales, to develop softwares implementing mathematical models on computer, and to have strong computing facilities. MSS should be performed within acceptable accuracy of simulation results, available computation capacity, and reasonable efficiency of calculation. Macroscopic and microscopic scale simulations have been developed relatively well but mesoscale simulation shows a bottleneck in MSS. Therefore, advances on mesoscale models and simulation tools are required to accurately and reliably predict physical phenomena. PD-MSS will find its way into a sustainable technology being able to shorten the duration and to reduce the cost for process development.
Optimal Design of Natural Gas Liquefaction Processes
Cho, Hyun Jun ; Yeo, Yeong-Koo ; Kim, Jin-Kuk ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 25~34
DOI : 10.9713/kcer.2013.51.1.25
The paper reviews the state of art in the design of liquefaction processes for the production of liquified natural gas, and addresses key design aspects to be considered in the design and how these design issues are systematically reflected in industrial applications. Various design options to improve energy efficiency of refrigeration cycles are discussed, including cascaded or multi-level pure refrigeration cycles which are used for covering wide range of cooling temperature, as well as mixed refrigerant cycle which can maintain a simple structure. Heat integration technique has been used for graphically examining differences of commercial cycles discussed in this paper, while energy efficiency and economics of commercial liquefaction processes has been summarized. Discussion also has been made about how to select the most appropriate set of drivers for compressors used in the liquefaction plant.
Hydrolysis Reaction Using Co-P-B Catalyst Supported on FeCrAlloy
Hwang, Byungchan ; Jo, Ara ; Sin, Sukjae ; Choi, Daeki ; Nam, Sukwoo ; Park, Kwonpil ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 35~41
DOI : 10.9713/kcer.2013.51.1.35
hydrolysis reaction using Co-P-B/FeCrAlloy catalyst and the catalyst durability were studied. Co-P-B/FeCrAlloy catalyst showed low activation energy such as 25.2 kJ/mol in 5 wt%
solution, which was similar that of noble metal catalyst. The activation energy increased as the
concentration increased. Formation of gel at high concentration of
seriously affected hydrogen evolution rate and the catalyst durability. The catalyst loss decreased as reaction temperature increased due to lower gel formation when the concentration of
was over 20 wt%. Considering hydrogen generation rate and durability of catalyst, the catalyst supported with FeCrAlloy heat-treated at
without ultra vibration during dipping and calcination after catalyst dipping was best catalyst. To use catalyst more than three times in 25 wt%
solution, it should be reacted at higher temperature than
Extraction of Fucoxanthin from Undaria pinnatifida and Stability of Fucoxanthin
Shin, Soo Cheol ; Ahn, Myeong Won ; Lee, Jung Shik ; Kim, Young Suk ; Park, Kwon Pil ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 42~46
DOI : 10.9713/kcer.2013.51.1.42
Extraction process of fucoxanthin from Undaria pinnatifida and stability of fucoxanthin was studied. In this study, to utilized extracted components as a functional food material, ethanol was used as a solvent. The maximum concentration of fucoxanthin was obtained when 80% ethanol solvent was used. The extraction yield of fucoxanthin increased as extraction temperature raised to
. Water washing of raw material for 5 minutes reduced the salt content about 94%. From the experiment that fucoxanthin content reduced by 30% for 1 day storage at
, it was demonstrated that fucoxanthin was thermal-unstable above
. And experimental result of light- stability showed that fucoxanthin was very unstable with light.
Autothermal Reforming of Propane over Ni/Ce
Kong, Jin-Hwa ; Park, Nam-Cook ; Kim, Young-Chul ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 47~52
DOI : 10.9713/kcer.2013.51.1.47
In this study, the catalytic performance and characterization of
were investigated using an autothermal reforming (ATR) process for hydrogen production. The
catalysts were prepared using the following methods: the water method (CZ-W), urea water method (CZ-UW) and urea, water and ethanol method (CZ-UWA). The performance of
catalysts in autothermal reforming of propane for hydrogen production was studied in a fixed-bed flow reactor. Reaction tests were conducted by using a feed of
. The CZ-UW and CZ-UWA catalysts showed higher propane conversion and hydrogen yield than the CZ-W catalyst. The activity test confirmed that the improvement in the water-ethanol catalyst was due to the low level of carbon deposition. SEM showed that the surface carbon consisted of clusters on the used CZ-UW catalyst, which is incontrast to the nano-fiber morphology observed on the used CZ-UWA catalyst. It was found that the amount of carbon deposition depends on the preparation method. Especially the
was showed higher propane conversion and hydrogen yield than the other catalysts. Also TGA showed that the resistance of carbon deposition increase to Co addition.
Solvent Extraction of Lithium Ion in Aqueous Solution Using TTA and TOPO
Lee, Jeon-Kyu ; Jeong, Sang-Gu ; Koo, Su-Jin ; Kim, Si-Young ; Ju, Chang-Sik ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 53~57
DOI : 10.9713/kcer.2013.51.1.53
For the purpose of development of the extraction process of lithium ion from concentrated water eliminated from desalination process, an experimental research on the solvent extraction of lithium ion from aqueous solutions was performed. The effects of operating parameters, such as concentration of extractant, ratio of extracting solution/aqueous solution, pH of aqueous solution, were examined. The effect of sodium chloride, the major component of sea water, was also examined. Lithium ion in aqueous solutions of pH=10.2~10.6 adjusted by ammonia solution was most effectively extracted by extracting solution composed of 0.02 M TTA and 0.04 M TOPO in kerosine. The addition of sodium chloride in lithium aqueous solution significantly interfered the extraction of lithium ion.
Transesterification Kinetics of Dimethyl Terephthalate with 1,4-Butanediol
Cho, Impyo ; Lee, Jinhong ; Jo, Sanhwan ; Cho, Minjung ; Han, Myungwan ; Kang, Kyungsuk ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 58~67
DOI : 10.9713/kcer.2013.51.1.58
PBT (polybutylene terephthalate) has excellent mechanical properties such as low absorption, dimensional stability, abrasion resistance. It is used in manufacturing electronic components, the automobile part and the various precise parts. Bis (hydroxybutyl) terephthalate (BHBT) which is a PBT monomer, can be produced by transesterification reaction of DMT (dimethyl terephthalate) with 1,4-butandiol (BD). The kinetics of transesterification reaction of DMT with BD using zinc acetate as a catalyst was studied in a batch reactor. Previous kinetic studies was carried out in a semibatch reactor where generated methanol was removed so that reverse reactions were not considered in the kinetic expressions, resulting in inaccuracy of the kinetic model. Mathematical models of a batch reactor for the transesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. More accurate models than previous models was obtained and found to have a good agreement between model predictions and experimental data.
Effect of Electrode Degradation on the Membrane Degradation in PEMFC
Song, Jinhoon ; Kim, Saehoon ; Ahn, Byungki ; Ko, Jaijoon ; Park, Kwonpil ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 68~72
DOI : 10.9713/kcer.2013.51.1.68
Until a recent day, degradation of PEMFC MEA (membrane and electrode assembly) has been studied, separated with membrane degradation and electrode degradation, respectively. But membrane and electrode were degraded coincidentally at real PEMFC operation condition. During simultaneous degradation, there was interaction between membrane degradation and electrode degradation. The effect of electrode degradation on membrane degradation was studied in this work. We compared membrane degradation after electrode degradation and membrane degradation without electrode degradation. I-V performance, hydrogen crossover current, fluoride emission rate (FER), impedance and TEM were measured after and before degradation of MEA. Electrode degradation reduced active area of Pt catalyst, and then radical/
evolution rate decreased on Pt. Decrease of radical/
reduced the velocity of membrane degradation.
Preparation of Conductive Coating Solutions by Blending Waterborne Acrylic Polyurethane Dispersion with Carbon Nanotube
Huh, Woo Young ; Yun, Dong Gu ; Song, Ki Chang ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 73~79
DOI : 10.9713/kcer.2013.51.1.73
Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions.
Photocatalytic Treatment of Waste Air Containing Malodor and VOC by Photocatalytic Reactor Equipped with the Cartridges Containing the Media Carrying Photocatalyst
Lim, Kwang-Hee ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 80~86
DOI : 10.9713/kcer.2013.51.1.80
In this study, the photocatalytic reactor system equipped with photocatalyst-carrying-silica-media cartridges [photocatalytic reactor system (1)] was used to perform the treatment of waste air containing malodor and volatile organic compound (VOC). The result of its performance was evaluated and compared with that of the photocatalytic reactor system equipped with commercial photocatalyst-carrying-nonwoven filter-media cartridges [photocatalytic reactor system (2)]. In case of photocatalytic reactor system (1), at the 1st stage of run the removal efficiencies of ethanol and toluene continued to be 80% and 20%, respectively. However, unlike toluene, the removal efficiency of ethanol dropped to 40% at the end of the 1st stage of run. The removal efficiency of hydrogen sulfide decreased from 100% to 90%. At the 2nd stage of its run the removal efficiency of ethanol decreased to 10% while the removal efficiencies of hydrogen sulfide and toluene remained as same as 90% and 20%, respectively, even though the inlet load of toluene increased by factor of four. In the 3rd stage of its run, as the result of application of aluminium-coated reflector film to the inner wall of photocatalytic reactor system, the removal efficiencies of ethanol and toluene increased by 5% to be 15% and 25%, respectively. In case of photocatalytic reactor system (2), at the 1st stage of its run, the removal efficiencies of ethanol, hydrogen sulfide and toluene continued to be 10%, 97% and 100%, respectively. However, at 2nd stage of its run their removal efficiencies became 5%, 95% and 2~3%, respectively, which showed that the removal efficiencies of ethanol and hydrogen sulfide decreased insignificantly while the removal efficiency of toluene dropped significantly from the perfect elimination. Moreover, the reflector film did not affect the performance of photocatalytic reactor system (2) at all. Therefore the removal of ethanol, hydrogen sulfide and toluene by photocatalytic reactor system (2) was mainly attributed to hydrophobic adsorption of its nonwoven filter media and its extent of photocatalytic removal turned out to be negligible, compared to that of photocatalytic reactor system (1).
Sensitivity Analysis with Optimal Input Design and Model Predictive Control for Microalgal Bioreactor Systems
Yoo, Sung Jin ; Oh, Se-Kyu ; Lee, Jong Min ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 87~92
DOI : 10.9713/kcer.2013.51.1.87
Microalgae have been suggested as a promising feedstock for producing biofuel because of their potential of lipid production. In this study, a first principles ODE model for microalgae growth and neutral lipid synthesis proposed by Surisetty et al. (2010) is investigated for the purpose of maximizing the rate of microalgae growth and the amount of neutral lipid. The model has 6 states and 12 parameters and follows the assumption of Droop model which explains the growth as a two-step phenomenon; the uptake of nutrients is first occurred in the cell, and then use of intra-cellular nutrient to support cells growth. In this study, optimal input design using D-optimality criterion is performed to compute the system input profile and sensitivity analysis is also performed to determine which parameters have a negligible effect on the model predictions. Furthermore, model predictive control based on successive linearization is implemented to maximize the amount of neutral lipid contents.
Experimental Distillation of Ethanol-Propanol Mixture Using a Horizontal Column
Kim, Byoung Chul ; Kim, Young Han ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 93~97
DOI : 10.9713/kcer.2013.51.1.93
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.
Characteristic of Water Pervaporation Using Hydrophilic Composite Membrane Containing Functional Nano Sized NaA zeolites
Oh, Duckkyu ; Lee, Yongtaek ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 98~105
DOI : 10.9713/kcer.2013.51.1.98
The NaA zeolite particles were dispersed in a poly(vinyl alcohol) (PVA) matrix to prepare a composite membrane. The nano sized zeolite particles of NaA were synthesized in the laboratory and the mean size was approximately 60 nm. Pervaporation characteristics such as a permeation flux and a separation factor were investigated using the membrane as a function of the feed concentration from 0.01 to 0.05 mole fraction and the weight % of NaA particles between 0 wt% and 5 wt% in the membrane. Also, the micro sized particles of
were dispersed in the membrane for a comparison purpose. When the ethanol concentration in the feed solution was 0.01 mole fraction, the flux of water significantly increased from
as the content of the nano NaA particles in the membrane increased from 0 wt% to 5 wt%, while the NaA particles improved the separation factor from 1.5 to 7.9. When the flux of water through the membrane containing nano sized particles was roughly 15% increased compared to the micro sized particles, whereas the separation factor of water was found to be approximately 5% increased. It can be said that the role of the nano sized NaA particles is quite important since both the flux and the separation factor are strongly affected.
Production of Reducing Sugar from Macroalgae Saccharina japonica Using Ionic Liquid Catalyst
Park, Don-Hee ; Jeong, Gwi-Taek ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 106~110
DOI : 10.9713/kcer.2013.51.1.106
In this work, we investigated 20 kinds of ionic liquids as catalyst during the hydrolysis of Saccharina japonica. Three kinds of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate, n-butyl-4-methylpyridinium tetrafluoroborate, and n-methylmorpholine [
], are selected, and then investigated the effect of reaction temperature, catalyst amount and reaction time. The hydrolysis of S. japonica was increased by the increasing of reaction temperature and ionic liquid amount. Also, the hydrolysis presented the linear increase by the increasing of reaction time. After 90 min of reaction, the concentrations of reducing sugar of 1-ethyl-3-methylimidazolium tetrafluoroborate, n-butyl-4-methylpyridinium tetrafluoroborate, and n-methylmorpholine [
] are reached to 6.2 g/L, 6.4 g/L and 6.0 g/L, respectively. As an overall result, we obtained the possibility of hydrolysis of marine biomass using ionic liquids.
Enzymatic Synthesis of Flame Retardant Phenolic Polymers Catalyzed by Horseradish Peroxidase
Park, Han Sol ; Park, Jung Hee ; Lee, Hak Sung ; Ryu, Keungarp ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 111~115
DOI : 10.9713/kcer.2013.51.1.111
The optimum synthetic conditions of poly(p-phenylphenol) by horseradish peroxidase in dioxane:water (80:20 v/v) mixtures were studied. The stability against thermal degradation and structural properties of the synthesized phenolic resins were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The synthetic yield of poly(p-phenylphenol) increased upon the increase of the amount of enzyme up to 0.25 mg HRP/mL, then leveled off for further increase of the enzyme usage. When sodium acetate (100 mM, pH 4~6) and sodium phosphate (100 mM, pH 7~9) were used as the buffering salts for the aqueous component (20% v/v), the synthetic yield of the resin increased at higher pH of the aqueous buffer. But when the pHs of the aqueous buffer were 6 and 9, the synthetic yield strongly depended on the types of the buffering salts; if sodium phosphate was used instead of sodium acetate at pH 6, the yield decreased by about 15% and if sodium bicarbonate was used instead of sodium phosphate, the yield decreased by almost 20%. When the pH range of the aqueous buffer was from 4 to 7, the addition of a radical mediator, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS), up to 2 mM improved the synthetic yield of the resin by about 10%. TGA experiments revealed that the thermal stability of the resin synthesized in dioxane:water (100 mM sodium phosphate, pH 9) (80:20 v/v) was high having the char yield of 47% upon the heating at
. DCS results showed that the structures of the polymers synthesized in acidic aqueous buffers were different from those of the polymers synthesized in the basic aqueous buffers. However, all the synthesized resins were found to have the property of the thermosetting resins.
Characteristics of CO Removal Process Using TiO
Kim, Jin-Kil ; Lee, Sang-Moon ; Hong, Sung-Chang ; Lee, Eui-Dong ; Kang, Yong ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 116~120
DOI : 10.9713/kcer.2013.51.1.116
Characteristics of photocatalytic CO removal process conducting CO conversion by using Pt loaded
photocatalyst were investigated in a photocatalytic tubular reactor. Effects of Pt loading method onto
, linear velocity of gas stream containing CO gas, CO concentration and moisture content in the gas stream on the conversion of CO to
were examined. It was found that the CO gas could be removed almost 100% by using photocatalytic tubular reactor internally coated with Pt/
photocatalyst under UV irradiation, when the linear velocity of gas stream was in the range of 0.01~0.25 m/s and CO concentration in the gas stream was ranged from 20 to 100 ppm and the relative humidity of the gas stream was in the range of 20~40%. The conversion of CO gas decreased gradually with increasing linear velocity of gas stream and CO concentration in the gas stream. The moisture in the gas stream could promote the removal of CO gas by means of the generation of OHradicals.
Thermal Behavior and Kinetics of Coal Blends during Devolatilization
Ryu, Kwang-Il ; Kim, Ryang-Gyoon ; Li, Dong-Fang ; Wu, Ze-Lin ; Jeon, Chung-Hwan ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 121~126
DOI : 10.9713/kcer.2013.51.1.121
The objective of this research is to predict the TG curve of blends of bituminous coal and sub-bituminous coal during devolatilization. TSL (Thermal Shock Large) TGA was used for Experiments, and Coats-redfern method was used for reaction order calculation. Based on reaction order, sum method was verified to be suitable for a single coal, then, prediction and comparison of TG curve of coal blends was conducted using both of WSM (Weight Sum Method) and MWSM (Modified Weight Sum Method), where the latter was developed in this research. The presented experiment results and WSM & MWSM were showed to be reasonable using linear least square method. MWSM performed more accurately than WSM for the case that TG curve had different slopes and the case that sharp weight loss happened due to release of volatile matter. The results showed that it's possible to predict the thermal behavior of coal blends during devolatilization based on the thermal behavior of single coals.
Biofilter Treatment of Waste Air Containing Malodor and VOC: 1. Pressure Drop and Microbe-population Distribution of Biofilter with Improved Design
Lee, Eun Ju ; Lim, Kwang-Hee ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 127~135
DOI : 10.9713/kcer.2013.51.1.127
In this study, both pressure drop and microbe-population-distribution were observed while running a novel biofilter system with improved design in which the biofilter system is composed of two, upper and lower biofilters with both equal feed-rates of up-flow and down-flow, respectively. Then they were compared with the pressure drop and microbe-population-distribution observed in a conventional biofilter of the same effective volume with unidirectional flow. The pressure drop-value of biofilter system with improved design turned out to be less at the incipient stage of run or steady-state long term operation by more than 40~80% of that of the conventional biofilter. The microbe-population-distribution was observed to be lower and higher at higher and lower column of biofilter, respectively, for both the conventional biofilter and the biofilter system with improved design. The microbe-media of waste-tire crumb showed much greater CFU counts than GAC. In the biofilter system with improved design, the
feeding of waste air showed greater microbe-population growth than the
feeding for both the microbe-media of waste-tire crumb and GAC. However, it was more prominent for the former than the latter. Comparing the microbe-population-distributions of both of the conventional biofilter and the biofilter system with improved design, the microbe-population of latter was distributed ca. 15 and 2.5 times more evenly for GAC and the media of waste-tire crumb, respectively, than that of former.
Biofilter Treatment of Waste Air Containing Malodor and VOC: 2. Transient Behavior of Biofilter with Improved Design to Eliminate Malodor and VOC
Lee, Eun Ju ; Lim, Kwang-Hee ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 136~143
DOI : 10.9713/kcer.2013.51.1.136
In this study, both transient behaviors of a biofilter system with improved design and a conventional biofilter were observed to perform the treatment of waste air containing malodor and volatile organic compound (VOC). Their behaviors of removal efficiency and treated concentration of malodor and VOC were compared each other. During 1st~7th stages of improved biofilter system operation it was observed that the order of treated ethanol concentration at each sampling port was switched due to the difference of microbe-population-distribution in spite of the difference of biofilter effective height. However, at 8th stage of its operation, the order of treated ethanol concentration at each sampling port was consistent to the order of biofilter effective height at each sampling port. The same was applied to the case of hydrogen sulfide, even though the difference of switched treated-hydrogen sulfide-concentrations was less than that of switched treated-ethanol-concentrations. The ethanol-removal efficiency of the biofilter system with improved design was ca. 96%, which was greater by 2% than that of the conventional biofilter. The transient behavior of treated hydrogen sulfide concentration of both biofilters were similar to each other. However, the concentration of hydrogen sulfide treated by the biofilter system with improved design was observed lower than that by the conventional biofilter. The hydrogen sulfide-removal efficiency of the biofilter system with improved design was higher by ca. 2% than that of the conventional biofilter. Therefore, the hydrogen sulfide-removal efficiency of the biofilter system with improved design was observed to be enhanced by the same as its ethanol-removal efficiency.
Transesterification of Dimethyl Terephthalate with Ethylene Glycol
Lee, Jinhong ; Cho, Impyo ; Jo, Sanhwan ; Cho, Minjung ; Han, Myungwan ; Kang, Kyungsuk ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 144~150
DOI : 10.9713/kcer.2013.51.1.144
The kinetics of the transesterification of dimethyl terephthalate (DMT) with ethylene glycol (EG) was studied in a batch reactor. Bishydroxyethyl terephthalate (BHET), which is poly(ethylene terephthalate) (PET) monomer, can be produced by the transesterification reaction. Zinc acetate was used as a catalyst. Previous kinetic studies was carried out in a semi-batch reactor where generated methanol was removed so that reverse reactions were not considered in the kinetic expressions, resulting in inaccuracy of the kinetic model. Mathematical models of a batch reactor for the tranesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. More accurate models than previous ones were obtained and found to have a good agreement between model predictions and experimental data. Effect of process variables on the esterification reaction was investigated based on the experimental and simulation results.
Biomineralization in Microfluidic Crystallizer
Seo, Seung Woo ; Ko, Kwan Young ; Lee, Chang Soo ; Kim, In Ho ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 151~156
DOI : 10.9713/kcer.2013.51.1.151
is practiced on a polymethylsiloxane (PDMS) - based microfluidic system. Liquid- liquid reaction was investigated by mixing calcium chloride (
) and sodium carbonate (
) solution to crystallize
. Aspartic acid (Asp) was added to investigate the morphology change such as vaterite and calcite. Suitable ratio of
was searched for initial seed formation. Christmas tree model was used as microfluidic device to form concentration gradient of
. After observing microfluidic channel by using optical microscope, we found that seeds of
were formed under the condition that the ratio of
was 2:1. Morphology of crystals were also observed as
crystals grow. When Asp was added, vaterite crystal was more frequently found in two morphologies (vaterite and calcite) and seed formation and crystal growth were inhibited.
Preparation of Dye Sensitized Solar Cell Using Coumarin Dyes Extracted from Plants
Jung, Onyu ; Lee, Sang-Soo ;
Korean Chemical Engineering Research, volume 51, issue 1, 2013, Pages 157~161
DOI : 10.9713/kcer.2013.51.1.157
Low priced and environment-friendly natural dye from coumarin- containing plants for the dye sensitized solar cell (DSSC) was developed. Dyes were extracted from cinnamon and angelica that contained coumarin derivatives, and DSSCs employing these dyes were prepared. PV efficiency of 0.75% was obtained from cinnamon dye, which is comparable to the highest efficiency reported in precedent studies about natural dye DSSC. It was confirmed by UV-visible and FT-IR spectroscopy that coumarin derivatives in the plants acted as photosensitive material.