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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
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Volume & Issues
Volume 54, Issue 4 - Aug 2016
Volume 54, Issue 3 - Jun 2016
Volume 54, Issue 2 - Apr 2016
Volume 54, Issue 1 - Feb 2016
Selecting the target year
Production of PBT(polybutylene terephthalate) Oligomer from Recycled PET(polyethylene terephthalate)
Cho, Minjeong ; Yang, Jeongin ; Noh, Seunghyun ; Joe, Hongjae ; Han, Myungwan ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 437~442
DOI : 10.9713/kcer.2016.54.4.437
A new route for PBT (Poly butylene terephthalate) production from recycled PET (Poly ethylene terephthalate) has been explored. The route consists of glycolysis of PET (Poly ethylene terephthalate) wastes using 1,4-butandiol into BHBT oligomers and polycondensation of the oligomers into PBT oligomer. This process uses post-consumer or post-industrial recycled PET and converts it into high-end PBT type engineering thermoplastic via a chemical recycling process. Zink acetate was used as a catalyst for both glycolysis and polycondensation. Two types of reactor for the glycolysis, batch and semi-batch reactor, were investigated and their performances were compared. Semi-batch reactor removes ethylene glycol (EG) and THF (tetrahydrofuran) during the reaction. Amounts of EG and THF generated during the glycolysis reaction were measured and used as criteria for the reactor performance. Performance of semi-batch reactor was shown to be better than that of batch reactor. Optimum reaction condition for the semi-batch reactor was BD/PET ratio of 4, and reaction temperature of
, giving high EG yield (max 91%) and low production of THF. In addition, it was confirmed that the molecular weight of PBT oligomer increases in accordance with the progress of the polycondensation reaction.
Production of Fermentable Sugar from Lipid Extracted Algae using Hot Water Pretreatment
Lee, Jihyun ; Shin, Seulgi ; Choi, Kanghoon ; Jo, Jaemin ; Kim, JinWoo ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 443~447
DOI : 10.9713/kcer.2016.54.4.443
The microalgae have cellulose as a main structural component of their cell wall and the lignin content in microalgae is much lower than other lignocellulosic biomass. Therefore, fermentable sugar production from microalgae (Tetraselmis KCTC 12236BP) can be carried out under pretreatment without high temperature and high pressure. It was investigated that the effect of hot-water pretreatment using sulfuric acid for lipid extracted algae which is expected to be a next generation biomass. The effects of three major variables including extraction temperature, acid concentration and time on the enzymatic hydrolysis were investigated. Among the tested variables, temperature and acid concentration showed significant effects and optimum pretreatment conditions for the economic operation criteria were obtained as follows: reaction temperature of
, sulfuric acid concentration of 2 mol and pretreatment time of 40 min. Under the optimum conditions of acidic hot water pretreatment, experimentally obtained hydrolysis yield were 95.9% which showed about 2.1 fold higher compared with enzymatic hydrolysis process. Therefore, acid pretreatment under mild condition was proven to be an effective method for fermentable sugar production from lipid extracted microalgae.
The Effect of Enzymatic Hydrolysis by Ethanol Organosolv Pretreatment of Corn Stover
Park, Jang Han ; Kim, Tae Huyn ; Kim, Jun Seok ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 448~452
DOI : 10.9713/kcer.2016.54.4.448
This study is for the effective pretreatment and saccharification of lignocellulosic biomass for a transport fuel receiving attention. The waste water during the pretreatment of biomass is major factor for determining the price of biofuel. Therefore, we conducted high concentration of organosolv pretreatment for decline waste water and reusing the solvent. We confirmed effect of organosolv pretreatment by components analysis and enzymatic hydrolysis of pretreated biomass. The corn stover was used for and 99.5 wt% of ethanol as a organosolv pretreatment. The pretreatment condition was varied 130 to
during the designated reaction times and the effect of pretreatment was investigated by enzymatic hydrolysis. The highest glucose conversion was more than 68% the pretreatment condition of
for 70 min or more. The solid remaining was more than 70% and almost of cellulose and hemicellulose were survived.
Characteristics of Microbial Fuel Cells Using Pig Waste and sPAES Membrane
Lee, Se-Hoon ; Mun, Ji-Yoon ; Kim, Young-Sook ; Chu, Cheun-Ho ; Na, Il-Chai ; Lee, Jeong-Hoon ; Lee, Moo-Seok ; Lee, Dong-Hoon ; Park, Kwon-Pil ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 453~458
DOI : 10.9713/kcer.2016.54.4.453
Microbial fuel cells (MFC) were operated with pig wastes and PEMFC (Proton Exchange Membrane Fuel Cells) MEA (Membrane and Electrode Assembly). Performance of hydrocarbon membrane was compared with that of perfluoro membrane at MFC condition. Sulfonated-Poly(Arylene Ether Sulfone) was used as hydrocarbon membrane and Gore membrane was used as perfluoro membrane. OCV of sPAES MEA was 50mV higher than that of Gore MEA and power density of sPAES MEA was similar that of Gore MEA. Reinforcement of sPAES membrane stabilized the performance of MEA in MFC. The highest performance was obtained at temperature of
and with culture solution circulation rate of 50 ml/min. The highest power density was
at optimum condition in MFC using pig waste.
Electrochemical Characteristics of Porous Silicon/Carbon Composite Anode Using Spherical Nano Silica
Lee, Ho Yong ; Lee, Jong Dae ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 459~464
DOI : 10.9713/kcer.2016.54.4.459
In this study, the electrochemical characteristics of porous silicon/carbon composite anode were investigated to improve the cycle stability and rate performance in lithium ion batteries. In this study, the effect of TEOS and
concentration, mixing speed and temperature on particle size of nano silica was investigated using
method. Nano porous Si/C composites were prepared by the fabrication processes including the synthesis of nano
, magnesiothermic reduction of nano
to obtain nano porous Si by HCl etching, and carbonization of phenolic resin. Also the electrochemical performances of nano porous Si/C composites as the anode were performed by constant current charge/discharge test, cyclic voltammetry and impedance tests in the electrolyte of
dissolved inorganic solvents (EC:DMC:EMC=1:1:1vol%). It is found that the coin cell using nano porous Si/C composite has the capacity of 2,006 mAh/g and the capacity retention ratio was 55.4% after 40 cycle.
Measurement and Prediction of the Combustible Properties of Cumene
Ha, Dong-Myeong ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 465~469
DOI : 10.9713/kcer.2016.54.4.465
The usage of the correct combustion characteristic of the treated substance for the safety of the process is critical. For the safe handling of cumene being used in various ways in the chemical industry, the flash point and the autoignition temperature (AIT) of cumene was experimented. And, the lower explosion limit of cumene was calculated by using the lower flash point obtained in the experiment. The flash points of cumene by using the Setaflash and Pensky-Martens closed-cup testers measured
, respectively. The flash points of cumene by using the Tag and Cleveland open cup testers are measured
. The AIT of cumene by ASTM 659E tester was measured as
. The lower explosion limit by the measured flash point
was calculated as 0.87 vol%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.
The Optimal Design and Economic Evaluation of a Stand-Alone RES Energy System for Residential, Agricultural and Commercial Sectors
Kim, Kihyeon ; Kim, Jiyong ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 470~478
DOI : 10.9713/kcer.2016.54.4.470
Greenhouse gas (GHG) emissions caused by fossil fuels consumption is one of the challenging issues worldwide. Renewable energy source (RES)-based energy supply system can be a promising alternative to the current fossil fuel-based system. In this study, we propose an optimization approach for designing a stand-alone hybrid energy supply system using RES and evaluating economic performances of the energy systems. The suggested approach is used to answer the questions; i) what technology is suitable to various demand sectors in different regions, and ii) how does it cost to meet the demand in term of the levelized costs of energy (LCOE). We illustrate the applicability of the proposed approach by applying to the design problem of energy supply systems for residential, agricultural and commercial sectors of Korea. As the results of LCOE analysis, for the residential sector has the LCOE ranging of $0.37~$0.44/kWh, the agricultural sector of $0.15~$0.61/kWh and the commercial sector of $0.12~$0.28/kWh.
Development of Three-dimensional Thermo-fluid Numerical Model for Steam Drum of a Basic Oxygen Furnace
Jeong, Soo-Jin ; Moon, Seong-Joon ; Jang, Won-Joon ; Kho, Suntak ; Kwak, Hotaek ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 479~486
DOI : 10.9713/kcer.2016.54.4.479
The efficient steam drum should be required to reduce carbon oxide emissions and heat recovery in oxygen converter hood system. However, steam generation is limited to the time of the oxygen blowing period, which is intermittent or cyclical in operation of steel-making process. Thus, steam drum should be optimized for an effective steam generation during the oxygen blowing portion of the converter cycle. In this study, a three-dimensional computational fluid dynamics (CFD) model has been developed to describe the impacts of changing various operating conditions and geometric shape on thermo-fluid characteristics and performance of the steam drum. This model encompasses not only fluid flow and heat transfer but also evaporation and condensation at the interfacial surface in the steam drum by using VOF (Volume of Fluid) method. To validate the prediction performance of this model, comparison of the steam flow rate between numerical and experimental result has been performed, resulting in the accuracy of the relative error by less than 3.2%.
Moment Analysis (MA) of Lysozyme in Cation Exchange High Performance Liquid Chromatography (HPLC)
Ko, Kwan Young ; Kim, In Ho ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 487~493
DOI : 10.9713/kcer.2016.54.4.487
The moment analysis of lysozyme was implemented using chromatograms that were obtained from weak cation exchange column in high performance liquid chromatography system. Three elution sodium phosphate buffers containing 1.0, 0.75, 0.5M sodium chloride were used. Experiments were conducted by varying flow rate, elution sodium chloride concentration, and lysozyme solute concentration. The general rate (GR) model was employed to calculate the first moment and the second moment. By plotting
] equilibrium constants (K) were obtained from first moment analysis. Intra-particle diffusivity was obtained from theoretical plate number data. Based on the results of moment analysis, van Deemter plots were drawn in order to investigate the contributions of
to total Height Equivalent to a Theoretical Plate (HETP,
). The effect of intra-particle diffusion (
) was the most dominant factor contributing to HETP while external mass transfer (
) was negligible factor.
Improved Ethanol Production from Deacetylated Yellow Poplar (Liriodendron tulipifera) by Detoxification of Hydrolysate and Semi-SSF
Kim, Jo-Eun ; Lee, Jae-Won ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 494~500
DOI : 10.9713/kcer.2016.54.4.494
In order to remove acetyl group from yellow poplar, deacetylation was performed using sodium hydroxide (NaOH) prior to oxalic acid pretreatment. During the deacetylation (
for 80 min, 0.8% NaOH), most of the acetyl group were removed from hemicellulose. Simultaneous saccharification and fermentation (SSF) and semi-SSF were carried out based on solid loading (10, 12.5, 15%) of deacetylated biomass and pre-hydrolysis with enzymes (0, 6, 12, 24 h). The highest ethanol was obtained as 26.73 g/L after 120 h when 10% of biomass was used for SSF. It is corresponding to 88.41% of theoretical ethanol yield. At the 12.5% and 15% of biomass loading, the highest ethanol was obtained from 6 h pre-hydrolysis. It was 32.34 g/L and 27.15 g/L, respectively, and corresponding to ethanol yield of 85.58 and 59.87%. In order to remove fermentation inhibitors from hydrolysates, overliming was performed using calcium hydroxide (
). The highest ethanol was 5.28 g/L after 72 h of fermentation.
Economic Assessment of a Indirect Liquefaction Process using a Gasification with Petroleum Coke/Coal Mixtures
Shin, Ji-Hoon ; Lee, Lu-Se ; Lee, See-Hoon ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 501~509
DOI : 10.9713/kcer.2016.54.4.501
The economic feasibility of a commercial indirect liquefaction process with the co-gasification process of petroleum coke which has been recognized as hazardous waste because of high sulfur content and bituminous coal and sub-bituminous coal mixtures was assessed. The 2,000 ton/day scale indirect liquefaction process including co-gasification, clean up, Fischer-Tropsch conversion and so on was assumed and used to analyze economical efficiencies with various conditions. Financial data from previous studies were modified and used and economical sensitivities with various mixture ratios were evaluated in this study. As a result, economic values of petroleum coke were superior than those of coals because of increasing sulfur sale. Also, mixtures with petroleum coke and bituminous coal was more favorable that those with petroleum coke and sub-bituminous coal due to lower moisture content. In case of sub-bituminous coal, the mixture ratio with petroleum coke had to be over 40wt% for the IRR of mixture to surpass 10%.
Thin-Film Composite (TFC) Membranes with Hydrophilic Ethyl Cellulose-g-poly(ethylene glycol) (EP) Substrates for Forward Osmosis (FO) Application
Yu, Yun Ah ; Kim, Jin-joo ; Kang, Hyo ; Lee, Jong-Chan ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 510~518
DOI : 10.9713/kcer.2016.54.4.510
Ethyl cellulose-g-poly(ethylene glycol) (EP) was synthesized by esterification of carboxylic acid functionalized methoxy polyethylene glycol (MPEG-COOH) with ethyl cellulose (EC) in order to develop a hydrophilic substrate for thin-film composite (TFC) membrane in a forward osmosis (FO) system. A porous EP substrate, fabricated by a non-solvent induced phase separation method, was found to be more hydrophilic than the EC substrate due to the presence of polyethylene glycol (PEG) side chains in the EP. Since the EP substrate exhibits smaller water contact angles and higher porosity, the structural parameter (S) of TFC-EP is smaller than that of TFC-EC, indicating that internal concentration polarization (ICP) within porous substrates can occur less when TFC-EP is used as a membrane. For example, the water flux value of the TFC-EP is 15.7 LMH, whereas the water flux value of the TFC-EC is only 6.6 LMH. Therefore, we strongly believe that the TFC-EP could be a promising candidate with good FO performances.
Synthesis of Renewable Jet Fuel Precursors from C-C Bond Condensation of Furfural and Ethyl Levulinate in Water
Cai, Chiliu ; Liu, Qiying ; Tan, Jin ; Wang, Tiejun ; Zhang, Qi ; Ma, Longlong ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 519~526
DOI : 10.9713/kcer.2016.54.4.519
Biomass derived jet fuel is proven as a potential alternative for the currently used fossil oriented energy. The efficient production of jet fuel precursor with special molecular structure is prerequisite in producing biomass derived jet fuel. We synthesized a new jet fuel precursor containing branched
framework by aldol condensation of furfural (FA) and ethyl levulinate (EL), where the latter of two could be easily produced from lignocellulose by acid catalyzed processes. The highest yield of 56% for target jet fuel precursor could be obtained at the optimal reaction condition (molar ratio of FA/EL of 2, 323 K, 50 min) by using KOH as catalyst. The chemical structure of
precursor was specified as (3E, 5E)-6-(furan-2-yl)-3-(furan-2-ylmethylene)-4-oxohex-5-enoic acid (
). For stabilization, this yellowish solid precursor was hydrogenated at low temperature to obtain C=C bonds saturated product, and the chemical structure was proposed as 4-oxo-6-(tetrahydrofuran-2-yl)-3-(tetrahydrofuran-2-yl)-methyl hexanoic acid (
). The successful synthesis of the new jet fuel precursors showed the significance that branched jet fuel could be potentially produced from biomass derived FA and EL via fewer steps.
Axial Solid Holdup in a Circulating Fluidized Bed Plasma Reactor under Reduced Pressure
Park, Sounghee ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 527~532
DOI : 10.9713/kcer.2016.54.4.527
The effects of gas velocity and solid circulation rate on the axial solid holdup distribution have been determined in a 10 mm-I.D.
800 mm-high circulating fluidized bed plasma reactor under reduced pressure (1torr). Polystyrene polymer powder and nitrogen gas are used as solid and gas materials respectively. The change of solid circulation rate by a large gas flow rate of the riser (40~80 sccm) is also possible by a relatively small gas flow rate of the solid recirculation part (6.6~9.9 sccm). The solid circulation rate in the reactor under reduced pressure increases with increasing aeration velocity in the solid recirculation part. The axial solid holdup in the riser decreases from the dense at the bottom to the dilute phase at the top section of the riser. Solid holdups at the axial positions in the riser increase linearly with increasing solid circulating velocity. From these results, we could determine the position of plasma load for good plasma ignition, maintain and plasma reaction.
Flow Behavior and Mixing Characteristics of Rice Husk/Silica Sand/Rice Husk Ash
Kim, Bo Hwa ; Seo, Myung Won ; Kook, Jin Woo ; Choi, Hee Mang ; Ra, Ho Won ; Yoon, Sang Jun ; Mun, Tae Young ; Kim, Yong Ku ; Lee, Jae Goo ; Rhee, Young Woo ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 533~542
DOI : 10.9713/kcer.2016.54.4.533
We investigate fluidization characteristics of the mixture of rice husk, silica sand and rice husk ash as a preliminary study for valuable utilization of rice husk ash obtained from gasification of rice husk in a fluidized bed reactor. As experiment valuables, the blending ratio of rice husk and sand (rice husk: sand) is selected as 5:95, 10:90, 20:80 and 30:70 on a volume base. Rice husk ash was added with 6 vol% of rice husk for each experiment and air velocity to the reactor was 0~0.63 m/s. In both rice husk/sand and rice husk/sand/ash mixture, the minimum fluidization velocity (Umf) is observed as 0.19~0.21 m/s at feeding of 0~10 vol.% of rice husk and 0.30 m/s at feeding of 20 vol.% of rice husk. With increasing the amount of rice husk up to 30 vol.%,
can not measure due to segregation behavior. The mixing index for each experiment is determined using mixing index equation proposed by Brereton and Grace. The mixing index of the mixture of rice husk/sand and rice husk/sand/ash was 0.8~1 and 0.88~1, respectively. The optimum fluidization condition was found for the good mixing and separation of rice husk ash.
Bubble Properties in Bubble Columns with Electrolyte Solutions
Yoo, D.J. ; Lim, D.H. ; Jeon, J.S. ; Yang, S.W. ; Kang, Y. ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 543~547
DOI : 10.9713/kcer.2016.54.4.543
Bubble properties such as size (chord length) and rising velocity were investigated in a bubble column with electrolyte solutions, of which diameter was 0.152m and 2.5m in height, respectively. The size and rising velocity of bubbles were measured by using the dual electrical resistivity probe method. Effects of gas and liquid velocities and ionic strength of liquid phase on the size and rising velocity of bubbles were determined. The bubble size increased with increasing gas velocity but decreased with increasing liquid velocity or ionic strength of liquid phase. The rising velocity of bubbles increased with increasing gas velocity and decreased with increasing ionic strength of liquid phase, however, it showed a slight maximum value with varying liquid velocity. The size and rising velocity of bubbles were well correlated with operating variables.
Characteristics of Semi-Aqueous Cleaning Solution with Carboxylic Acid for the Removal of Copper Oxides Residues
Ko, Cheonkwang ; Lee, Won Gyu ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 548~554
DOI : 10.9713/kcer.2016.54.4.548
In this study, semi-aqueous solutions containing carboxylic acids such as oxalic acid (OA), lactic acid (LA) and citric acid (CA) were formulated for the removal of copper etching residues produced at the interconnection process, and their characteristics were analyzed. Carboxylic acids in the solutions were apt to form various copper complexes according to the value of pH. Semi-aqueous solution containing 10 wt% CA showed the lowest etching rate of copper in the range from pH2 to pH7 and the highest selectivity in the range of pH 2 to pH 4. However, the cleaning solution containing 10 wt% LA revealed the superior selectivity at the range from pH 5 to pH 7. Appropriate selection of carboxylic acid should be required to improve the performance of cleaning solution. In the case of CA, the etching selectivity of copper oxide complex to copper was increased with the concentration of CA in the solution, when the solutions contain over 5 wt% CA, the copper interconnection layer has a metallic copper surface more than 88% in the area. The result shows that CA contained semi-aqueous solution has a relatively good cleaning ability.
A Synthesis and Characterization of Pt(II) Complexes with Bipyrimidin-based Back-bone System
Son, Seokhwan ; Ahn, Hogeun ; Chung, Minchul ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 555~559
DOI : 10.9713/kcer.2016.54.4.555
In this study, new platinum complexes were synthesized utilizing the ligand of a 2,2'-bispyrimidine (bpim), 2,2'-bipyridine (bpy), 5,5'-dimethyl-2,2'-bipyridine (5,5-mebpy), 5'-bromo-2,2'-bipyridine (5-brbpy), 5,5'-dibromo-2,2'-bipyridine (5,5-brbpy), 4,4'-dimethyl-2,2'-bipyridine (4,4-mebpy), 4,4'-dihexyl-2,2'-Bipyridine (4,4-hebpy), 1,10'-Phenanthroline (phen), 3,4,7,8'-tetramethyl-1,10'-Phenanthroline (3,4,7,8-phen). In order to determine chemical structure of Synthesized platinum complexes,
-NMR, UV-vis and FT-IR were used and optical physics and chemical properties were measured PL. In the case of platinum complexes, wavelength has been identified 356~421 nm. Quantum efficiency in DMSO solution was appeared 0.05~0.46.
Study on Effects of Ni/Al
Catalysts Added with Mo on Durability Improvement in Steam Reforming Reactions
Won, Jong Min ; Park, Gi Woo ; Lee, Jin Woo ; Hong, Sung Chang ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 560~567
DOI : 10.9713/kcer.2016.54.4.560
In this study, we characterized steam reforming reactions and surface of
catalysts. Ni-Mo based catalysts were prepared by loading Mo as the co-catalyst and reaction activities of the Ni-Mo based catalysts were compared with those of Ni-based catalysts. Through the
-TPR and XPS analysis it was confirmed that this characteristic efficiency.
-TPO analysis was performed to examine the deposition characteristics, bonding structures and evaporation characteristics of carbon deposited on the surface of catalysts after long run experiments were performed for steam reforming reactions. As the results, it was found that durability was improved in Ni-Mo based catalysts inhibiting formation of graphitic carbon species which reduced reaction activities of the catalysts by strongly interacting with Ni in the steam reforming reaction.
Contact Charging and Electrphoresis of a Glassy Carbon Microsphere
Choi, Chang Yong ; Im, Do Jin ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 568~573
DOI : 10.9713/kcer.2016.54.4.568
We investigated the charging characteristics of a conducting solid sphere (glassy carbon sphere) comparing with that of a water droplet and check the applicability of the perfect conductor theory. For the systematic research, sphere size, applied voltages, viscosity of the medium were changed and the results were compared with that of corresponding water droplets and the perfect conductor theory. Basically, a glassy carbon sphere follows the perfect conductor theory but the charging amount was lower as much as 70~80% of theoretical prediction value due to oil film formed between electrode and a carbon sphere. We hope this result provides basic understandings on the solid sphere contact charging phenomenon and related applications.
Immobilization of Homogeneous Catalyst on Functionalized Carbon Nanotube via 1,3-Dipolar Cycloaddition Reaction and its Ethylene Polymerization
Lee, Jeong Suk ; Lee, Se Young ; Lee, Jin Woo ; Ko, Young Soo ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 574~581
DOI : 10.9713/kcer.2016.54.4.574
In this study, CNT functionalized with pyrrolidine ring via 1,3-dipolar cycloaddition reaction with various amino acid and aldehyde was synthesized. Metallocene was subsequently immobilized on the functionalized CNT and CNT/polyethylene composite was prepared via in-situ ethylene polymerization. The polymerization activities of metallocene supported on CNT functionalized with glycine and benzaldehyde (Gly+BA-CNT) were similar to those of metallocene supported on CNT functionalized with N-benzyloxycarbonylglycine and paraformaldehyde (Z-Gly+PFA-CNT) although its Zr content was lower than that of Z-Gly+PFA-CNT. In the case of metallocene supported on Z-Gly+PFA-CNT, the even distribution of active sites hindered the diffusion of ethylene monomer and cocatalyst MAO due to steric hindrance during ethylene polymerization. Compared to polyethylene produced from homogeneous metallocene catalysts, CNT/PE composites had a higher initial degradation temperature (
) and maximum mass loss temperature (
). It suggests that pyrrolidine functionalized CNT is uniformly dispersed and strongly interacted with the PE matrix, enhancing the thermal stability of PE.
Offsite Consequence Modeling for Evacuation Distances against Accidental Hydrogen Fluoride (HF) Release Scenarios
Kim, Jeonghwan ; Jung, Seungho ;
Korean Chemical Engineering Research, volume 54, issue 4, 2016, Pages 582~585
DOI : 10.9713/kcer.2016.54.4.582
This study intends to provide initial evacuation distances for the public in case of accidental releases of hydrogen fluoride (HF). HF is a very toxic chemical that is widely used in the chemical, electrical, and electronics industries. Consequence modeling programs, such as ALOHA and PHAST, were used to help formulate a contingency plan in case of an HF leak. For the purpose of this study, the release of entire quantity of HF in 10 min is defined as a worst-case scenario and the release from a partial line rupture is used as an alternative case scenario as National Institute of Chemical Safety (NICS) guidelines. Once the discharge rates were calculated based on the scenarios, the ERPG-2 endpoint distances have been obtained for representative daytime and nighttime weather conditions. This paper presents graphs that can be used to enact swift evacuation orders and emergency response plans in the case of accidental releases of HF.