Korean Journal of Chemical Engineering (v.29, #8)

Optimal strategy for carbon capture and storage infrastructure: A review by Jee-Hoon Han; Yu-Chan Ahn; Jae-Uk Lee; In-Beum Lee (975-984).
To effectively reduce CO2, CO2 mitigation technologies should be employed tactically. This paper focuses on carbon capture and storage (CCS) as the most promising CO2 reduction technology and investigates how to establish CCS strategy suitably. We confirm a major part of the optimal strategy for CCS infrastructure planning through a literature review according to mathematical optimization criteria associated with facility location models. In particular, the feasibility of large scale CCS infrastructure is evaluated through economic, environmental, and technical assessment. The current state-of-the-art optimization techniques for CCS infrastructure planning are also addressed while taking numerous factors into account. Finally, a list of issues for future research is highlighted.
Keywords: Carbon Capture and Storage; Infrastructure Planning; Optimization; Feasibility Evaluation

Structural design of 3-dimensional disk electrode based on Cu-CoO composite for Li-ion battery by Cheol-Woo Ahn; Young-Hoon Chung; Byung-Dong Hahn; Dong-Soo Park; Yung-Eun Sung (985-988).
A 3-dimensional disk electrode structure was designed to further improve the capacity and reduce the weight in the anode of a Li-ion battery. The additives, such as binding and carbon based conducting materials, were removed. In particular, Cu foil was not used in this 3-dimensional disk electrode. All the specimens were fabricated using conventional ceramic process, which was appropriate for the scale-up in industry. In the 3-dimensional disk electrode, the Cu-CoO composite was selected and excellent capacity was observed.
Keywords: Ceramic Composites; Porous Materials; Composite Materials

A novel and simple approach for the synthesis of Fe3O4-graphene composite by Feng-Jun Zhang; Jin Liu; Kan Zhang; Wei Zhao; Won-Kweon Jang; Won-Chun Oh (989-993).
High crystalline Fe3O4-graphene composite has been successfully synthesized via one-step thermolysis reaction. The results demonstrated that the attachment of iron-organic complex with graphene oxide sheets can facilely lead to magnetic graphene composites with a time-dependent calcination process. The composite was characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The high efficient removal of methylene blue determined that Fe3O4-graphene is a promising sorbent material for wastewater treatment.
Keywords: Graphene; Fe3O4 ; Thermolysis Reaction; Remova

Analysis and prediction of indoor air pollutants in a subway station using a new key variable selection method by JungJin Lim; YongSu Kim; TaeSuk Oh; MinJung Kim; OnYu Kang; Jeong Tai Kim; In-Won Kim; Jo-Chun Kim; Jae-Sik Jeon; ChangKyoo Yoo (994-1003).
A new key variable selection and prediction model of IAQ that can select key variables governing indoor air quality (IAQ), such as PM10, CO2, CO, VOCs and formaldehyde, are suggested in this paper. The essential problem of the prediction model is the question of which of the original variables are the most important for predicting IAQ. The next issue is determining the number of key variables that should be ranked. A new index of discriminant importance in the projection (DIP) of Fisher’s linear discriminant (FLD) is suggested for selecting key variables of the prediction models with multiple linear regression (MLR) and partial least squares (PLS), as well as for ranking the importance of input measurement variables on IAQ prediction. The prediction models were applied to a real IAQ dataset from telemonitoring data (TMS) in a metro system. The prediction results of the model using all variables were compared with the results of the model using only key variables of DIP. It shows that the use of our new variable selection method cannot only reduce computational effort, but will also enhance the prediction performances of the models.
Keywords: Indoor Air Quality (IAQ); Pollution Prediction; Fisher’s Linear Discriminant (FLD); Platform Screen Door (PSD) System; Variable Selection

Commercial design programs do not provide a ready-to-use process simulation of tray-by-tray heat-integrated distillation columns, so the computation of the columns using the programs is difficult due to their convergence problem. An approximate procedure for the design of the internally heat-integrated distillation column (HIDiC) is proposed here, and its performance of the design and cost evaluation is demonstrated with two example processes. The approximate design procedure eliminates the artificial heat exchangers and in-tray streams required in the design with the commercial programs, and therefore no information of the exchangers and streams is necessary except the amount of the in-tray heat transfer rate. The economic evaluation indicates that a reduction of the total annual cost of 8.1% is possible with benzene-toluene process and that 59.3% is yielded with the propylene-propane process. The results also demonstrate that the HIDiC is especially efficient for the tight separation system.
Keywords: Internally Heat-integrated Distillation; Energy-efficient Distillation; Approximate Design; Cost Evaluation

Model prediction of non-symmetric normal stresses under oscillatory squeeze flow by Jae Hee Kim; Kyung Hyun Ahn; Seung Jong Lee (1010-1018).
The non-symmetric responses of normal stresses in oscillatory squeeze flow have been investigated with model calculations. The simplest and most widely used constitutive equations were employed to predict the non-symmetric normal stresses, which is a distinctive feature of oscillatory squeeze flow. The model prediction was compared with experimental data of polymer solution in terms of stress shape, Lissajous plot, stress decomposition, and Fourier transformation. The upper-convected Maxwell, Giesekus, and exponential Phan-Thien Tanner models predicted the nonsymmetric characteristics of normal stresses under oscillatory squeeze flow. The predictions showed fairly good agreement with experimental data. However, the upper-convected Maxwell model showed unrealistic result in the Lissajous plot of [stress vs. strain] and [stress vs. strain rate]. From stress decomposition, it could be confirmed that the non-symmetric nature arises from the elastic contribution of the normal stress, which was verified in both experiment and model calculation. This study is expected to provide useful insights for further understanding of the nonlinear and non-symmetric characteristics of oscillatory squeeze flow.
Keywords: Oscillatory Squeeze Flow; Non-symmetric Stress; Normal Stress; Stress Decomposition

XGa2O3-CeO2-ZrO2 (X=0, 1, 3, 5, 7, and 9) catalysts were prepared by a single-step sol-gel method with a variation of Ga2O3 content (X, wt%) for use in the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. The ratio of cerium oxide:zirconium oxide in the XGa2O3-CeO2-ZrO2 catalysts was fixed to be Ce0.6Zr0.4O2. Effect of acidity and basicity of XGa2O3-CeO2-ZrO2 on the catalytic performance in the direct synthesis of dimethyl carbonate from methanol and carbon dioxide was investigated using NH3-TPD and CO2-TPD experiments, respectively. Experimental results revealed that both acidity and basicity of the catalysts played important roles in determining the catalytic performance in the reaction. The amount of dimethyl carbonate increased with increasing both acidity and basicity of the catalyst. Among the catalysts tested, 3Ga2O3-CeO2-ZrO2, which retained the largest acidity and basicity, exhibited the best catalytic performance in the direct synthesis of dimethyl carbonate from methanol and carbon dioxide.
Keywords: Dimethyl Carbonate; Methanol; Carbon Dioxide; Ga2O3-CeO2-ZrO2 ; Acid-base Property

In the analytical model of iron dust cloud combustion presented in this article, by solving the 3D energy equations, the gas temperature distribution in the channel and a new equation for flame speed are obtained. This equation can determine the relationship between flame speed and particle radius and dust concentration. The equations are written in two limiting cases: lean and rich mixtures. Flame structure consists of preheat, reaction, and post-flame zones for the lean mixture and preheat and reaction zones for the rich mixture. Equations in both mixture conditions are solved using the finite Fourier transform method. By solving the energy equations in each zone and matching the temperature and heat flux at the interfacial boundaries, algebraic equations of flame speed are obtained. The obtained gas temperature distribution in different flame zones in the channel and also flame speed changes in terms of particles’ radius, equivalence ratio, and channel width in both lean and rich mixtures are presented in the results section.
Keywords: Combustion; Iron Dust Cloud; Laminar Premixed Flame; Lean Mixture; Rich Mixture

To improve the conversion rate of a saccharification liquid from food wastes containing pentoses and hexoses into bioethanol, after selecting Saccharomyces coreanus and Pichia stipitis, the respective fermentation and co-fermentation properties were investigated. In the fermentation using S. coreanus, the result under anaerobic condition was better than under aerobic conditions. In the anaerobic fermentation, the concentration of the reducing sugar and glucose remaining after 24 hrs was 9.09 and 1.88 g/L, respectively, with 40.59 g/L of ethanol produced; the ethanol productivity was 1.69 g/L-h. Also, even with the fermentation using P. stipitis, the reducing sugars and glucose were rapidly reduced, with a marked production of ethanol, but the ethanol produced was lower than those under anaerobic and aerobic conditions with the use of S. coreanus. Therefore, for the production of a high concentration of bioethanol from food wastes, ethanol fermentation was induced using S. coreanus until the middle of the fermentation, with P. stipitis used during the latter stage of the fermentation, where the circumstance favored its use, and thus, the carbon source not converted by S. coreanus was later converted to ethanol. As a result, both ethanol production of 48.63 g/L and productivity of 2.03 g/L-h increased over those of the anaerobic fermentation using S. coreanus.
Keywords: Bioethanol; Food Wastes; Hexose; Pentose; Co-fermentation

Development of a PM2.5 sampler with inertial impaction for sampling airborne particulate matter by Panich Intra; Artit Yawootti; Usanee Vinitketkumnuen; Nakorn Tippayawong (1044-1049).
A simple and low cost PM2.5 impactor for sampling airborne particulate matter was developed, designed and evaluated. The design was an assembly of an acceleration nozzle and an impaction plate. Particles with sufficient inertia were unable to follow air streamlines and impacted on the plate. Smaller particles followed the streamlines, avoided being captured by the plate and could then be collected on a downstream filter. Analytical and numerical models were formulated to predict collection efficiency, flow fields and vectors, and particle trajectories in the impactor. The modeling suggested that an optimal operational domain exists for the PM2.5 impactor. A prototype was then built and tested. The collected particles on the impaction plate and downstream of the PM2.5 impactor were analyzed by using scanning electron microscopy. Experimental results agreed well with the theoretical predictions. Testing of the PM2.5 impactor prototype showed promising results for this airborne particulate matter sampler.
Keywords: Particulate Matter; PM2.5 ; Impactor; Numerical Model; SEM

The instability of the premise of direct quantitative contaminant reduction by elemental iron (Fe0) materials in Fe0/H2O systems is pointed out. Basic knowledge of aqueous iron corrosion shows that the Fe0 surface is not available for decontamination in nature. A comparison of the reactivity of Fe0 and Zn0 shows that the effectiveness of Fe0 materials for environmental remediation is due to the formation of a non-adhesive, porous oxide scale on Fe0. Contaminants are enmeshed within the scale and possibly reduced by Fe II and H/H2. An evaluation of current experimental conditions shows that well-mixed batch systems have disturbed the process of scale formation. Therefore, the majority of published works have operatively created conditions for contaminant reduction that are not likely to occur in nature. Since working under such unrealistic conditions has mediated the above-mentioned premise, interactions in Fe0/H2O systems yielding contaminant removal should be revisited.
Keywords: Adsorption; Decontamination; Reduction; Remediation; Zerovalent Iron

Activated Carbon supported Fe(0) nanoparticles (AC-Fe(0)) were applied to the reductive removal of nitrate to investigate the effects of AC support on the reactivity of Fe(0) nanoparticle. XRD, SEM and EDS, XPS analyses on AC-Fe(0) revealed that AC-Fe(0) is more susceptible to oxidation compared to the unsupported Fe(0) nanoparticles, and that the extent of oxidation of the AC-Fe(0) particles will vary depending on the ratios of AC to Fe(0). Nitrate reduction rate of AC-Fe(0) was much slower than that of unsupported Fe(0) nanoparticles. AC-Fe(0) (0.5: 1) particles reduced the nitrate to ca. 40% of the initial concentration, and AC-Fe(0) (5: 1) particles performed poorly with only 10% removal of the nitrate. Besides the deactivation of AC-Fe(0) due to corrosion of Fe(0), the mass transport limitation caused by the thick layering of Fe(0) on porous AC seemed to be another negative factor for the decreased reactivity of AC-Fe(0).
Keywords: Supported Fe(0); Fe(0) Nanoparticles; Activated Carbon; Nitrate Reduction; SEM-EDS; XPS

Self-assembly electrode based on silver nanoparticle toward electrogenerated chemiluminescence analysis of glucose by Ali Shokuhi Rad; Mehdi Ardjmand; Mohsen Jahanshahi; Ali-Akbar Safekordi (1063-1068).
Electrogenerated Chemiluminescence (ECL) involves applying a certain electric potential to a chemical reaction, resulting in the oxidation or reduction of the substance which reacts to produce light. We determined the amount of glucose by its reaction to glucose oxidase (GO X ) on the surface of the proposed modified electrode, which results hydrogen peroxide (H2O2) as side product. After that the reactions between luminol and H2O2 under oxidizing conditions generate dependent light which can be used to analyze. In the current article at first we proposed a convenient method to obtaining a self-assembly modified electrode. A nano based modified glassy carbon (GC) electrode (Glucose oxidase/Ag nanoparticles/cysteamine (CA)/p-aminobenzene sulfonic acid/GC electrode) was prepared, and the ECL behavior of luminol in the presence of glucose was examined. Compared to the bare GC electrode, the modified electrode incorporating glucose oxidase significantly enhanced the response of the ECL biosensor to glucose due to the enhanced specificity of the modified surface to enzymatic reaction, and the sensitivity of the luminol ECL reaction. Under optimal conditions, the electrode was established to respond linearly to glucose in the concentration range 5.0×10−7 to 8.0×10−3 mol/L, and the detection limit was established to be a glucose concentration of 4.0×10−8 mol/L.
Keywords: ECL; Luminol; Glucose; Modified Electrode; Ag Nanoparticle

Antioxidant and antibacterial behavior for sediment removed ethanol extract from sea buckthorn seed by Moon Young Yoon; Ji Sun Oh; Hoduck Kang; Jung-Keug Park (1069-1073).
The purpose of this study was to develop the separation process removing sediment in sea buckthorn seed ethanol extract, and to investigate the antioxidant and antibacterial behavior for the sediment removed ethanol extract (SBS extract). Sediment such as low solubility materials and oil component was simply removed by filtering after storing the crude extract containing celite for 16 h in a refrigerator at 4 °C. The SBS extract displayed strong antioxidant activity in the stability test as a function of both storage time and temperature when compared to vitamin C and BHA (Butylated hydroxyanisole) as typical antioxidant ingredients. The bactericidal ratio of the SBS extract against E. coli increased with an increase in the addition of the test agent, and this was particularly significant at concentrations greater than 1,000 μg/ml addition. The bactericidal ratio of 1,000 μg/ml SBS extract against B. subtilis, S. aureus, P. aerusinosa and E. coli was 96.4, 98.6, 91.5, and 52.2% after 2 h, and 98.2, 99.7, 99.3, and 82.6% after 4 h, respectively. These results suggest that the SBS extract may be used as a functional food, pharmaceutical, and cosmetic agent.
Keywords: Sea Buckthorn Seed; Hippophae rhamnoides L.; Sediment Separation; Antioxidant and Antibacterial Behavior; Ethanol Extract; Stability

This research was performed to evaluate the toxicity for composting and slurry phase bioreactor processes of TNT (2,4,6-trinitrotoluene)-contaminated soils by Salmonella mutagenicity assay. For composting, the percentage reductions of final composts in strain TA98 and TA100 with S9 metabolic activation were 90.3–93.7% and 96.7–97.5%, respectively. For slurry phase bioreactor processes, the percentage reductions of final residuals in strain TA98 and TA100 with S9 metabolic activation were 95.0% and 99.1% for anaerobic, 96.2% and 99.2% for anaerobic/aerobic, and 96.6 and 97.4% for anaerobic treatment. Slurry phase treatment showed higher mutagenicity reduction than composting. It was implied that slurry phase treatment was a more effective process than composting in reducing toxicity. This research has the advantage of speed and ease of performance in comparison to testing of other higher life forms due to the shorter life cycles of microorganisms.
Keywords: TNT; Toxicity; Composting; Slurry Phase Bioreactor; Mutagenicity

Separation of N2/SF6 binary mixtures using polyethersulfone (PESf) hollow fiber membrane by Dae-Hoon Kim; Yong-Hae Ko; Tae-Hwan Kim; Jong-Soo Park; Hyung-Keun Lee (1081-1085).
PESf hollow fiber membrane was used to recover sulfur hexafluoride (SF6) from N2/SF6 binary mixture gas. To fabricate a hollow fiber membrane, a dry-wet phase inversion method was used. Fiber was post-treated by methanol to increase permeance. Fabricated membrane was characterized by scanning electron microscopy (SEM) and N2, SF6 single gas permeation according to temperature and pressure difference. Using N2/SF6 binary mixture gas (10 vol% of SF6), we checked the separation of mixture gas in a manufactured single module according to temperature, pressure difference, and retentate flow rate. The highest SF6 purity in recovered gas was 50.4 vol% when the pressure difference, temperature, and stage cut was highest in experimental conditions, but the recovery ratio marked the lowest value.
Keywords: Polyethersulfone; Sulfur Hexafluoride; Greenhouse Gas; Mixture Gas Separation; Hollow Fiber Membrane

The feasibility of applying natural, untreated clayey soil as low-cost alternative adsorbent for Pb(II) removal from aqueous solutions was investigated with a batch experimental set-up. Experiments were carried out as a function of initial solution pH (1–8), contact time (10–360 min), initial Pb(II) concentration (20–100 mg L−1), adsorbent dose (0.5–5 g) and temperature (303–333 K). Adsorption equilibrium data were well described by the Langmuir isotherm with maximum adsorption capacity of 121.86 mg g−1 at 303 K. Adsorption of Pb(II) followed pseudo-second-order kinetics. Gibbs free energy (ΔG0) was spontaneous for all interactions, and the adsorption process exhibited exothermic enthalpy values. The adsorbent was easily regenerated by using 0.1M HNO3 solution and was reused for five sorptiondesorption cycles without any considerable loss in adsorption capacity. It could be concluded that clayey soil may be used as an inexpensive and effective adsorbent without any treatment or any other modification for the removal of Pb(II) ions from aqueous solutions.
Keywords: Adsorption; Clayey Soil; Pb(II); Equilibrium; Kinetics; Thermodynamics

A novel synthesis of spherical LiFePO4/C composite using Fe1.5P and mixed lithium salts via oxygen permeation by Guixin Wang; Rui Liu; Miao Chen; Hanchang Kang; Xiuli Li; Kangping Yan (1094-1101).
A novel route was designed to synthesize LiFePO4/C composites by using the Fe1.5P byproduct, mixed lithium salts, and permeated oxygen from air via a rheological phase method. The reaction process was investigated with various techniques. When the calcining time was increased from 10 to 30 h, the gradual formation of olivine structure was observed. The growth kinetics of the crystals was analyzed. SEM and TEM results indicated the as-synthesized LiFePO4 was constituted of small spheres covered with carbon particles. The discharge capacity of the LiFePO4/C composite prepared at ∼700 °C for ∼25 h could reach 139.7 mAh g−1 and still remained 130.2 mAh g−1 after 15 cycles at 0.2 C rate, comparable to that of the reported LiFePO4/C composite using conventional methods. Cyclic voltammogram confirmed the LiFePO4/C composite had a high purity and good lithium ion insertion/desertion redox behavior.
Keywords: LiFePO4/C Composite; Fe1.5P Byproduct; Rheological Phase Method; Thermal Analysis; Electrochemical Performance

Nonspherical snowman-shaped micro-sized particles were synthesized via monomer swelling and the polymerization of crosslinked seed particles. Monodispersed crosslinked polystyrene microspheres and methylmethacrylate were used as seed particles and the swelling monomer, respectively. Methylmethacrylate (MMA) induced crosslinked polystyrene microparticle swelling; however, compared to polystyrene, MMA is relatively hydrophilic. As a result, phase separation was observed, resulting in monomer-swollen, cross-linked particles protruding from the surface of the seed particles. By changing the monomer-to-particle weight ratio from 4 to 8, the ratio of the size of the head to the body of the snowman-shaped particles was varied from 0.3 to 0.7. The morphologies of the snowman-shaped particles were predicted using Surface Evolver software, and the simulation was applied to show the unique self-organization morphologies of snowman-shaped particles. We synthesized snowman-shaped microparticles by swelling and polymerizing cross-linked PS seed particles with methylmethacrylate. The monomer-swollen, cross-linked particles exhibited protrusions from the surface of the microparticles due to the phase separation of seeds from the particles. The size of the protrusion or head of the snowmanshaped particles was controlled by changing the monomer-to-particle weight ratio during the swelling process. Simulations were applied to estimate the aspect ratio of snowman-shaped particles and their self-assembled morphologies.
Keywords: Swelling; Seeded Polymerization; Nonspherical Particles

Poly(vinyl alcohol) hollow microcapsules prepared by emulsification, salting out, and photo cross-linking method by Mi Sun Lee; Eun Young Mok; Won Cheol Shin; Jong Dai Kim; Jin-Chul Kim (1108-1113).
Coumarin residues were conjugated to poly(vinyl alcohol) (PVA) by reacting epoxypropoxy coumarin (EPC) with the polymer. According to the peak areas on the 1H NMR spectrum, EPC was calculated to be conjugated to every 283 repeating units (vinyl alcohols). A cyclic photo-dimerization and dedimerization of EPC of PVA-EPC conjugate were observed under a cyclic irradiation of 365 nm and 254 nm. The salting-out of the conjugate significantly took a place in the range of 0–2.0M NaCl, and the phenomenon was observed at a lower concentration than that of unmodified PVA was. Oil-in-water emulsion was prepared as a template for the preparation of hollow microcapsules using chloroform as an oil phase and PVA-EPC as an emulsifier. The emulsion was stable for 24 hr in terms of droplet size. The wall surrounding droplets was built-up by the salting-out of PVA-EPC, and it was cross-linked by the irradiation of 365 nm. After chloroform was evaporated and salt was removed by a dialysis, hollow microcapsules were successfully obtained.
Keywords: Poly(vinyl alcohol); Coumarin; Salting-out; Emulsion; Photo-crosslinking Hollow Microcapsules