Korean Journal of Chemical Engineering (v.31, #2)

Breakthrough analysis of carbon dioxide adsorption on zeolite synthesized from fly ash by Chang-Han Lee; Sang-Wook Park; Seong-Soo Kim (179-187).
Zeolite (FAZ) was synthesized by the fusion method using coal fly ash to adsorb carbon dioxide. The experimental adsorption was operated batchwise in a laboratory-scale packed-bed adsorber to obtain the breakthrough curves of CO2 under conditions such as adsorption temperatures (20–80 °C), flow rates of gaseous mixture of carbon dioxide and nitrogen (40–100 cm3/min), and concentration of CO2 (3000–10000 ppmv) at atmospheric pressure of 101.3 kPa. The influence of the experimental conditions, such as the gas flow rate, concentration of CO2 and adsorption temperature on adsorption behavior, was discussed. The deactivation model, combined the adsorption with the deactivation of adsorbent, was used to analyze the physicochemical properties, such as the adsorption kinetics, capacity and heat of adsorption, by fitting the experimental data of the breakthrough curves to this model. The adsorptive activity and capacity of FAZ were as almost same as those of the commercial zeolite of Wako 4A.
Keywords: Adsorption; Carbon Dioxide; Zeolite; Breakthrough Curve; Deactivation Model

Enzyme attached on polymeric micelles as a nanoscale reactor by Moo-Yeal Lee; Kyung-Jin Hong; Seung Pil Han; Toshio Kajiuchi (188-193).
Similar to what lipase does, a surface-active enzyme was developed by attaching peroxidase on combshaped polymaleic anhydride-alt-1-tetradecene (PMA-TD) in a microemulsion system composed of n-butyl acetate and buffer solution, and its catalytic characteristics of polyphenol synthesis were investigated in an aqueous solution. The modified peroxidase with PMA-TD tended to form self-assembled aggregates like micelles in the aqueous solution and could be concentrated at solvent/water interfaces without unfolding of the enzyme. The efficiency of conversion of 2,4-dichlorophenol to phenolic oligomers was approximately 2-fold improved with the modified peroxidase compared to native peroxidase. The K m and V max values for the modified peroxidase were 1.5-fold lower and 2-fold higher, respectively. The hydrodynamic diameter of the micelle on the modified peroxidase increased with the reaction time, indicating that phenolic products were accumulated in the hydrophobic interior of micelles. In addition, the molecular weight (MW) of phenolic polymers was much larger in the system with the modified peroxidase. These observations implied that the modified peroxidase with hydrophobic side chains formed micellar structures by solubilization of phenolic products and further polymerization reaction could occur in the hydrophobic interior of the micelles.
Keywords: Peroxidase; Chemical Modification; Self-assembled Aggregates; Nanoscale Reactor

Simulation of a bubbling fluidized bed process for capturing CO2 from flue gas by Jeong-Hoo Choi; Chang-Keun Yi; Sung-Ho Jo; Ho-Jung Ryu; Young-Cheol Park (194-200).
We simulated a bubbling bed process capturing CO2 from flue gas. It applied for a laboratory scale process to investigate effects of operating parameters on capture efficiency. The adsorber temperature had a stronger effect than the regenerator temperature. The effect of regenerator temperature was minor for high adsorber temperature. The effect of regenerator temperature decreased to level off for the temperature >250 °C. The capture efficiency was rather dominated by the adsorption reaction than the regeneration reaction. The effect of gas velocity was as appreciable as that of adsorber temperature. The capture efficiency increased with the solids circulation rate since it was ruled by the molar ratio of K to CO2 for solids circulation smaller than the minimum required one (G s, min ). However, it leveled off for solids circulation rate >G s, min . As the ratio of adsorber solids inventory to the total solids inventory (x w1) increased, the capture efficiency increased until x w1=0.705, but decreased for x w1>0.705 because the regeneration time decreased too small. It revealed that the regeneration reaction was faster than the adsorption reaction. Increase of total solids inventory is a good way to get further increase in capture efficiency.
Keywords: CO2 Capture; Flue Gas; Simulation; Fluidized Bed; Dual Bed

Evaluation of bubble suspension behavior in electrolyte melts by Minseong Kim; Kangwook Kim; Munkyeong Hwang; Kyubo Kim; Juhun Song (201-210).
The viscosity of a molten electrolyte mixture commonly used in direct coal fuel cells (DCFCs) was evaluated. The measurements were obtained from near the melting temperature to a high temperature at which a considerably bubbly flow was induced by decomposition. A gravity-driven capillary viscometer was employed to obtain the viscosity data under low Reynolds flow conditions, using a modified Poiseuille flow relationship. The importance of carbon dioxide addition in measuring the intrinsic viscosity was clearly observed. In addition, the effect of the bubble suspension on the viscosity was quantified in terms of the volume fraction and capillary number. The results showed that the increase in viscosity was best explained only by the difference in the volume fraction of spherical bubbles in the electrolyte melt.
Keywords: Direct Coal Fuel Cell (DCFC); Electrolyte Melt; Viscosity; Bubble Suspension; Volume Fraction

Photocatalytic oxidative desulfurization of dibenzothiophene catalyzed by amorphous TiO2 in ionic liquid by Wenshuai Zhu; Yehai Xu; Huaming Li; Bilian Dai; Hui Xu; Chao Wang; Yanhong Chao; Hui Liu (211-217).
Three types of TiO2 were synthesized by a hydrolysis and calcination method. The catalysts were characterized by X-ray powder diffraction (XRD), diffuse reflectance spectrum (DRS), Raman spectra, and X-ray photoelectron spectroscopy (XPS). The XRD and Raman spectra indicated that amorphous TiO2 was successfully obtained at 100 °C. The results indicated that amorphous TiO2 achieved the highest efficiency of desulfurization. The photocatalytic oxidation of dibenzothiophene (DBT), benzothiophene (BT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and dodecanethiol (RSH) in model oil was studied at room temperature (30 °C) with three catalysts. The system contained amorphous TiO2, H2O2, and [Bmim]BF4 ionic liquid, ultraviolet (UV), which played vitally important roles in the photocatalytic oxidative desulfurization. Especially, the molar ratio of H2O2 and sulfur (O/S) was only 2: 1, which corresponded to the stoichiometric reaction. The sulfur removal of DBT-containing model oil with amorphous TiO2 could reach 96.6%, which was apparently superior to a system with anatase TiO2 (23.6%) or with anatase — rutile TiO2 (18.2%). The system could be recycled seven times without a signicant decrease in photocatalytic activity.
Keywords: Amorphous TiO2 ; Photocatalytic Oxidative; Desulfurization

The photocatalytic activity of cobalt tetrasulphophthalocyanine immobilized onto MCM-41 was investigated for photocatalytic degradation of 4-chlorophenol (4-CP) in aqueous solutions. Immobilization of cobalt tetrasulphophthalocyanine complex to the walls of MCM-41 was performed by pre-anchorage of 3-(aminopropyl)-triethoxysilane (APTES) onto MCM-41 via post-synthesis method. X-ray diffraction, nitrogen physisorption, diffuse reflectance spectroscopy, energy-dispersive X-ray and FT-IR methods were used to characterize the product. Photocatalytic efficiency of the prepared photocatalyst for degradation of 4-CP was tested under illumination of UV-A and visible light. The reaction intermediates were identified by gas chromatography-mass spectrometry (GC-MS) technique.
Keywords: Phthalocyanine; MCM-41; Immobilization; 4-Chlorophenol; Photocatalytic Degradation

The influence of calcination temperature on catalytic activities in a Co based catalyst for CO2 dry reforming by Sang-Hoon Song; Ju-Hee Son; Anatta Wahyu Budiman; Myoung-Jae Choi; Tae-Sun Chang; Chae-Ho Shin (224-229).
The carbon dioxide dry reforming of methane (CDR) reaction could be thermodynamically favored in the range of 800 to 1,000 °C. However, the catalyst in this reaction should be avoided at the calcination temperature over 800 °C since strong metal support interaction (SMSI) in this temperature range can decrease activity due to loss of active sites. Therefore, we focused on optimizing the temperature of pretreatment and a comparison of surface characterization results for CDR. Results related to metal sintering over support, re-dispersion by changing of particle size of metal-support, and strong metal support interaction were observed and confirmed in this work. In our conclusion, optimum calcination temperature for a preparation of catalyst was proposed that 400 °C showed a higher and more stable catalytic activity without changing of support characteristics.
Keywords: Dry Reforming; CO2 Utilization; Sintering; Metal-support Interaction; Synthesis Gas; Pre-treatment Effect

The sorption enhanced chemical looping reforming of glycerol (SECLRG) was proposed. This process can produce high purity H2 without need for additional gas separation equipment. Thermodynamic analysis on the reformer of SECLRG was conducted based on the minimization of Gibbs free energy. The results show that the favorable operation conditions for reformer are pressures around 1–20 atm, temperatures around 800 K, oxygen excess number of 1, and sorbent excess number of 1. The thermal efficiency with steam addition is higher than that without steam addition. The SECLRG was also examined in a fixed bed reactor, with NiO/Al2O3 and CaO particles as bed material and glycerol as fuel. Experimental results showed that the H2 molar fraction was higher with CaO than without it. Initially, high purity hydrogen (>95%) was obtained by SECLR of glycerol at 800 K and 1 atm.
Keywords: Hydrogen; Sorption Enhanced Chemical Looping Reforming (SECLR); CO2 Capture; Glycerol; Thermodynamic Analysis

A photo impinging streams cyclone reactor has been used as a novel apparatus in photocatalytic degradation of organic compounds using titanium dioxide nanoparticles in wastewater. The operating parameters, including catalyst loading, pH, initial phenol concentration and light intensity have been optimized to increase the efficiency of the photocatalytic degradation process within this photoreactor. The results have demonstrated a higher efficiency and an increased performance capability of the present reactor in comparison with the conventional processes. In the next step, residence time distribution (RTD) of the slurry phase within the reactor was measured using the impulse tracer method. A CFD-based model for predicting the RTD was also developed which compared well with the experimental results. The RTD data was finally applied in conjunction with the phenol degradation kinetic model to predict the apparent rate coefficient for such a reaction.
Keywords: Phenol; Photo-impinging Cyclone Reactor; Degradation; TiO2 ; RTD; CFD

We evaluated the effects of Na, K, Ca, and the steam-to-biomass (S/B) ratio on gasification efficiency during syngas production. The results show that H2 production was positively correlated with the S/B ratio. However, increases in the S/B ratio were limited because excessive steam decreased the reactor temperature and hampered the gasification process. Regarding the effects of alkali metals on syngas composition, we found that the addition of either Na or K increased the molar percentages of H2 and CO, but decreased CH4 and CO2. The results also clearly show that the addition of Na or K improved the yield of syngas, the carbon conversion efficiency, and the cold gas efficiency. Improvements were especially pronounced with K. Furthermore, Ca had different interactions with Na and K during gasification. When Na and Ca existed simultaneously, H2 production was enhanced.
Keywords: Gasification; Biomass; Alkali Metal; Alkaline Earth Metal; Fluidized Bed

Effect of pH, ionic strength, foreign ions, humic acid and temperature on Zn(II) sorption onto γ-Al2O3 by Jiang Xiao; Lanping Zhao; Wei Zhang; Xia Liu; Yuantao Chen (253-261).
The sorption of Zn(II) on γ-alumina was investigated as a function of contact time, pH, ionic strength, foreign ions, solid amount, humic acid (HA) and temperature by using batch technique. The results indicated that the sorption of Zn(II) onto γ-alumina was strongly dependent on pH and ionic strength. The sorption of Zn(II) increased slowly with increasing pH at pH 2–5, then increased sharply with pH increasing from 5 to 8.5, and at last maintained a maximum value at pH>8.5. A positive effect of HA on Zn(II) sorption was found at pH<7, whereas a negative effect was observed at pH>7. The thermodynamic data (ΔG0, ΔS0, ΔH0) were calculated from the temperature-dependent sorption isotherms, and the results suggested that the sorption of Zn(II) on γ-alumina was endothermic and spontaneous. The sorption results revealed that the γ-alumina can be as a cost-effective sorbent for pre-concentration of Zn(II) from large volumes of aqueous solutions in environmental pollution cleanup.
Keywords: Zn(II); γ-Alumina; Sorption; pH; Humic Acid; Thermodynamic Data

The effect of a marine bacterial Cytophaga lytica (C. lytica) biofilm on the adhesion and retention of a pseudobarnacle (epoxy adhesive) to platinum-cured silicone coatings was investigated at varying coating thickness (100–800 μm), modulus (E=0.08–1.3 MPa), and shear rate (2–22 μm/s). The initial adhesion of C. lytica biofilm on the silicone coating surfaces was increased as the coating modulus was increased. Nonetheless, the adhesion strength of the pseudobarnacle was not significantly influenced by the attached biofilms, with its strength decreasing with increasing the coating modulus. Thus, these results suggest that the pseudobarnacle adhesion strength would be primarily determined by physico-mechanical properties of the silicone coatings. Also, the adhesion/detachment tests demonstrated that the retention of the pseudobarnacle after water jetting was minimal for the soft silicone coating (VP1), which showed better performance than the widely acceptable silicone resin of DC 3140.
Keywords: Biofilm; Biofouling; Silicone Coating; Pseudobarnacle; Adhesion

Preparation and electrochemical behaviour of biomass based porous carbons as electrodes for supercapacitors — a comparative investigation by Adinaveen Thambidurai; John Kennedy Lourdusamy; Judith Vijaya John; Sekaran Ganesan (268-275).
We compared the relationship of the behavior and performance of sugarcane baggase and rice straw as supercapacitor electrodes. X-ray diffraction revealed the evolution of crystallites of carbon and silica during activation at higher temperature. The morphology of the carbon samples was determined by SEM. The surface area, pore volume, and pore size distribution of carbon composites were measured. The electrochemical responses were studied by using cyclic voltammetry experiment at 25 °C in a three-electrode configuration. The specific capacitance of the sugarcane bagasse carbon electrodes was in the range 92-340 F/g, whereas for rice straw, it was found to be 56–112 F/g at scan rates of 2-3 mV/s. The sugarcane bagasse carbon exhibited better performance than rice straw carbon using H2SO4 as the electrolyte. However, the results clearly show that lignocellulosic wastes possess a new biomass source of carbonaceous materials for high-performance supercapacitors.
Keywords: Porous Carbon; Surface Morphology; X-ray Diffraction; Supercapacitors

A new electrode reactor with in-built recirculation mode for the enhancement of methylene blue dye removal from the aqueous solution: Comparison of adsorption, electrolysis and combined effect by Ponnusamy Senthil Kumar; Maria Jacob Stani Raja; Mahathevan Kumaresan; Dinesh Kumar Loganathan; Prabhakaran Chandrasekaran (276-283).
The removal of basic dye such as methylene blue (MB) dye from the synthetic wastewater was experimentally investigated using an electrolytic cell (EC), adsorption and the combined effect of EC and adsorption technology called a three-phase three-dimensional electrode reactor (TPTDER). The performance of the each technology was checked on the basis of the efficiency of the systems. The experimental results are expressed in terms of the removal efficiency of the dye molecules. The results show that the TPTDER could efficiently remove the dye molecules from the aqueous solutions when compared with the EC and adsorption process. The removal efficiency reached as high as about 99% for an initial MB dye concentration in the range of 100–1,000 mg/L by TPTDER for 10 min at 12 V cell voltage and at specific airflow conditions. It was also observed that the removal of dye molecules depends upon the initial solution pH, applied cell voltage, contact time, and initial dye concentration. The recyclability of the particle electrodes in the TPTDER process was also checked. These findings suggest that TPTDER is a promising technology for the removal of dyes from the aqueous solution, and can be applied to the removal of dyes from the industrial effluents.
Keywords: Adsorption; Methylene Blue Dye; Three-phase Three-dimensional Electrode Reactor; Particle Electrodes

Synthesis and application of alumina supported nano zero valent zinc as adsorbent for the removal of arsenic and nitrate by Hafiz Badaruddin Ahmad; Yasir Abbas; Mazhar Hussain; Naeem Akhtar; Tariq Mahmood Ansari; Muhammad Zuber; Khalid Mahmood Zia; Shafiq Ahmad Arain (284-288).
Arsenic and nitrate are ill-famed environmental pollutants that are responsible for various lethal diseases. Their removal from drinking water is very essential. In present study, newly synthesized alumina supported nano zerovalent zinc (Alumina-nZvZ) has been tested to remove arsenic and nitrate. Quantitative analyses of arsenic have been performed spectrophotometrically and while that of nitrates ions colorimetrically. After optimization of time and amount of adsorbent, Langmuir, Freundlich and D-R isotherms were applied to determine different parameters for the assessment of adsorption. Synthesized samples were characterized by scanning electron microscopy (SEM) to evaluate porosity and void size. Alumina coated with reduced ZnCl 2 showed better efficiency for removal of arsenic and nitrate ions. Kinetics of adsorption was evaluated by using pseudo first-order and pseudo second-order rate equations.
Keywords: Adsorption; Alumina; SEM; Arsenic; Nitrates

The potential use of a biosorbent, Cystoseira indica, obtained from the Persian Gulf was investigated for the removal of Th (IV) ions from aqueous solutions by considering equilibrium, kinetic and thermodynamic aspects. The FT-IR spectra of unloaded and Th-loaded biomass indicated various functionalities on the biomass surface including hydroxyl, amide and carboxyl groups, which are responsible for the binding of thorium ions. Th (IV) uptake by C. indica was pH dependent. An increase in biosorbent dosage up to 1 g/L caused an increase in the Th (IV) percentage removal. Biosorption process at all studied initial Th (IV) ion concentrations follows the pseudo-second order kinetic model. The biosorption data could be well described by Redlich-Peterson isotherm in comparison to Langmuir and Freundlich isotherms. The maximum sorption capacity of Th (IV) by Langmuir isotherm was estimated to be 169.49 mg/g at 45 °C with pH of 3. The thermodynamic parameters indicated the biosorption of Th on the biomass was a feasible, spontaneous and endothermic process. Th sorption capacity remained unaffected or slightly affected (<10% inhibition) in the presence of several interfering ions such as uranium (VI), nickel (II) and copper (II). The reusability of the biomass was also determined after five sorption-desorption cycles.
Keywords: Cystoseira indica ; Biosorption; Thorium; Kinetic; Isotherm; Interfering Ions

Medium optimization and in vitro antioxidant activity of exopolysaccharide produced by Bacillus subtilis by Sirajunnisa Abdul Razack; Vijayagopal Velayutham; Viruthagiri Thangavelu (296-303).
The present study involves medium formulation using an agro waste, cane molasses, as the carbon substrate that was used instead of sucrose, to produce exopolysaccharide from Bacillus subtilis. Plackett Burman design was applied to evaluate twenty selected components, from which cane molasses, yeast extract, CaCl2, NaCl were found to be significant for fermentation. To study the concentration of each component, response surface methodology experimental design was performed using central composite design. The response plots resulted in optimized conditions—Cane molasses-2.36%, Yeast extract-0.56%, NaCl–0.71%, CaCl2 — 0.05%—which yielded 4.92 g/L at 48 h, at a temperature of 37 °C, initial pH 7 under still conditions. Antioxidant activity of EPS on DPPH resulted in a reducing capacity of 61.19%, at a concentration of 0.8mg/ml, greater than standard, Vitamin C. The biopolymer could thus be an ecofriendly product which can be subjected to various industrial and pharmaceutical applications.
Keywords: Bacillus subtilis ; Exopolysaccharide; Optimization; Response Surface Method; FTIR Spectrophotometry; Antioxidant Activity

Synthesis of polymer membranes of different porosity and their application for phenol removal from liquid phase by Magdalena Hofman-Bieniek; Katarzyna Jasiewicz; Robert Pietrzak (304-309).
Preparation of polymeric membranes based on polyethersulfone (PES) modified by adding different amounts of a pore-forming agent (PVP) is presented, and potential application of the membranes obtained for removal of phenol from the liquid phase is examined. The addition of various amounts of PVP has been shown to bring about changes in the content of the surface oxygen groups, but has no significant effect on the chemical character of the groups and acidic groups dominate. Filtration by phenol solution leads to significant changes in the total content of surface oxides; however, the acidic groups remain dominant. Membranes characterized by higher porosity exhibited more stable and higher rejection ratio for phenol removal. Although all the membranes were characterized by similar rejection ratios for phenol removal, the cake resistance (Rc) and pore resistance (Rp) values were found to depend significantly on the structure and porosity of the membrane applied for filtration.
Keywords: Polyethersulfone Membranes; Phase Inversion; Porosity; Surface Chemistry; Phenol Removal

Adsorption of heavy-metal ions (Pb2+, Cu2+) on perm-lotion-treated human hair by Hee Gwang Roh; Soon Geun Kim; Jihoon Jung (310-314).
Removal of toxic heavy metal ions from environmental and biological systems is important, but the use of commercially available heavy metal adsorbents is complicated by the need for specific pretreatment steps. We chose to study human hair treated with perm lotion as a heavy metal adsorbent because it is readily available and contains a large number of sulfur atoms for strong coordination to heavy metal ions. The optimal pH of adsorption by perm lotion-treated human hair was 4.16, which was slightly higher than the isoelectric point (pI) of the hair. The maximum removal ratio at pH 4.16 was 88.5% for a 50 ppm Cu2+ solution, and 96.79% for a 50 ppm Pb2+ solution. Almost 90% of the Pb2+ was removed from a 120 ppm Pb2+ solution. The perm-lotion-treated human hair was a cation-selective adsorbent.
Keywords: Human Hair; Heavy Metal; Adsorption

Excess molar enthalpies for the ternary system of {1,2-dichloropropane (1,2-DCP)+2-pentanol+3-pentanol} and their constituent binary mixtures {1,2-DCP+2-pentanol}, {1,2-DCP+3-pentanol}, and {2-pentanol+3-pentanol} have been measured over the whole range of composition using an isothermal micro-calorimeter with flow-mixing cell at T=298.15 K and atmospheric pressure. The experimental excess molar enthalpies of all the binaries and ternary mixture, including three pseudo-binary mixtures, are positive (endothermic effect) throughout the mole fraction range, except for the binary mixture {2-pentanol+3-pentanol} in which shows a small negative values over the entire composition range. The experimental binary H m, ij E data were fitted to Redlich-Kister equation, and the Cibulka and the Morris equations were employed to correlate the ternary H m, 123 E data. Several empirical equations for predicting ternary excess enthalpies from constituent binary mixing data have been also examined and compared. The experimental results have been qualitatively discussed in terms of molecular interactions.
Keywords: Excess Molar Enthalpy; Ternary Mixture; 1,2-Dichloropropane; 2-Pentanol; 3-Pentanol; Empirical Equation

A bi-modal porous structure MCM-41 (BPS-MCM-41) was synthesized and functionalized by 3-[2-(2-Aminoethylamino)ethylamino]propyltrimethoxysilane (TRI); also, its performance in amine grafting and CO2 capturing was compared with that of pore-expanded MCM-41 [1]. To create larger pores beside the mesoporous structure of MCM-41, carbon black nanoparticles were used as the solid template. Characterizing the BPS-MCM-41 using the BET and BJH techniques resulted in the surface reduction of 29.3 percent and volume increase of 68.46 percent. The pore size distribution showed two peaks: a narrow peak at 2.24 nm diameter, which belonged to micelles, and a wide one at about 50 nm due to the presence of used nanoparticles. The functionalization confirmed that BPS-MCM-41 is capable of accommodating a large quantity of amine groups. The CO2 adsorption measurement indicated that internal volume of the adsorbent was a critical factor affecting the adsorption capacity of the amine grafted adsorbents.
Keywords: Amine Grafted Adsorbent; BPS-MCM-41; CO2 Capture; Hierarchical Structure; Amine Loading

Separation performance of polyamide composite membranes is affected by several parameters during formation of thin upper layer via interfacial polymerization. We investigated the effect of various polyamide synthesis conditions on the performance of organic solvent resistant polyamide composite membranes through the model equations designed by 2-level fractional factorial design. The dewaxing solvent recovery was selected as separation process. Five factors were changed in two level includin; TMC concentration (0.05–0.1%), MPD concentration (1–2%), support immersion time in organic solution (2–4 min), support immersion time in aqueous solution (1–2 min), and curing temperature (70–80 °C). The resultant equations showed 93.48% and 94.82% of the variability (R adj 2 ) in data used to fit oil rejection and permeate flux models, respectively. The analysis of variance revealed that both models were high significant. It was also observed that TMC concentration, MPD concentration and immersion time in TMC have more pronounced effect on the oil rejection and permeate flux than other factors and interactions. Optimal polyamide preparation conditions were obtained using multiple response method for 94% oil rejection as target value. According to the results, the best value of permeate flux (8.86 l/(m2·h)) was found at TMC concentration of 0.1%, MPD concentration of 1.94%, immersion time in TMC of 3.88 min, immersion time in MPD of 1.95 min and curing temperature of 71.96 °C with desirability factor of 1.
Keywords: Organic Solvent Nanofiltration; Thin Film Composite Membrane; Factorial Design; Polyamide; Interfacial Polymerization; ANOVA

Enhanced oil recovery using nanoparticle-stabilized oil/water emulsions by Hanam Son; Hyuntae Kim; Geunju Lee; Jinwoong Kim; Wonmo Sung (338-342).
We experimentally investigated nanoparticle-stabilized emulsions for enhanced oil recovery (EOR) applications. The emulsions were injected into a silica bead column containing mineral oil, and the oil recovery was calculated using a mass-balance approach. The experiments were carried out as follows: 1) The emulsions were injected into a column with 100% water saturation to investigate the mobility of the water and emulsions, 2) Water flooding was then carried out at initial oil and water saturation, and the emulsion flooding was injected to calculate the enhancement in the oil recovery rate. The results indicate that the nanoparticle-stabilized emulsions increased the oil recovery rate by 11% after water flooding. The mechanism for this is attributed to a greater pressure difference across the porous medium, leading to oil remaining in the pores being produced via a piston effect. These results indicate that nanoparticle-stabilized emulsions may be effective EOR agents.
Keywords: Nanoparticle-stabilized Emulsions; Oil-in-water Emulsions; Enhanced Oil Recovery (EOR); Water Flooding; Silica Bead Column

Poly(ethyleneimine)-functionalized organic-inorganic hybrid silica adsorbent was synthesized by hydrothermal-assisted surface grafting technique for the removal of Ni(II) ions from aqueous solution, and was characterized by FT-IR, nitrogen adsorption and the static adsorption-desorption experiment method. The results indicated that the maximum static adsorption capacity of Ni(II) on poly(ethyleneimine)-functionalized hybrid silica adsorbent by hydrothermal heating method was 1.6 times as much as the conventional heating method. The poly(ethyleneimine)-functionalized hybrid silica adsorbent offered a fast kinetics for the adsorption of Ni(II), had a substantial binding capacity in the range of pH 4-8 and could be used repeatedly. The Langmuir adsorption model was more favorable than the Freundlich and Dubinin-Radushkevich adsorption models. The adsorption followed a pseudo-second-order model compared with pseudo-first-order model. Various thermodynamic parameters such as ΔG°, ΔH° and ΔS° indicated that the adsorption process was spontaneous and endothermic. The results showed that poly(ethyleneimine)-functionalized hybrid silica adsorbent could be employed as an effective material for the removal of Ni(II) ions from aqueous solution.
Keywords: Nickel; Poly(ethyleneimine); Hydrothermal-assisted; Organic-inorganic Hybrid; Removal

Characterization of fluidization regime in circulating fluidized bed reactor with high solid particle concentration using computational fluid dynamics by Benjapon Chalermsinsuwan; Theeranan Thummakul; Dimitri Gidaspow; Pornpote Piumsomboon (350-363).
The hydrodynamics inside a high solid particle concentration circulating fluidized bed reactor was investigated using computational fluid dynamics simulation. Compared to a low solid particle reactor, all the conventional fluidization regimes were observed. In addition, two unconventional fluidization regimes, circulating-turbulent and dense suspension bypassing regimes, were found with only primary gas injection. The circulating-turbulent fluidization regime showed uniformly dense solid particle distribution in all the system directions, while the dense suspension bypassing fluidization regime exhibited the flow of solid particles at only one side system wall. Then, comprehensive fluidization regime clarification and mapping were evaluated using in-depth system parameters. In the circulating-turbulent fluidization regime, the total granular temperature was low compared to the adjacent fluidization regimes. In the dense suspension bypassing fluidization regime, the highest total granular temperature was obtained. The circulating-turbulent and dense suspension bypassing fluidization regimes are suitable for sorption and transportation applications, respectively.
Keywords: Circulating Fluidized Bed Reactor; Computational Fluid Dynamics Simulation; Fluidization; Total Granular Temperature; Hydrodynamics