Korean Journal of Chemical Engineering (v.33, #10)

Flow control in paper-based microfluidic device for automatic multistep assays: A focused minireview by Seong-Geun Jeong; Jongmin Kim; Si Hyung Jin; Ki-Su Park; Chang-Soo Lee (2761-2770).
Although lateral flow tests (LFTs) are easy-to-use diagnostics, they have fundamental limitations for sequential multistep assay that can be reduced to a single chemical reaction step. Paper-based microfluidic devices have attracted considerable attention for use in automatic multi-step assays because paper can be an excellent platform to control sequential fluid flow without external equipment. This review focuses on recent developments on how to control flow rate in paper-based microfluidic devices for automating sequential multi-step assays. The aim of this review is to discuss the limitations of LFTs and potential paper-based microfluidic devices for automated sequential multi-step assays in developing countries; and the existing fluidic control technologies for sequential multi-step assays. In addition, we present future challenges for commercialization of paper-based microfluidic devices to perform automatic multi-step assays.
Keywords: Paper-based Microfluidic Device; Multistep Assays; Fluidic Time Delays; Flow Control; Diagnosis

Stretchable carbon nanotube conductors and their applications by Sunju Hwang; Soo-Hwan Jeong (2771-2787).
Stretchable electronics has evolved rapidly in the past decade because of its promising applications, as electronic devices undergo large mechanical deformation (e.g., bending, folding, twisting, and stretching). Stretchable conductors are particularly crucial for the realization of stretchable electronic devices. Therefore, tremendous efforts have been dedicated toward developing stretchable conductors, with a focus on conductive material/polymer composites. This review summarizes the recent progress in stretchable conductors and related stretchable devices based on carbon nanotubes (CNTs), which was enabled by their outstanding electrical and mechanical properties. Various strategies for developing highly stretchable conductors that can deform into nonplanar shapes without significant degradation in their electronic performance are described in terms of preparation processes. Finally, challenges and perspectives for further advances in CNT-based stretchable conductors are discussed.
Keywords: Carbon Nanotube; Stretchable Conductors; Nanomaterials; Strain Sensors; Supercapacitors

Advances in the biological treatment of coal for synthetic natural gas and chemicals by Pamidimarri D.V.N. Sudheer; Yokimiko David; Cheol Gi Chae; You Jin Kim; Mary Grace Baylon; Kei-Anne Baritugo; Tae Wan Kim; Min-Sik Kim; Jeong Geol Na; Si Jae Park (2788-2801).
Coal, the most primitive fossil fuel, has been exploited for ages, and reserves dictate the economies of many countries. Presently, most energy is generated by direct combustion, raising concerns over global warming. Biological pretreatment of fossil resources and generation of alternative green energy can address the environmental issues associated with global coal utilization. Biological coal treatment can produce industrially important chemicals and bio-methane by employing microorganisms able to depolymerize/degrade coal. This review discusses current advances in microbial coal conversion, such as the efforts made to comprehend microbial processes, significant outputs of coal conversion, principle components responsible for coal conversion, and factors affecting the biological processes to convert coal. Development of these biological processes can be a stepping stone for greener coal; however, integration of multidisciplinary technologies is needed to increase the efficiency of economic coal utilization and production of economically and industrially feasible biomethane.
Keywords: Coal; Coal Biodegradation; Coal Depolymerization; Biological Treatment; Biomethane

Photocatalytic degradation of bromophenol blue in aqueous medium using chitosan conjugated magnetic nanoparticles by Hamayun Khan; Abdul Kabir Khalil; Adnan Khan; Khalid Saeed; Nauman Ali (2802-2807).
Three different chitosan conjugated magnetic nanoparticles (CCMN) of Co, Ni and Fe were prepared using co-precipitation method. The prepared CCMN were characterized by scanning electron microscopy (SEM), Xray diffraction (XRD) and Fourier transform infra-red (FT-IR) spectroscopic techniques. The SEM results showed a smooth surface morphology with almost uniform particle size and irregular shape structure for all CCMN. The XRD study revealed the crystalline structure in case of Co-CCMN and Ni-CCMN, while amorphous nature of Fe-CCMN was observed. The particle size of the prepared CCMN was found to be <95 nm, as confirmed from SEM and XRD analyses. Similarly, FT-IR analysis showed the incorporation and conjugation of Co, Ni and Fe magnetic nanoparticles into the chitosan polymer matrix. The point of zero charge (PZC) was found to be 7.41 for Co-CCMN and Ni-CCMN and 7.70 for Fe-CCMN. The photocatalytic activity of the prepared CCMN was investigated under UV light irradiation (254 nm and 15 W) in the aqueous medium using bromophenol blue (BPB). The photocatalytic process was monitored by UV-visible spectrophotometer for different irradiation times (0 to 10 h). The results showed that all the prepared CCMN displayed good to excellent photocatalytic property where the highest degradation was exhibited by Fe-CCMN (94.5%), followed by Co-CCMN (85.1%) and Ni-CCMN (83.0%). The prepared catalysts were recycled and reused, maintaining good photocatalytic activity for four consecutive batches.
Keywords: Photocatalysis; Chitosan; Magnetic Nanoparticles; Bromophenol Blue

A strategic investment plan to establish renewable energy source (RES) systems plays an important role in various decision-making processes, from a stakeholder in business purposes to a policy maker for public benefits. In this study, we have developed a new optimization model to establish efficient investment strategies to design and operate a biomass to hydrogen (B2H2) system, which includes the features of RES (e.g., intermittent availability) and RES technologies (e.g., low conversion efficiency) along with various external factors on energy economy (energy price fluctuation and demand uncertainty). As a result, we identified the optimal long-term plan of investment strategy including timing, utilized amount, and capacity of facilities. In addition, we performed an economic sensitivity analysis for major parameters and evaluated a sustainability of the B2H2 system using additional metrics such as energy security and environmental protection.
Keywords: Biomass; Investment Strategy; Optimization; Hydrogen; Korea

Modeling of low viscosity oil-water annular flow in horizontal and slightly inclined pipes: Experiments and CFD simulations by Yi-Xin Pan; Hong-Bing Zhang; Rong-Hua Xie; Xing-Bin Liu; Min Wang (2820-2829).
To characterize the effect of pipe inclination, low viscosity, flow rate and inlet water cut on annular flow pattern, a low viscosity oil-water two-phase annular flow in horizontal and slightly inclined (+1°, +3° and +5°) pipes with diameter of 20 mm has been experimentally investigated. A modified VOF model based on the CFD software package FLUENT was used to predict the in-situ oil fraction and pressure drop. The experimental data indicate that annular flow appears at a medium-high water cut. The slip ratio increases with flow rate increase but decreases with increasing water cut. The changes are more significant as the degree of inclination increases. Pressure drop is strongly dependent on flow rate, as it increases rapidly as inlet flow rate increase. Good agreement between the experimental data and calculated results of slip ratio and pressure drop was obtained.
Keywords: Oil-water Annular Flow; Inclined Pipe; Low Viscosity; Pressure Drop

We introduce a coupled smoothed particle hydrodynamics-discrete element method (SPH-DEM) to describe the two-way interaction between the two phases of a solid-liquid flow. To validate the model, we simulated two test problems: a solid-liquid counter-flow in a periodic box and particle settlement. The simulations correctly predicted the dynamics, and the results showed good agreement with the theory. The developed model was then applied to simulate the slurry coagulation process to examine the coagulation efficiency. When the rotational speed exceeded the normal range, the coagulation rate decreased with time, even though the rate was high during the early stage due to the size separation effect of the particles. Given this result, overly fast stirring appears to have an adverse effect on the coagulation efficiency. The model is applicable to the design of various types of solid-liquid flows.
Keywords: Solid-liquid Flow; SPH; DEM; Particle-laden Flow; Particle Method

Comparison of physically mixed and separated MgO and WO3/SiO2 catalyst for propylene production via 1-butene metathesis by Nattapong Kasempremchit; Piyasan Praserthdam; Suttichai Assabumrungrat (2842-2848).
We examined the catalyst bed design of MgO and WO3/SiO2 for production of propylene via metathesis of 1-butene. WO3/SiO2 was used as a bi-functional catalyst for isomerization and metathesis reactions. Addition of MgO was proposed to help improve the isomerization activity and hence the propylene yield. Experimental studies were carried out to determine activity and reaction kinetics of 1-butene isomerization over MgO isomerization catalyst and 1-butene metathesis over WO3/SiO2 bi-functional catalyst for designing a suitable catalyst bed. Two types of catalyst bed arrangement—physically mixed bed and separated bed—were considered and compared by computer simulation. The simulations reveal that adding MgO in the separated bed by packing MgO before WO3/SiO2 offers superior propylene yield to the physically mixed bed. The appropriate %MgO loading in catalyst bed which offers a maximum propylene yield was found to vary (3 and 23%), depending on operating condition.
Keywords: Metathesis; Propylene; 1-Butene Isomerization; Kinetics; Catalyst Bed Design

The sulfidation and regeneration properties of lignite char-supported iron-based sorbent for coke oven gas (COG) desulfurization prepared by mechanical stirring (MS), ultrasonic assisted impregnation (UAI), and high pressure impregnation (HPI) were investigated in a fixed-bed reactor. During desulfurization, the effects of process parameters on sulfidation properties were studied systematically. The physical and chemical properties of the sorbents were analyzed by X-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared (FTIR) and BET surface area analysis. The results of desulfurization experiments showed that high pressure impregnation (HPI) enhanced the sulfidation properties of the sorbents at the breakthrough time for char-supported iron sorbents. HPI method also increased the surface area and pore volume of sorbents. Sulfur capacity of sorbents was enhanced with increasing sulfidation temperatures and reached its maximum value at 400 °C. It was observed that the presence of steam in coke oven gas can inhibit the desulfurization performance of sorbent. SO2 regeneration of sorbent resulted in formation of elemental sulfur. HPIF10 sorbent showed good stability during sulfide-regeneration cycles without changing its performance significantly.
Keywords: Lignite Char; Coke Oven Gas; Pressurized Impregnation; Iron-based Sorbent; Regeneration

Liquefaction and characterization of residue of oleaginous yeast in polyhydric alcohols by Gaoxiang Qi; Hairong Zhang; Chao Huang; Haijun Guo; Lian Xiong; Can Wang; Xinde Chen (2858-2862).
The residue of oleaginous yeast (ROY) was liquefied in polyhydric alcohols using sulfuric acid as catalyst. The effects of some liquefaction conditions on the liquefied residue rate, such as liquefaction temperature, catalyst loading, reaction time, glycerol concentration and solvent/ROY ratio, were discussed. The liquefied residue rate decreased as the reaction time, liquefaction temperature, catalyst loading, solvent/ROY ratio increased. The re-polymerization of liquefied products was favored in later stage reaction. Higher catalyst loading and lower solvent/ROY ratio could accelerate the re-polymerization of liquefied products; thus the liquefied residue increased. Fourier transform infrared (FT-IR) analyses showed that the main component of ROY is polysaccharide. The gas chromatography and mass spectrometry (GC-MS) analysis showed that liquefied products of ROY included alcohols, acids, ketones, aldehydes, amide, ester and their derivatives.
Keywords: Liquefaction; Oleaginous Yeast; Polyhydric Alcohol; Polysaccharide

Conversion of corn fiber (CF), a by-product from the corn-to-ethanol conversion process, into fermentable sugar and succinic acid was investigated using soaking in aqueous ammonia (SAA) pretreatment followed by biological conversions, including enzymatic hydrolysis and fermentation using genetically engineered E. coli (AFP184). The SAA pretreatment (using a 15% w/w NH4OH solution at a solid-to-liquid ratio of 1: 10 at 60 °C for 24 h) removed 20-38% of lignin and significantly improved the digestibility of the treated solid (85-99% of glucan digestibility). Following the enzymatic hydrolysis, the sugar-rich hydrolysate was subjected to dilute sulfuric acid treatment (1 wt% sulfuric acid and 120 °C for 1 h), which hydrolyzed the oligosaccharides in the hydrolysate into fermentable monomeric sugars. The mixed sugar hydrolysates containing hexose and pentose obtained from the two-step hydrolysis and SAA pretreatment were fermented to succinic acid using a genetically engineered microorganism, Escherichia coli AFP184, for evaluating the fermentability. Engineered E. coli AFP184 effectively converted soluble sugars in the hydrolysate to succinic acid (20.7 g/L), and the production rate and yield were further enhanced with additional nutrients; the highest concentration of succinic acid was 26.3 g/L for 48 h of fermentation.
Keywords: Corn Fiber; Ammonia Pretreatment; Succinic Acid; Fermentable Sugars

Density functional theory study on Hg removal mechanisms of Cu-impregnated activated carbon prepared by simplified method by Yaming Fan; Yuqun Zhuo; Zhenwu Zhu; Liangliang Li; Qun Chen; Yu Lou (2869-2877).
The preparation of activated carbon sorbent for Hg removal was simplified by combining activation and functionalization processes into one step. Jujube-based carbon material was first mixed with CuCl2 solution and then activated for the preparation of Cu-impregnated activated carbon. Physical and chemical properties of prepared activated carbon were investigated by means of N2 adsorption, SEM-EDS, XRD. A fixed-bed reactor with CEMS (Continuous emission monitoring system) was used to test the Hg adsorption ability of prepared activated carbon. DFT (Density functional theory) method of computational chemistry calculation was applied to identify the Hg adsorption mechanisms on sorbent surface.
Keywords: One-step Preparation; Activated Carbon; Cu-impregnated; Hg Removal; Density Functional Theory

Application of mesoporous magnetic carbon composite for reactive dyes removal: Process optimization using response surface methodology by Ahmad Jonidi Jafari; Babak Kakavandi; Roshanak Rezaei Kalantary; Hamed Gharibi; Anvar Asadi; Ali Azari; Ali Akbar Babaei; Afshin Takdastan (2878-2890).
Discharging the effluents of textile wastewaters into potable water resources can endanger the ecosystem, due to their reactivity, toxicity, and chemical stability. In this research, the application of powder activated carbon modified with magnetite nanoparticles (PAC-MNPs) as an adsorbent for removal of reactive dyes (Reactive black 5 (RB5) and reactive red 120 (RR120)) was studied in a batch system. The adsorption performance was evaluated as a function of temperature, contact time and different adsorbent and adsorbate concentrations. The levels of factors were statistically optimized using Box-Behnken Design (BBD) from the response surface methodology (RSM) to maximize the efficiency of the system. The adsorption process of both dyes was fit with the pseudo-second order kinetic and Langmuir isotherm models. The identified optimum conditions of adsorption were 38.7 °C, 46.3 min, 0.8 g/L and 102 mg/L for temperature, contact time, adsorbent dose, and initial dyes concentration, respectively. According to the Langmuir isotherm, the maximum sorption capacities of 175.4 and 172.4 mg/g were obtained for RB5 and RR120, respectively. Thermodynamics studies indicated that the adsorption process of the reactive dyes was spontaneous, feasible, and endothermic. After five cycles, the adsorption efficiency was around 84 and 83% for RB5 and RR120, respectively. A high value of desorption was achieved, suggesting that the PAC-MNPs have a good potential in regeneration and reusability, and also can be effectively utilized in industrial applications. PAC-MNPs also show a good anti-interference potential for removal of reactive dyes in dye-industry wastewaters.
Keywords: Reactive Dyes; Response Surface Method; Box-Behnken Design; Adsorption; Magnetic Composite

Thermo-catalytic decomposition of waste lubricating oil over carbon catalyst by Yongjae Lee; Jong Tak Jang; Jong Wook Bae; Ki June Yoon; Gui Young Han (2891-2897).
The thermo-catalytic decomposition of waste lubricating oil over a carbon catalyst was investigated in an I.D. of 14.5mm and length of 640mm quartz tube reactor. The carbon catalysts were activated carbon and rubber grade carbon blacks. The decomposition products of waste lubricating oil were hydrogen, methane, and ethylene in a gas phase, carbon in a solid phase and naphthalene in a liquid phase occurring within the temperature ranges of 700 °C-850 °C. The thermo-catalytic decomposition showed higher hydrogen yield and lower methane yield than that of a non-catalytic decomposition. The carbon black catalyst showed higher hydrogen yield than the activated carbon catalyst and maintained constant catalytic activity for hydrogen production, while activated carbon catalyst showed a deactivation in catalytic activity for hydrogen production. As the operating temperature increased from 700 °C to 800 °C, the hydrogen yield increased and was particularly higher with carbon black catalyst than activated carbon. As a result, carbon black catalyst was found to be an effective catalyst for the decomposition of waste lubricating oil into valuable chemicals such as hydrogen and methane.
Keywords: Catalytic Decomposition; Waste Lubricating Oil; Carbon Black; Hydrogen

Equilibrium kinetic and thermodynamic studies of Cr(VI) adsorption onto a novel adsorbent of Eucalyptus camaldulensis waste: Batch and column reactors by Hajira Haroon; Tayyab Ashfaq; Syed Mubashar Hussain Gardazi; Tauqir Ali Sherazi; Muhammad Ali; Naim Rashid; Muhammad Bilal (2898-2907).
Cr(VI) adsorption onto Eucalyptus camaldulensis sawdust (ECS) waste was investigated in batch and column reactors. Various parameters, including the adsorbent dose, pH, initial concentration, particle size, contact time and temperature were optimized. The maximum adsorption capacity (35.58mg g-1, 71.16%) was achieved at pH 2.0. Data fitted well to Freundlich and Halsey’s models (R2=0.992), indicating the multilayer adsorption of Cr(VI). It obeys the pseudo-second order kinetics. Endothermic and non-spontaneous nature of Cr(VI) adsorption was observed with positive values of changes in enthalpy (9.83 kJ mol-1), and Gibbs-free energy (1.52, 1.38, 1.24, 1.10 and 0.97 kJ mol-1), respectively. In this column study, the breakthrough curve time increased from 670 to 1,270min by increasing the bed height from 5 to 15 cm, respectively. Column data was found well fitted to bed depth service time model. Adsorption capacity at 60% breakthrough was 2,443.636mg L-1. The study indicates that ECS waste can be a promising adsorbent for Cr(VI) remediation from industrial effluents.
Keywords: Eucalyptus camaldulensis ; Chromium (VI); Adsorption Kinetics; Equilibrium Isotherms; Thermodynamics; Column Reactor

Potential industrial application of Actinobacillus succinogenes NJ113 for pyruvic acid production by microaerobic fermentation by Zhen Wang; Wen Xiao; Alie Zhang; Hanxiao Ying; Kequan Chen; Pingkai Ouyang (2908-2914).
Actinobacillus succinogenes NJ113 is capable of microaerobic fermentation, which offers the possibility of a novel type of pyruvic acid production. A dissolved oxygen environment with stirring at 300 rpm was a key factor in the fermentative production of a maximum concentration of pyruvic acid. Potassium carbonate (K2CO3) was found to have a role in promoting pyruvic acid production, influencing the concentration of pyruvic acid and production of the by-product succinic acid. The final titer of pyruvic acid production was 36.8±0.1 g L−1 with an overall yield of 0.639±0.056 g g−1 glucose and 3.12±0.03mmol g−1 dry cell weight h−1.This study is the first to illustrate the advantage of using Actinobacillus succinogenes NJ113 with no genetic modification under microaerobic conditions for the production of pyruvic acid.
Keywords: Actinobacillus succinogenes ; Dissolved Oxygen Environment; Microaerobic Fermentation; Potassium Carbonate; Pyruvic Acid

Production of bio-epoxide and bio-adhesive from non-edible oil by Srikanta Dinda; Nikhil Sainath Reddy Veeram; Ramesh Babu Adusumalli (2915-2922).
Epoxidation of Nahor oil was performed by H2O2 in the presence of acid catalyst at 50 °C. It was possible to obtain around 70% epoxide yield within 8 hrs of reaction. Amberlite IR 120H showed better epoxide yield compared to H2SO4 and Dowex 50 WX8. The performance of carboxylic acids was found to be in the order of formic acid>acetic acid>propanoic acid. The curing of epoxidized nahor oil involved using ethylenediamine (EDA) and diethylenetriamine (DETA). The adhesive property of the cured resins was tested and compared with commercially available glue. The force required to detach the cardboard joint was about 36.3 N for DETA-cured resin.
Keywords: Nahor Oil; Carboxylic Acid; Acid Catalyst; Epoxy Resin; Amine Curing; Adhesive

Synergistic effect in low temperature co-pyrolysis of sugarcane bagasse and lignite by Shuang Yi; Xuan-ming He; Hong-tao Lin; Hui Zheng; Cui-hua Li; Chong Li (2923-2929).
Sugarcane bagasse was co-pyrolyzed with lignite in a fixed bed reactor to investigate the possible interaction during co-pyrolysis. GC-MS revealed that the concentration of phenols and aliphatic compounds in the tar increased with the addition of sugarcane bagasse, while the content of aromatic compounds had the contradictory tendency. The phenol content in co-pyrolyzed tar reached 20.35%, which increased by 142.26% compared with the calculated values. The sugarcane bagasse decomposition peak partly overlapped with lignite pyrolysis peak from TG-DTG curves, which meant more interaction between lignite and sugarcane bagasse during the pyrolysis process. The difference between the experimental and calculated values of pyrolysis products yield, tar components, DTG values and kinetics analysis indicated the synergetic effect between lignite and sugarcane bagasse.
Keywords: Sugarcane Bagasse; Lignite; Co-pyrolysis; Synergetic; Thermogravimetric Analysis

A simple accurate model for prediction of physical properties of petroleum fractions by Hossein Parhizgar; Mohammad Reza Dehghani (2930-2942).
We utilized genetic programming approach for generation of a new model for prediction of critical properties and acentric factor of petroleum fractions. Usually for estimation of critical properties, molecular weight, specific gravity and boiling point are needed, while in this work in order to present an applicable model, just the boiling point and specific gravity have been used as the model parameters. Our results showed that using new correlations, critical temperature, pressure, volume and acentric of petroleum fractions can be correlated within 0.07, 0.65, 0.45 and 0.79 percent average absolute relative deviation. respectively.
Keywords: Genetic Programming; Critical Properties; Acentric Factor; Petroleum Fraction

Adsorption of pure carbon dioxide and methane was examined on activated carbon prepared from pine cone by chemical activation with H3PO4 to determine the potential for the separation of CO2 from CH4. The prepared adsorbent was characterized by N2 adsorption-desorption, elemental analysis, FTIR, SEM and TEM. The equilibrium adsorption of CO2 and CH4 on AC was determined at 298, 308 and 318 K and pressure range of 1–16 bar. The experimental data of both gases were analyzed using Langmuir and Freundlich models. For CO2, the Langmuir isotherm presented a perfect fit, whereas the isotherm of CH4 was well described by Freundlich model. The selectivity of CO2 over CH4 by AC (CO2: CH4=50: 50, 298K, 5 bar), predicted by ideal adsorbed solution theory (IAST) model, was achieved at 1.68. These data demonstrated that pine cone-based AC prepared in this study can be successfully used in separation of CO2 from CH4.
Keywords: Activated Carbon; Pine Cone; Carbon Dioxide; Methane; IAST

A comparative study was conducted to evaluate the performance of two membrane types of electrospun poly(vinylidene fluoride) (PVDF) and commercial ploytetrafluoroethylene (PTFE). The optimized needleless electrospinning technique was used to prepare PVDF membranes. Scanning electron microscopy (SEM), wettability tests, water flux, mechanical strength and liquid entry pressure (LEP) measurements were performed to evaluate the prepared membrane. Air gap membrane distillation (AGMD) experiments were carried out to investigate the salt rejection performance and the durability of membranes. The results show that our nanofibrous PVDF membrane presents higher water permeation flux (>20 kg/m2 h) compared to commonly used PTFE. In addition, the experimental data confirms that competitive salt rejection efficiency (>99.8%) was obtained in this new membrane.
Keywords: AGMD; PVDF; Nanofibrous Membrane; Desalination; Needle-less Electrospinning

VLE data for binary systems of methanol (1)+cyclopentyl methyl ether (2) were measured at five equal-spaced temperatures between 313.15 and 353.15 K using a circulation-type equilibrium apparatus with on-line gas chromatography analysis. This binary system shows strong positive deviation from Raoult’s law and forms an azeotrope at each temperature. The experimental data were correlated with the Peng-Robinson equation of state using the Wong-Sandler mixing rule combined with the NRTL excess Gibbs free energy model. The overall average relative deviations of pressure (ARD-P (%)) and vapor phase compositions (ARD-y (%)) between experimental and calculated values through the temperature range from 313.15 to 353.15 K were 0.298 and 0.499%, respectively. In the range of experimental temperature, azeotropic compositions showed a linear relationship with temperature and were correlated by the empirical equation of x azeo =0.001 T/K+0.617.
Keywords: Vapor Liquid Equilibria; Cyclopentyl Methyl Ether (CPME); Peng-Robinson Equation of State (PR-EoS); Wong-Sandler Mixing Rule

Self-cleaning behavior of nanocomposite membrane induced by photocatalytic WO3 nanoparticles for landfill leachate treatment by Nader Shafaei; Mohsen Jahanshahi; Majid Peyravi; Qasem Najafpour (2968-2981).
Photocatalytic self-cleaning polysulfone (PSf) membranes were fabricated by adding different concentrations of WO3 nanoparticles (0-2 wt%) via phase inversion method for ultrafiltration of landfill leachate. To evaluate the feasibility of self-cleaning property by WO3 nanoparticles, all synthesized membranes were tested with and without UV. After UV irradiation, the value of the contact angle for a membrane with 2wt% WO3 decreased from 67.15° to 37.9°. Results showed that the addition of WO3 affected the pore size, porosity and hydrophilicity of the WO3/PSf membrane, so that the porosity of membrane with 2 wt% WO3 reached 84.86%. The flux of the nanocomposite membrane after irradiation by UV light rose in comparison with the same membrane without UV light, and the flux decline rates also decreased. The flux of the membrane with 2wt% WO3 was also better than the other membranes, which shows the self-cleaning property. The chemical oxygen demand (COD) removal of leachate for modified membranes was also improved by increasing the WO3 nanoparticles. The highest COD removal of the modified membrane with 2 wt% WO3 was 54.91%. This value increased to 77.45% after UV radiation.
Keywords: Self-cleaning Property; Leachate Treatment; WO3 Nanoparticle; Polysulfone; Nanocomposite Mmembrane; UV Light

The selectivity of alkyl-substituted imidazolium cation-based ionic liquids (ILs) with different anion: Tf2N, PF6, Tf2N and BF4, namely 1-Butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ([BMIM][Tf2N]), 1-Butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][Tf2N]), 1-Methyl-3-octyl imidazolium tetrafluoroborate ([OMIM][BF4]), was tested for the extraction of benzene, toluene and p-xylene(BTX) aromatics with hexane mixtures. Liquid-liquid equilibrium (LLE) data were determined for the six ternary mixtures {hexane (1)+BTX (2)+ILs (3)} at 298.15 K and atmospheric pressure. In addition, binary LLE data from 293.15 K to 318.15 K are also reported for the system {hexane (1)+[BMIM][Tf2N] (2)}. The ternary experimental LLE data were satisfactorily correlated with the NRTL activity coefficient model. The degree of consistency of the tie lines was estimated by using the Othmer-Tobias equation, for which a good linear correlation coefficient (R2) was obtained. As a result, the selectivity of ILs as potential solvents for the extraction of BTX from aliphatic components was found to be much higher than unity and PF6 anion showed higher selectivity compared to other anions.
Keywords: Liquid-liquid Equilibrium; Separation; Aliphatic; Aromatic; Ionic Liquid

Synthesis and characterization of silver nanoparticles via green route by Niharika Nagar; Shikha Jain; Pranav Kachhawah; Vijay Devra (2990-2997).
The development of competent green chemistry methods for synthesis of metal nanoparticles has become a main focus of researchers. In this study we report the green synthesis of silver nanoparticles (AgNps) by reduction of silver nitrate, using leaf broth of Azadirakta indica (Neem). The plant leaf broth simultaneously acts as reducing agent as well as capping agent at 30 °C. The effect of different concentration of silver ions, percentage of leaf broth and temperature on morphology of dispersed silver nanoparticles was studied. The formation of silver nanoparticles in dispersion was monitored through the analysis of absorbance spectra by UV-Visible spectrophotometer at different stages during the process of synthesis. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis revealed that silver nanoparticles were pure and monodispersed and size was ranging from 9-56 nm. Fourier transform infrared (FTIR) analysis indicates prominent bands of absorbance, which are responsible for reducing of Ag+ ions and stabilization of obtained silver nanoparticles. Results confirmed this protocol as simple, rapid, cost effective, eco-friendly and alternative conventional physical/chemical methods.
Keywords: Silver Nitrate; Azadirakta indica (Neem); Silver Nanoparticles; Green Synthesis; Characterization

Process design and optimization methodology for high pressure membrane removal of CO2 from natural gas was developed. An approximate model based on plasticization pressure and permeability parameters at plasticization was proposed for quick evaluation of membrane materials for the high pressure operation. The model was derived by applying the partial immobilization assumption to the fundamental model of solution - diffusion mechanism along with a modified upper-bound curve. About ninety membranes obtained from literature were used to illustrate this methodology. The best three were selected for detailed process modeling and optimization. Process optimization was achieved via non-linear programming constraint optimization model. Gas processing cost was used as the objective function, while plasticization pressure and the CO2 concentration in the feed were used as the constraints. Membrane of 6FDA-durene had the lowest annual gas processing cost while 6FDA-DAM : DABA 2 : 1 had the highest optimum product purity.
Keywords: Penetrant-induced Plasticization; Plasticizing Feed Stream; Productivity Loss; Permeability Parameter; Nonlinear Programming

Laccase-catalyzed polymerization of m-phenylenediamine in aqueous buffers by Nasrin Raseda; Junghee Park; Keungarp Ryu (3011-3015).
In the laccase-catalyzed polymerization of m-phenylendiamine in 100% aqueous buffers, the yield of the polymer was strongly influenced by various reaction conditions such as the solution pH and the concentrations of laccase and m-phenylendiamine. When the reaction was performed at pH 3, the 100% synthetic yield of the polymer was achieved. As pH increased, the yield of the polymer decreased significantly to only 4.4% at pH 9. Effects of solution pH on the morphology and the thermal stability of the polymer were investigated in detail. The polymer synthesized at pH 3 has the typical aggregated morphology of globular particles, but being synthesized at pH 7, it has non-aggregated morphology. The thermal stability of the polymer deteriorated as reaction pH increased.
Keywords: Laccase; Morphology; Polyphenylenediamine; Thermal Property

Combustion of boron particles coated with an energetic polymer material by Weon Gyu Shin; Doohee Han; Yohan Park; Hyung Soo Hyun; Hong-Gye Sung; Youngku Sohn (3016-3020).
Elemental boron has attracted considerable attention as a potential high energetic material for explosives and propellants. However, its use has been hindered by its high vaporization temperature and surface oxide layer. In this study, boron particles were coated with glycidyl azide polymer (GAP) to improve their combustion characteristics. The coated particles were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy. XPS performed before and after Ar+ ion sputtering confirmed that the azide (−N3) group of GAP was positioned at the proximity of the boron surface. In addition, B@GAP particles could be decorated with metallic Ag (∼10 nm) nanoparticles. The combustion characteristics were examined using a newly designed pre-heated (1,800 K) drop tube furnace and a high speed camera. Two stages of combustion were observed for a dust cloud of GAP-coated boron particles. The burning time was estimated to be approximately 37.5 msec.
Keywords: Boron; Glycidyl Azide Polymer; Drop Tube Furnace; Combustion; Burning Time

Simulation of large biomass pellets in fluidized bed by DEM-CFD by Lingli Zhu; Zhaoping Zhong; Heng Wang; Zeyu Wang (3021-3028).
An improved numerical model was proposed to solve the problem that the traditional DEM-CFD (Discrete element method-computational fluid dynamics) method was not suitable for the flow simulation of large particles. In the improved model, the large particle was regarded as an agglomerate of many small fictitious spheres. Herein, the drag force between gas and large pellets was assumed as a combined effect of that between gas and fictitious spheres by volume penalty method. Based on the proposed model, the flow of the mixtures of large biomass pellets and quartz sands in fluidized bed was simulated. It shows that the existence of the biomass pellets has a great impact on the flow field. The flow patterns and pressure drops under different working conditions in simulation results have a good agreement with that in experimental results partially, which also tests the proposed model.
Keywords: Multi-phase Systems; Computational Fluid Dynamics; Fluidization; Fluid-particle Dynamics

Manganese oxides nanocrystals supported on mesoporous carbon microspheres for energy storage application by Dae-Hoon Yeom; Jaeho Choi; Woo Jin Byun; Jung Kyoo Lee (3029-3034).
Mesoporous carbon microspheres (MCM) with a uniform size distribution (1–2 μm in diameter) were replicated from mesoporous silica microspheres (MSM) by using sucrose as a carbon source. MCM (BET surface area=1,001 m2/g, total pore volume=0.82 cc/g, average pore size=3.4 nm) was used as the support of MnO x nanocrystals (Mn3O4 with MnO as a minor phase). The MnO x /MCM composite was prepared by pore-filling wet-impregnation of Mn nitrate solution followed by a moderate annealing under Ar flow. Thus obtained MnO x /MCM composite was characterized as a high capacity anode for lithium ion battery (LIB). The electrochemical responses of MnO x /MCM were investigated in comparison with those of commercial graphite. The MnO x /MCM composite exhibited the reversible capacity of ∼720 mAh g−1 at the current density of 200 mA g−1 with an excellent cycling stability up to 100 cycles. The MnO x /MCM composite also showed much higher volumetric capacity and better rate capability than the state of the art graphite anode, suggesting its potential use as a new anode material for LIBs.
Keywords: Lithium-ion Battery; Anode; Manganese Oxide; Mesoporous Carbon Microsphere; Transition Metal Oxide