Korean Journal of Chemical Engineering (v.33, #9)
Design and control of energy-efficient distillation columns by Young Han Kim (2513-2521).
Distillation is the best option for the separation of hydrocarbon mixtures, unless the boiling points of the constituents are close together. Despite being widely utilized in field applications, the high energy demand of distillation calls for efficient columns in order to save energy. The efficient divided wall column (DWC), diabatic distillation column, and internally heat-integrated distillation column (HIDiC) are introduced here, and the design and control of the columns are briefly reviewed. The practical applications of the columns in the processes of natural gas production from raw gas drawn from underground and benzene separation from naphtha reformate are presented to show the energy-saving performance of the energy-efficient distillation columns. The side-rectifier DWC reduced the heating duty of the conventional system by 5.9%, and provided a compact construction, replacing the three-column conventional system with a single column suitable for offshore application. Moreover, the controllability of DWC was improved by utilizing the side-rectifier. The benzene removal process utilizing the extended DWC lowered the heating duty of the whole conventional process by 56.8%.
Keywords: Energy-efficient Distillation; Divided Wall Column; Diabatic Distillation; Internally Heat-integrated Distillation; Distillation Column Design
Viscosity and rheological properties of ethylene glycol+water+Fe3O4 nanofluids at various temperatures: Experimental and thermodynamics modeling by Saeid Atashrouz; Mehrdad Mozaffarian; Gholamreza Pazuki (2522-2529).
The viscosity and rheological behavior of an ethylene glycol-water mixture based Fe3O4 nanofluid have been experimentally investigated. The nanofluids for this study were prepared by a two-step method in which Fe3O4 nanoparticles were added to a base fluid mixture consisting of 60% (w/w) ethylene glycol and 40% (w/w) water. The measurements were conducted at temperatures ranging from 288.15 to 343.15 K, and at nanoparticle volume fractions ranging from 0.0022 to 0.0055. Furthermore, the dependency of viscosity of nanofluids on shear rate was examined. The results indicate that increasing the shear rate leads to a reduction in the viscosity (shear thinning behavior). Finally, the obtained experimental data was correlated by both a thermodynamic model and a hybrid GMDH-type polynomial neural network, where the mean absolute relative deviation (MARD) of these models was calculated as 3.64% and 3.88%, respectively.
Keywords: Nanofluid; Ethylene Glycol; Fe3O4 Nanoparticle; Eyring-MTSM; Carreau-Yasuda
Desulfurization of liquid fuels by air assisted peracid oxidation system in the presence of Fe-ZSM-5 catalyst by Waqas Ahmad; Imtiaz Ahmad; Muhammad Yaseen (2530-2537).
Catalytic oxidative desulfurization of the model oil or synthetic sulfur oil (SSO) and the different real/industrial industrial oil fractions was investigated using air assisted hydrogen peroxide and formic acid oxidation in the presence of Fe-ZSM-5 as catalyst. The reactivity of the different model sulfur compounds increased in the order of thiophene< dibenzothiophene (BT)<4-methyl dibenzothiophene (4-MDBT). The desulfurization yield in case of the model oil was increased in the presence of Fe-ZSM-5 and the sulfur content of the model oil was reduced from 1275 to less than 50 ppm in 60 min at 60 °C temperature. The catalyst also performed efficiently in ODS of real industrial oil fractions, i.e., untreated naphtha (UN), light gas oil (LGO), cooker derived combined heavy gas oil (HGO) and Athabasca oil sands derived bitumen (At. Bit.), and sulfur removal of 80, 78, 62 and 60% was attained, respectively. Kinetic investigation revealed that the ODS catalyzed by Fe-ZSM-5 followed the first-order kinetics.
Keywords: Catalytic Oxidative Desulfurization; Ion Exchange; ZSM-5; Iron Catalyst; Air Oxidation
A two-dimensional discrete lumped model for a trickle-bed vacuum gas oil hydrocracking reactor by Sepehr Sadighi (2538-2546).
A two-dimensional (2D) computational fluid dynamics model based on discrete lumping approach was used to predict the product yields of a pilot scale vacuum gas oil (VGO) hydrocracking reactor. This model was developed by solving mass conservation equations in conjunction with the continuity and momentum balances in the z-r cylindrical plane. The kinetic parameters of the model were estimated from the experimental data, and validated by using actual values. Results show that the proposed model can appreciably improve the accuracy of the yield prediction in comparison to the predicted value using the 1D model. Moreover, it is confirmed that the order of magnitude of the radial liquid velocity against the axial one is considerably low, and there is no significant pressure drop along the r-direction. Additionally, results show that two-dimensional model is a reliable tool for evaluating the catalyst performance and also for designing commercial reactors.
Keywords: Hydrocracking; Computational Fluid Dynamics; Trickle Bed Reactor; Discrete-lump Model
CeO2-TiO2 catalyst prepared by physical mixing for NH3 selective catalytic reduction: Evidence about the migration of sulfates from TiO2 to CeO2 via simple calcination by Inhak Song; Seunghee Youn; Hwangho Lee; Do Heui Kim (2547-2554).
A mechanical mixture of CeO2 and TiO2 powder with a small amount of sulfate was applied for the selective catalytic reduction (SCR) of NO with NH3. After calcination at 500 oC, the mixed sample showed significantly enhanced activity and selectivity compared to the uncalcined one and, moreover, demonstrated even higher activity than the conventional V2O5/TiO2 catalyst above 300 °C. Combined characterization results revealed that the main active sites were newly formed sulfate species on CeO2, the number of which increased with calcination. Temperatureresolved DRIFT spectra provided convincing evidence about the migration of sulfate species from TiO2 to CeO2, as confirmed from the shift of v(S=O) band as a result of the mechanical mixing and the subsequent calcination.
Keywords: Selective Catalytic Reduction; Sulfation; CeO2 ; TiO2 ; Sulfate Migration
C2H6/CO2 oxidative dehydrogenation (ODH) reaction on nanostructured CrAPSO-34 catalyst: One-pot hydrothermal vs. conventional hydrothermal/impregnation catalyst synthesis by Farhad Rahmani; Mohammad Haghighi (2555-2566).
A series of Cr incorporated SAPO-34 catalysts varying in Cr content and a Cr supported SAPO-34 catalyst were prepared by one-pot hydrothermal and incipient-wetness impregnation methods, respectively. The synthesized materials were characterized by XRD, FESEM, TEM, BET, EDX dot mapping, TPD-NH3 and FTIR, and tested in ethane dehydrogenation with CO2 reaction. The incorporation of Cr3+ into the SAPO-34 framework and impregnation of Cr species were proved by TEM technique. With increase in the incorporated Cr content, smaller cubic crystals and amorphous particles were obtained. However, the extra-framework species probably appeared. Chromium impregnation led to micropore blockage and surface coverage partly, resulting in morphology change somewhat, significant decrease of surface area and acidity as evidenced by FESEM, TEM, BET and TPD-NH3 analysis. However, one-pot synthesis not only preserved the structure of SAPO-34 but also allowed higher surface area, more effective surface acidity and better chromium dispersion to be achieved, features that account for superior catalytic performance and stability of directly synthesized Cr rich catalyst. The Cr incorporated SAPO-34 catalyst containing rich amount of Cr exhibited the best catalytic activity, showing 38% ethylene yield at 700 °C even after 5 h on-stream operation.
Keywords: CrAPSO-34; One-pot Hydrothermal; C2H6/CO2 Oxidative Dehydrogenation; Ethane; Ethylene
Parametric study of pyrolysis and steam gasification of rice straw in presence of K2CO3 by Humair Ahmed Baloch; Tianhua Yang; Haipeng Sun; Jie Li; Sabzoi Nizamuddin; Rundong Li; Zhanguo Kou; Yang Sun; Abdul Waheed Bhutto (2567-2574).
A parametric study of pyrolysis and steam gasification of rice straw (RS) was performed to investigate the effect of the presence of K2CO3 on the behavior of gas evolution, gas component distribution, pyrolysis/gasification reactivity, the quality and volume of synthetic gas. During pyrolysis, with the increase in K2CO3 content in RS (i) the instantaneous CO2 concentration was increased while CO concentration was relatively stable; (ii) the yield of CO2 and H2 increased on the cost of CH4. During steam gasification of RS, with the increase in K2CO3 content in RS (i) the instantaneous concentration of CO2 and H2 increased while instantaneous concentration of CO and CH4 decreased; (ii) the yield of CO2 and H2 production and total yield increased; and (iii) yield of CO and CH4 production followed the order: 9% K2CO3 RS<6% K2CO3 RS2CO3 RS2CO3 content in RS. The results of this study reveal that the presence of K2CO3 during pyrolysis and steam gasification of RS effectively improves production of H2 rich gas.
Keywords: Pyrolysis; Steam Gasification; Biomass; Rice Straw; K2CO3
Optimization of algal lipid extraction by mixture of ethyl acetate and ethanol via response surface methodology for biodiesel production by Weidong Lu; Md Asraful Alam; Ying Pan; William Junior Nock; Zhongming Wang; Zhenhong Yuan (2575-2581).
The effects of extraction time, extraction temperature, solvent to biomass ratio and solvent composition on lipid yield from lyophilized Chlorococcum sp. biomass using a mixture of ethyl acetate and ethanol (EAE), a new proposed solvent, were studied. Subsequently, the process conditions of extraction by EAE were optimized using Box-Behnken design (BBD). The results revealed that the extraction temperature had the greatest effect on lipid extraction efficiency, followed by volume ratio of ethyl acetate to ethanol (EA/E) and extraction time. The largest lipid extraction yield of 15.74% was obtained under the following extraction conditions: 40mL solvents per gram of biomass for 270 min with gentle stirring at 80 °C by EAE with an EA/E of 1.0. Furthermore, palmitic acid, stearic acid, oleic acid, and linoleic acid were the most abundant fatty acids in the lipids extracted, indicating the great potential of the proposed lipid extraction procedure for microalgae-based biodiesel production.
Keywords: Biomass; Lipids; Microalgae; Biodiesel
Fe/N/C catalysts systhesized using graphene aerogel for electrocatalytic oxygen reduction reaction in an acidic condition by Chi-Woo Roh; Hyunjoo Lee (2582-2588).
Graphene aerogel was modified with polyaniline and Fe precursors to produce Fe/N/C catalysts for electrocatalytic oxygen reduction reaction in the acidic condition. The graphene aerogel was produced by a simple hydrothermal treatment of graphene oxide dispersion with a high surface area. Aniline was polymerized with the graphene aerogel powder, and the pyrolysis of the resulting material with FeCl3 produced Fe/N/C catalyst. The loading amount on the electrode and the catalyst ink concentration was carefully selected to avoid the mass transfer limitation inside the catalyst layer. The pyrolysis temperature affected the states of nitrogen sites on the catalyst; the sample prepared at 900 °C presented the highest mass activity. The sulfur was also doped with various amounts of FeSO4 with enhanced mass activity of up to 2.1 mA/mg at 0.8 V in 0.5 M H2SO4 solution. Its durability was also tested by repeating cyclic voltammetry in a range of 0.6–1.1 V 5000 cycles. This graphene-aerogel-based carbon catalysts showed improved activity and durability for the oxygen reduction reaction in the acidic condition.
Keywords: Fe/N/C; Polyaniline; Oxygen Reduction Reaction; Acidic Condition; Graphene Aerogel
Physico-chemical study of dew melon peel biochar for chromium attenuation from simulated and actual wastewaters by Mehdi Ahmadi; Esmaeil Kouhgardi; Bahman Ramavandi (2589-2601).
This work introduces a biochar as novel adsorbent prepared from the dew melon peel by pyrolysis method, and demonstrates its potential for eliminating Cr(VI) from simulated and actual wastewaters. The dew melon peel biochar (DPB) was characterized by several techniques and methodologies such as, BET, SEM, FTIR, Boehm titration, ultimate analysis, and pHzpc. DPB is a microporous material with the BET specific surface area of 196 m2/g. The effects of different parameters including pH, amount of adsorbent, Cr(VI) concentration, and mixing time on the removal of Cr(VI) from wastewater were studied. Maximum adsorption (98.6%) was observed at pH 6 and 100 mg/L metal concentration. The equilibrium adsorption was analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms. Kinetic data were evaluated by pseudo-first order, pseudo-second order, intraparticle diffusion, film diffusion (Boyd), Elovich, and Avrami models. The kinetic data were best fitted to the pseudo-second order model. The Langmuir isotherm model gives the better correlation to predict the adsorption equilibrium, with a maximum adsorption capacity of 198.7 mg/g. The thermodynamic parameters showed that the adsorption of Cr(VI) was endothermic and spontaneous. Competition between the co-existing ions of Cl−, NO 3 − , SO 4 2− , PO 4 3− , and HCO 3 − on the adsorption process was studied. The efficacy of DPB was successfully examined by analyzing the removal of Cr(VI) from two industrial wastewaters. The results indicate that DPB is promising as an effective and economical adsorbent for Cr(VI) ions removal and could be repeatedly used with no significant loss of adsorption efficiency.
Keywords: Biochar; Dew Melon Peel; Actual Wastewater; Chromium Ion; Industrial Wastewater
Electrochemical removal of the insecticide imidacloprid from water on a boron-doped diamond and Ta/PbO2 anodes using anodic oxidation process by Mabrouk Ben Brahim; Hafedh Belhadj Ammar; Ridha Abdelhédi; Youssef Samet (2602-2609).
The removal of pesticides from water is a major environmental concern. This study investigates the electrochemical removal of the insecticide imidacloprid (IMD) from aqueous solutions on a boron-doped diamond (BDD) and Ta/PbO2 anodes under galvanostatic electrolysis. The influence of operating parameters, such as applied current density (50–100 mA cm−2), initial chemical oxygen demand COD (0) (281–953 mg L−1), temperature (25–65 °C) and pH (3.0–10.0) on COD and instantaneous current efficiency (ICE), was studied using the BDD electrode. The degradation efficiency of IMD increased by increasing current density and temperature, but noticeably decreased by the increase of initial pH value and initial concentration of IMD. The COD decay follows a pseudo-first-order kinetic, and the process was under mass transport control. COD removal reaches 90% when using an apparent current density of 100 mA cm−2, initial COD of 953 mg L−1, pH of 3.0 and at 25 °C after 4.5 h electrolysis time. Compared with Ta/PbO2, BDD anode has shown better performance and rapidity in the COD removal using the same electrolysis device.
Keywords: Pesticides; Imidacloprid; Electrochemical Degradation; Electrolysis; Boron-doped Diamond; Hydroxyl Radicals
Operational characteristics of the pilot-scale coal gasification with filtration and hot fuel gas desulfurization by Jieun Lee; Suk-Hwan Kang; Hyo-Sik Kim; Dong-Hwan Jeon; Seung-Jong Lee; Seok-Woo Chung; Jin Wook Lee; Yongseung Yun; Ho-Jung Ryu; Jeom-In Baek (2610-2621).
Experimental research on coal gasification with a filtration and desulfurization system for the development of an integrated gasification combined cycle (IGCC) was performed with Indonesian LG, KPU and Canadian Arch coals. A dry-feeding entrained-bed type gasifier was operated below the fusion temperature of the coal and at 20 bar of pressure. The filtration system was designed for continuous capture and subsequent removal of the fly ash and the unreacted coal residue via a specialty metal filter. The hot fuel gas desulfurization unit (HGD) consisted of a transport desulfurizer, a bubbling regenerator and a multi-cyclone. The research objective was to investigate the feasibility of applying a partial slagging coal gasifier to attain high carbon conversion and cold gas efficiencies as well as to attain an operational capability for combining with filtration and HGD. A Pilot-scale test demonstrated that the coal fines were effectively removed and the overall sulfur removal efficiency of the hot fuel gas desulfurization unit was higher than 95.3%.
Keywords: Entrained-bed; Coal Gasification; Filtration; Hot Fuel Gas Desulfurization; Metal Filter
Efficient continuous epoxidation of biodiesel in a microstructured reactor by Xingjun Yao; Yan Zhang; Lingyun Du; Huiqiang Liu; Song Jiang (2622-2627).
Efficient continuous epoxidation of biodiesel with peracetic acid generated in situ from hydrogen peroxide and acetic acid was studied in detail in a microstructured reactor. The effects of micromixer type, reaction temperature, catalyst usage, flow rate and residence time were considered. Results show the T-type glass micro-structured reactor (TTGMR) outperforms the interdigital multilamination micromixer. Under the optimized conditions, the final product from TTGMR has an epoxy value of 6.5 and an iodine value of 2.2.
Keywords: Epoxidation; Fatty Acid Methylesters; Biodiesel; Microreactor; Liquid-liquid Flow
An experimental and kinetic study of toluene oxidation over LaMn1−x B x O3 and La0.8A0.2Mn0.3B0.7O3 (A=Sr, Ce and B=Cu, Fe) nano-perovskite catalysts by Ali Tarjomannejad; Ali Farzi; Aligholi Niaei; Dariush Salari (2628-2637).
Catalytic oxidation of toluene over perovskite-type oxides of the general formula LaMn1-xBxO3 (B=Cu, Fe and x=0, 0.3, 0.7) and La0.8A0.2Mn0.3B0.7O3 (A=Sr, Ce and B=Cu, Fe) was investigated, where the catalysts were synthesized by sol-gel auto combustion method. The catalysts were characterized by XRD, BET, H2-TPR, XPS, and SEM. Obtained XRD patterns confirmed the perovskites to be single-phase perovskite-type oxides. Specific surface areas of perovskites were obtained between 25-40m2/g. The perovskite catalysts showed high activity for the toluene oxidation. Based on the results, Fe-containing perovskite catalysts exhibited higher activity than Cu-containing perovskite catalysts. The substitution of Sr and Ce in A-site of the perovskite catalysts enhanced their activity for toluene oxidation. Among different synthesized catalysts in this research, La0.8Ce0.2Mn0.3Fe0.7O3 has the highest activity. Nearly complete elimination of toluene was achieved at 200 °C with this catalyst. Based on Langmuir–Hinshelwood mechanisms, kinetic studies were conducted on toluene oxidation, indicating LH-OS-ND (adsorption of reagents on same types of sites and non-dissociative adsorption of oxygen) as the most probable mechanism which could predict the experimental data with correlation coefficient of R2=0.9952.
Keywords: Toluene Oxidation; La0.8A0.2B0.7Mn0.3O3 ; Perovskite; Sol-gel; Kinetic
Interactions among biomass components during co-pyrolysis in (macro)thermogravimetric analyzers by Yanqiu Long; Hui Zhou; Aihong Meng; Qinghai Li; Yanguo Zhang (2638-2643).
The interactions of biomass components (hemicellulose, cellulose, and lignin) during co-pyrolysis were investigated in a thermogravimetric analyzer (TGA) as well as a self-designed Macro-TGA with higher heating rate and larger amount of sample. The overlap ratio (OR) was used to evaluate the interaction of biomass components quantitatively. In TGA, the pyrolysis of xylan was not significantly affected by cellulose, whereas the pyrolysis of cellulose was markedly influenced by xylan. The interactions between xylan and lignin were weak with an overlap ratio of 0.9869, whereas co-pyrolysis of cellulose and lignin was strongly inhibited by interactions with the overlap ratio of 0.9737. In Macro-TGA, interactions between components were stronger than that in TGA due to more considerable heat and mass transfer effect.
Keywords: Biomass; Interaction; Pyrolysis; TGA; Cellulose; Lignin
An integrated slidable direct polymerase chain reaction-capillary electrophoresis microdevice for rapid Y chromosome short tandem repeat analysis by Dohwan Lee; Yong Tae Kim; Jee Won Lee; Do Hyun Kim; Tae Seok Seo (2644-2649).
We have developed an integrated slidable direct polymerase chain reaction-capillary electrophoresis (Direct PCR-CE) microdevice to analyze mini-Y chromosome short tandem repeat (mini-Y STR) typing without a DNA purification step. The Direct PCR has been recently commercialized as a simple DNA amplification technique, which does not require any sample preparation steps such as cell lysis, DNA extraction and purification for amplifying specific target genes. By implementing the advantages of Direct PCR on a microdevice, we can amplify target min-Y STR loci directly from human whole blood in a micro-reactor (2μL) and the amplicons were successively separated by micro-capillary electrophoresis. The utilization of a slidable plate enables us to manually control the fluid without use of microvalves and microtubes, and the functional units of sample injection, Direct PCR, and CE analysis were sequentially and independently performed by switching the slidable plate to each unit. On the integrated slidable Direct PCR-CE microdevice, we could complete monoplex and multiplex mini-Y STR typing directly using human whole blood within 1 h.
Keywords: Microdevice; Direct Polymerase Chain Reaction; Capillary Electrophoresis; Mini-Y STR Typing
Modeling and simulation of Bacillus cereus chitosanase activity during purification using expanded bed chromatography by Carlos Eduardo de Araújo Padilha; Nathália Kelly de Araújo; Domingos Fabiano de Santana Souza; Jackson Araújo de Oliveira; Gorete Ribeiro de Macedo; Everaldo Silvino dos Santos (2650-2658).
A phenomenological model was used to describe sequentially the three steps (flowthrough, washing and elution) of expanded bed adsorption chromatography for recovery of chitosanases from Bacillus cereus. Additionally, a hybrid strategy for model parameter estimation was carried out using particle swarm optimization and Gauss-Newton algorithms. The model was validated with independent experimental data and the statistical criteria (χ 2 and mean squared error tests) showed that the hybrid strategy was more promising than just the heuristic method. With the calibrated model, surface response methodology was applied to obtain the optimal operational conditions, and experiments were performed to confirm these results. Overall, a value of 41.08% for yield was obtained using 700 mM NaCl during elution. In summary, all approach employed in this work was relevant for maximizing the yield of the chromatographic process.
Keywords: Modeling; Expanded Bed Adsorption; Chitosanases; Particle Swarm Optimization; Gauss-Newton; Optimization
Synthesis of acrylic-lignosulfonate resin for crystal violet removal from aqueous solution by Wenjing Xu; Wensheng Zhang; Yan Li; Wei Li (2659-2667).
A new acrylic-lignosulfonate resin (ALR) was obtained by radical polymerization using calcium lignosulfonate (LS-Ca) and acrylic acid (AA) as raw materials. ALR was characterized using FT-IR, SEM, TG-DSC and N2 adsorption–desorption surface area and pore size analyzer. Batch adsorption, including initial concentration, time, pH, dosage and temperature on the adsorption of crystal violet (CV) by ALR, was systematically studied. The ALR contained porous structure and the specific surface area of ALR was 190.55 m2/g with average pore diameter 11.34 nm. The kinetic and equilibrium data fitted into the pseudo-second-order model and Freundlich isotherm model, respectively. The adsorption process was slightly influenced in the range of pH=3–12. The maximum adsorption capacity of CV was found to be as high as 150.40±4.80mg/g for 24 h at 25 °C. Thermodynamic parameters were evaluated, and their values indicated that adsorption of CV on ALR was an exothermic process and spontaneous.
Keywords: Adsorption; Calcium Lignosulfonate; Crystal Violet; Modification; Wastewater
On the cleaning procedure of reverse osmosis membrane fouled by steel wastewater by Yingxin Mei; Haigang Li; Huanjin Xia (2668-2673).
The proper cleaning procedure for reverse osmosis (RO) membranes holds the key to achieving sustainable operation of RO processes during long-term filtration such as the reclamation of wastewater. In this study, the most adequate cleaning protocol was tested for RO membranes fouled by the steel wastewater. X-ray photoelectron spectroscopy (XPS) analysis of the fouling layer revealed the presence of the aromatics, aliphatic hydrocarbons, metallic oxides and hydroxides. An integrated cleaning procedure was developed for flux recovery. That is, metal chelating agent (MCA) plus alkaline-oxidant cleaning procedure consisting in one cleaning stage or two cleaning stages in series. MCA cleaning with 2 mM disodium ethylenediaminetetraacetate (Na2-EDTA) solution followed by alkaline-oxidant cleaning with 5 mM NaOCl+NaOH/pH 12.0 solution provided the maximum cleaning efficiency.
Keywords: Reverse Osmosis; Cleaning; Steel Wastewater; Integrated Cleaning; Metallic Oxides
Fabrication of novel polyethersulfone based nanofiltration membrane by embedding polyaniline-co-graphene oxide nanoplates by Mojtaba Moochani; Abdolreza Moghadassi; Sayed Mohsen Hosseini; Ehsan Bagheripour; Fahime Parvizian (2674-2683).
Mixed matrix polyethersulfone (PES) based nanofiltration membrane was prepared through phase inversion method by using of polyvinylpyrrolidone (PVP) as pore former and N, N dimethylacetamide (DMAc) as solvent. Polyaniline-co-graphene oxide nanoplates (PANI/GO) were utilized as additive in membrane fabrication. The PANI/GO nanoplates were prepared by polymerization of aniline in the presence of graphene oxide nanoplates. FTIR analysis, scanning electron microscopy (SEM), scanning optical microscopy (SOM), 3D images surface analysis, water contact angle, water content tests, tensile strength tests, porosity tests, salt rejection and flux tests were used in membrane characterization. FT-IR results verified formation of PANI on graphene oxide nanoplates. SOM images showed uniform particles distribution for the mixed matrix membranes. SEM images also showed formation of wide pores for the modified membranes. Water flux showed constant trend nearly by use of PANI/GO in the casting solution. Opposite trend was found for the membrane surface hydrophilicity. Salt rejection was enhanced sharply by utilizing of PANI/GO. The membrane’s tensile strength was improved by increase of PANI/GO concentration. The water content was increased initially by use of PANI/GO nanoplates up to 0.05%wt into the casting solution and then decreased. Membrane porosity was also enhanced by using of PANI/GO nanoplates. Modified membrane containing 0.5%wt PANI/GO nanoplates showed more appropriate antifouling characteristic compared to others.
Keywords: Mixed Matrix; Nanofiltration; PANI-co-GO Nanoplates; Physico/Chemical Characterization; Antifouling Property
Selective recovery of Fe(III), Pd(II), Pt(IV), Rh(III) and Ce(III) from simulated leach liquors of spent automobile catalyst by solvent extraction and cementation by Thi Hong Nguyen; Batchu Nagaphani Kumar; Man Seung Lee (2684-2690).
A hydrometallurical process was developed to recover Fe(III), Pd(II), Pt(IV), Rh(III) and Ce(III) from the leach liquor of spent automobile catalysts. Fe(III) was first separated by extraction with tri-butyl-phosphate (TBP). Extraction of the raffinate with tri-isooctylamine (Alamine 308) led to co-extraction of Pd(II) and Pt(IV). They were separately stripped from the loaded Alamine 308 by using a mixture of HCl and thiourea with different concentration. After the recovery of HCl in the raffinate by extraction with tri-2-ethylhexyl amine (TEHA), Rh(III) was recovered by cementation with zinc metal powder. A process flow sheet with the corresponding McCabe-Thiele plots for extraction and stripping was proposed.
Keywords: Spent Automobile Catalyst; Palladium; Platinum; Rhodium; Solvent Extraction
Characterization of the bio-oil and bio-char produced by fixed bed pyrolysis of the brown alga Saccharina japonica by Jae Hyung Choi; Seung-Soo Kim; Dong Jin Suh; Eun-Jung Jang; Kyung-Il Min; Hee Chul Woo (2691-2698).
Brown alga Saccharina japonica was pyrolyzed in a fixed bed reactor under conditions intended to maximize the yield of bio-oil and bio-char. The results revealed that the product distribution of bio-oil, bio-char, and gas was considerably influenced by the pyrolysis temperature (430-530 °C) and holding time (4-10min). The maximum yields of bio-oil and bio-char were approximately 48.4 and 32.3wt%, respectively, when prepared at 450 °C for 8min with a carrier gas flow rate of 2.2 cm/s. The fuel properties of dewatered S. japonica bio-oil (DSB) included higher heating value (HHV), kinematic viscosity, density, moisture and ash content, pH, and flash and pour point. The possibility of blending 5-20 vol% DSB with No. 6 fuel oil (Bunker C oil) was also examined. The physicochemical properties of the bio-char exhibited decreased carbon and HHV, and increased inorganic elements and surface area, with increasing pyrolysis temperature.
Keywords: Fixed Bed Pyrolysis; Saccharina japonica ; Bio-oil; Bio-char; Fuel Property
Ultra-thin Ni dense membrane prepared by polishing treatment of porous nickel support for high-temperature H2 separation by Shin-Kun Ryi; Jae-Yun Han; Chang-Hyun Kim; Beom-Seok Seo (2699-2702).
Ultra-thin nickel dense membranes (∼0.5 μm) were developed by polishing treatment of porous nickel supports. The polishing treatment involved the use of 400 grit sand paper, 1000 grit, and 1500 grit, which was able to remove the surface pores due to the ductility of the PNS. The hydrogen permeation test showed that 4.53×10−2 mol m−2 s−1 of hydrogen permeation flux through the membrane could be achieved at a temperature of 973K and a pressure difference of 136 kPa. The nitrogen leakage tests confirmed that there were no pinholes on the surface of the ultra-thin nickel dense membrane.
Keywords: High-temperature; Hydrogen Separation; Ultra-thin Nickel Membrane; Polishing Treatment; Metal Membrane
Hydrochar preparation from black liquor by CO2 assisted hydrothermal treatment: Optimization of its performance for Pb2+ removal by Yong Sun; Jing Ping Zhang; Fei Guo; Lian Zhang (2703-2710).
Hydrochar was produced from hydrothermal treatment of corn straw black liquor. Response surface methodology (RSM) and the central composite design (CCD) were employed for determination of optimal char with maximum Pb2+ removal capacity. The operational parameters such as hydrothermal temperature (°C), duration (min) and solid liquid ratio (LSR) were chosen as independent variables in CCD. The statistical analysis indicates that the effects of hydrothermal temperature, duration, LSR and combined effect of hydrothermal temperature and duration are all significant for the Pb2+ removal capacity. The optimal condition for achieving the maximum Pb2+ adsorption capacity is obtained as the following: hydrothermal temperature (205 °C), duration (28min), LSR (12) with Pb2+ removal capacity reaching 47mg/g. The BET specific surface area of char prepared at optimal conditions could reach 85m2/g.
Keywords: Hydrochar; Black Liquor; Hydrothermal; Pb2 ; CCD
Effect of oxygen flow rate on the electrical and optical characteristics of dopantless tin oxide films fabricated by low pressure chemical vapor deposition by Jun-Hyun Kim; Hae-Min Lee; Doo Won Kang; Kyung Mi Lee; Chang-Koo Kim (2711-2715).
The effect of oxygen flow rate on the electrical and optical characteristics of dopantless tin oxide films prepared by low pressure chemical vapor deposition (LPCVD) was investigated. A decrease in the sheet resistance of the film with increasing oxygen flow rate in the range of 200-300 sccm was attributed to an increase in the film thickness (and correspondingly, in the grain size); while at oxygen flow rates higher than 300 sccm, the increase in the sheet resistance of the film resulted from an increase in the X-ray diffraction peak intensities of the (110), (101), and (201) planes. The optical bandgap of the film decreased when the oxygen flow rate was increased from 200 to 300 sccm, but it remained nearly constant for oxygen flow rates higher than 300 sccm. A maximum figure-of-merit was achieved for films prepared with an oxygen flow rate of 300 sccm.
Keywords: LPCVD; Dopantless; Tin Oxide; Sheet Resistance; Optical Bandgap; Figure of Merit
Influence of ultrasonication on preparation of novel material for heavy metal removal from wastewater by Saravanan Anbalagan; Senthil Kumar Ponnusamy; Sundar Rajan Panneer Selvam; Abishek Sankaranarayan; Abhishek Dutta (2716-2731).
The present research introduces a new concept on rapid removal of Pb(II) ions from wastewater using novel agro-based material. The two types of materials such as sulfuric acid modified Caryota urens seeds (SMCUS) and ultrasonic assisted Caryota urens seeds (UACUS) were prepared and performance was compared for Pb(II) ions removal. The functional groups available on the C. urens were discussed by using FT-IR report. Adsorption influencing parameters such as initial metal ion concentration, pH, contact time, adsorbent dosage and temperature were studied to predict the optimum conditions. Several isotherm and kinetic models were applied to examine the experimental data. The present adsorption-adsorbate system best obeys the Freundlich and pseudo-first-order models. Langmuir monolayer capacity of the SMCUS and UACUS for Pb(II) ions was found to be 93.7 and 175.9mg/g, respectively. Thermodynamic parameters explain that the adsorption of Pb(II) ions was spontaneous and exothermic.
Keywords: Heavy Metal Ions; Caryota urens Seeds; Ultrasonication; Equilibrium; Kinetics; Process Design
Formation of uniform TiO2 nanoshell on α-alumina nanoplates for effective metallic luster pigments by Su Jin Lee; Myoung Sang You; Sang Hyuk Im (2732-2737).
To synthesize non-corroding effect pigment appearing metallic silver in color, we coated uniform anatase TiO2 nanoshell via sol-gel chemistry. Under the reaction condition using 3M TiCl4 aqueous solution: deionized water: HCl solution=0.75mL: 20 mL: 0 mL, ∼50 nm-thick smooth TiO2 nano-shell was fully coated on the surface of α-alumina nanoplates; consequently, the synthesized effect pigments exhibited similar lustering effect and structuring color to commercial effect pigment. Under relatively acidic condition and higher TiCl4 precursor concentration condition (3 M TiCl4 aqueous solution: deionized water:HCl solution=0.75mL: 20 mL: 0.05mL for acidic condition and 1.0 or 1.5mL: 20 mL: 0 mL for higher TiCl4 precursor concentration condition), rougher TiO2 shell was formed.
Keywords: α-Alumina Nanoplates; TiO2 Shell; Roughness Control; Effect Pigment; Metallic Silver Color
Physical characteristics and in vitro skin permeation of elastic liposomes loaded with caffeic acid-hydroxypropyl-β-cyclodextrin by Na Ri Im; Kyoung Mi Kim; Suh Ji Young; Soo Nam Park (2738-2746).
We developed a drug-in-cyclodextrin-in-elastic liposomes (DCEL) system to enhance transdermal delivery of caffeic acid (CA). Hydroxypropyl-β-cyclodextrin (HP-β-CD) was used as a hydrophilic CD. Elastic liposomes (EL) contained polyethylene glycol-free Tego® care 450 as an edge activator. Properties of the CA-HP-β-CD inclusion complex loaded in EL (CD-EL) as DCEL system were compared to characteristics of conventional liposomes (CL), EL, and CD-CL. Particle size, deformability, entrapment efficiency (EE%), stability, and vesicle morphology were characterized in liposome preparations. In addition, in vitro release and skin permeation were analyzed. We found that including Tego® care 450 reduced vesicle size and increased membrane deformability. The addition of HP-β-CD enhanced CA EE% of liposomes almost 1.6-fold that of liposomes without HP-β-CD. Moreover, CD-EL complex showed better controlled release profiles and higher skin permeability than CL and EL. We propose that the DCEL system can be a promising drug delivery vehicle for transdermal delivery of CA.
Keywords: Caffeic Acid; Hydroxypropyl-β-cyclodextrin; Elastic Liposome; Drug-in-cyclodextrin-in-elastic Liposome; Skin Permeation
Synthesis of metal organic framework (MOF-5) with high selectivity for CO2/N2 separation in flue gas by maximum water concentration approach by Ning Jiang; Zhiyong Deng; Shaoying Liu; Congming Tang; Gongying Wang (2747-2755).
Water plays a crucial role in the synthesis mechanism of metal organic framework-5 (MOF-5). Synthesized MOF-5 with good phase structure and large specific surface area is largely determined by an important synthesis factor: the total water concentration of the initial synthesis solution (C tw ). An understanding of the effects of different and high C tw on the synthesis of MOF-5 and the investigation of the maximum C tw suitable for the synthesis of MOF-5 are important to guide the synthesis of MOF-5. Through the research of the maximum C tw , a favorable synthetic approach was established which could realize the synthesis of MOF-5 with fine performance on CO2 adsorption and separation. The research results show that the maximum C tw could be as high as 1,440mmol/L, and synthesized MOF-5 still has a good phase structure and a large specific surface area of 2,136m2/g (BET). Synthesized MOF-5 by the maximum C tw exhibits a high CO2 adsorption capacity of 2.5mmol/g and a low N2 adsorption capacity of 0.2mmol/g at 298 K and 100 kPa. More importantly, synthesized MOF-5 by the maximum C tw exhibits a high selectivity for CO2/N2 of 18-22 at 298 K and 20-130 kPa in simulated flue gas.
Keywords: Metal Organic Framework-5 (MOF-5); Water; CO2 ; Adsorption; Separation
A novel rapid mist spray technique for synthesis of single phase precipitated calcium carbonate using solid-liquid-gas process by Jimoh Abdullateef Onimisi; Roniza Ismail; Kamar Shah Ariffin; Norlia Baharun; Hashim Bin Hussin (2756-2760).
Various techniques and approaches have been designed to synthesize precipitated calcium carbonate. We used a continuous sprayed-mist technique that induced spontaneous precipitation reaction of the droplets with the higher surface area when in contact with the gas. The effects of optimum reactant concentration, gas flow rate, and reactant feeding rate including reaction conditions were investigated. The effectiveness of the techniques was scrutinized by analyzing the resultant PCC characteristics, especially the particle phase morphology and size distribution using XRD, FTIR, and SEM. The variation of initial concentration of milk of lime with different gas flow rate was studied. Experimental results, as well as XRD and FTIR, indicated that all the products produced were favorable for the formation of calcite. SEM revealed that the morphologies of PCC were all rhombohedral and tended to adhere to each other (twinning). It was found that production of PCC by using spray-mist method is suitable for lower initial concentration of Ca(OH)2 and higher gas flow rate only.
Keywords: Precipitated Calcium Carbonate (PCC); Spray Mist; Continuous; Calcite; Gas-flow