Korean Journal of Chemical Engineering (v.30, #2)
Waste paper sludge as a potential biomass for bio-ethanol production by Joni Prasetyo; Enoch Y. Park (253-261).
This review describes the utilization of paper sludge (PS), which is waste from the pulp and paper industry. Its advantages make PS the cellulosic biomass with the most potential for bio-refinery research and applicable for industrial scale. Some of the grain based biofuels and chemicals have already been in commercial operation, including fuel ethanol or biochemical products. Unfortunately, research and application of PS are yet in their infancy and suffer from large scale because of low productivity. Reviewing the many researches that are working at the utilization of PS for bio-refineries could encourage the utilization of PS from laboratory research to be applied in industry. For this reason, PS usage as industrial raw material will be effective in solving the environmental problems caused by PS with clean technology. In addition, its conversion to bio-ethanol could offer an alternative solution to the energy crisis from fossil fuel. Two methods of PS utilization as raw material for bio-ethanol production are introduced. The simultaneous saccharification and fermentation (SSF) using cellulase produced by A. cellulolyticus and thermotolerant S. cerevisiae TJ14 gave ethanol yield 0.208 (g ethanol/g PS organic material) or 0.051 (g ethanol/g PS). One pot bioethanol production as a modified consolidated biomass processing (CBP) technology gave ethanol yield 0.19 (g ethanol/g Solka floc) and is considered to be the practical CBP technology for its minimizing process.
Keywords: Paper Sludge; Cellulase; Bio-refinery; SSF; Acremonium cellulolyticus ; Saccharomyces cerevisiae
The solids concentration distribution in the deep cone thickener: A pilot scale test by Huazhe Jiao; Aixiang Wu; Hongjiang Wang; Shuiping Zhong; Renman Ruan; ShengHua Yin (262-268).
Cemented backfill or surface deposition of paste tailings is increasingly being considered as a simple and effective means of reducing the hazards of conventional slurry deposition and recovering water for recycle. Although gravity thickening has been widely used in the mineral industry to increase the solids concentration of tailings, the accurate prediction of the concentration distribution in three-dimensions and discontinuous operational state has proven to be difficult. We investigated the axial and radial solids concentration distribution at discontinuous state in a pilot deep cone thickener as a function of bed height and residence time. The feed flux of lead/zinc tailings was 0.254 t·h−1· m−2 with a flocculant (high molecular weight anionic polyacrylamide) dose of 20 g/t. The thickened solids bed was sheared by a rotating rake at a rate of 0.2 rpm. The underflow was recirculated at a flux of 0.5 t·h−1·m−2, which can introduce additional shear stresses into the bed. The results of the bed density profile showed that, beside the clarification zone, the area below the feedwell could be divided into four zones: the dilution zone caused by free settling and diffusing action, the hindered settling zone in which the concentration was lower than the gel point, the unraked bed zone with a large concentration gradient and, finally, the raking zone with the highest slurry concentration and lower concentration gradient.
Keywords: Thickening; Dewatering; Concentration Distribution; Pilot Scale Deep Cone Thickener
A quasi-sequential parameter estimation for nonlinear dynamic systems based on multiple data profiles by Chao Zhao; Quoc Dong Vu; Pu Li (269-277).
A three-stage computation framework for solving parameter estimation problems for dynamic systems with multiple data profiles is developed. The dynamic parameter estimation problem is transformed into a nonlinear programming (NLP) problem by using collocation on finite elements. The model parameters to be estimated are treated in the upper stage by solving an NLP problem. The middle stage consists of multiple NLP problems nested in the upper stage, representing the data reconciliation step for each data profile. We use the quasi-sequential dynamic optimization approach to solve these problems. In the lower stage, the state variables and their gradients are evaluated through integrating the model equations. Since the second-order derivatives are not required in the computation framework this proposed method will be efficient for solving nonlinear dynamic parameter estimation problems. The computational results obtained on a parameter estimation problem for two CSTR models demonstrate the effectiveness of the proposed approach.
Keywords: Dynamic Parameter Estimation Problem; Nonlinear Programming; Quasi-sequential Dynamic Optimization; Multiple Data Sets; CSTR
Developing a heuristics for glass cutting process optimization: A case of two-dimensional two-stage guillotine cutting with multiple stock sizes by Kyung Tae Park; Jun-Hyung Ryu; Ho-Kyung Lee; In-Beum Lee (278-285).
This paper presents a heuristic algorithm for a two-dimensional two-stage guillotine cutting problem with multiple stock sizes by allowing the rotation of items by 90°. The proposed algorithm generates levels or strips where the first item or base item is selected according to the length of the strip and packs the next items beside the base item in the strip. For each type of item, strips are generated for packing each type of item in a base item. The best n orders in a yield of strips or the best n strips are selected for each type of item. The selected best n strips are packed in one type of bin. For the other types of bins, another best n strips are selected and packed in each type of bin. The best yield in all types of bins is then selected. This iteration is executed until the number of item demands in the overall demands is less than the number of item demands in the bin. Four numerical examples generated from actual industries are illustrated to highlight the applicability of the proposed algorithm with some comments.
Keywords: Glass Production; Two-dimensional Two-stage; Guillotine Cut; Level Packing Problem
Design and optimization of heat integrated dividing wall columns for improved debutanizing and deisobutanizing fractionation of NGL by Nguyen Van Duc Long; Moon Yong Lee (286-294).
Dividing wall columns, capable of reducing the energy required for the separation of ternary mixtures, were explored for the energy-efficient integration of debutanization and deisobutanization. A new practical approach to the design and optimization of dividing wall columns was used to optimize dividing wall columns. A conventional dividing wall column and a multi-effect prefractionator arrangement were shown to reduce total annual cost considerably compared with conventional distillation sequence. Various configurations incorporating a heat pump in a bottom diving wall columns were also proposed to enhance energy efficiency further. The result showed that operating cost could be reduced most significantly through novel combinations of internal and external heat integration: bottom dividing wall columns employing either a top vapor recompression heat pump or a partial bottom flashing heat pump.
Keywords: Distillation; Dividing Wall Column; DWC; Natural Gas Recovery; Fully Thermally Coupled Distillation Column; Heat Integrating; Process Intensification
Experimental investigation and stability analysis on dense-phase pneumatic conveying of coal and biomass at high pressure by Liang Cai; Cai Jiaying; Xu Guiling; Xu Pan; Chen Xiaoping; Zhao Changsui (295-305).
Conveying characteristics and flow stability are very important for design and control of a conveying system at high pressure. The influences of operating parameters and material properties on conveying characteristics were investigated in an experimental test facility with a conveying pressure up to 4MPa. Wavelet transform and Shannon entropy analysis were applied to analyzing pressure drops through horizontal pipe in order to obtain the stability criterion. Results indicated that the mass flow rate of biomass decreased, while the mass flow rate of pulverized coal increased at first and then decreased with the increase in fluidization velocity. Solid loading ratios for four kinds of powders decreased with the increase in fluidization velocity. Conveying phase diagrams and pressure drops through different test sections of pulverized coal and biomass at high pressure were obtained and analyzed. The influences of coal category, fracture characteristics and particle size on conveying characteristics were determined.
Keywords: Pneumatic Conveying; Flow Characteristics; High Pressure; Stability; Shannon Entropy
Selective hydrogenation of 4-isobutylacetophenone over a sodium-promoted Pd/C catalyst by Hong-Baek Cho; Bae Uk Lee; Chung-Han Ryu; Tadachika Nakayama; Yeung-Ho Park (306-313).
The effect of sodium promotion on the selective hydrogenation of 4-isobutylacetophenone, 4-IBAP, was investigated over a Pd/C catalyst. A precipitation and deposition method was used to prepare the catalyst, and sodium was promoted on the Pd/C catalyst via post-impregnation while varying the sodium content. The sodium-promoted Pd/C catalyst resulted in a significantly improved yield greater than 96% of the desired product, 1-(4-isobutylphenyl) ethanol (4-IBPE), compared with the non-patented literature results under a mild hydrogenation condition. A detailed hydrogenation network over the Pd/C catalyst was suggested. The reaction mechanism for the yield and selectivity enhancement of 4-IBPE induced-by the promoted Pd/C was elucidated in relation to the geometric and electronic effects of reactant molecules in the microporous support depending on the reaction steps.
Keywords: Selective Hydrogenation; 1-(4-Isobutylphenyl)ethanol; Pd/C Preparation; Sodium Promotion; 4-Isobytylacetophenone
A novel [Bmim]PW/HMS catalyst with high catalytic performance for the oxidative desulfurization process by Ling Tang; Guangqing Luo; Lihua Kang; Mingyuan Zhu; Bin Dai (314-320).
To effectively reduce the sulfur content in model fuel, [Bmim]PW/HMS catalyst was synthesized through impregnating the hexagonal mesoporous silica (HMS) support by phosphotungstic acid (HPW) and ionic liquid [Bmim] HSO4. Physical structure characterizations of the catalysts showed that HMS retained mesoporous structure, and [Bmim] PW was well dispersed on the support of HMS. The catalytic activity of the [Bmim]PW/HMS was evaluated in the oxidative desulfurization process, and the optimal reaction conditions including loading of the catalysts, reaction temperature, catalyst amount, O/S (H2O2/sulfur) molar ratio and agitation speed were investigated. Under the optimal reaction conditions, the conversion of benzothiophene (BT), dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) could reach 79%, 98%, 88%, respectively.
Keywords: [Bmim]PW/HMS; Catalytic Oxidation Desulfurization; Dibenzothiophene
Synthesis gas and char production from Mongolian coals in the continuous devolatilization process by Jong-Soo Bae; Dong-Wook Lee; Se-Joon Park; Young-Joo Lee; Jai-Chang Hong; Choon Han; Young-Chan Choi (321-326).
Devolatilization of Mongolian coal (Baganuur coal (BC), Shievee Ovoo coal (SOC), and Shievee Ovoo dried coal (SOC-D)) was investigated by using bench-sized fixed-bed and rotary kiln-type reactors. Devolatilization was assessed by comparing the coal’s type and dry basis, temperature, gaseous flux, tar formation/generation, devolatilization rate, char yield, heating value, and the components of the raw coal and char. In the fixed bed reactor, higher temperatures increased the rate of devolatilization but decreased char production. BC showed higher rates of devolatilization and char yields than SOC or SOC-D. Each coal showed inversely proportional devolatilization and char yields, though the relation was not maintained between the different coal samples because of their different contents of inherent moisture, ash, fixed carbon, and volatile matter. Higher temperatures led to the formation of less tar, though with more diverse components that had higher boiling points. The coal gas produced from all three samples contained more hydrogen and less carbon dioxide at higher temperatures. Cracking by multiple functional groups, steam gasification of char or volatiles, and reforming of light hydrocarbon gas increased with increasing temperature, resulting in more hydrogen. The water gas shift (WGS) reaction decreased with increasing temperature, reducing the concentration of carbon dioxide. BC and SOC, with retained inherent moisture, produced substantially higher amounts of hydrogen at high temperature, indicating that hydrogen production occurred under high-temperature steam. The continuous supply of steam from coal in the rotary kiln reactor allowed further exploration of coal gas production. Coal gas mainly comprising syngas was generated at 700–800 °C under a steam atmosphere, with production greatest at 800 °C. These results suggest that clean char and high value-added syngas can be produced simultaneously through the devolatilization of coal at lower temperature at atmospheric pressure than the entrained-bed type gasification temperature of 1,300–1,600 °C.
Keywords: Mongolia Coal; Devolatilization; Syngas; Char; Rotary Kiln
Epoxidation of waste used-oil biodiesel: Effect of reaction factors and its impact on the oxidative stability by Chainarong Kongyai; Benjapon Chalermsinsuwan; Mali Hunsom (327-336).
Epoxidation of waste used-oil biodiesel (WUO-B) was performed to test the feasibility of properties improvement. The effects of the reaction temperature (30–50 °C) and time (2–12 h), molar ratio of H2O2: HCOOH (1: 7 to 1: 1) and the stirring rate (100–300 rpm) on the level of unsaturated carbon bond conversion and the epoxy compound selectivity were identified using a 2 k (two levels) factorial design. Besides epoxy biodiesel as the main product, only one by-product, hydroxyl-biodiesel, was generated. The conversion of unsaturated carbon bonds was positively affected by the molar ratio of H2O2: HCOOH and the stirring rate, while the reaction temperature and time had no significant affect (in the investigated ranges). In contrast, with respect to the epoxy compound selectivity, the stirring rate had a positive effect, while both the reaction temperature and time each had a negative effect. The oxidative stability (OS) of the epoxy waste used-oil biodiesel (EWUO-B) revealed a linear relationship to the unsaturated carbon bond conversion level, but no significant relationship to the epoxy compound selectivity. EWUO-B prepared from a 1: 1 molar ratio of H2O2: HCOOH at 50 °C with stirring at 300 rpm for 12 h exhibited a higher OS (around 37.85 h) than that of the WUO-B. Except for the cold flow properties and methyl ester content, all other key properties of the EWUOB were within the specifications of the EN14214 standard set by the Department of Energy Business.
Keywords: Waste Used-oil Biodiesel; Epoxidation; Factorial Design; Oxidative Stability
Experimental study on interaction and excess heat release under oxy-fuel combustion of blended coals by Yonmo Sung; Cheoreon Moon; Seongyool Ahn; Gyungmin Choi; Duckjool Kim (337-344).
The combustion behavior and excess heat release during the oxy-fuel combustion of blended coals were investigated experimentally using a non-isothermal thermogravimetric analyzer. The atmospheres were set to 10%O2/90%CO2, 21%O2/79%N2, 30%O2/70%CO2, and 50%O2/50%CO2, and Arthur coal (bituminous coal, BA) and KPU (sub-bituminous coal, SK) were selected as fuel with blending ratios of BA25%/SK75%, BA50%/SK50%, and BA75%/SK25%. The purpose of this study is to investigate the interaction between the blended coals and the effects of blending ratio and oxygen concentration on the excess heat release under oxy-fuel combustion. The results showed that as the oxygen concentration and proportion of sub-bituminous coal increased, the peak value in the differential thermal analysis curve increased by the enhanced reaction rate. A higher oxygen concentration led to excess heat release. The ignition temperatures depended on the volatile matter content of the sub-bituminous coal, whereas the burnout temperature was largely affected by the fixed carbon content of the bituminous coal. For interaction behaviors on characteristic temperatures, the volatile release temperature shows an additive behavior; however, ignition and burnout temperatures show non-additive behaviors for blended coals.
Keywords: Blended Coals; Interactions; Excess Heat Release; Oxy-fuel Combustion
Effect of soil organic carbon on sorption and desorption of perchloroethylene in soils by Youn-Goog Lee; Jeong-Hun Park (345-350).
The objective of this study was to elucidate the sorption and desorption behaviors of PCE (Perchloroethylene, C2Cl4) in seven soils with different organic carbon (OC) content. Sorption/desorption kinetic and serial dilution desorption experiments were conducted in batch slurries. The sorption distribution coefficient (K d ) of PCE ranged from 0.60 to 4.66 L kg−1. K d tended to increase as the soil OC increased, but K oc tended to decrease, suggesting that adsorption into the mineral surface was not negligible in soils with low OC. Desorption kinetic data were analyzed by the two-site desorption model. The sorption/desorption of PCE was not reversible over short incubation times due to the presence of a non-desorbable site. The desorbable site fractions of PCE increased and non-desorbable site fractions decreased as the soil OC increased. It is suggested that partition of PCE into soil organic carbon is more reversible than adsorption on soil minerals.
Keywords: Sorption; Desorption; Organic Carbon; Hysteresis; Perchloroethylene
Removal characteristics and distribution of indoor tobacco smoke particles using a room air cleaner by Sunghak Jung; Youngchull Ahn; Yoochul Lee; Jaekeun Lee (351-356).
The objective of this study is to analyze the removal characteristics and distribution of indoor air pollutants by a room air cleaner. A pollutant removal effect according to room volume and measurement point was evaluated in an indoor room. A series of filtration efficiency tests were performed on only the electrostatic precipitator of the room air cleaner. The measurements of filter efficiency and pressure drop across the electrostatic precipitator were made using an ASHRAE 52.1-1992 filter test system and an opacity meter to measure the particle concentration upstream and downstream of the test filter. Also the performance of the air cleaner in the room was evaluated by examining tobacco smoke particle concentration. The size distribution of the tobacco smoke particles was 1.27 μm in mass median diameter and a geometric standard deviation of 1.313 μm. The efficiency of the electrostatic filter was measured as 78.6% with dust particles of 1.96 μm in mass median diameter and 1.5m/s face velocity. The tobacco smoke particle concentration as a function of time decayed exponentially. The contaminant removal effect was increased when increasing the effective clean air exchange rate (ηQ/V), which is 0.0780 min−1 for 51 m3 room and 0.0235 min−1 for 149 m3 room. This study clearly shows that a room air cleaner with an electrostatic precipitator is effective in removing tobacco smoke particles. The removal characteristics and distribution of indoor air pollutants in other rooms is predicted based on empirical modeling.
Keywords: Indoor Air Quality; Ventilation; Natural Decay; Electrostatic Precipitator; Tobacco Smoke; Effective Clear Air Rate
Synthesis of a novel carbon nanofiber structure for removal of lead by Hossein Faghihian; Masoume Kooravand; Homa Atarodi (357-363).
A new structure of carbon nanofibers was synthesized by chemical vapor deposition method. Kaolin was used as substrate and cyclohexanol and ferrocene as carbon source and catalyst, respectively. The morphology of the product was studied by scanning electron microscopy. Carbon nanofiber was modified with a mixture of nitric acid and sulfuric acid to enhance its adsorption capacity. The presence of functional groups on the treated adsorbent was assessed by FT-IR spectroscopy. The surface activity of the oxidized sample was estimated by Boehm’s titration. The pH(PZC) of the samples was also measured. The adsorbent was then used for adsorption of Pb2+ at different experimental conditions. The optimized capacity of 211mg·g−1 was obtained. Kinetic and thermodynamic of the reaction were studied. It was concluded that the adsorption process is spontaneous and endothermic. Equilibrium data were well fitted to the Langmuir model and the pseudo-second-order kinetic model described the adsorption process.
Keywords: Carbon Nanofiber; Chemical Vapor Deposition; Lead; Adsorption; pH(PZC)
Effect of agglomeration of silver nanoparticle on nanotoxicity depression by Eunjoo Bae; Byung-Cheun Lee; Younghun Kim; Kyunghee Choi; Jongheop Yi (364-368).
Silver nanoparticles (AgNPs) are used commercially in a variety of applications, including textiles, cosmetics, spray cleaning agents, and metal products. AgNP itself, however, is classified as an environmental hazard by Environmental Protection Agency (EPA, USA) Nanotechnology White Paper, due to its toxic, persistent and bioaccumulative characteristics when exposed to the environment. We investigated the cumulative mortality and abnormalities in Japanese medaka (Oryziaslatipes) embryos after exposure to AgNPs. Free AgNPs in solution have a high activity with respect to biological interactions regarding blocking blood flow and distribution of AgNPs into the cells from head to tail of hatched O. latipes. Interestingly, the agglomeration of AgNPs (loss of nanosized characteristics) played an important role in the environmental toxicity. The present study demonstrated that when the AgNPs were exposed in the ecosystem and then formed agglomerates, nanotoxicity was reduced.
Keywords: Nanomaterials; Silver Nanoparticles; Nano-hazard; Bioaccumulation; Agglomeration
Batch and continuous (fixed-bed column) biosorption of Cu(II) by Tamarindus indica fruit shell by Shamik Chowdhury; Papita Das Saha (369-378).
The feasibility of employing Tamarindus indica (tamarind) fruit shell (TFS) as low-cost biosorbent for removal of Cu(II) from aqueous solutions was investigated. Batch experiments were carried out as function of initial solution pH (2–7), contact time (10–240 min), initial Cu(II) concentration (20–100 mg L−1), biosorbent dose (0.5–5 g) and temperature (293–313 K). Biosorption equilibrium data were well described by the Langmuir isotherm model with maximum biosorption capacity of 80.01 mg g−1 at 313 K. Biosorption of Cu(II) followed pseudo-second-order kinetics. Gibbs free energy (ΔG0) was spontaneous for all interactions, and the biosorption process exhibited endothermic enthalpy values. To ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the Bed Depth Service Time (BDST) model was fitted to the dynamic flow experimental data to determine the column kinetic parameters useful for designing large-scale column studies. The Thomas model showed good agreement with the experimental results at all the process parameters studied. It could be concluded that TFS may be used as an inexpensive and effective biosorbent without any treatment or any other modification for the removal of Cu(II) ions from aqueous solutions.
Keywords: Biosorption; Cu(II); Tamarindus indica Fruit Shell; Batch; Fixed-bed Column
Effect of supplying a carbon extracting solution on denitrification in horizontal subsurface flow constructed wetlands by Yi Ding; Xinshan Song; Yuhui Wang; Denghua Yan (379-384).
Denitrification strongly depends on the availability of carbon source in constructed wetlands (CWs). In this study, several relevant carbon source extracting solutions made from hydrolyzate of selected wetland litters were added to CWs for nitrogen removal enhancement. The feasibility of supplying a carbon extracting solution to improve potential denitrification rate in horizontal subsurface flow constructed wetland was deeply investigated. Combinations of different hydraulic retention time (HRT, especially for 2-day and 4-day) with different influent COD/N ratios were designed to prove the enhancement on denitrification by carbon source supplement. In addition, specific denitrification rate (SDNR) was calculated for the comparison of the nitrogen removal at different COD/N ratios. The sequential operation results on total nitrogen (TN) and nitrate (NO 3 − -N) removal efficiencies were obtained in CW system with an influent COD/N ratio of 4.0. The accumulation of nitrite (NO 2 − -N) was found to be closely related to the removal of NO 3 − -N. Meanwhile, no obvious accumulation of NO 2 − -N was found when the removal of NO 3 − -N was relatively high.
Keywords: Carbon Extracting Solution; COD/N Ratio; Denitrification; Horizontal Subsurface Flow Constructed Wetland; Nitrogen Removal
Neural network prediction of fluidized bed bioreactor performance for sulfide oxidation by Varsha Midha; Mithilesh Kumar Jha; Apurba Dey (385-391).
Sulfide oxidation rate of a fluidized bed bioreactor was predicted using ANN, with upflow velocity, hydraulic retention time, reactor operation time and pH given as input. The reactor was fed with 100mg/L synthetic sulfide wastewater after biofilm formation on nylon support particles. Feedforward neural network model was prepared using 81 data sets, of which 63 were used for training and 18 for testing in a three-way cross validation. Prediction performance of the network was evaluated by calculating the percent error of each data set and mean square error for test data set in three partitions. The mean square error for test data set was 5.55, 4.08 and 2.30 for partition 1, partition 2 and partition 3, respectively. The predicted sulfide oxidation values correlated with the experimental values and a correlation coefficient of 0.96, 0.97 and 0.98 was obtained for partition 1, partition 2 and partition 3, respectively.
Keywords: FBBR; Mean Square Error; Neural Network; Sulfide; Sulfur
Recovery of nickel from chromite overburden, Sukinda using Aspergillus niger supplemented with manganese by Sunil Kumar Behera; Prangya Parimita Panda; Sandeep Kumar Saini; Nilotpala Pradhan; Lala Behari Sukla; Barada Kanta Mishra (392-399).
Oxalic acid is a prominent metabolite secreted by several fungi under specific conditions, which acts as a metal chelating agent. Amongst different fungal species, Aspergillus niger is favored as the best option for microbial production of oxalic acid. The present study deals with the oxalic acid over production by A. niger in response to manganese supplement to its growth medium, which in turn improves the recovery of nickel from pre-treated chromite overburden(COB) during fungal bioleaching. The metabolic pathway in oxalate bio-synthesis by A. niger involves one prominent cytoplasmic enzyme oxaloacetate acetylhydrolase (OAH), which catalyzes the breakdown of oxaloacetate metabolic intermediate to oxalate and acetate. Oxalic acid production was increased due to supplement of manganese to the culture medium of the A. niger. Manganese acts as cofactor for OAH enzyme; further, it enhances the catalytic activity of OAH to produce more oxalate. With oxalic acid production by A. niger, nickel recovery from pre-treated COB was improved. During the study, a maximum of nickel recovery was achieved up to 38.6% from pre-treated COB by adding 80 ppm of manganese to the culture media, whereas 24.0% of nickel was recovered without supplement of manganese (experiments were performed at 30 °C and the COB pulp density 2% w/v).
Keywords: Aspergillus niger; Chromite Overburden; Manganese; Nickel; Oxalic Acid
Aqueous processing of nickel spent catalyst for a value added product by Abdul Rauf Sheik; Malay Kumar Ghosh; Kali Sanjay; Tondepu Subbaiah; Barada Kanta Mishra; Abdullahi Aalafara Baba (400-404).
Nickel was recovered from a fertilizer industry spent catalyst by leaching with nitric acid followed by nickel hydroxide precipitation. The optimization of temperature, initial acid concentration and particle size for leaching of the spent catalyst was done through 23 factorial design. A maximum extraction of 91.9% was achieved at 90 °C, 1.5M HNO3 and 62.5 μm particle size. Temperature and acid concentration showed positive effect, while particle size showed no effect. A regression equation was developed and employed to predict conditions for 100% extraction which were experimentally tested. Nickel hydroxide was electrochemically precipitated from the leach liquor and its maximum discharge capacity was found to be 155 mAh/g. A 3-stage counter current leaching circuit was designed to obtain a leach liquor of suitable pH. XRD characterization of the precipitated Ni(OH)2 shows to consist of both α- and β-forms.
Keywords: Factorial Design; Nickel Spent Catalyst; Nitric Acid Leaching; Nickel Hydroxide; Counter Current Leaching
Lipase from Penicillium camembertii KCCM 11268: Optimization of solid state fermentation and application to biodiesel production by Waraporn Malilas; Seong Woo Kang; Sung Bong Kim; Hah Young Yoo; Warawut Chulalaksananukul; Seung Wook Kim (405-412).
Lipase was produced by Penicillium camembertii KCCM 11268 under solid state fermentation (SSF), and the production process was optimized by using statistical experimental designs. The initial moisture content, cultivation time, inoculum size and concentration of basal medium were considered as the factors of optimum conditions for SSF. P. Camembertii KCCM 11268 was cultivated in SSF using wheat bran as the substrate for lipase production. Under the optimized condition, lipase activity was reached around 7.8 U/ml after eight days fermentation. To partially purify the lipase, ammonium sulfate (80% saturation) was added to the crude lipase solution and concentrated using a diafiltration (VIVAFLOW 50). The concentrated lipase solution from P. Camembertii KCCM 11268 (PCL) was immobilized on silica gel by cross-linking method. Also, PCL was mixed with a commercial lipase solution from Candida rugosa (CRL), and this mixture was co-immobilized on silica gel. The immobilized and co-immobilized lipase activities were 1150.1 and 7924.8 U/g matrix, respectively. Palm oil and methanol were used as substrates and 1mmol of methanol was added every 1.5 h and 2 times during biodiesel production. The reaction was carried out at temperatures of 30, 40, 50, 60 and 70 °C. The maximum biodiesel conversion by co-immobilized lipase was 99% after 5 h at 50 °C.
Keywords: Penicillium camembertii KCCM 11268; Solid State Fermentation; Lipase Production; Statistical Experimental Design; Biodiesel Production; Immobilization
Isolation and characterization of autoflocculating mutants of cyanobacterium Arthrospira platensis by Young-Hwa Kim; Hyun-Jin Park; Sang-Hoon Lee; Jae-Hwa Lee (413-416).
Harvesting microalgae is a major concern for mass culture in industry. Flocculation is an easy and effective way to harvest microalgae. However, flocculation using chemical flocculants is not feasible for scaling-up due to their toxicity. As an alternative technique, mutation breeding of autoflocculating microalgae strain has been reported in this study. We characterized autoflocculating mutants of Arthrospira platensis (A. platensis) by ethyl methane sulfonate (EMS). The cells of mutants were aggregated during the culture and dry cell weight increased 1.2- to 1.8-fold compared to the wild type. Autoflocculation was induced highly at an optimal pH level of 9 and the flocculation efficiency reached almost 90%. Mutants showed higher flocculation efficiency irrespective of the addition of chemical flocculants. Thus, it is definitely useful to harvest microalgae using autoflocculating mutants in large-scale culture without any drawbacks of harvested algal biomass.
Keywords: Microalgae; Arthrospira platensis ; Autoflocculation; Ethyl Methane Sulfonate; Mutation
A new flow path design for multidimensional protein identification technology using nano-liquid chromatography electrospray ionization mass spectrometry by Thangamani Rajesh; Hyung-Yeon Park; Eunjung Song; Changmin Sung; Sung-Hee Park; Jae-Hun Lee; Dongwon Yoo; Yun-Gon Kim; Jong-Min Jeon; Byung-Gee Kim; Yung-Hun Yang (417-421).
Multidimensional protein identification technology (MudPIT) is one of the most versatile methods for separating and identifying highly complex peptides or proteins. However, there are still inherent problems resulting from salt in eluent systems and instrumentation with MudPIT. We designed a novel and simple flow path using two-valve system and successfully performed a fully automated peptide analysis using MudPIT coupled with nano-liquid chromatography electrospray ionization mass spectrometry (nLC-ESI-MS). It enables to generate a remarkably stable nanospray during the MudPIT analysis and realize the fully automated MudPIT system. This column arrangement could be easily installed to avoid laborious loading steps and unstable ionization from discontinuous flow. Consequently, the new flow path design for MudPIT system guarantees the detection of more peptides and higher protein coverage in proteome analysis.
Keywords: MudPIT; Nano LC-ESI-MS; SCX; C18; Peptide Identification
Preparation of nylon-6/chitosan composites by nanospider technology and their use as candidate for antibacterial agents by Salem Slayyem Al-Deyab; Mohamed Hassan El-Newehy; Rajkumar Nirmala; Ahmed Abdel-Megeed; Hak Yong Kim (422-428).
Electrospun nylon-6/chitosan (nylon-6/Ch) nanofibers were prepared by nanospider technology. Quaternary ammonium salts as antibacterial agent were immobilized onto electrospun nylon-6/Ch nanofibers via surface modification by soaking the mat in aqueous solution of glycidyltrimethylammonium chloride (GTMAC) at room temperature overnight to give nylon-6/N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride (nylon-6/HTCC). The morphological, structural and thermal properties of the nylon-6/ch nanofibers were studied by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). Biological screening has demonstrated the antibacterial activity of the electrospun nanofibers against Gram negative bacteria, Escherichia coli 35218, and Pseudomonas aeruginosa and Gram positive bacteria, Staphylococcus aureus 24213 among the tested microbes. Thus, the study ascertains the value of the use of electrospun nanofibers, which could be of considerable interest to the development of new antibacterial materials for biomedical applications.
Keywords: Chitosan; Nylon-6; Onium Salts; Antibacterial Polymers
Inhibition effect of CO2 on asphaltene precipitation for an Iranian crude oil and comparison with N2 and CH4 by Mohsen Mohammadi; Mahdi Akbari; Alireza Bahramian; Mahdi Sadeghi Naeeni; Zahra Fakhroueian (429-433).
The effects of N2, CH4 and CO2 injection on asphaltene precipitation have been experimentally investigated using a reservoir oil fluid from south of Iran, making use of light transmission method. The results are compared and the effects of injected gases on reducing asphaltene colloidal stability in oil are found in the following order: CH4> N2>CO2. It is observed that CO2 can act like an inhibitor and can increase the solubility of asphaltene, decreasing the asphaltene precipitation onset. A thermodynamic discussion explains the effect of CO2 on the solubility of asphaltene based on the solubility parameters of recombined oil and CO2, calculated from Peng-Robinson equation of state along with an empirical correlation for volumetric properties of CO2.
Keywords: Asphaltene; Asphaltene Precipitation Onset; Light Transmission Method; Gas Injection; Solubility Parameter
Isothermal vapor-liquid equilibria for the binary systems of ethylene glycol monopropyl ether with 2,2-dimethylbutane and 2,3-dimethylbutane by Seonghoon Hyeong; Sunghyun Jang; Kab-Soo Lee; Hwayong Kim (434-439).
Isothermal vapor liquid equilibria for the binary system of ethylene glycol monopropyl ether with 2,2-dimehylbutane and 2,3-dimethylbutane were measured in a circulating water bath at 303.15, 318.15, and 333.15 K. The apparatus was in-house designed and manufactured. Consistency testing of the apparatus was done by comparing the measured vapor pressures to the calculated vapor pressures from the Antoine equation. The measured systems were correlated with a Peng-Robinson equation of state (PR) combined with Wong-Sandler mixing rule for the vapor phase, and NRTL, UNIQUAC, and Wilson activity coefficient models for the liquid phase. All the measured systems showed good agreement with the correlation results.
Keywords: Vapor-liquid Equilibria; Surfactant; Ethylene Glycol Monopropyl Ether; 2,2-Dimethylbutane; 2,3-Dimethylbutane
Kinetic and thermodynamic study of Eu(III) sorption on natural red earth in South China by Tao Yu; Wang-Suo Wu; Zhi-Rong Liu; Si-Wei Zhang; Zheng-Wei Nie (440-447).
We did a kinetic and thermodynamic study of Eu(III) sorption on natural red earth (NRE) in South China as a function of contact time, pH values, ionic strength, humic acid (HA) and temperature under ambient conditions. Linear and nonlinear regression methods in selecting the optimum sorption isotherm were applied on the experimental data. The results suggest that sorption of Eu(III) on NRE can be described by a pseudo-second-order rate equation and strongly dependent on ionic strength at pH<7. Sorption of Eu(III) on NRE increased with increasing temperature, two-parameter and three-parameter isotherms were applied to analysis the equilibrium adsorption data, and a comparison of linear and nonlinear regression methods was done. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) of Eu(III) sorption on NRE at different temperatures were calculated from the temperature-dependent sorption isotherms, indicating that the sorption process of Eu(III) was spontaneous. The results showed that the nonlinear method is a better way to obtain the isotherm parameters and the data were in good agreement with the Freundlich isotherm model.
Keywords: Kinetic; Thermodynamic; Sorption; Eu(III); NRE
Adsorption ability of oxidized multiwalled carbon nanotubes towards aqueous Ce(III) and Sm(III) by Fattaneh Naderi Behdani; Alireza Talebizadeh Rafsanjani; Meisam Torab-Mostaedi; Seyed Mohammad Amin Koochaki Mohammadpour (448-455).
The aim of the present work was to investigate the adsorption of Ce(III) and Sm(III) onto multiwalled carbon nanotubes (MWCNTs) oxidized with concentrate nitric acid. The effects of solution pH, adsorbent dosage, and contact time were studied by batch technique. Langmuir, Freundlich and D-R isotherms were used to describe the adsorption behavior of Ce(III) and Sm(III) by oxidized MWCNTs, and the experimental results fitted Freundlich model well. The maximum uptake capacities (q m ) calculated by applying the Langmuir equation for samarium and cerium ions were found to be 89.28 and 92.59 (mg/g), respectively. A comparison of the kinetic models and the overall experimental data was best fitted by the pseudo second-order kinetic model. The calculated thermodynamic parameters (ΔGo, ΔHo, and ΔSo) showed that the adsorption for Ce(III) and Sm(III) is feasible, spontaneous and exothermic at 30–60 °C. Moreover, more than 70% of Ce(III) and Sm(III) adsorbed onto Oxidized MWCNTs could be desorbed with HNO3.
Keywords: Multiwalled Carbon Nanotubes (MWCNTs); Cerium; Samarium; Adsorption; Desorption; Isotherm; Kinetics
Influence of particle distribution on filter coefficient in the initial stage of filtration by Xing Min; Longcang Shu; Wei Li; Emmanuel Kwame Appiah-Adjei (456-464).
Under the condition that the size of suspended particles is nonhomogeneous, we studied how filter grain and suspended particles affect filter coefficient in the early stage. A stochastic method was used to study the variation of the initial filter coefficient. Through physical experiment, the collected data include the initial inflow and outflow concentration, the size distributions of particles in suspension and so on. By introducing the standard capture probability function P(d) and the characteristic length of filter bed L c , this separated the grains’ and particles’ influence on filter coefficient. An example showed that we could use P(d), L c to ascertain the result of effluent distribution, ratio of C out to C in in any depths and equivalent filter coefficient λ m . We also studied the filter coefficient λ l during the experiment and the first-order derivative of λ l .
Keywords: Variation of Filter Coefficient; Particle Size Distribution; The Characteristic Length of Filter Bed
Structural modeling of petroleum fractions based on mixture viscosity and Watson K factor by Abbas Mohammadi; Mohammadreza Omidkhah; Ramin Karimzadeh; Ali Haghtalab (465-473).
Two procedures have been developed for structural modeling of petroleum fractions based on mixture viscosity and Watson K factor. The representative molecules of paraffinic, naphthenic and aromatic hydrocarbons, based upon Ruzicka’s structural model, have been determined for lube-oil cut SAE 10 from Tehran oil refinery. Unlike previous methods, the newly developed procedures do not require time-consuming and costly laboratory data such as true boiling point profile. Good agreement between predictions of the new models and experimental results has been observed. Moreover, the proposed methods take less run-time than previous models due to less experimental and computational complexities. The results indicate that Ruzicka’s procedure, based on vapor pressure, is only applicable for light hydrocarbon mixtures, while the new methods can be applied for structural modeling of a wide range of petroleum fractions. Furthermore, as a result of this study, the application of a vapor pressure constraint leads to a higher degree of accuracy than the earlier suggested constraint, partial pressure, by Ruzicka.
Keywords: Characterization; Petroleum; Representative Molecule; Structural Modeling; Viscosity
Solubility of carbon dioxide in ammonium-based ionic liquids: Butyltrimethylammonium bis(trifluoromethylsulfonyl)imide and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide by Sang Gyu Nam; Byung-Chul Lee (474-481).
Solubility results of carbon dioxide (CO2) in two ammonium-based ionic liquids, butyltrimethylammonium bis(trifluoromethylsulfonyl)imide ([N4,1,1,1][Tf2N]) and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([N1,8,8,8][Tf2N]), are presented at pressures up to approximately 45 MPa and temperatures ranging from 303.15 K to 343.15 K. The solubility was determined by measuring bubble point pressures of mixtures of CO2 and ionic liquid using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. Sharp increase of equilibrium pressure was observed at high CO2 compositions. The CO2 solubility in ionic liquids increased with the increase of the total length of alkyl chains attached to the ammonium cation of the ionic liquids. The experimental data for the CO2+ionic liquid systems were correlated using the Peng-Robinson equation of state.
Keywords: Solubility; Carbon Dioxide; Ionic Liquid; Ammonium; Correlation; Peng-Robinson Equation of State
Surface plasmon resonance study of (positive, neutral, negative) vesicles rupture by AgNPs’ attack for screening of cytotoxicity induced by nanoparticles by Ha Nee Umh; Younghun Kim (482-487).
As the use of nanomaterials in industrial and commercial applications is growing, official reports concerning possible environmental and health effects of nanoparticles are also steadily increasing. Many toxicological studies on the adverse effects of silver nanoparticles (AgNPs) have used living organisms, which is a time consuming process. Therefore, we propose an alternative method to assess the in-vivo and in-vitro cytotoxicity of nanomaterials, involving a fast and simple screening procedure for vesicle rupture or fusion by the attack of AgNPs. With the assumption that particle interaction between AgNPs and vesicles is induced by electrostatic repulsion or attraction of surface charge, three vesicles with different charges (positive, neutral, and negative) were prepared and they were dispersed with AgNPs in different pH (3, 7, and 10) solutions to control the surface charge of AgNPs. Based on the results of vesicle rupture analyzed by SPR and TEM, screening of cell rupture through vesicles by AgNPs’ attack is determined to be most suitable at pH 7.
Keywords: Silver Nanoparticles; Vesicles; Nanotoxicity; Cell Rupture; SPR
Synthesis and characterization of waterborne polyurethane acrylate copolymers by Misbah Sultan; Haq Nawaz Bhatti; Mohammad Zuber; Mehdi Barikani (488-493).
Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties.
Keywords: Polyurethane; Acrylate; Emulsion Polymerization; Copolymers; Eco-friendly; Coating
Substitution effect of silica by silane-modified titania on the tensile and dynamic properties of silica-filled SBR compounds by Young Woo Lim; Jong-Ho Kim; Gon Seo (494-500).
Titania prepared by the calcination of sludge from waste water coagulated by titanium chloride was used as a substituent of the reinforcing material for silica-filled SBR compounds. The titania, mainly composed of anatase, was loosely aggregated and treated with various alkoxy silanes. The partial substitution of silica by the titania and silanemodified titania usually accelerated the cure rate and enhanced the thermal stability of the silica-filled SBR compounds. The extremely low concentration of hydroxyl groups of titania lowered the silica-silica interaction by introducing titania into the moieties of silica particles, resulting in decreases of the Payne effect and fractional hysteresis. Although the titanias modified with silanes were generally effective in enhancing the tensile and dynamic properties of the silicafilled SBR compounds, the silanes which contained mercapto groups, enabling them to react with rubber molecules, exhibited a high wet traction and low rolling resistance without sacrificing their tensile properties.
Keywords: Titania; Silane; Silica; SBR Compounds; Tensile and Dynamic Properties
A model for estimating agglomerate sizes of non-magnetic nanoparticles in magnetic fluidized beds by Li Zhou; Feng Zhang; Tao Zhou; Hiroyuki Kage; Yoshihide Mawatari (501-507).
The behavior of SiO2, TiO2 and ZnO non-magnetic nanoparticles and the effects of processing parameters on agglomerate sizes were investigated systematically in a magnetic fluidized bed (MFB) by adding coarse magnets. A mathematical model is developed based on energy balance among the agglomerate collision energy, magnetic energy, energy generated by turbulent shear and cohesive energy to predict the agglomerate sizes. The results showed that slugging of the bed disappeared and the measured agglomerate sizes decreased, so that the fluidization quality of non-magnetic nanoparticles was significantly improved by adding coarse magnets due to introduction of magnetic field. The average agglomerate sizes predicted by this model are in agreement with the experimental data.
Keywords: Non-magnetic Nanoparticles; Magnetic Fluidized Bed; Agglomerate Size; Energy Balance Model; Coarse Magnets