International Journal of Chemical Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Unsteady Flow of Reactive Viscous, Heat Generating/Absorbing Fluid with Soret and Variable Thermal Conductivity Wed, 23 Jul 2014 09:21:08 +0000 http://www.hindawi.com/journals/ijce/2014/291857/ This study investigates the unsteady natural convection and mass transfer flow of viscous reactive, heat generating/absorbing fluid in a vertical channel formed by two infinite parallel porous plates having temperature dependent thermal conductivity. The motion of the fluid is induced due to natural convection caused by the reactive property as well as the heat generating/absorbing nature of the fluid. The solutions for unsteady state temperature, concentration, and velocity fields are obtained using semi-implicit finite difference schemes. Perturbation techniques are used to get steady state expressions of velocity, concentration, temperature, skin friction, Nusselt number, and Sherwood number. The effects of various flow parameters such as suction/injection (), heat source/sinks (S), Soret number (Sr), variable thermal conductivity , Frank-Kamenetskii parameter , Prandtl number (Pr), and nondimensional time on the dynamics are analyzed. The skin friction, heat transfer coefficients, and Sherwood number are graphically presented for a range of values of the said parameters. I. J. Uwanta and M. M. Hamza Copyright © 2014 I. J. Uwanta and M. M. Hamza. All rights reserved. Hydrogenation of Styrene Oxide to 2-Phenylethanol over Nanocrystalline Ni Prepared by Ethylene Glycol Reduction Method Thu, 17 Jul 2014 06:34:39 +0000 http://www.hindawi.com/journals/ijce/2014/406939/ Nanocrystalline nickel prepared by glycol reduction method and characterized by XRD and magnetic measurements has been used as a catalyst for hydrogenation of styrene oxide to 2-phenylethanol. Effect of process variables such as particle size of the catalyst, temperature, and pressure have been optimized to achieve a maximum conversion of 98% of styrene oxide with 99% selectivity towards 2-phenylethanol. The structure of the transition state has been computed employing density functional theory and using Gaussian 09 suite. The enthalpy of reaction (ΔH) and activation energy () are calculated to be 85.3 kcal·mol−1 and 123.03 kcal·mol−1, respectively. A tentative mechanism for the reaction is proposed according to which atomized hydrogen and styrene oxide react together over the catalyst surface to produce 2-phenylethanol. Sunil K. Kanojiya, G. Shukla, S. Sharma, R. Dwivedi, P. Sharma, R. Prasad, M. Satalkar, and S. N. Kane Copyright © 2014 Sunil K. Kanojiya et al. All rights reserved. Performance Assessment of Sintered Metal Fiber Filters in Fluid Catalytic Cracking Unit Wed, 16 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/371853/ A long-term test was performed in a fluid catalytic cracking (FCC) hot gas filtration facility using sintered metal candle filters. The operating temperature and pressure were maximum 55°C and 0.28 MPa, respectively. Specific particle sampling systems were used to measure the particle size and concentration directly at high temperature. The range of inlet particle concentration is from 150 to 165 mg/Nm3. The outlet particle concentration is in the range of 0.71–2.77 mg/Nm3 in stable operation. The filtration efficiency is from 98.23% to 99.55%. The inlet volume median diameter and the outlet volume median diameter of the particle are about 1 μm and 2.2 μm, respectively. The cake thickness is calculated based on the equation of Carman-Kozeny. The effects of operating parameters including face velocity, gas cleaning pressure, pulse duration, and maximum pressure drop were investigated. The optimal operating conditions and cleaning strategies were determined. The results show that sintered metal fiber filters are suitable for industrial application due to the good performance and high efficiency observed. Liang Yang, Zhongli Ji, Qiaoqi Xu, and Hao Li Copyright © 2014 Liang Yang et al. All rights reserved. Effect of Sulfation on Zirconia-Pillared Montmorillonite to the Catalytic Activity in Microwave-Assisted Citronellal Conversion Thu, 10 Jul 2014 11:59:12 +0000 http://www.hindawi.com/journals/ijce/2014/950190/ Preparation of sulfated zirconia-pillared montmorillonite was carried out in two steps; zirconia pillarization and sulfation to zirconia-pillared montmorillonite. The prepared materials were characterized by using X-ray diffraction (XRD), measurement of the specific surface area, total pore volume and pore size distribution by the N2 adsorption method, scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and surface acidity determination by using pyridine adsorption-FTIR analysis. The activity of the materials as catalysts was evaluated for a microwave-assisted conversion of citronellal. The results showed that the prepared materials had a physicochemical character that promoted high catalytic activity to convert citronellal. From varied Zr content and study of the effect of sulfation on the activity, it was found that Zr content and sulfation increase the surface acidity of the material as shown by the higher total conversion and tendency to produce menthol as a product of the tandem cyclization-hydrogenation mechanism. Is Fatimah, Dwiarso Rubiyanto, and Thorikul Huda Copyright © 2014 Is Fatimah et al. All rights reserved. Experimental Research and Numerical Simulation on Gas-Liquid Separation Performance at High Gas Void Fraction of Helically Coiled Tube Separator Wed, 09 Jul 2014 11:05:17 +0000 http://www.hindawi.com/journals/ijce/2014/674925/ The industrial removal process of the light hydrocarbon and water from wet natural gas can be simulated in laboratory with the independently designed helically coiled tube gas-liquid separator. Experiment and numerical simulation are combined to analyze the influences of various inlet velocities and gas void fractions on the gas-liquid separation efficiency and pressure-drop between the inlet and outlet of the helically coiled tube. The results show that, at the inlet velocity of 4 m/s to 18 m/s and the gas void fraction of 88% to 97% for the gas-liquid mixture, the gas-liquid separation efficiency increases at the beginning and then decreases with increasing inlet velocity. Afterwards there is another increasing trend again. The gradient of pressure-drop increases slowly and then fast with the increasing inlet velocity. On the other hand, the gas-liquid separation efficiency first increases with the gas void fraction and then shows a decreasing trend while the pressure-drop keeps falling down with the gas void fraction increasing. Above all the optimal operating parameters of the helically coiled tube separator are inlet velocity of 13 m/s and gas void fraction of 93%, and the separation efficiency and pressure-drop are 95.2% and 0.3 MPa, respectively. Yongxue Zhang, Chan Guo, Hucan Hou, and Guomin Xue Copyright © 2014 Yongxue Zhang et al. All rights reserved. Growing Chlorella vulgaris in Photobioreactor by Continuous Process Using Concentrated Desalination: Effect of Dilution Rate on Biochemical Composition Wed, 02 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/310285/ Desalination wastewater, which contains large amount of salt waste, might lead to severely environmental pollution. This study evaluated the effect of dilution rate ( day−1) on microalgal biomass productivity, lipid content, and fatty acid profile under steady-state condition of Chlorella vulgaris supplemented with concentrated desalination. Continuous culture was conducted for 55 days. Results show that the biomass productivity () varied from 57 to 126 mg L−1 d−1 (dry mass) when the dilution rate ranged from 0.1 to 0.3 day−1. At lowest dilution rate ( day−1), the continuous culture regime ensured the highest values of maximum biomass concentration ( mL−1) and protein content (52%). Biomass lipid content was an increasing function of . The most abundant fatty acids were the palmitic () at day−1 and the gamma-linolenic acid () at day−1 ones. These fatty acids present 14 to 18 carbons in the carbon chain, being mainly saturated and polyunsaturated, respectively. Overall, the results show that continuous culture is a powerful tool to investigate the cell growth kinetics and physiological behaviors of the algae growing on desalination wastewater. Ângelo Paggi Matos, Regina Coeli de Oliveira Torres, Luiz Rodrigo Ito Morioka, Elisa Helena Siegel Moecke, Kepler Borges França, and Ernani Sebastião Sant’Anna Copyright © 2014 Ângelo Paggi Matos et al. All rights reserved. Multimicronutrient Slow-Release Fertilizer of Zinc, Iron, Manganese, and Copper Tue, 01 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/327153/ The process for the production of a slow-release micronutrient fertilizer is described. The compound contains zinc, iron, manganese, and copper as micronutrients and is produced by polymerizing a system containing phosphoric acid, zinc oxide, hematite, pyrolusite, copper sulfate, and magnesium oxide followed by neutralization of the polyphosphate chain with ammonium hydroxide. Changes in temperature, density, and viscosity of the reaction system during polymerization were studied. Reaction kinetics was studied at three different temperatures. Rate curves revealed a multistage process with essentially linear rates at each stage. Thus, each stage displayed zero order kinetics. The product was crystalline and revealed ordering of P-O-P chains. It had low solubility in water but high solubility in 0.33 M citric acid and 0.005 M DTPA. Three different field trials showed significant yield increments using the slow-release micronutrient fertilizer compared to the conventional micronutrients. Yield increments in rice were in the range of 10–55% over control (with no micronutrient) and up to 17% over the conventional micronutrient fertilizers. There were significant increases in total uptake of zinc, iron, and manganese in the grain. Slow-release fertilizers also produced significant yield increases in potato as well as significant increase in vitamin C content of the tuber. Siladitya Bandyopadhyay, Kunal Ghosh, and Chandrika Varadachari Copyright © 2014 Siladitya Bandyopadhyay et al. All rights reserved. Multiphase CFD Simulation of Solid Propellant Combustion in a Small Gun Chamber Wed, 25 Jun 2014 06:51:02 +0000 http://www.hindawi.com/journals/ijce/2014/971808/ The interior ballistics simulations in 9 mm small gun chamber were conducted by implementing the process into the mixture multiphase model of Fluent V6.3 platform. The pressure of the combustion chamber, the velocity, and the travel of the projectile were investigated. The performance of the process, namely, the maximum pressure, the muzzle velocity, and the duration of the process was assessed. The calculation method is validated by the comparison of the numerical simulations results in the small gun with practical tests, and with lumped-parameter model results. In the current numerical study, both the characteristics and the performance of the interior ballistic process were reasonably predicted compared with the practical tests results. The impact of the weight charge on the interior ballistic performances was investigated. It has been found that the maximum pressure and the muzzle velocity increase with the increase of the charge weight. Ahmed Bougamra and Huilin Lu Copyright © 2014 Ahmed Bougamra and Huilin Lu. All rights reserved. Anaerobic Digestion and Biogas Production: Combine Effluent Treatment with Energy Generation in UASB Reactor as Biorefinery Annex Wed, 25 Jun 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/543529/ The issue of residues and industrial effluents represents an unprecedented environmental challenge in terms of recovery, storage, and treatment. This work discusses the perspectives of treating effluents through anaerobic digestion as well as reporting the experience of using an upflow anaerobic sludge blanket (UASB) reactor as biorefinery annex in a pulp and paper industrial plant to be burned in the boilers. The performance of the reactors has shown to be stable under considerable variations in load and showed a significant potential in terms of biogas production. The reactors UASB treated 3600.00 m3 of effluent daily from a production of 150.00 tons. The biogas generation was 234.000 kg/year/mill, equivalent in combustible oil. The results of methane gas generated by the anaerobic system UASB (8846.00 kcal/m3) dislocate the equivalent of 650.0 kg of combustible oil (10000.00 kcal/kg) per day (or 234.000 kg/year). The production of 8846.00 Kcal/m3 of energy from biogas can make a run at industrial plant for 2 hours. This substitution can save US$ 128.700 annually (or US$ 550.0 of fuel oil/tons). The companies are invested in the use of the biogas in diesel stationary motors cycle that feed the boilers with water in case of storage electricity. Mauro Berni, Ivo Dorileo, Grazielle Nathia, Tânia Forster-Carneiro, Daniel Lachos, and Breno G. M. Santos Copyright © 2014 Mauro Berni et al. All rights reserved. Waste Material Adsorbents for Zinc Removal from Wastewater: A Comprehensive Review Tue, 24 Jun 2014 06:52:46 +0000 http://www.hindawi.com/journals/ijce/2014/347912/ This review examines a variety of adsorbents and discusses mechanisms, modification methods, recovery and regeneration, and commercial applications. A summary of available researches has been composed by a wide range of potentially low-cost modified adsorbents including activated carbon, natural source adsorbents (clay, bentonite, zeolite, etc.), biosorbents (black gram husk, sugar-beet pectin gels, citrus peels, banana and orange peels, carrot residues, cassava waste, algae, algal, marine green macroalgae, etc.), and byproduct adsorbents (sawdust, lignin, rice husk, rice husk ash, coal fly ash, etc.). From the literature survey, different adsorbents were compared in terms of Zn2+ adsorption capacity; also Zn2+ adsorption capacity was compared with other metals adsorption. Thus, some of the highest adsorption capacities reported for Zn2+ are 168 mg/g powdered waste sludge, 128.8 mg/g dried marine green macroalgae, 73.2 mg/g lignin, 55.82 mg/g cassava waste, and 52.91 mg/g bentonite. Furthermore, modification of adsorbents can improve adsorption capacity. Regeneration cost is important, but if consumption of virgin adsorbent is reduced, then multiple economic, industrial, and environmental benefits can be gained. Finally, the main drawback of the already published Zn2+ adsorption researches is that their use is still in the laboratory stage mostly without scale-up, pilot studies, or commercialization. Haider M. Zwain, Mohammadtaghi Vakili, and Irvan Dahlan Copyright © 2014 Haider M. Zwain et al. All rights reserved. CFD Simulation for Separation of Carbon Dioxide-Methane Mixture by Pressure Swing Adsorption Thu, 19 Jun 2014 13:00:20 +0000 http://www.hindawi.com/journals/ijce/2014/402756/ A developing technology for gas separations is pressure swing adsorption, which has been proven to be more economical and energy efficient compared to other separation methods like cryogenic distillation and membrane separation. A pressure swing adsorption (PSA) column, with carbon dioxide-methane as feed mixture and 6-FDA based polyimides as the adsorbent, was modeled and simulated in this work. Ansys Fluent 12.1, along with supplementary user defined functions, was used to develop a 2D transient Eulerian laminar viscous flow model for the PSA column. The model was validated by comparing the simulated results with established analytical models for PSA. The developed numerical model was used to determine the carbon dioxide concentration in the column as a function of time based on different operating conditions. Effect of various operating parameters like pressure, temperature, and flow rate on the separation efficiency has been studied and reported. Optimization studies were carried out to obtain suitable operating conditions for the feed gases separation. Simulation studies were carried out to determine the separation length required for complete separation of the feed mixture corresponding to different inlet feed concentrations which were entering the column at a given flow rate. K. Rambabu, L. Muruganandam, and S. Velu Copyright © 2014 K. Rambabu et al. All rights reserved. Comparative Study of Textural Characteristics on Methane Adsorption for Carbon Spheres Produced by CO2 Activation Tue, 17 Jun 2014 09:54:40 +0000 http://www.hindawi.com/journals/ijce/2014/916913/ Resorcinol-formaldehyde resin polymer was used as raw material for preparation of carbon spheres. Samples were treated with CO2 flow at 850°C by varying activation times. The CO2 activation granted better pore development of pore structure. The experimental data of CH4 adsorption as a function of equilibrium pressure was fitted by Langmuir and Dubinin-Astakhov (D-A) models. It was concluded that the high surface area and micropore volume of carbon spheres did unequivocally determine methane capacities. In addition, a thermodynamic study of the heat of adsorption of CH4 on the carbon spheres was carried out. Adsorption of CH4 on carbon spheres showed a decrease in the adsorption heat with CH4 occupancy, and the heat of adsorption fell from 20.51 to 12.50 kJ/mol at 298 K and then increased to a little higher values at a very high loading (>0.70), indicating that CH4/CH4 interactions within the adsorption layer became significant. Wen Yang, Yanyan Feng, and Wei Chu Copyright © 2014 Wen Yang et al. All rights reserved. Experimental Investigation of Based Oxygen Carriers Used in Continuous Chemical-Looping Combustion Thu, 12 Jun 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/412517/ Three materials of perovskite structure, (M = Mg or Mg and Ti), have been examined as oxygen carriers in continuous operation of chemical-looping combustion (CLC) in a circulating fluidized bed system with the designed fuel power 300 W. Natural gas was used as fuel. All three materials were capable of completely converting the fuel to carbon dioxide and water at 900°C. All materials also showed the ability to release gas phase oxygen when fluidized by inert gas at elevated temperature (700–950°C); that is, they were suitable for chemical looping with oxygen uncoupling (CLOU). Both fuel conversion and oxygen release improved with temperature. All three materials also showed good mechanical integrity, as the fraction of fines collected during experiments was small. These results indicate that the materials are promising oxygen carriers for chemical-looping combustion. Peter Hallberg, Malin Källén, Dazheng Jing, Frans Snijkers, Jasper van Noyen, Magnus Rydén, and Anders Lyngfelt Copyright © 2014 Peter Hallberg et al. All rights reserved. Optimization of Two-Step Acid-Catalyzed Hydrolysis of Oil Palm Empty Fruit Bunch for High Sugar Concentration in Hydrolysate Wed, 11 Jun 2014 13:18:32 +0000 http://www.hindawi.com/journals/ijce/2014/954632/ Getting high sugar concentrations in lignocellulosic biomass hydrolysate with reasonable yields of sugars is commercially attractive but very challenging. Two-step acid-catalyzed hydrolysis of oil palm empty fruit bunch (EFB) was conducted to get high sugar concentrations in the hydrolysate. The biphasic kinetic model was used to guide the optimization of the first step dilute acid-catalyzed hydrolysis of EFB. A total sugar concentration of 83.0 g/L with a xylose concentration of 69.5 g/L and a xylose yield of 84.0% was experimentally achieved, which is in well agreement with the model predictions under optimal conditions (3% H2SO4 and 1.2% H3PO4, w/v, liquid to solid ratio 3 mL/g, 130°C, and 36 min). To further increase total sugar and xylose concentrations in hydrolysate, a second step hydrolysis was performed by adding fresh EFB to the hydrolysate at 130°C for 30 min, giving a total sugar concentration of 114.4 g/L with a xylose concentration of 93.5 g/L and a xylose yield of 56.5%. To the best of our knowledge, the total sugar and xylose concentrations are the highest among those ever reported for acid-catalyzed hydrolysis of lignocellulose. Dongxu Zhang, Yee Ling Ong, Zhi Li, and Jin Chuan Wu Copyright © 2014 Dongxu Zhang et al. All rights reserved. Bioethanol Production from Sugarcane Bagasse by a Novel Brazilian Pentose Fermenting Yeast Scheffersomyces shehatae UFMG-HM 52.2: Evaluation of Fermentation Medium Tue, 27 May 2014 10:16:53 +0000 http://www.hindawi.com/journals/ijce/2014/180681/ Bioconversion of hemicellulosic sugars into second generation (2G) ethanol plays a pivotal role in the overall success of biorefineries. In this study, ethanol production performance of a novel xylose-fermenting yeast, Scheffersomyces shehatae UFMG-HM 52.2, was evaluated under batch fermentation conditions using sugarcane bagasse (SB) hemicellulosic hydrolysate as carbon source. Dilute acid hydrolysis of SB was performed to obtain sugarcane bagasse hemicellulosic hydrolysate (SBHH). It was concentrated, detoxified, and supplemented with nutrients in different formulations to prepare the fermentation medium to the yeast evaluation performance. S. shehatae UFMG-HM 52.2 (isolated from Brazilian Atlantic rain forest ecosystem) was used in fermentations carried out in Erlenmeyer flasks maintained in a rotator shaker at 30°C and 200 rpm for 72 h. The use of a fermentation medium composed of SBHH supplemented with 5 g/L ammonium sulfate, 3 g/L yeast extract, and 3 g/L malt extract resulted in 0.38 g/g of ethanol yield and 0.19 g L.h of volumetric productivity after 48 h of incubation time. F. A. F. Antunes, A. K. Chandel, T. S. S. Milessi, J. C. Santos, C. A. Rosa, and S. S. da Silva Copyright © 2014 F. A. F. Antunes et al. All rights reserved. Experimental Investigation of Biogas Reforming in Gliding Arc Plasma Reactors Mon, 26 May 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/609836/ Biogas is an important renewable energy source. Its utilization is restricted to vicinity of farm areas, unless pipeline networks or compression facilities are established. Alternatively, biogas may be upgraded into synthetic gas via reforming reaction. In this work, plasma assisted reforming of biogas was investigated. A laboratory gliding arc plasma setup was developed. Effects of CH4/CO2 ratio (1, 2.33, 9), feed flow rate (16.67–83.33 cm3/s), power input (100–600 W), number of reactor, and air addition (0–60% v/v) on process performances in terms of yield, selectivity, conversion, and energy consumption were investigated. High power inputs and long reaction time from low flow rates, or use of two cascade reactors were found to promote dry reforming of biogas. High H2 and CO yields can be obtained at low energy consumption. Presence of air enabled partial oxidation reforming that produced higher CH4 conversion, compared to purely dry CO2 reforming process. P. Thanompongchart and N. Tippayawong Copyright © 2014 P. Thanompongchart and N. Tippayawong. All rights reserved. Separation Process of Nonpolar Gas Hydrate in Food Solution under High Pressure Apparatus Sun, 25 May 2014 11:01:08 +0000 http://www.hindawi.com/journals/ijce/2014/262968/ Separation process of nonpolar gas hydrate formation in liquid food was experimentally studied under high pressure container. Xenon (Xe) gas was selected as hydrate forming gas and coffee solution was used as a sample of liquid food. The high-pressure stainless steel container having the inner diameter of 60 mm and the volume of 700 mL with a U-shaped stirrer was designed to carry out this experiment. A temperature of 9.0°C and Xe partial pressure of 0.9 MPa were set as a given condition. The experiment was designed to examine the effect of steel screen size, formation rate, temperature condition, and amount of Xe gas dissolving in the solution on the separation process which was indicated by concentration efficiency. Screen size of 200 and 280 mesh resulted in higher concentration efficiency than that of 100 mesh. The higher stirring rate caused the higher formation rate of Xe hydrate and created the smaller Xe hydrate crystals. At the condition giving the same solubility in water, temperature of 14.8°C resulted in lower concentration efficiency than 9.0°C. The increase in the amount of Xe gas dissolving in coffee solution caused the concentration efficiency to decrease; however, the concentration ratio between the final and initial concentration of the solution increased. Yohanes Aris Purwanto, Seiichi Oshita, Yasuhisa Seo, and Yoshinori Kawagoe Copyright © 2014 Yohanes Aris Purwanto et al. All rights reserved. A Numerical Study of Spray Characteristics in Medium Speed Engine Fueled by Different HFO/n-Butanol Blends Thu, 22 May 2014 09:10:40 +0000 http://www.hindawi.com/journals/ijce/2014/702890/ In the present study, nonreacting and nonevaporating spray characteristics of heavy fuel oil (HFO)/n-butanol blends are numerically investigated under two different high pressure injections in medium speed engines. An Eulerian-Lagrangian multiphase scheme is used to simulate blend of C14H30 as HFO and 0%, 10%, 15%, and 20% by volume of n-butanol. OpenFOAM CFD toolbox is modified and implemented to study the effect of different blends of HFO/n-butanol on the spray characteristics at 600 and 1000 bar. To validate the presented simulations, current numerical results are compared against existing experimental data and good compliance is achieved. Based on the numerical findings, addition of n-butanol to HFO increases the particles volume in parcels at 600 bar. It was also found that blend fuels increase the number of spray particles and the average velocity of spray compared to pure HFO. Moreover, under injection pressure of 1000 bar, HFO/n-butanol blends compared to pure HFO fuel decrease particles volume in parcels of spray. Another influence of HFO/n-butanol blends is the decrease in average of particles diameter in parcels. Meanwhile, the effect of HFO/n-butanol on spray length is proved to be negligible. Finally, it can be concluded that higher injection pressure improves the spray efficiency. Hashem Nowruzi, Parviz Ghadimi, and Mehdi Yousefifard Copyright © 2014 Hashem Nowruzi et al. All rights reserved. A New Proposal of Cellulosic Ethanol to Boost Sugarcane Biorefineries: Techno-Economic Evaluation Wed, 21 May 2014 11:27:57 +0000 http://www.hindawi.com/journals/ijce/2014/537408/ Commercial simulator Aspen Plus was used to simulate a biorefinery producing ethanol from sugarcane juice and second generation ethanol production using bagasse fine fraction composed of parenchyma cells (P-fraction). Liquid hot water and steam explosion pretreatment technologies were evaluated. The processes were thermal and water integrated and compared to a biorefinery producing ethanol from juice and sugarcane bagasse. The results indicated that after thermal and water integration, the evaluated processes were self-sufficient in energy demand, being able to sell the surplus electricity to the grid, and presented water intake inside the environmental limit for São Paulo State, Brazil. The processes that evaluated the use of the bagasse fine fraction presented higher economic results compared with the use of the entire bagasse. Even though, due to the high enzyme costs, the payback calculated for the biorefineries were higher than 8 years for all cases that considered second generation ethanol and the net present value for the investment was negative. The reduction on the enzyme load, in a way that the conversion rates could be maintained, is the limiting factor to make second generation ethanol competitive with the most immediate uses of bagasse: fuel for the cogeneration system to surplus electricity production. Juliana Q. Albarelli, Adriano V. Ensinas, and Maria A. Silva Copyright © 2014 Juliana Q. Albarelli et al. All rights reserved. Investigation of Horizontal Velocity Fields in Stirred Vessels with Helical Coils by PIV Mon, 19 May 2014 08:21:11 +0000 http://www.hindawi.com/journals/ijce/2014/763473/ Horizontal velocity flow fields were measured by particle image velocimetry for a stirred vessel with baffles and two helical coils for enlargement of heat transfer area. The investigation was carried out in a cylindrical vessel with flat base and two different stirrers (radial-flow Rushton turbine and axial-flow propeller stirrer). Combined velocity plots for flow fields at different locations are presented. It was found that helical coils change the flow pattern significantly. Measurements for the axial-flow Rushton turbine showed a strong deflection by the coils, leading to a mainly tangential flow pattern. Behind baffles large areas of unused heat transfer area were found. First results for the axial-flow propeller reveal an extensive absence of fluid movement in the horizontal plane. Improved design considerations for enhanced heat transfer by more compatible equipment compilation are proposed. Volker Bliem and Heyko Jürgen Schultz Copyright © 2014 Volker Bliem and Heyko Jürgen Schultz. All rights reserved. Contribution of Ash Content Related to Methane Adsorption Behaviors of Bituminous Coals Mon, 19 May 2014 04:59:30 +0000 http://www.hindawi.com/journals/ijce/2014/956543/ Methane adsorption isotherms on coals with varying ash contents were investigated. The textural properties were characterized by N2 adsorption/desorption isotherm at 77 K, and methane adsorption characteristics were measured at pressures up to 4.0 MPa at 298 K, 313 K, and 328 K, respectively. The Dubinin-Astakhov model and the Polanyi potential theory were employed to fit the experimental data. As a result, ash content correlated strongly to methane adsorption capacity. Over the ash range studied, 9.35% to 21.24%, the average increase in methane adsorption capacity was 0.021 mmol/g for each 1.0% rise in ash content. With the increasing ash content range of 21.24%~43.47%, a reduction in the maximum adsorption capacities of coals was observed. In addition, there was a positive correlation between the saturated adsorption capacity and the specific surface area and micropore volume of samples. Further, this study presented the heat of adsorption, the isosteric heat of adsorption, and the adsorbed phase specific heat capacity for methane adsorption on various coals. Employing the proposed thermodynamic approaches, the thermodynamic maps of the adsorption processes of coalbed methane were conducive to the understanding of the coal and gas simultaneous extraction. Yanyan Feng, Wen Yang, and Wei Chu Copyright © 2014 Yanyan Feng et al. All rights reserved. The Reactants’ Phase State: A Nonnegligible Factor in Tetralin Hydrogenation Catalysts Evaluation Tue, 13 May 2014 06:38:17 +0000 http://www.hindawi.com/journals/ijce/2014/405703/ The effects of reactants’ phase states (gas-liquid and single gas phase) on tetralin hydrogenation were investigated in the fixed bed. The kinetics of tetralin hydrogenation under different phase states was analyzed. Results showed that, without phase transition, the tetralin conversion increased with the rise of temperature. However, it decreased dramatically around the dew point of the feed at which the reactants’ phase state transferred from gas-liquid phase into gas phase. It was also observed that the gas-liquid phase state was favorable to reduce the deactivation of catalyst in the tetralin hydrogenation. Mingjian Luo, Qingfa Wang, Xiangwen Zhang, and Bing Hu Copyright © 2014 Mingjian Luo et al. All rights reserved. Aspergillus fumigatus NITDGPKA3 Provides for Increased Cellulase Production Sun, 11 May 2014 14:17:56 +0000 http://www.hindawi.com/journals/ijce/2014/959845/ A cellulolytic fungal strain, Aspergillus fumigatus NITDGPKA3, was isolated from straw retting ground. Cellulase and xylanase production by A. fumigatus NITDGPKA3 in submerged fermentation of rice straw was studied. The culture conditions for maximum enzyme production were found to be initial pH 4, 1% substrate concentration, temperature 30°C, incubation time 5 days, 0.2% tryptone as nitrogen source, and inoculum volumes 7% v/v (for cellulase) and 5% v/v (for xylanase). Addition of Tween 80 in fermentation broth improved xylanase production (193.58 IU/ml) much more compared to cellulase production (6.53 IU/ml). Xylanase activity found in the culture broth was approximately 50% higher compared to most of the reported data. The crude enzyme was further applied for reducing sugar production from alkali pretreated rice straw, where a dosage of 40 IU/g CMCase produced 0.522 g reducing sugar/g dry substrate after 36 hours which was higher than that in the reported literature. The high concentration of reducing sugar yield was most probably due to the extraordinarily high titer of β-glucosidase (80.1 IU/ml) found in the crude enzyme. The crude enzymes secreted by Aspergillus fumigatus NITDGPKA3 efficiently hydrolyzed alkali pretreated rice straw suggesting that Aspergillus fumigatus NITDGPKA3 is a robust microorganism. Nibedita Sarkar and Kaustav Aikat Copyright © 2014 Nibedita Sarkar and Kaustav Aikat. All rights reserved. Analytical Solution of Nonlinear Dynamics of a Self-Igniting Reaction-Diffusion System Using Modified Adomian Decomposition Method Thu, 24 Apr 2014 09:18:44 +0000 http://www.hindawi.com/journals/ijce/2014/825797/ A mathematical model of the dynamics of the self-ignition of a reaction-diffusion system is studied in this paper. An approximate analytical method (modified Adomian decomposition method) is used to solve nonlinear differential equations under steady-state condition. Analytical expressions for concentrations of the gas reactant and the temperature have been derived for Lewis number (Le) and parameters , , and . Furthermore, in this work, the numerical simulation of the problem is also reported using MATLAB program. An agreement between analytical and numerical results is noted. Felicia Shirly Peace, Narmatha Sathiyaseelan, and Lakshmanan Rajendran Copyright © 2014 Felicia Shirly Peace et al. All rights reserved. A Novel Method of Mechanical Oxidation of CNT for Polymer Nanocomposite Application: Evaluation of Mechanical, Dynamic Mechanical, and Rheological Properties Thu, 17 Apr 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijce/2014/623109/ A new approach of oxidation of carbon nanotubes has been used to oxidize the CNTs. A comparative aspect of the mechanical oxidation and acid oxidation process has been established. FTIR analysis and titration method have shown the higher feasibility of the mechanical oxidation method to oxidize the CNTs. Comparatively less damage to the CNTs has been observed in case of mechanically oxidized as compared to acid oxidized CNTs. The mechanical properties of the nanocomposites reinforced with the acid oxidized CNT (ACNT) and mechanically oxidized CNTs (McCNT) were analyzed and relatively higher properties in the nanocomposites reinforced with McCNT were noticed. The less degree of entanglement in the McCNTs was noticed as compared to ACNTs. The dynamic mechanical analysis of the nanocomposites revealed much improved load transfer capability in the McCNT reinforced composites. Further, the rheological properties of the nanocomposites revealed the higher performance of McCNT reinforced composites. Priyanka Pandey, Smita Mohanty, and Sanjay Kumar Nayak Copyright © 2014 Priyanka Pandey et al. All rights reserved. A Novel Biosorbent, Water-Hyacinth, Uptaking Methylene Blue from Aqueous Solution: Kinetics and Equilibrium Studies Tue, 15 Apr 2014 14:08:02 +0000 http://www.hindawi.com/journals/ijce/2014/819536/ The adsorption of MB dye from aqueous solution onto HCl acid treated water-hyacinth (H-WH) was investigated by carried out batch sorption experiments. The effect of process parameters such as pH, adsorbent dosage, concentrations and contact time, and ionic strength were studied. Adsorption of MB onto H-WH was found highly pH dependent and ionic strength shows negative impact on MB removal. To predict the biosorption isotherms and to determine the characteristic parameters for process design, Langmuir, Freundlich, Temkin, and Halsey isotherms models were utilized to equilibrium data. The adsorption kinetics was tested for pseudo-first-order (PFO), pseudo-second-order (PSO), intraparticle diffusion (IPD), and Bangham’s kinetic models. The Langmuir isotherm model showed the goodness-of-fit among the tested models for equilibrium adsorption of MB over H-WH and indicated the maximum adsorption capacity as 63.30 mg/g. Higher coefficient of determination () and better agreement between the qe (experimental) and (calculated) values predicted that PSO kinetic model showed the goodness-of-fit for kinetic data along with rate constant , , and , respectively, for the studied concentration range. At the initial stage of adsorption, the overall rate of dye uptake was found to be dominated by external mass transfer, and afterwards, it is controlled by IPD mechanism. Md. Nasir Uddin, Md. Tariqul Islam, and Sreejon Das Copyright © 2014 Md. Nasir Uddin et al. All rights reserved. The Experimental and Simulation Study of Selective Catalytic Reduction System in a Single Cylinder Diesel Engine Using NH3 as a Reducing Agent Tue, 15 Apr 2014 08:17:56 +0000 http://www.hindawi.com/journals/ijce/2014/350185/ Selective catalytic reduction (SCR) technology has been widely used in automotive applications in order to meet the stringent limits on emission standards. The maximum NO conversion efficiency of an SCR depends on temperature and mass flow rate of an exhaust gas. In order to assess the suitability of Cordierite/Pt catalyst for low temperature application, an experimental work is carried out using single cylinder diesel engine for different load conditions by varying ammonia induction rate from 0.2 kg/hr to 0.8 kg/hr. The simulation is carried out using AVL FIRE for the validation of experimental results. From the study, it has been found that for 0.6 kg/hr ammonia induction rate the maximum conversion is achieved, whereas, for 0.8 kg/hr, conversion is reduced due to desorption of ammonia. Also it has been found that, at 75% of load, for all mass flow rates of ammonia the conversion was drastically reduced due to higher exhaust gas temperature and higher emission of unburnt hydrocarbons. More than 55% of NO conversion was achieved using Cordierite/Pt catalyst at a temperature of 320°C. Manoj Kumar Athrashalil Phaily, Sreekumar Jayachandra Sreekala, and Padmanabha Mohanan Copyright © 2014 Manoj Kumar Athrashalil Phaily et al. All rights reserved. Corrosion Inhibition Effect of Carbon Steel in Sea Water by L-Arginine-Zn2+ System Tue, 15 Apr 2014 07:16:05 +0000 http://www.hindawi.com/journals/ijce/2014/607209/ The inhibition efficiency of L-Arginine-Zn2+ system in controlling corrosion of carbon steel in sea water has been evaluated by the weight-loss method. The formulation consisting of 250 ppm of L-Arginine and 25 ppm of Zn2+ has 91% IE. A synergistic effect exists between L-Arginine and Zn2+. Polarization study reveals that the L-Arginine-Zn2+ system functions as an anodic inhibitor and the formulation controls the anodic reaction predominantly. AC impedance spectra reveal that protective film is formed on the metal surface. Cyclic voltammetry study reveals that the protective film is more compact and stable even in a 3.5% NaCl environment. The nature of the protective film on a metal surface has been analyzed by FTIR, SEM, and AFM analysis. S. Gowri, J. Sathiyabama, and S. Rajendran Copyright © 2014 S. Gowri et al. All rights reserved. Neutralization of Soybean Oil Deodorizer Distillate for Vitamin Supplement Production Tue, 01 Apr 2014 08:10:12 +0000 http://www.hindawi.com/journals/ijce/2014/742846/ Soybean oil deodorizer distillate (SODD), a byproduct of the soybean oil refining process, is a complex mixture of compounds, such as free fatty acids (FFA), hydrocarbons, and sterols, such as tocopherols, a class of major natural antioxidants with vitamin E activity. As the utilization of SODD for tocopherol extraction is shown to be not economically viable, SODD in the semirefined form (neutral) is an interesting alternative to animal and possibly human diet enrichment. This study aimed to evaluate the SODD neutralization process varying the alkali (Na2CO3) concentration, temperature, and homogenization time. The optimal conditions for the neutralizing process, in order to obtain the greatest reduction in FFA content, the lowest leaching of tocopherols, and the greatest yield, were the following: Na2CO2 concentration of 4.34 N, temperature of 45.8°C, and homogenization time of 3 min 20 s. The FFA content was reduced from 53.4% to 6.1% after the initial neutralization, thus requiring a second neutralization step. The final FFA content was of 1.8% and total tocopherol (TT) accounted for about 11% of SODD. Cibelem Iribarrem Benites, Bruno Colling Klein, and Soely Maria Pissini Machado Reis Copyright © 2014 Cibelem Iribarrem Benites et al. All rights reserved. Catalytic Cascade Dehydration-Etherification of Fructose into 5-Ethoxymethylfurfural with SO3H-Functionalized Polymers Mon, 31 Mar 2014 07:52:28 +0000 http://www.hindawi.com/journals/ijce/2014/481627/ A series of SO3H-functionalized polymers were prepared and employed as heterogeneous catalysts for one-pot transformation of fructose into 5-ethoxymethylfurfural (EMF) that is considered to be one of potential liquid biofuels. A high EMF yield of 72.8% could be obtained at 110°C for 10 h, and the polymeric acid catalysts could be recycled for five times without significant loss of catalytic performance. Hu Li, Qiuyun Zhang, and Song Yang Copyright © 2014 Hu Li et al. All rights reserved.