International Journal of Chemical Engineering The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Corrigendum to “Heat and Mass Transfer Effect on MHD Flow of a Viscoelastic Fluid through a Porous Medium Bounded by an Oscillating Porous Plate in Slip Flow Regime” Wed, 12 Jul 2017 06:52:44 +0000 S. N. Sahoo Copyright © 2017 S. N. Sahoo. All rights reserved. Multiphase Flow and Transfer Phenomenon Sun, 09 Jul 2017 07:11:39 +0000 Wei Wang, Panagiota Angeli, Yueshe Wang, and Bin Hu Copyright © 2017 Wei Wang et al. All rights reserved. In Situ Bioremediation of Crude Petroleum Oil Polluted Soil Using Mathematical Experimentation Tue, 04 Jul 2017 10:23:44 +0000 Mathematical modelling of in situ (on site) bioremediation of crude petroleum polluted soil was investigated. An unsteady state mathematical model based on bulk flow of oil through the soil and molecular diffusion through the pores of the soil was developed. The parabolic partial differential equation developed was resolved into a system of ordinary differential equations (ODEs) by orthogonal collocation method and the necessary boundary condition was used. The resultant system of ODE was solved using fourth-order Runge-Kutta method. The simulated data gave a good agreement with experimental data. Modupe Elizabeth Ojewumi, Moses Eterigho Emetere, Damilola Elizabeth Babatunde, and Joshua Olusegun Okeniyi Copyright © 2017 Modupe Elizabeth Ojewumi et al. All rights reserved. Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle Mon, 03 Jul 2017 00:00:00 +0000 An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS) process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles. Kefeng Xiao, Weiqiang Wang, Dedong Hu, Yanpeng Qu, Zhihui Hao, and Leilei Wang Copyright © 2017 Kefeng Xiao et al. All rights reserved. A Three-Dimensional, Immersed Boundary, Finite Volume Method for the Simulation of Incompressible Heat Transfer Flows around Complex Geometries Mon, 19 Jun 2017 10:30:39 +0000 The current work focuses on the development and application of a new finite volume immersed boundary method (IBM) to simulate three-dimensional fluid flows and heat transfer around complex geometries. First, the discretization of the governing equations based on the second-order finite volume method on Cartesian, structured, staggered grid is outlined, followed by the description of modifications which have to be applied to the discretized system once a body is immersed into the grid. To validate the new approach, the heat conduction equation with a source term is solved inside a cavity with an immersed body. The approach is then tested for a natural convection flow in a square cavity with and without circular cylinder for different Rayleigh numbers. The results computed with the present approach compare very well with the benchmark solutions. As a next step in the validation procedure, the method is tested for Direct Numerical Simulation (DNS) of a turbulent flow around a surface-mounted matrix of cubes. The results computed with the present method compare very well with Laser Doppler Anemometry (LDA) measurements of the same case, showing that the method can be used for scale-resolving simulations of turbulence as well. Hassan Badreddine, Yohei Sato, Matthias Berger, and Bojan Ničeno Copyright © 2017 Hassan Badreddine et al. All rights reserved. Study on Influence of Fluid Parameters on Axial Coupled Vibration of Pipeline Conveying Multiphase Flow Mon, 12 Jun 2017 07:48:12 +0000 Taking a slurry reservoir-pipeline-valve system as research object, axial dynamic vibrations of pipe system were induced by coupled hydraulic transient due to rapid closure of valve at the end of pipe. The influences of fluid parameters in multiphase flow, including void fraction, density ratio, and elastic modulus ratio between solid phase and liquid phase, on vibration behaviors of pipe system were analyzed. Results of this study show that wave velocities of pressure and stress can be attenuated evidently when void fraction in multiphase fluid is increased appropriately; meanwhile, the amplitudes of pressure fluctuation and pipe vibration are also weakened obviously. With the increase of density ratio between solid phase and liquid phase, the vibrational intension of pipe system becomes stronger and stronger. In this instance, the increments of vibrational energy mainly concentrate in fluid, which leads the pressure energy of fluid to rise up quickly. When elastic modulus ratio between solid phase and liquid phase increases, the total elasticity of fluid decreases gradually. At the same time, both pressure energy of fluid and vibrational intension of pipe are enhanced but the increments are very slight. Ming Chen, Jimiao Duan, Dan Shu, Long Huang, and Xiaochen Chen Copyright © 2017 Ming Chen et al. All rights reserved. Prediction of a Small-Scale Pool Fire with FireFoam Thu, 01 Jun 2017 08:02:19 +0000 A computational model using Large Eddy Simulation (LES) for turbulence modelling was implemented, by means of the Eddy Dissipation Concept (EDC) combustion model using the fireFoam solver. A small methanol pool fire experiment was simulated in order to validate and compare the numerical results, hence trying to validate the effectiveness of the solver. A detailed convergence analysis is performed showing that a mesh of approximately two million elements is sufficient to achieve satisfactory numerical results (including chemical kinetics). A good agreement was achieved with some of the experimental and previous computational results, especially in the prediction of the flame height and the average temperature contours. Camilo Andrés Sedano, Omar Darío López, Alexander Ladino, and Felipe Muñoz Copyright © 2017 Camilo Andrés Sedano et al. All rights reserved. Comment on “Heat and Mass Transfer Effect on MHD Flow of a Viscoelastic Fluid through a Porous Medium Bounded by an Oscillating Porous Plate in Slip Flow Regime” Tue, 30 May 2017 09:39:59 +0000 The present comment concerns some doubtful results included in the above paper. Asterios Pantokratoras Copyright © 2017 Asterios Pantokratoras. All rights reserved. Phytoremediation of Nitrogen as Green Chemistry for Wastewater Treatment System Tue, 30 May 2017 00:00:00 +0000 It is noteworthy that ammoniacal nitrogen contamination in wastewater has reportedly posed a great threat to the environment. Although there are several conventional technologies being employed to remediate ammoniacal nitrogen contamination in wastewater, they are not sustainable and cost-effective. Along this line, the present study aims to highlight the significance of green chemistry characteristics of phytoremediation in nitrogen for wastewater treatment. Notably, ammoniacal nitrogen can be found in many types of sources and it brings harmful effects to the environment. Hence, the present study also reviews the phytoremediation of nitrogen and describes its green chemistry characteristics. Additionally, the different types of wastewater contaminants and their effects on phytoremediation and the phytoremediation consideration in wastewater treatment application and sustainable waste management of harvested aquatic macrophytes were reviewed. Finally, the present study explicates the future perspectives of phytoremediation. Based on the reviews, it can be concluded that green chemistry characteristics of phytoremediation in nitrogen have proved that it is sustainable and cost-effective in relation to other existing ammoniacal nitrogen remediation technologies. Therefore, it can be deduced that a cheaper and more environmental friendly ammoniacal nitrogen technology can be achieved with the utilization of phytoremediation in wastewater treatment. Lennevey Kinidi and Shanti Salleh Copyright © 2017 Lennevey Kinidi and Shanti Salleh. All rights reserved. Seed Oil of Morinda citrifolia L. as a Surfactant for Deinking Flotation Tue, 23 May 2017 00:00:00 +0000 Surfactants are essential in the pulp recovery process for the removal of ink on paper to be recycled. In order to create a “green” surfactant, seed oil was extracted from Morinda citrifolia L. by Soxhlet extraction for 4–8 h and its composition evaluated by gas chromatography-mass spectrometry (GC-MS). The total ion chromatogram (TIC) of fatty acids of Morinda citrifolia L. (FAMC) indicated that extraction yields the largest amount of unsaturated fatty acids (UFA), specifically C19H34O2 and C21H38O2, at 6 h. All FAMC fractions were evaluated for their suitability as a surfactant for deinking flotation. FAMC isolated after 6 h of extraction yields fatty acids that are the most suitable surfactants, as the fraction consists of mostly unsaturated fatty acids that show good interactions with the structure of common ink molecules. Our results show that the performance of the FAMC taken after 6 h of extraction approaches that of a synthetic surfactant (SS). The appropriate viscous force for deinking flotation was found to be 1.5–2.0 × 10−4 mg/mm s2 when the synthetic surfactant is used compared to 1.0–1.5 × 10−4 mg/mm s2 for FAMC. The higher intermolecular bonding strength in the synthetic surfactant-ink particle system requires higher viscous force. Trismawati Trismawati, I. N. G. Wardana, Nurkholis Hamidi, and Mega Nur Sasongko Copyright © 2017 Trismawati Trismawati et al. All rights reserved. Retracted: Oxygen Mass Transfer in an Aerated Stirred Tank with Double Impellers: A Generalized Correlation Including Spacing Impact Thu, 11 May 2017 00:00:00 +0000 International Journal of Chemical Engineering Copyright © 2017 International Journal of Chemical Engineering. All rights reserved. Investigation on the Transition Criterion of Smooth Stratified Flow to Other Flow Patterns for Gas-Hydrate Slurry Flow Tue, 02 May 2017 08:47:48 +0000 A stability criterion for gas-hydrate slurry stratified flow was developed. The model was based on one-dimensional gas-liquid two-fluid model and perturbation method, considering unstable factors including shear stress, gravity, and surface tension. In addition, mass transfer between gas and liquid phase caused by hydrate formation was taken into account by implementing an inward and outward natural gas hydrates growth shell model for water-in-oil emulsion. A series of gas-hydrate slurry flow experiments were carried out in a high-pressure (>10 MPa) horizontal flow loop. The transition criterion of smooth stratified flow to other flow patterns for gas-hydrate slurry flow was established and validated and combined with experimental data at different water cuts. Meanwhile, parameters of this stability criterion were defined. This stability criterion was proved to be efficient for predicting the transition from smooth to nonsmooth stratified flow for gas-hydrate slurry. Bohui Shi, Jiaqi Wang, Yifan Yu, Lin Ding, Yang Liu, and Haihao Wu Copyright © 2017 Bohui Shi et al. All rights reserved. Physicochemical Characterization of Representative Firewood Species Used for Cooking in Some Colombian Regions Tue, 18 Apr 2017 00:00:00 +0000 Socioeconomic conditions and the main firewood species used for cooking in three Colombian regions are studied in this work. The species collected were Cordia alliodora, Guazuma ulmifolia, Eucalyptus grandis, and Pinus patula. The used patterns of biomass and socioeconomic conditions of the selected regions were defined by means of secondary information. Firewood was physicochemically characterized and the species are compared with fossil fuels with regard to emissions of CO2, energy density, and costs. The studied regions require solutions to use firewood in eco-efficient systems, since in these rural regions people use biomass as an energy source. Studied firewood species are suitable to be gasified in fixed bed reactors due to their high volatile matter content (>80%) and low ash content (<1.8%). Pinus patula is the one with the highest fuel value index, mainly due to its low ash content (0.4%). The firewood consumption in advanced stoves has environmental advantages resulting from its low CO2 emissions: a cubic meter of Eucalyptus could replace 113 liters of kerosene or 120 m3 of natural gas for cooking applications. Hernán E. Díez and Juan F. Pérez Copyright © 2017 Hernán E. Díez and Juan F. Pérez. All rights reserved. Effect of Surfactants on Gas Holdup in Shear-Thinning Fluids Sun, 16 Apr 2017 09:37:30 +0000 In this study, the gas holdup of bubble swarms in shear-thinning fluids was experimentally studied at superficial gas velocities ranging from 0.001 to 0.02 m·s−1. Carboxylmethyl cellulose (CMC) solutions of 0.2 wt%, 0.6 wt%, and 1.0 wt% with sodium dodecyl sulfate (SDS) as the surfactant were used as the power-law (liquid phase), and nitrogen was used as the gas phase. Effects of SDS concentration, rheological behavior, and physical properties of the liquid phase and superficial gas velocity on gas holdup were investigated. Results indicated that gas holdup increases with increasing superficial gas velocity and decreasing CMC concentration. Moreover, the addition of SDS in CMC solutions increased gas holdup, and the degree increased with the surfactant concentration. An empirical correlation was proposed for evaluating gas holdup as a function of liquid surface tension, density, effective viscosity, rheological property, superficial gas velocity, and geometric characteristics of bubble columns using the experimental data obtained for the different superficial gas velocities and CMC solution concentrations with different surfactant solutions. These proposed correlations reasonably fitted the experimental data obtained for gas holdup in this system. Shaobai Li, Siyuan Huang, and Jungeng Fan Copyright © 2017 Shaobai Li et al. All rights reserved. Investigations of a Gas Turbine Low-Emission Combustor Operating on the Synthesis Gas Wed, 05 Apr 2017 08:48:37 +0000 Investigations of the working processes in a gas turbine low-emission combustor operating on the synthesis gas, in which the principle of RQL (Rich-Burn, Quick-Mix, and Lean-Burn) combustion technology is realized, have been performed. Selected concept of a gas turbine combustor can provide higher performance and lower emission of nitrogen oxides and demonstrates satisfactory major key parameters. Obtained results and recommendations can be used for the gas turbine combustor operation modes modeling, geometry optimization, and prospective power generation units design and engineering. Serhiy Serbin and Nataliia Goncharova Copyright © 2017 Serhiy Serbin and Nataliia Goncharova. All rights reserved. Study on Carbonyl Emissions of Diesel Engine Fueled with Biodiesel Mon, 20 Mar 2017 00:00:00 +0000 Biodiesel is a kind of high-quality alternative fuel of diesel engine. In this study, biodiesel and biodiesel/diesel blend were used in a single cylinder diesel engine to study the carbonyl emissions. The result shows that carbonyl pollutants of biodiesel and biodiesel/diesel blend are mainly aldehyde and ketone compounds with 1–3 carbon atoms, and formaldehyde concentration is higher than 80% of the total carbonyl pollutants for biodiesel. The formaldehyde concentration peak is reduced with the increase of intake temperature (), intake pressure (), and exhaust gas recirculation (EGR) ratio and increased with the increase of compression ratio (). When excess air coefficient () is lower than 1.7, the formaldehyde concentration is increased with the increase of excess air ratio. When is higher than 1.7, the formaldehyde concentration is reduced with the increase of excess air ratio. The dilution of air can reduce formaldehyde concentration in the premixed flame of diesel effectively; however, it has less effect on biodiesel. Among the fuel pretreatment measures of adding hydrogen, CO, and methane, the addition of hydrogen shows the best effect on reducing formaldehyde of biodiesel. Ruina Li, Zhong Wang, and Guangju Xu Copyright © 2017 Ruina Li et al. All rights reserved. Removal of Reactive Anionic Dyes from Binary Solutions by Adsorption onto Quaternized Kenaf Core Fiber Wed, 08 Mar 2017 00:00:00 +0000 The most challenging mission in wastewater treatment plants is the removal of anionic dyes, because they are water-soluble and produce very shining colours in the water. In this regard, kenaf core fiber (KCF) was chemically modified by the quaternized agent (3-chloro-2-hydroxypropyl)trimethylammonium chloride to increase surface area and change the surface properties in order to improve the removing reactive anionic dyes from binary aqueous solution. The influencing operating factors like dye concentration, pH, adsorbent dosage, and contact time were examined in a batch mode. The results indicate that the percentage of removal of Reactive Red-RB (RR-RB) and Reactive Black-5 (RB-5) dyes from binary solution was increased with increasing dyes concentrations and the maximum percentage of removal reached up to 98.4% and 99.9% for RR-RB and RB-5, respectively. Studies on effect of pH showed that the adsorption was not significantly influenced by pH. The equilibrium analyses explain that, in spite of the extended Langmuir model failure to describe the data in the binary system, it is better than the Jain and Snoeyink model in describing the adsorption behavior of binary dyes onto QKCF. Also, the pseudo-second-order model was better to represent the adsorption kinetics for RR-RB and RB-5 dyes on QKCF. Intidhar Jabir Idan, Siti Nurul Ain Binti Md. Jamil, Luqman Chuah Abdullah, and Thomas Shean Yaw Choong Copyright © 2017 Intidhar Jabir Idan et al. All rights reserved. Mesoporous (Ta, Nb)3W7 Modified with Stearic Acid Used as Solid Acids for Esterification Tue, 07 Mar 2017 08:40:02 +0000 Mesoporous solid acids Ta3W7 and Nb3W7 were prepared from TaCl5 and NbCl5 with WCl6 in the presence of stearic acid (SA) via a sol-gel method, respectively. For comparison, mesoporous Ta3W7-P123 mixed oxides and mesoporous Nb3W7-P123 mixed oxides were synthesized in the same way. The catalysts were characterized through TGA, XRD, SEM, TEM, BET, and NH3-TPD. Experimental results showed that Ta3W7-SA and Nb3W7-SA exhibited several advantages such as higher activity, shorter preparation period, lower cost, stronger acid sites, and higher surface area, which had potential to be used as mesoporous heterogeneous catalysts in biodiesel production. Fei Chang, Rui Wang, Quan Zhou, Hu Pan, and Heng Zhang Copyright © 2017 Fei Chang et al. All rights reserved. Enhancement of Methane Concentration by Removing Contaminants from Biogas Mixtures Using Combined Method of Absorption and Adsorption Mon, 06 Mar 2017 06:39:34 +0000 We report a laboratory scale combined absorption and adsorption chemical process to remove contaminants from anaerobically produced biogas using cafeteria (food), vegetable, fruit, and cattle manure wastes. Iron oxide (Fe2O3), zero valent iron (), and iron chloride (FeCl2) react with hydrogen sulfide (H2S) to deposit colloidal sulfur. Silica gel, sodium sulfate (Na2SO4), and calcium oxide (CaO) reduce the water vapour (H2O) and carbon dioxide (CO2). It is possible to upgrade methane (CH4) above 95% in biogas using chemical or physical absorption or adsorption process. The removal efficiency of CO2, H2S, and H2O depends on the mass of removing agent and system pH. The results showed that Ca(OH)2 solutions are capable of reducing CO2 below 6%. The H2S concentration was reduced to 89%, 90%, 86%, 85%, and 96% for treating with 10 g of FeCl2, (with pH), Fe2O3, , and activated carbon, respectively. The H2O concentration was reduced to 0.2%, 0.7%, 0.2%, 0.2%, and 0.3% for treating raw biogas with 10 g of silica gel and Na2SO4 for runs R1, R2, R3, R4, and R5, respectively. Thus, given the successful contaminant elimination, the combined absorption and adsorption process is a feasible system for biogas purification. Muhammad Rashed Al Mamun and Shuichi Torii Copyright © 2017 Muhammad Rashed Al Mamun and Shuichi Torii. All rights reserved. Modelling the Evaporation Rate in an Impingement Jet Dryer with Multiple Nozzles Thu, 02 Mar 2017 00:00:00 +0000 Impinging jets are often used in industry to dry, cool, or heat items. In this work, a two-dimensional Computational Fluid Dynamics model is created to model an impingement jet dryer with a total of 9 pairs of nozzles that dries sheets of metal. Different methods to model the evaporation rate are studied, as well as the influence of recirculating the outlet air. For the studied conditions, the simulations show that the difference in evaporation rate between single- and two-component treatment of moist air is only around 5%, hence indicating that drying can be predicted with a simplified model where vapor is included as a nonreacting scalar. Furthermore, the humidity of the inlet air, as determined from the degree of recirculating outlet air, has a strong effect on the water evaporation rate. Results show that the metal sheet is dry at the exit if 85% of the air is recirculated, while approximately only 60% of the water has evaporated at a recirculation of 92,5%. Anna-Lena Ljung, L. Robin Andersson, Anders G. Andersson, T. Staffan Lundström, and Mats Eriksson Copyright © 2017 Anna-Lena Ljung et al. All rights reserved. Coalbed Methane Production System Simulation and Deliverability Forecasting: Coupled Surface Network/Wellbore/Reservoir Calculation Tue, 31 Jan 2017 06:07:50 +0000 As an unconventional energy, coalbed methane (CBM) mainly exists in coal bed with adsorption, whose productivity is different from conventional gas reservoir. This paper explains the wellbore pressure drop, surface pipeline network simulation, and reservoir calculation model of CBM. A coupled surface/wellbore/reservoir calculation architecture was presented, to coordinate the gas production in each calculation period until the balance of surface/wellbore/reservoir. This coupled calculation method was applied to a CBM field for predicting production. The daily gas production increased year by year at the first time and then decreased gradually after several years, while the daily water production was reduced all the time with the successive decline of the formation pressure. The production of gas and water in each well is almost the same when the structure is a star. When system structure is a dendritic surface system, the daily gas production ranked highest at the well which is the nearest to the surface system collection point and lowest at the well which is the farthest to the surface system collection point. This coupled calculation method could be used to predict the water production, gas production, and formation pressure of a CBM field during a period of time. Jun Zhou, Guangchuan Liang, Tao Deng, Shiwei Zhou, and Jing Gong Copyright © 2017 Jun Zhou et al. All rights reserved. Systematic Prioritization of Sensor Improvements in an Industrial Gas Supply Network Tue, 31 Jan 2017 00:00:00 +0000 The paper analyzes the impact of the sensor reading errors on parameters that affect the production costs of a leading US industrial gas supply company. For this purpose, a systematic methodology is applied first to determine the relationship between the system output and input parameters and second to identify the assigned input sensors whose readings need to be improved in a prioritized manner based on the strength of those input-output relationships. The two main criteria used to prioritize these sensors are the decrease in production costs and the decrease in production costs’ volatility obtained when the selected sensor’s precision is improved. To illustrate the effectiveness of the proposed approach, we first apply it to a simplified version of the real supply network model where the results can be readily validated with the simulated data. Next, we apply and test the proposed approach in the real supply network model with historical data. Onur Babat, Ali Esmaili, Joshua D. Isom, Camilo Mancilla, and Luis F. Zuluaga Copyright © 2017 Onur Babat et al. All rights reserved. Route Optimization of Pipeline in Gas-Liquid Two-Phase Flow Based on Genetic Algorithm Thu, 19 Jan 2017 09:18:11 +0000 This paper describes the problems in route optimization of two-phase pipelines. Combining the hydraulic calculation with route optimization theory, this paper establishes an automatic route optimization model and adopts the general genetic algorithm (gGA) and steady-state genetic algorithm (ssGA) to solve the model, respectively, gets the optimal route, and discusses the influence of parameters setting to the result. This algorithm was applied in determining pipelines routes in coalbed methane gathering and transporting system in Shanxi Province, China. The result shows that the algorithm is feasible, which improves the hydraulic properties by reducing the pressure drop along the line while the pipeline length is still acceptable. Jun Zhou, Guangchuan Liang, Tao Deng, and Jing Gong Copyright © 2017 Jun Zhou et al. All rights reserved. Optimal Design of a Solar Desalination Unit with Heliostats Mon, 16 Jan 2017 09:36:10 +0000 The objective is to improve the yield of a solar desalination cell using concentration of solar rays by means of automatically controlled heliostats. The vertical cell is orientated towards the north. It is mainly composed of two plates; the one being heated by the solar rays reflected by the mirrors is used for evaporation of a falling water film; the other one is used for water vapor condensation. Each heliostat consists of an altitude-azimuth mount having two degrees of freedom and supporting a plane mirror. The heliostat permanently follows the sun trajectory and reflects the solar rays on the cell by means of automatic control implemented in a control card based on a microcontroller. Model predictive control allows us to maximize the distilled water production. M. Abidi, S. Ben Jabrallah, and J. P. Corriou Copyright © 2017 M. Abidi et al. All rights reserved. Effects of Thermal Radiation on Mixed Convection Flow of a Micropolar Fluid from an Unsteady Stretching Surface with Viscous Dissipation and Heat Generation/Absorption Thu, 01 Dec 2016 07:25:16 +0000 A numerical model is developed to examine the effects of thermal radiation on unsteady mixed convection flow of a viscous dissipating incompressible micropolar fluid adjacent to a heated vertical stretching surface in the presence of the buoyancy force and heat generation/absorption. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The model contains nonlinear coupled partial differential equations which have been converted into ordinary differential equation by using the similarity transformations. The dimensionless governing equations for this investigation are solved by Runge-Kutta-Fehlberg fourth fifth-order method with shooting technique. Numerical solutions are then obtained and investigated in detail for different interesting parameters such as the local skin-friction coefficient, wall couple stress, and Nusselt number as well as other parametric values such as the velocity, angular velocity, and temperature. Khilap Singh and Manoj Kumar Copyright © 2016 Khilap Singh and Manoj Kumar. All rights reserved. Numerical Simulation on Structure Optimization of Liquid-Gas Cylindrical Cyclone Separator Wed, 30 Nov 2016 12:54:35 +0000 With the further development of oilfield, liquid-gas separation has become an essential problem. Cylindrical cyclone separators are popular in the industrial process due to the advantage that they are simple, compact, and inexpensive to manufacture. In this paper, a three-dimensional turbulence model including Reynolds stress model was established to describe the mixture flow field in the separator. Through the numerical simulation, the separation efficiency was investigated under different parameter cases such as separator length, gas phase outlet diameter, and inlet shape. It can be indicated from the simulation results that the separation efficiency decreases with the increase of the separator length, and the separation efficiency increases firstly and then decreases with the increase of the gas phase outlet diameter as well as the liquid phase outlet. Furthermore, the rectangular inlet is more suitable than the circular inlet with the separation efficiency changing from 66.45% to 79.04%. In the end, the optimal geometrical structure was presented with separation efficiency of 86.15%. Peng Chang, Tian Hu, Li Wang, Sen Chang, Tianjing Wang, and Yueshe Wang Copyright © 2016 Peng Chang et al. All rights reserved. Biosorption and Diffusion Modeling of Pb(II) by Malt Bagasse Tue, 22 Nov 2016 13:48:13 +0000 The removal of Pb(II) from water by biosorption processes onto malt bagasse was investigated and the kinetic and thermodynamic parameters were obtained; additionally a diffusion modeling was proposed. The characterization of malt bagasse was performed by FTIR and SEM/EDS. The experiments were conducted in batch system and an experimental design based response surface methodology was applied for agitation speed and pH optimization. The kinetics of biosorption followed pseudo-second-order model and the temperature of the process affected the biosorption capacity. Isotherm models of Langmuir, Freundlich, and Elovich were applied and the Langmuir model showed better fit and the estimated biosorption capacity was 29.1 mg g−1. The negative values obtained for and positive values of confirm, respectively, the spontaneous and endothermic nature of the process. The diffusion modeling was performed based on experiments in the absence of agitation to investigate the influence of the biosorbent on the sorption process of Pb(II) ions. Klaiani B. Fontana, Giane Gonçalves Lenzi, Erica R. L. R. Watanabe, Ervin Kaminski Lenzi, Juliana A. M. T. Pietrobelli, and Eduardo S. Chaves Copyright © 2016 Klaiani B. Fontana et al. All rights reserved. Comparison of the Accuracy and Performance of Different Numbers of Classes in Discretised Solution Method for Population Balance Model Tue, 22 Nov 2016 12:00:42 +0000 One way of solving population balance model (PBM) in a time efficient way is by means of discretisation of the population property of interest. A computational grid, for example, ( is the volume of particle in class ), could be used to classify the particles in discretisation techniques. However, there are still disagreements in the appropriate number of classes divided by the grids. In this study, the different numbers of classes for solving PBM were compared in terms of accuracy and performance to describe the particle size distribution (PSD) from the flocculation of activated sludge. It is found that the simulated PSDs are similar to the experimental data for all the geometric grids , and there is no obvious difference among the values of calibrated parameter, ratio of breakage rate coefficient and collision efficiency, for each velocity gradient. However, the simulation results with less error could be obtained with larger number of classes, and more computational times, which show exponential relationship with the number of classes, are needed. Considering numerical accuracy and efficiency, the classes 35 or a geometric grid with factor 1.6, aligning with the Fibonacci sequence , is recommended for the particles in the size range of 5.5~1086 μm. Zhenliang Li, Zhien Zhou, Sheng Zhang, and Hongqiang Jiang Copyright © 2016 Zhenliang Li et al. All rights reserved. Batch and Continuous Flow Adsorption of Phenolic Compounds from Olive Mill Wastewater: A Comparison between Nonionic and Ion Exchange Resins Tue, 23 Aug 2016 17:04:17 +0000 The goals of this work were (i) to compare two anion ion exchange resins (IRA958 Cl and IRA67) and a nonionic resin (XAD16) in terms of phenolic compounds adsorption capacity from olive mill wastewater and (ii) to compare the adsorption capacity of the best resin on columns of different length. The ion exchange resins performed worse than nonionic XAD16 in terms of resin utilization efficiency (20% versus 43%) and phenolic compounds/COD enrichment factor (1.0 versus 2.5). The addition of volatile fatty acids did not hinder phenolic compounds adsorption on either resin, suggesting a noncompetitive adsorption mechanism. A pH increase from 4.9 to 7.2 did not affect the result of this comparison. For the best performing resin (XAD16), an increase in column length from 0.5 to 1.8 m determined an increase in resin utilization efficiency (from 12% to 43%), resin productivity (from 3.4 to 7.6 ), and phenolics/COD enrichment factor (from 1.2 to 2.5). An axial dispersion model with nonequilibrium adsorption accurately interpreted the phenolic compounds and COD experimental curves. Davide Pinelli, Aurora Esther Molina Bacca, Ankita Kaushik, Subhankar Basu, Massimo Nocentini, Lorenzo Bertin, and Dario Frascari Copyright © 2016 Davide Pinelli et al. All rights reserved. Parametric Analysis of a High Temperature PEM Fuel Cell Based Microcogeneration System Thu, 23 Jun 2016 10:53:05 +0000 This study focuses on performance analysis of a 1  microcogeneration system based on a high temperature proton exchange membrane (HT-PEM) fuel cell by means of parametric investigation. A mathematical model for a system consisting of a fuel processor (steam reforming reactor and water-gas shift reactor), a HT-PEM fuel cell stack, and the balance-of-plant components was developed. Firstly, the fuel processor performance at different fuel ratios and equivalence ratio was examined. It is shown that high fuel ratios of 0.9–0.95 and equivalence ratios of less than 0.56 are suitable for acceptable carbon monoxide content in the synthetic gas produced. Secondly, a parametric study of the system performance at different fuel and equivalence ratios using key system operating parameters was conducted. Steam-to-carbon ratio, stack operating temperature, and anode stoichiometry were varied to observe the changes in the microcogeneration system. The analysis shows that the system can reach electrical and cogeneration efficiencies of 30% and 84%, respectively. Myalelo Nomnqa, Daniel Ikhu-Omoregbe, and Ademola Rabiu Copyright © 2016 Myalelo Nomnqa et al. All rights reserved.