International Journal of Chemical Engineering The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Exergy and Exergoenvironmental Analysis of a CCHP System Based on a Parallel Flow Double-Effect Absorption Chiller Wed, 25 May 2016 09:22:02 +0000 A combined cooling, heating, and power (CCHP) system which produces electricity, heating, and cooling is modeled and analyzed. This system is comprised of a gas turbine, a heat recovery steam generator, and a double-effect absorption chiller. Exergy analysis is conducted to address the magnitude and the location of irreversibilities. In order to enhance understanding, a comprehensive parametric study is performed to see the effect of some major design parameters on the system performance. These design parameters are compressor pressure ratio, gas turbine inlet temperature, gas turbine isentropic efficiency, compressor isentropic efficiency, and temperature of absorption chiller generator inlet. The results show that exergy efficiency of the CCHP system is higher than the power generation system and the cogeneration system. In addition, the results indicate that when waste heat is utilized in the heat recovery steam generator, the greenhouse gasses are reduced when the fixed power output is generated. According to the parametric study results, an increase in compressor pressure ratio shows that the network output first increases and then decreases. Furthermore, an increase in gas turbine inlet temperature increases the system exergy efficiency, decreasing the total exergy destruction rate consequently. Ali Mousafarash Copyright © 2016 Ali Mousafarash. All rights reserved. Exergy and Environmental Impact Assessment between Solar Powered Gas Turbine and Conventional Gas Turbine Power Plant Mon, 23 May 2016 11:50:04 +0000 Recuperator is a heat exchanger that is used in gas turbine power plants to recover energy from outlet hot gases to heat up the air entering the combustion chamber. Similarly, the combustion chamber inlet air can be heated up to temperatures up to 1000 (°C) by solar power tower (SPT) as a renewable and environmentally benign energy source. In this study, comprehensive comparison between these two systems in terms of energy, exergy, and environmental impacts is carried out. Thermodynamic simulation of both cycles is conducted using a developed program in MATLAB environment. Exergetic performances of both cycles and their emissions are compared and parametric study is carried out. A new parameter (renewable factor) is proposed to evaluate resources quality and measure how green an exergy loss or destruction or a system as a whole is. Nonrenewable exergy destruction and loss are reduced compared to GT with recuperator cycle by 34.89% and 47.41%, respectively. Reductions in CO2, , and CO compared to GT with recuperator cycle by 49.92%, 66.14%, and 39.77%, respectively, are in line with renewable factor value of around 55.7 which proves the ability of the proposed green measure to evaluate and compare the cycles performances. Ali Rajaei, Hasan Barzegar Avval, and Elmira Eslami Copyright © 2016 Ali Rajaei et al. All rights reserved. An Improved Empirical Fuel Cell Polarization Curve Model Based on Review Analysis Mon, 16 May 2016 14:19:16 +0000 Based on a review analysis of empirical fuel cell polarization curve models in the literature, an improved model that can predict fuel cell performance with only measured current-voltage data is developed. The fitting characteristics of this new model are validated by fitting bench test data and road test data. In the case of bench test data, a comparison of the new model and two representative models is conducted, and the results show that the new model presents the best fitting effects over a whole range of current densities. Moreover, the fitted ohmic resistances derived from the new model show good agreement with the measured values obtained through a current interruption test. In the case of using road test data, the new model also presents excellent fitting characteristics and convenience for application. It is the author’s belief that the new model is beneficial for the application-oriented research of fuel cells due to its prominent features, such as conciseness, flexibility, and high accuracy. Dong Hao, Jianping Shen, Yongping Hou, Yi Zhou, and Hong Wang Copyright © 2016 Dong Hao et al. All rights reserved. Performance Assessment of a Hybrid Solar-Geothermal Air Conditioning System for Residential Application: Energy, Exergy, and Sustainability Analysis Thu, 12 May 2016 13:07:03 +0000 This paper investigates the performance of a ground source heat pump that is coupled with a photovoltaic system to provide cooling and heating demands of a zero-energy residential building. Exergy and sustainability analyses have been conducted to evaluate the exergy destruction rate and SI of different compartments of the hybrid system. The effects of monthly thermal load variations on the performance of the hybrid system are investigated. The hybrid system consists of a vertical ground source heat exchanger, rooftop photovoltaic panels, and a heat pump cycle. Exergetic efficiency of the solar-geothermal heat pump system does not exceed 10 percent, and most exergy destruction takes place in photovoltaic panel, condenser, and evaporator. Although SI of PV system remains constant during a year, SI of GSHP varies depending on cooling and heating mode. The results also show that utilization of this hybrid system can reduce CO2 emissions by almost 70 tons per year. Yasser Abbasi, Ehsan Baniasadi, and Hossein Ahmadikia Copyright © 2016 Yasser Abbasi et al. All rights reserved. Synthesis, Spectral Characterization, and Antibacterial and Antifungal Studies of PANI/V2O5 Nanocomposites Sat, 30 Apr 2016 13:45:43 +0000 The present study deals with the synthesis and characterization of nanocrystalline vanadium pentoxide (V2O5) nanoparticles and their antibacterial and antifungal activity on Staphylococcus aureus and Aspergillus niger, respectively, by agar diffusion method. The metal oxide has been synthesized by employing the sol-gel method, polyaniline (PANI) has been synthesized by chemical oxidation, and PANI/V2O5 composites have been synthesized by in situ polymerization method with different ratios (10, 20, 30, 40, and 50 weight%) of V2O5 in PANI. The newly prepared composites were characterized by FTIR and powder X-ray diffraction (P-XRD) techniques and are found to be formed of PANI/V2O5 nanocomposites, and also the compounds showed moderate antibacterial and antifungal activity. Chakradhar Sridhar B, Nagesh Gunvanthrao Yernale, and M. V. N. Ambika Prasad Copyright © 2016 Chakradhar Sridhar B et al. All rights reserved. Biodiesel Production by Reactive Flash: A Numerical Simulation Thu, 28 Apr 2016 09:17:10 +0000 Reactive flash (RF) in biodiesel production has been studied in order to investigate steady-state multiplicities, singularities, and effect of biodiesel quality when the RF system approaches to bubble point. The RF was modeled by an index-2 system of differential algebraic equations, the vapor split () was computed by modified Rachford-Rice equation and modified Raoult’s law computed bubble point, and the continuation analysis was tracked on MATCONT. Results of this study show the existence of turning points, leading to a unique bubble point manifold, , which is a globally stable flashing operation. Also, the results of the simulation in MATLAB® of the dynamic behavior of the RF show that conversion of triglycerides reaches 97% for a residence time of 5.8 minutes and a methanol to triglyceride molar flow ratio of 5 : 1. Alejandro Regalado-Méndez, Sigurd Skogestad, Reyna Natividad, and Rubí Romero Copyright © 2016 Alejandro Regalado-Méndez et al. All rights reserved. Natural Polymer of Iraqi Apricot Tree Gum as a Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution Sun, 24 Apr 2016 15:35:07 +0000 Corrosion inhibition of mild steel in 1 M hydrochloric acid using Iraqi apricot tree gum Arabic as natural polymer was studied. The weight loss method was used to predict the efficiency of the inhibitor on corrosion of mild steel in a temperature range of 17–40°C. The FTIR result of natural polymer revealed that the C=O and O-H groups were found in the structure of the natural polymer. The results of weight loss method showed that the inhibition efficiency (%) increased with the increase in both the natural polymer concentration and the temperature; therefore, chemical adsorption mechanism was suggested in this system. The different mathematical models of the adsorption isotherms were studied and the results revealed that natural polymer was found to obey Temkin, Langmuir, and Freundlich adsorption isotherm. The activation energy of adsorption, enthalpy of adsorption, and entropy of adsorption were obtained for different concentrations of natural polymer (0, 0.1, 0.2, and 0.3 g/L) and the results showed that the thermodynamic properties decreased with the loading of a natural polymer. Gibbs free energy of adsorption results was a minus value that led to the conclusion of the spontaneous adsorption of the natural polymer in this system. I. M. Alwaan and Fouad Kadhim Mahdi Copyright © 2016 I. M. Alwaan and Fouad Kadhim Mahdi. All rights reserved. Simultaneous Recovery of Hydrogen and Chlorine from Industrial Waste Dilute Hydrochloric Acid Wed, 20 Apr 2016 08:45:52 +0000 Recovery of chlorine from byproduct HCl has inevitable commercial importance in industries lately because of insufficient purity or too low concentration to recycle it. Instead it is being neutralized in industries before disposing to meet stringent environmental conditions. Although recovery through catalytic oxidation processes is studied since the 19th century, their high operating conditions combined with sluggish reaction kinetics and low single pass conversions make electrolysis a better alternative. The present motive of this work is to develop a novel electrolysis process which in contrast to traditional processes effectively recovers both hydrogen and chlorine from dilute HCl. For this, an electrolytic cell with an Anionic Exchange Membrane has been designed which only allows the passage of chlorine anions from catholyte to anolyte separating the gasses in a single step. The catholyte can be as low as 3.59 wt% because of fixed anolyte concentration of 1.99 wt% which minimizes oxygen formation. Preliminary results show that the simultaneous recovery of hydrogen and chlorine is possible with high conversion up to 98%. The maximum current density value for 4.96 cm2 membrane surface area (70% active surface area) is 2.54 kAm−2, which is comparable with reported commercial processes. This study is expected to be useful for process intensification of the same in a continuous process environment. N. Paidimarri, U. Virendra, and S. Vedantam Copyright © 2016 N. Paidimarri et al. All rights reserved. Microwave-Assisted Method for Simultaneous Hydrolysis and Extraction for Preparation of Geniposidic Acid from Eucommia ulmoides Bark Using Basic Imidazolide Ionic Liquid Mon, 18 Apr 2016 10:56:41 +0000 In order to hydrolyze geniposide and extract geniposidic acid, a novel microwave irradiation heating method for simultaneous hydrolysis and extraction for preparation of geniposidic acid from Eucommia ulmoides bark using basic imidazolide ionic liquid was developed in this work. Basic ionic liquid paired by imidazolide anion and 1-hexyl-3-methylimidazolium cation ([C6mim]Im) was used as a dual hydrolysis catalyst and extraction solvent in the proposed approach. The optimal concentration of [C6mim]Im was 0.4 mol/L. And the independent parameters optimized by Box-Behnken design (BBD) based on single-factor tests were as follows: microwave irradiation time of 20 min at power of 415 W and liquid-solid ratio of 15 mL/g. Yield of geniposidic acid was increased to  μmol/g. DM130 macroporous resin, after reaction, was selected to separate geniposidic acid from hydrolysate. The plant materials with different treatment were analyzed by scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The analysis of SEM and TG further indicated that IMSHE is an efficient preparation method for geniposidic acid. It is reasonable to assume that the method and the dual hydrolysis catalyst and extraction solvent would offer an alternative for the preparation of some other kinds of bioactive substances from plant materials. Lili Li, Yupin Guo, Chunchao Zhao, Mengxia Wei, Junling Liu, Yuangang Zu, Fei Wang, and Lei Yang Copyright © 2016 Lili Li et al. All rights reserved. Microbubble Distillation for Ethanol-Water Separation Wed, 13 Apr 2016 09:32:26 +0000 In the current study, a novel approach for separating ethanol-water mixture by microbubble distillation technology was investigated. Traditional distillation processes require large amounts of energy to raise the liquid to its boiling point to effect removal of volatile components. The concept of microbubble distillation by comparison is to heat the gas phase rather than the liquid phase to achieve separation. The removal of ethanol from the thermally sensitive fermentation broths was taken as a case of study. Consequently the results were then compared with those which could be obtained under equilibrium conditions expected in an “ideal” distillation unit. Microbubble distillation has achieved vapour compositions higher than that which could be obtained under traditional equilibrium conditions. The separation was achieved at liquid temperature significantly less than the boiling point of the mixture. In addition, it was observed that the separation efficiency of the microbubble distillation could be increased by raising the injected air temperature, while the temperature of the liquid mixture increased only moderately. The separation efficiency of microbubble distillation was compared with that of pervaporation for the recovery of bioethanol from the thermally sensitive fermentation broths. The technology could be controlled to give high separation and energy efficiency. This could contribute to improving commercial viability of biofuel production and other coproducts of biorefinery processing. Atheer Al-yaqoobi, David Hogg, and William B. Zimmerman Copyright © 2016 Atheer Al-yaqoobi et al. All rights reserved. Exact Optimum Design of Segmented Thermoelectric Generators Mon, 11 Apr 2016 15:20:01 +0000 A considerable difference between experimental and theoretical results has been observed in the studies of segmented thermoelectric generators (STEGs). Because of simplicity, the approximate methods are widely used for design and optimization of the STEGs. This study is focused on employment of exact method for design and optimization of STEGs and comparison of exact and approximate results. Thus, using new highly efficient thermoelectric materials, four STEGs are proposed to operate in the temperature range of 300 to 1300 kelvins. The proposed STEGs are optimally designed to achieve maximum efficiency. Design and performance characteristics of the optimized generators including maximum conversion efficiency and length of elements are calculated through both exact and approximate methods. The comparison indicates that the approximate method can cause a difference up to 20% in calculation of some design characteristics despite its appropriate results in efficiency calculation. The results also show that the maximum theoretical efficiency of 23.08% is achievable using the new proposed STEGs. Compatibility factor of the selected materials for the proposed STEGs is also calculated using both exact and approximate methods. The comparison indicates a negligible difference in calculation of compatibility factor, despite the considerable difference in calculation of reduced efficiency (temperature independence efficiency). M. Zare, H. Ramin, S. Naemi, and R. Hosseini Copyright © 2016 M. Zare et al. All rights reserved. Magneto Binary Nanofluid Convection in Porous Medium Sun, 10 Apr 2016 07:02:06 +0000 The effect of an externally impressed magnetic field on the stability of a binary nanofluid layer in porous medium is considered in this work. The conservation equations related to the system are solved using normal mode technique and Galerkin method to analyze the problem. The complex expressions are approximated to get useful results. Mode of heat transfer is stationary for top heavy distribution of nanoparticles in the fluid layer and top heavy nanofluids are very less stable than regular fluids. Oscillatory motions are possible for bottom heavy distribution of nanoparticles and they are not much influenced by properties of different nanoparticles. A comparative analysis of the instability of water based nanofluids with metallic (Cu, Ag) and semiconducting (TiO2, SiO2) nanoparticles under the influence of magnetic field is examined. Semiconducting nanofluids are found to be more stable than metallic nanofluids. Porosity destabilizes the layer while solute difference (at the boundaries of the layer) stabilizes it. Magnetic field stabilizes the fluid layer system significantly. Jyoti Sharma, Urvashi Gupta, and R. K. Wanchoo Copyright © 2016 Jyoti Sharma et al. All rights reserved. Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields Thu, 07 Apr 2016 07:47:00 +0000 The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application. Ye Peng, Tao Liu, Haifeng Gong, and Xianming Zhang Copyright © 2016 Ye Peng et al. All rights reserved. Nine-Lump Kinetic Study of Catalytic Pyrolysis of Gas Oils Derived from Canadian Synthetic Crude Oil Sun, 27 Mar 2016 11:51:17 +0000 Catalytic pyrolysis of gas oils derived from Canadian synthetic crude oil on a kind of zeolite catalyst was conducted in a confined fluidized bed reactor for the production of light olefins. The overall reactants and products were classified into nine species, and a nine-lump kinetic model was proposed to describe the reactions based on appropriate assumptions. This kinetic model had 24 rate constants and a catalyst deactivation constant. The kinetic constants at 620°C, 640°C, 660°C, and 680°C were estimated by means of nonlinear least-square regression method. Preexponential factors and apparent activation energies were then calculated according to the Arrhenius equation. The apparent activation energies of the three feed lumps were lower than those of the intermediate product lumps. The nine-lump kinetic model showed good calculation precision and the calculated yields were close to the experimental ones. Rui Zhang, Li Li, Zhichang Liu, and Xianghai Meng Copyright © 2016 Rui Zhang et al. All rights reserved. Formulation of the Settling Velocity of Small Particles Initially Situated inside an Inclined Vortex Sun, 20 Mar 2016 13:36:10 +0000 Both the estimation of the time that small heavy particles remain inside a 3D vortex and the estimation of the average settling velocity of those particles are some important features in many practical situations. Previous works focused on the case of a horizontal 2D vortex. In this paper, we simulate the dynamics of heavy particles initially situated inside a three-dimensional vortex obtaining a formula for their average settling velocity. In a previous paper we obtained the trajectories of the particles and a formula that provides the time that they need to escape, . This work simulates and analyses the escape process, and its main result is the obtaining, from numerical simulation, of a theoretical formulation of the average settling velocity and its relationship with the elapsed time. We prove that the permanence time is of the order of (with particle diameter) and that the average settling velocity is of the order of for sufficiently small particles. Some applications of the settling velocity formula developed in this work would be the design of mixture devices, the design of particle separation devices, and the prediction of the settling of pollutant particles, seeds, and pollen. Urbano Sánchez Copyright © 2016 Urbano Sánchez. All rights reserved. Promotion Effect of CaO Modification on Mesoporous Al2O3-Supported Ni Catalysts for CO2 Methanation Thu, 17 Mar 2016 12:46:19 +0000 The catalysts Ni/Al2O3 and CaO modified Ni/Al2O3 were prepared by impregnation method and applied for methanation of CO2. The catalysts were characterized by N2 adsorption/desorption, temperature-programmed reduction of H2 (H2-TPR), X-ray diffraction (XRD), and temperature-programmed desorption of CO2 and H2 (CO2-TPD and H2-TPD) techniques, respectively. TPR and XRD results indicated that CaO can effectively restrain the growth of NiO nanoparticles, improve the dispersion of NiO, and weaken the interaction between NiO and Al2O3. CO2-TPD and H2-TPD results suggested that CaO can change the environment surrounding of CO2 and H2 adsorption and thus the reactants on the Ni atoms can be activated more easily. The modified Ni/Al2O3 showed better catalytic activity than pure Ni/Al2O3. Ni/CaO-Al2O3 showed high CO2 conversion especially at low temperatures compared to Ni/Al2O3, and the selectivity to CH4 was very close to 1. The high CO2 conversion over Ni/CaO-Al2O3 was mainly caused by the surface coverage by CO2-derived species on CaO-Al2O3 surface. Wen Yang, Yanyan Feng, and Wei Chu Copyright © 2016 Wen Yang et al. All rights reserved. Influence of Sodium Bisulfite and Lithium Bromide Solutions on the Shape Fixation of Camel Guard Hairs in Slenderization Process Tue, 15 Mar 2016 09:46:11 +0000 Outstanding performance of natural camel hair has attracted much attention on the effective use of such specialty fiber to apparel textiles. In this paper, sodium bisulfide (SB) and lithium bromide (LB) solutions were used to process the camel guard hair before its slenderization. It is found that camel guard hair processed by SB solution shows the highest breaking elongation (~140%) due to the breakage of disulfide bonds (reflected by Raman spectra). LB ions result in the disruption of hair crystalline phase with slight benefit to the slenderization (determined by X-ray diffraction and differential scanning calorimetry). IR spectra indicate that hydrogen bonds of camel guard hair act as fixation switch in the programmed tensile test. It is discovered that guard hair reveals the best water-induced shape memory with 90% of stretching shape recovery, whereas the value remained to be 70% and 60% for hair processed by LB and SB solutions after breaking partial crystalline phase and disulfide cross-links separately (polymer net-points). The poorer shape memory of processed guard hair benefits its slenderization for more stable fixation of stretched length. Xueliang Xiao and Jinlian Hu Copyright © 2016 Xueliang Xiao and Jinlian Hu. All rights reserved. Numerical Investigation of the Effect of Bottom Shape on the Flow Field and Particle Suspension in a DTB Crystallizer Thu, 10 Mar 2016 09:18:00 +0000 The influence of the bottom shape on the flow field distribution and particle suspension in a DTB crystallizer was investigated by Computational Fluid Dynamics (CFD) coupled with Two-Fluid Model (Eulerian model). Volume fractions of three sections were monitored on time, and effect on particle suspension could be obtained by analyzing the variation tendency of volume fraction. The results showed that the protruding part of a type bottom could make the eddies smaller, leading to the increase of velocity in the vortex. Modulating the detailed structure of the type bottom to make the bottom surface conform to the streamlines can reduce the loss of the kinetic energy of the flow fluid and obtain a larger flow velocity, which made it possible for the particles in the bottom to reach a better suspension state. Suitable shape parameters were also obtained; the concave and protruding surface diameter are 0.32 and 0.373 times of the cylindrical shell diameter, respectively. It is helpful to provide a theoretical guidance for optimization of DTB crystallizer. Hao Pan, Jun Li, Yang Jin, Bo Yang, and Xing Li Copyright © 2016 Hao Pan et al. All rights reserved. Pilot-Scale Investigation of Forward/Reverse Osmosis Hybrid System for Seawater Desalination Using Impaired Water from Steel Industry Tue, 08 Mar 2016 14:14:33 +0000 This paper was focused on the investigation of a forward osmosis- (FO-) reverse osmosis (RO) hybrid process to cotreat seawater and impaired water from steel industry. By using this hybrid process, seawater can be diluted before desalination, hence reducing the energy cost of desalination, and simultaneously contaminants present in the impaired water are prevented from migrating into the product water through the FO and RO membranes. The main objective of this work was to investigate on pilot-scale system the performance of the combined FO pretreatment and RO desalination hybrid system and specifically its effects on membrane fouling and overall solute rejection. Firstly, optimization of the pilot-scale FO process to obtain the most suitable and stable operating conditions for practical application was investigated. Secondly, pilot-scale RO process performance as a posttreatment to FO process was evaluated in terms of water flux and rejection. The results indicated that the salinity of seawater reduced from 35000 to 13000 mg/L after 3 hrs using FO system, while after 6 hrs it approached 10000 mg/L. Finally, FO/RO system was tested on continuous operation for 15 hrs and it was demonstrated that no pollutant was detected neither in draw solution nor in RO permeate after the end of operating time. Hanaa M. Ali, Hanaa Gadallah, Sahar S. Ali, Rania Sabry, and A. G. Gadallah Copyright © 2016 Hanaa M. Ali et al. All rights reserved. Simultaneous Adsorption of Cr(VI) and Phenol from Binary Mixture Using Iron Incorporated Rice Husk: Insight to Multicomponent Equilibrium Isotherm Mon, 07 Mar 2016 09:21:21 +0000 Fe modified rice husk was prepared as a low cost biosorbent for the removal of Cr(VI) and phenol both singly and in combination from single and binary simulated synthetic waste water. Rice husk was modified by treating with FeSO4·7H2O. The results showed that impregnation of iron onto the surface of rice husk improved the adsorption capability of both Cr(VI) and phenol. The effects of process parameters for multicomponent system such as pH, adsorbent dose, and contact time onto the percentage removal of both Cr(VI) and phenol were investigated. The experimental data for the adsorption of both Cr(VI) and phenol onto the surface of Fe modified rice husk applied to various kinetic and adsorption isotherm models. Multicomponent isotherm models such as Nonmodified Langmuir, Modified Langmuir, Extended Langmuir, Extended Freundlich, Competitive Nonmodified Redlich Peterson, Competitive Modified Redlich Peterson were applied. The results show that Extended Freundlich model best described the experimental data for both Cr(VI) and phenol from binary solution. Pseudo second-order model agreed well with Cr(VI) while pseudo first-order model agreed well with phenol. Maximum adsorption capacity in synthetic binary solution of Cr(VI) and phenol was found to be 36.3817 mg g−1 for Cr(VI) and 6.569 mg g−1 for phenol, respectively. Ankur Gupta and Chandrajit Balomajumder Copyright © 2016 Ankur Gupta and Chandrajit Balomajumder. All rights reserved. Ag Doped ZnO Thin Films Synthesized by Spray Coating Technique for Methylene Blue Photodegradation under UV Irradiation Sun, 28 Feb 2016 16:23:27 +0000 Silver (Ag) substituted ZnO thin films were successfully deposited onto glass substrates by spray coating technique. Structure, morphology, and optical properties were evaluated by X-ray diffractometer (XRD), scanning electron microscopy (SEM), and UV-Vis spectrophotometer, respectively. XRD spectra had polycrystalline wurtzite structure; SEM images showed that thin films had different surface morphology at different Ag doping concentration. From transmittance spectra, thin films transparency decreased as well as band gap energy along with increase of Ag doping concentration. Methylene blue (MB) solution was used as a pollutant in the photodegradation studies. Under UV light irradiation, the optimal Ag doping is 25%, with 83% of the decolorizing efficiencies after 3 h irradiation time and apparent constant () about 9.69 × 10−3 min−1. Heri Sutanto, Singgih Wibowo, Iis Nurhasanah, Eko Hidayanto, and H. Hadiyanto Copyright © 2016 Heri Sutanto et al. All rights reserved. Power Prediction and Technoeconomic Analysis of a Solar PV Power Plant by MLP-ABC and COMFAR III, considering Cloudy Weather Conditions Sun, 28 Feb 2016 16:17:30 +0000 The prediction of power generated by photovoltaic (PV) panels in different climates is of great importance. The aim of this paper is to predict the output power of a 3.2 kW PV power plant using the MLP-ABC (multilayer perceptron-artificial bee colony) algorithm. Experimental data (ambient temperature, solar radiation, and relative humidity) was gathered at five-minute intervals from Tehran University’s PV Power Plant from September 22nd, 2012, to January 14th, 2013. Following data validation, 10665 data sets, equivalent to 35 days, were used in the analysis. The output power was predicted using the MLP-ABC algorithm with the mean absolute percentage error (MAPE), the mean bias error (MBE), and correlation coefficient (), of 3.7, 3.1, and 94.7%, respectively. The optimized configuration of the network consisted of two hidden layers. The first layer had four neurons and the second had two neurons. A detailed economic analysis is also presented for sunny and cloudy weather conditions using COMFAR III software. A detailed cost analysis indicated that the total investment’s payback period would be 3.83 years in sunny periods and 4.08 years in cloudy periods. The results showed that the solar PV power plant is feasible from an economic point of view in both cloudy and sunny weather conditions. M. Khademi, M. Moadel, and A. Khosravi Copyright © 2016 M. Khademi et al. All rights reserved. Mass Transfer Studies on Adsorption of Phenol from Wastewater Using Lantana camara, Forest Waste Thu, 25 Feb 2016 14:14:02 +0000 Adsorption is one of the important treatment methods for the removal of pollutants from wastewater. The determination of rate controlling step in the process is important in the design of the process. Therefore, in the present work, mass transfer studies were done to evaluate the rate-limiting step in the adsorption of phenol from aqueous solution onto Lantana camara. Different mass transfer models were used to find the rate-limiting step and also to find the values of external mass transfer coefficient and diffusion coefficient. The Biot number was found to investigate the importance of external mass transfer to intraparticle diffusion. From the various models studied and the Biot numbers obtained, it was found that the adsorption on Lantana camara was controlled by film diffusion. The sensitivity analysis was performed to study the significance of the model parameters on the adsorption process. C. R. Girish and V. Ramachandra Murty Copyright © 2016 C. R. Girish and V. Ramachandra Murty. All rights reserved. CO2 Capture by Carbon Aerogel–Potassium Carbonate Nanocomposites Tue, 23 Feb 2016 09:32:38 +0000 Recently, various composites for reducing CO2 emissions have been extensively studied. Because of their high sorption capacity and low cost, alkali metal carbonates are recognized as a potential candidate to capture CO2 from flue gas under moist conditions. However, undesirable effects and characteristics such as high regeneration temperatures or the formation of byproducts lead to high energy costs associated with the desorption process and impede the application of these materials. In this study, we focused on the regeneration temperature of carbon aerogel–potassium carbonate (CA–KC) nanocomposites, where KC nanocrystals were formed in the mesopores of the CAs. We observed that the nanopore size of the original CA plays an important role in decreasing the regeneration temperature and in enhancing the CO2 capture capacity. In particular, 7CA–KC, which was prepared from a CA with 7 nm pores, exhibited excellent performance, reducing the desorption temperature to 380 K and exhibiting a high CO2 capture capacity of 13.0 mmol/g-K2CO3, which is higher than the theoretical value for K2CO3 under moist conditions. Guang Yang, Hongchao Luo, Tomonori Ohba, and Hirofumi Kanoh Copyright © 2016 Guang Yang et al. All rights reserved. Modeling and Assessment of a Biomass Gasification Integrated System for Multigeneration Purpose Tue, 16 Feb 2016 13:02:52 +0000 The use of biomass due to the reduction in greenhouse gas emissions and environmental impacts has attracted many researchers’ attention in the recent years. Access to an energy conversion system which is able to have the optimum performance for applying valuable low heating value fuels has been considered by many practitioners and scholars. This paper focuses on the accurate modeling of biomass gasification process and the optimal design of a multigeneration system (heating, cooling, electrical power, and hydrogen as energy carrier) to take the advantage of this clean energy. In the process of gasification modeling, a thermodynamic equilibrium model based on Gibbs energy minimization is used. Also, in the present study, a detailed parametric analysis of multigeneration system for undersigning the behavior of objective functions with changing design parameters and obtaining the optimal design parameters of the system is done as well. The results show that with exergy efficiency as an objective function this parameter can increase from 19.6% in base case to 21.89% in the optimized case. Also, for the total cost rate of system as an objective function it can decrease from 154.4 $/h to 145.1 $/h. Shoaib Khanmohammadi, Kazem Atashkari, and Ramin Kouhikamali Copyright © 2016 Shoaib Khanmohammadi et al. All rights reserved. Oxygen Mass Transfer in an Aerated Stirred Tank with Double Impellers: A Generalized Correlation Including Spacing Impact Mon, 08 Feb 2016 11:30:43 +0000 Stirred aerated tanks by double impellers are used in fermentation and various biological processes for water treatment, food industry, and pharmaceutical production. In this study, a generalized correlation model was developed for the dependent parameter (). The oxygen mass transfer from air to liquid takes place by rotating the double impellers (IBRC and PBPU) in the aerated tank. This model considers Reynolds number, Froude number, power number, the liquid height, and the spacing between impellers as the most significant specifications that are related to aerated tank performance. The spacing between the impellers is considered to be a design factor of such industrial equipment due to its remarkable impact on the oxygen mass transfer. Hayder Mohammed Issa Copyright © 2016 Hayder Mohammed Issa. All rights reserved. Optimal Extraction of Gallic Acid from Suaeda glauca Bge. Leaves and Enhanced Efficiency by Ionic Liquids Tue, 26 Jan 2016 11:55:35 +0000 The ultrasound-assisted extraction (UAE) was initially applied to extract gallic acid from Suaeda glauca Bge. using 70% ethanol as extraction solvent. Temperature, liquid-solid ratio, and extraction time were optimized by response surface methodology (RSM), obtaining maximum levels of gallic acid (6.30 mg·g−1) at 51°C, 19.52 mL·g−1, and 42.68 min, respectively. The obtained model was statistically significant (). The verification experiments at the optimum conditions yielded gallic acid for 6.21 mg·g−1. Subsequently, under optimal conditions, four ionic liquids were used to extract gallic acid from Suaeda glauca Bge. The results indicated that the presence of 1-hexyl-3-methylimidazolium chloride allowed increasing the EE of gallic acid up to 8.90 mg·g−1. This might be interpreted in terms of the molecular interaction between ionic liquid and gallic acid. The use of ionic liquids involves a stronger gallic acid extraction capacity than conventional organic volatile solvents. A promising alternative process is proposed for the extraction of gallic acid of Suaeda glauca Bge. Xin-Hong Wang, Chen Cai, and Xue-Mei Li Copyright © 2016 Xin-Hong Wang et al. All rights reserved. Corrigendum to “Denaturation Kinetics of Whey Protein Isolate Solutions and Fouling Mass Distribution in a Plate Heat Exchanger” Wed, 20 Jan 2016 11:39:23 +0000 Marwa Khaldi, Gilles Ronse, Christophe André, Pascal Blanpain-Avet, Laurent Bouvier, Thierry Six, Saloua Bornaz, Thomas Croguennec, Romain Jeantet, and Guillaume Delaplace Copyright © 2016 Marwa Khaldi et al. All rights reserved. Modeling and Simulation of the Hydrogenation of α-Methylstyrene on Catalytically Active Metal Foams as Tubular Reactor Packing Thu, 14 Jan 2016 11:47:14 +0000 This work presents a one-dimensional reactor model for a tubular reactor packed with a catalytically active foam packing with a pore density of 30 PPI in cocurrent upward flow in the example of hydrogenation reaction of α-methylstyrene to cumene. This model includes material, enthalpy, and momentum balances as well as continuity equations. The model was solved within the parameter space applied for experimental studies under assumption of a bubbly flow. The method of orthogonal collocation on finite elements was applied. For isothermal and polytropic processes and steady state conditions, axial profiles for concentration, temperature, fluid velocities, pressure, and liquid holdup were computed and the conversions for various gas and liquid flow rates were validated with experimental results. The obtained results were also compared in terms of space time yield and catalytic activity with experimental results and stirred tank and also with random packed bed reactor. The comparison shows that the application of solid foams as reactor packing is advantageous compared to the monolithic honeycombs and random packed beds. Farzad Lali, Felix-Aron Pahner, and Rüdiger Lange Copyright © 2016 Farzad Lali et al. All rights reserved. Research on Gas Hydrate Plug Formation under Pipeline-Like Conditions Sun, 06 Dec 2015 11:48:03 +0000 Hydrates of natural gases like methane have become subject of great interest over the last few decades, mainly because of their potential as energy resource. The exploitation of these natural gases from gas hydrates is seen as a promising mean to solve future energetic problems. Furthermore, gas hydrates play an important role in gas transportation and gas storage: in pipelines, particularly in tubes and valves, gas hydrates are formed and obstruct the gas flow. This phenomenon is called “plugging” and causes high operational expenditure as well as precarious safety conditions. In this work, research on the formation of gas hydrates under pipeline-like conditions, with the aim to predict induction times as a mean to evaluate the plugging potential, is described. Florian Stephan Merkel, Carsten Schmuck, Heyko Jürgen Schultz, Timo Alexander Scholz, and Sven Wolinski Copyright © 2015 Florian Stephan Merkel et al. All rights reserved.