Iranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101An optimization study by response surface methodology (RSM) on viscosity reduction of residue fuel oil exposed ultrasonic waves and solvent injection31915369ENA. Mohammadi DoustDepartment of Chemical Engineering, Faculty of Engineering, Razi University, Kermanshah, IranM. RahimiDepartment of Chemical Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran0000-0002-1144-9351M. FeyziDepartment of Physical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, IranJournal Article20150825In this study, response surface methodology (RSM) based on central composite design (CCD) was applied for investigation of the effects of ultrasonic waves, temperature and solvent concentration on viscosity reduction of residue fuel oil (RFO). Ultrasonic irradiation was employed at low frequency of 24 kHz and power of 280 W. The results showed that the combination of ultrasonic waves and solvent injection caused to further reduce of viscosity. To obtain optimum conditions and significant parameters, the results were analyzed by CCD method. In this method, maximum viscosity reduction (133 cSt) was attained in ultrasonic irradiation for 5 min, temperature of 50 °C and acetonitrile volumetric concentration of 5 % by means of experimental and three dimensional response surface plots. The kinematic viscosity decreased from 494 cSt to 133 cSt at the optimum conditions. In addition, a multiple variables model was developed by RSM which the second-order effect of ultrasonic irradiation time was significant on viscosity reduction of FRO. Finally, a comparison between the RSM with artificial neural network (ANN) was applied. The results demonstrated that both models, , were powerful to predict of kinematic viscosity of RFO. The results demonstrated that both models, RSM and ANN, with R2 more than 0.99 were powerful to predict kinematic viscosity of RFO.https://www.ijche.com/article_15369_cb225a87336b9355e24ece7ec81c10b9.pdfIranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101Optimization of Synthesis of Expandable Polystyrene by Multi-Stage Initiator Dosing203115377ENF. DerakhshanfardDepartment of chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranA. VaziriDepartment of chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranN. FazeliDepartment of chemical Engineering, Science and Research Branch, Islamic Azad University, P.O. Box 14155/4933, Tehran, IranA. HeydarinasabDepartment of chemical Engineering, Science and Research Branch, Islamic Azad University, P.O. Box 14155/4933, Tehran, IranJournal Article20151009Suspension polymerization process is commonly used to produce expandable polystyrene. In the conventional method for producing this polymer, two different initiators are added to the process at two different temperature levels. In the industrial scale, this process is time consuming and difficult to control. A new method (Multi-Stage Initiator Dosing, MID) is proposed, in which, the initiator is dosed into the reactor. In the laboratory and bench scale tests of this new method results in better control of the process, shorter reaction times and better quality of the product. Optimum temperature and dosing intervals are determined. The properties of the prepared samples by MID and conventional methods are compared with each other. According to the results obtained with the implementation of new methods for the production of expandable polystyrene reduce time process and consuming amount of initiator and because the initiator dosing in several stages, the suspension control would be easier. Also absorption rate was higher pentane and grain size better than the conventional.https://www.ijche.com/article_15377_6d638f8bc05359f0dfee3a47c7afa450.pdfIranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101Lipase Immobilized into Novel GPTMS: TMOS Derived Sol-Gels and Its Application for Biodiesel Production from Waste Oil324615375ENM. NikpourDepartment of Energy, Materials and Energy Research Center, Meshkin Dasht, Karaj, IranM. PazoukiDepartment of Energy, Materials and Energy Research Center, Meshkin Dasht, Karaj, IranJournal Article20150917In this essay, lipase from Burkholderia cepacia was immobilized into 3-glycidoxypropyltrimethoxysilane (GPTMS) and tetramethoxysilane (TMOS) derived sol-gels. GPTMS:TMOS molar ratio of 1:3 was found to yield the best result. The morphological characteristics were investigated based on SEM and BET analysis. Sample mean pore diameter was 39.1 nm, it had a specific surface area of 60 m2/g prior to enzyme addition which decreased to 7.49 m2/g after immobilization. The enzyme activity was assessed through transesterification of waste cooking oil in the presence of ethanol with optimal conditions of: 40 ᵒC, 15 % immobilized lipase, 9:1 alcohol to oil molar ratio in 24 h of reaction which resulted to 91.70 % biodiesel production. In six-hour reaction time, 86.87 % biodiesel was obtained which is much shorter than conventional enzymatic transesterification which is 72 hours. Ethyl esters were characterized by determining their viscosity, density, and flash point based on ASTM D 6751-07b standards.https://www.ijche.com/article_15375_ac278a44649b4945a490b30e900ce1ab.pdfIranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101CO2 biofixation by Dunaliella Salina in batch and semi-continuous cultivations, using hydrophobic and hydrophilic poly ethylene (PE) hollow fiber membrane photobioreactors475915373ENV. MortezaeikiaProcess/production department, South Pars Gas Complex (SPGC), Asaluyeh, IranR. YeganiFaculty of Chemical Engineering, Sahand University of TechnologyM.A. HejaziAgricultural Biotechnology Research Institute of West & North-West, Tabriz, IranS. CheginiMembrane Technology Research Center, Faculty of Chemical Engineering, Sahand University of Technology, Tabriz, IranJournal Article20150909In this work, performance of hollow fiber membrane photobioreactor (HFMPB) on the growth of Dunaliella Salina (G26) at various aeration rates (0.1 and 0.2 VVm) and medium re-circulation flow rates (500 and 1000 mL/h) were studied. Cultivation was carried out at both batch and semi-continuous modes in HFMPBs containing neat and hydrophilized in-house fabricated poly ethylene (PE) membranes at fixed light intensity of 300 µmol m-2 s-1and temperature of 30 oC. Microalgae showed better growth in hydrophobic module in both cultivation modes and modules. Maximum biomass concentration, CO2 biofixation and specific growth rates equal with 0.71g L-1, 1.102g L-1 d-1 and 0.224d-1 were obtained for non-wetted membranes, respectively. Comparing the performance of both modules showed that the impact of cultivation mode on the CO2 biofixation rate and CO2 removal is more pronounced than the impact of mass transfer resistance in membrane contactors. The obtained results show that the mean CO2 biofixation rates in semi-continuous cultivation for both neat and hydrophilized modules are higher than that in batch cultivation in all operating conditions. It was also found that the hydrophobic membranes are much preferable than hydrophilic membrane in HFMPBs.https://www.ijche.com/article_15373_13d1dbfd8949afa056f5f981545a37e0.pdfIranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101Bubble formation on a single orifice in a gas solid fluidized bed using digital image analysis607215370ENA. Dehghan LotfabadSchool of Chemical Engineering, Iran University of Science and Technology (IUST), P.O. Box 16765-163, Tehran, IranS. MovahediradSchool of Chemical Engineering, Iran University of Science and Technology (IUST), P.O. Box 16765-163, Tehran, IranM.T. SadeghiSchool of Chemical Engineering, Iran University of Science and Technology (IUST), P.O. Box 16765-163, Tehran, IranJournal Article20150815Digital Image Analysis (DIA) has been employed to characterize the time evolution of a bubble injected from a single orifice into a pseudo 2-dimansional gas-solid fluidized bed. The injected bubble diameter increased with the square root of time before detachment. During bubble free flight in the bed, its diameter remains approximately constant. The center of mass of the bubble increases with the second power of the time. The results show that the classical models for bubble injection can predict the time evolution of bubble diameter, and its center of mass. Bubble tends to elongate during injection and after detachment its height to width aspect ratio decreases. Image analyzing results used also for the study of gas leakage from the bubble to emulsion phase, and it has been shown that the dense phase expands up to 1.04 times of the minimum fluidization condition for large bubbles. The expansion ratio of the dense phase increases linearly with bubble diameter.https://www.ijche.com/article_15370_fe46e1bc9d36bfb0cc71448686313e2d.pdfIranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101Prediction of the Effect of Polymer Membrane Composition in a Dry Air Humidification Process via Neural Network Modeling738315046ENM. FakhroleslamChemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, IranA. SamimiChemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, IranS.A. MousaviChemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave., Tehran, IranR. RezaeiChemical Engineering Department, Razi University, Kermanshah, IranJournal Article20150808Utilization of membrane humidifiers is one of the methods commonly used to humidify reactant gases in polymer electrolyte membrane fuel cells (PEMFC). In this study, polymeric porous membranes with different compositions were prepared to be used in a membrane humidifier module and were employed in a humidification test. Three different neural network models were developed to investigate several parameters, such as casting solution composition, membrane thickness, operating pressure, and flow rate of input dry air which have an impact on relative humidity of the exhausted air after humidification process. The three mentioned models included Feed- Forward Back- Propagation (FBP), Radial Basis Function (RBF), and Feed- Forward Genetic Algorithm (FFGA). The developed models were verified by experimental data. The results showed that the feed- forward neural network models, especially FFGA, were suitable for prediction of the effect of membrane composition and operating conditions on the performance of this type of membrane humidifiershttps://www.ijche.com/article_15046_1ab0ee14eaf84148a3e2f6f714d54452.pdfIranian Association of Chemical Engineers(IAChE)Iranian Journal of Chemical Engineering(IJChE)1735-539713120160101An Empirical Correlation to Predict the Ignition Delay Time for Some Hydrocarbon Fuels849712114ENF. S. ShariatmadarFaculty of Chemistry & Chemical Engineering, Malek-Ashtar University of Technology, Tehran, IranSh. Ghanbari PakdehiFaculty of Chemistry & Chemical Engineering, Malek-Ashtar University of Technology, Tehran, IranM. A. ZareiFaculty of Chemistry & Chemical Engineering, Malek-Ashtar University of Technology, Tehran, IranJournal Article20151221<span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>Examination of the available ignition delay time data and correlations</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>in the case of methane, butane, heptane, decane, kerosene, Jet-A and</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>ethylene fuels, allowed the derivation and recommendation of standard</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>equations for this property. In this study, a new accurate substance</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>dependent equation for ignition delay time as a function of pressure,</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>number of carbon atoms, mixture equivalence ratio, fuel mole fraction</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>and temperature has been developed to estimate ignition delay time of</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>some hydrocarbon fuels. With the presented model, ignition delay time</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>has been calculated and compared with the data reported in literature.</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>The accuracy of the obtained model has been compared to the mostly</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>used predictive models and the comparison indicated that the proposed</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>correlation provides more accurate results than other models used in</em> <span style="font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><em>the previous works.</em></span></span></span></span></span></span></span></span></span></span></span></span><br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" /><br class="Apple-interchange-newline" /></span>https://www.ijche.com/article_12114_159ea26035a75043ccec48f2f9f98ce0.pdf