Ali Asghar Hamidi; Asghar Sedighzadeh; Monireh Taherkhani; Ali Reza Kamizi
Abstract
In this investigation, the performance of a tower for absorption of sulphur dioxide gas into calcium carbonate solution has been studied. The trays had no downcomer and the tower itself was a scaled down pilot from industrial equipment. The industrial scale tower was used for clean up of 110000 m3/hr ...
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In this investigation, the performance of a tower for absorption of sulphur dioxide gas into calcium carbonate solution has been studied. The trays had no downcomer and the tower itself was a scaled down pilot from industrial equipment. The industrial scale tower was used for clean up of 110000 m3/hr gas using 40 m3/hr alkaline solution. The study was composed of two parts. In the first section, hydraulic experiments were carried out and the pressure drops both for dry and wet trays were measured. The measured data were in good agreement with the correlations found in literature. In the second part of the study, the effect of operating parameters such as liquid flow rate, gas flow rate, alkaline solution concentration and sulphur dioxide concentration on the separation efficiency were investigated. Overall, it has been concluded that the separation of sulphur dioxide from air in this tower is always above 80% complete and the equipment offers fairly good efficiency in all the operating conditions considered. The main operating parameters were alkaline solution flow rate 500 – 2000 Lit/hr, alkaline solution concentration 0.1 – 3%, air/sulphur dioxide flow rate 0.15 – 0.4 m3/s and sulphur dioxide concentration in inlet air 100ppm.
Amir Hossein Alizadeh; Ali Reza Keshavarz; Manouchehr Haghighi; Ali Reza Salehpour
Abstract
In this paper, the effect of flow rate on relative permeability curves was investigated in Iranian carbonate rocks. Core samples were prepared from outcrop of Asmari formation. The dynamic displacement experiments were performed at 2.55, 3.55, 4.55 and 5.55 cc/hr during waterflooding and oilflooding. ...
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In this paper, the effect of flow rate on relative permeability curves was investigated in Iranian carbonate rocks. Core samples were prepared from outcrop of Asmari formation. The dynamic displacement experiments were performed at 2.55, 3.55, 4.55 and 5.55 cc/hr during waterflooding and oilflooding. Relative permeabilities have been calculated with the Jones and Roszelle method and then the flow rate effect was investigated. The end-points and crossover saturations in the relative permeability curves indicate water wetness. In the waterflooding process, water relative permeability curves and end-point were not affected by the flow rate. It was observed that the oil curves vary with the flow rate, decreasing with its decrease. This variation vanishes at the middle saturations. Also, in the oilflooding, water relative permeabilities behave the same as it observed in waterflooding. It was not possible to find any trend in kro and end-point saturation with the flow rate. In contrast to sandstone, hysteresis was observed in both krw and kro curves. With increasing the flow rate, this phenomenon increases in water curves and decreases in oil curves.
Nasrin Mohammadbeygi; Ali Haghighi Asl; Faramarz Hormozi
Abstract
Cinnamon is the bark the cinnamomi cassia that exhibits many medical properties such as anti-cancer effect and anti-diabetic effect. Moreover, because of its antioxidant activity; it can be used in food industries. Many studies have already reported biological and chemical properties of the cinnamon ...
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Cinnamon is the bark the cinnamomi cassia that exhibits many medical properties such as anti-cancer effect and anti-diabetic effect. Moreover, because of its antioxidant activity; it can be used in food industries. Many studies have already reported biological and chemical properties of the cinnamon extracted essential oil such as their antimicrobial, antifungal, antimosquito, free radical scavenging activity, antioxidant and antipathogenic properties. In this article, the result of treatments for extraction cinnamon oil with high quality or in the other words with higher percentage of cinnamon aldehyde in different thermal powers, different solvent ratios and different solvent pH have been done. For extraction of the essential oil, the water distillation in atmospheric pressure was used. All the essential oils were analyzed with GC and in the same conditions. According to the results the cinnamon oil is not sensitive to the heat power, the best solvent ratio to cinnamon bark is 25 to 1 and the best water pH is 4.11.
Sohrab Ali Ghorbanian; Ali Reza Salehpour; Saeed Reza Radpour
Tal'at Ghomashchi; Zahra Akbari
Abstract
Corn steep water as effluent which arrives in environment from starch processing industry has adverse effects on the environment and also large volume of fresh water is wasted. Corn step water is composed of high concentration of proteins, sugar, starch, vitamin and minerals, so it can be used as substrate ...
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Corn steep water as effluent which arrives in environment from starch processing industry has adverse effects on the environment and also large volume of fresh water is wasted. Corn step water is composed of high concentration of proteins, sugar, starch, vitamin and minerals, so it can be used as substrate for production of biological products. Hence, corn steep water concentration is important task both in environmental consideration and reuse of water. In this study, reverse osmosis membrane was used for concentration of steep water. The pilot consisted of two parts: pretreatment and reverse osmosis membrane. Pretreatment section contains ceramic filter with pore size of 50 micron and polypropylene filter which operates at 3-7 bar pressure. Surface area of reverse osmosis membrane was 1.11 m2 and operating pressure is 250 psi. Results showed that permeate flux is reduced exponentially over time and transmission through the polyamide membrane of calcium ions are less than sodium and potassium ions. For membrane cleaning, at first acid solution (pH= 3.5) and then soda solution (pH= 11-11.5) were used. For removal of microorganism like bacteria from polyamide membrane, acetic acid solution (4000 ppm) or hydrogen peroxide (2000 ppm) could be used. In general, reverse osmosis system with polyamide membrane is suitable process for concentration of steep water.
Maryam Biglari; Abossamad Zarrin Ghalam Moghaddam; Mohammad Reza Nasrin Omidkhah
Rahmat Sotudeh Gharehbagh; Leila Niknam; Navid Mostofi
Abstract
In this paper, a batch hydrogenation reactor performance was modeled using a hydrodynamic and reaction sub-models. The reaction expressions were obtained from the information reported in literature. Experimental studies were conducted in order to generate the experimental data needed to validate the ...
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In this paper, a batch hydrogenation reactor performance was modeled using a hydrodynamic and reaction sub-models. The reaction expressions were obtained from the information reported in literature. Experimental studies were conducted in order to generate the experimental data needed to validate the model. The comparison between the experimental data and model predictions seems quite satisfactory considering the hydrodynamic limitations and simplifications made on the reaction scheme. The results of this study could be considered as framework in developing new process equipment and also soya oil product design for new applications.
Arezou Nikseir; Amir Rahimi
Abstract
Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co-current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and ...
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Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co-current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and enthalpy of gas and liquid streams are predicted along the tower length and are used in order to calculate the energy and exergy efficiencies. The model validity in prediction of gas and liquid characteristics changing along the tower length was examined against some operating data measured in a commercial cement plant. As a result, it was concluded that in spite of high energy efficiency, the cooling tower has a relatively low exergic efficiency which is because of thermodynamic irreversibilities and entropy production during heat and mass transfers. Also, the effect of some operating parameters including tower diameter, tower length, liquid drops size distribution and water flow rate was investigated on amount of exergy destruction. In all cases the results showed that the exergy of water does not completely absorbed by gas and a notable portion of the exergy is destructed. The result of these investigations may be employed to inform about the true energy potential caring by fluids.
Siamak Motahhari
Abstract
In the present research work, the flexural modulus and strength of glass fiber-epoxy resin and carbon fiber-epoxy resin composites have been enhanced through fiber tension during curing of the polymeric resin. This study showed that the tension applied on the fibers increased the flexural modulus of ...
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In the present research work, the flexural modulus and strength of glass fiber-epoxy resin and carbon fiber-epoxy resin composites have been enhanced through fiber tension during curing of the polymeric resin. This study showed that the tension applied on the fibers increased the flexural modulus of the glass-epoxy composites up to 12% and the flexural strength up to 19%. The flexural modulus and strength of carbon-epoxy were also increased up to 25% and 13%, respectively. It was shown that the optimum fiber tension to obtain the maximum flexural properties depends on the fiber the composite is made of. The mechanism through which the improvement has been achieved was also presented.
Ali Reza Salehpour; Khashayar Nasrifar
Abstract
In this contribution, two approaches are followed to predict the saturated liquid density of liquefied natural gas (LNG) mixtures. In one approach, 12 cubic equations of state (EoSs), comprising the popular Peng-Robinson (PR) and Redlich-Kwong-Soave (RKS), are employed to predict the saturated liquid ...
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In this contribution, two approaches are followed to predict the saturated liquid density of liquefied natural gas (LNG) mixtures. In one approach, 12 cubic equations of state (EoSs), comprising the popular Peng-Robinson (PR) and Redlich-Kwong-Soave (RKS), are employed to predict the saturated liquid density of 20 LNG mixtures. In the other approach, these EoS are used in conjunction with a recently developed correlation to predict the liquid density of the same LNG mixtures. This correlation takes the advantages of the EoSs functions and is remarkably accurate for LNG mixtures. The results for both approaches are presented and the best predicting methods are ranked. Also the liquid density of 3 gas condensate mixtures are predicted using 10 EoSs and the results are compared with experimental data. The method employed is discussed and the best EoSs are ranked. Our evaluation indicates that in general, the EoSs used in this study are not accurate enough for predicting the liquid density of gas condensate mixtures. The PR, Patel-Teja (PT) EoSs or one of their variant are recommended, however.
Mirhamed Mousavi; Parisa Khadivparsi; Seyyed Mohammad Ali Mousavian
Abstract
In this research, effect of bicomponent mixed surfactant was studied on drop interface coalescence phenomenon in ambient temperature. First basic chemical system was water and toluene and 0.01 gr of sodium dodecyle sulfate (SDS) and the second basic system was water and toluene and 0.01 gr of cethyl ...
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In this research, effect of bicomponent mixed surfactant was studied on drop interface coalescence phenomenon in ambient temperature. First basic chemical system was water and toluene and 0.01 gr of sodium dodecyle sulfate (SDS) and the second basic system was water and toluene and 0.01 gr of cethyl trimethy amonium bromide (CTAB). Various weight fractions of second surfactant including 2-heptanol (non-ionic) and aniline (cationic) added to each of these systems, respectively, in order to study the effect of mixed surfactant on coalescence time. It was shown that chemical systems including mixture of nonionic/anionic surfactant increased coalescence time. However, chemical systems including mixture of nonionic/cationic surfactant decreased coalescence time. If a mixture of anionic/cationic surfactant was considered, in terms of being weak or powerful cationic surfactant, coalescence time would have been decreased in the later and for mixture of ctionic/ctionic surfactant, coalescence time increased in small diameter and decreased in further diameter. Effect of sodium chloride (NaCl) on selected systems, including 40% CTAB in the basic system of water and toluene and SDS, 40% 2-heptanol in basic system of water and toluene and CTAB and 40% 2-heptanol in basic system of water and toluene and SDS was considered and it was shown that in general, coalescence time decreases.
