نشریه شریف
پیاپی 41 (فروردین و اردیبهشت 1387)

One of the chemicals formaldehyde and consumed values ​​in the petrochemical industry is always check and optimize its production processes a large part of the investigation is taken. The present partial oxidation of methanol in formaldehyde using a catalyst of iron oxide, molybdenum oxide in the temperature range $ ^ circ C $ 410-270 in a continuous reactive fluid bed has been studied. Catalyst needed for the process, a process during Hmrsvby of ammonium and nitrate solutions Polar Hptamvlybdat iron is produced. In order to increase the mechanical strength and resistance to catalyst synthesis, the action inoculated with bismuth nitrate on it and then taken up again by calcination reaction in order Bstrsyal useful. During the impact of various parameters such as reaction temperature, gas superficial velocity and the percentage of feed, the reaction rate and operational capacity has been studied reagent. Experimental results obtained with the results of the models presented for fluid bed reactors have been compared. Finally the best model based on reagent performance is marked.

Beet pulp which is rich in polysaccharides, lesions of the beet sugar factories preparation can be produced. Examples of this form leaves wet and dry pulp, was prepared from the sugar factory anymore. More samples for studies beginning at temperatures $ - {20} ^ {circ} c $ maintenance, and then 100-50 ° C temperature in tray dryer with hot air were. Results indicate that the optimum temperature for producing dried leaf pulp is good 80 degrees Celsius, and the quality of the dried sample temperature is better than the other samples. Studies also indicate statistically significant differences between samples were dried at different temperatures.

Drying behavior of materials in the study and design of industrial drying Knhay one of the parameters necessary to attract and repel curves are isotherms. Curves indicates the relationship between moisture content and quilibrium relative humidity atmosphere surrounding material) Water Activities (are. Determine isotherms absorb moisture and repel static and dynamic system with two possible. As to achieve equilibrium conditions in the static system may Bhtvl days and even weeks lead. isotherms to determine the moisture absorption and excretion of a laboratory apparatus was designed and built the dynamic method. moisture absorption tests on the example of wheat flour in the machines and the three temperatures 25, 35 and 50 degrees Celsius, and various water activities were performed. order compliance test data obtained from the absorption process, absorption models BET, GAB, Azvyn, Smith, Noble Iglesias, Chang fast, Halsy and Henderson were used. models of GAB, Henderson Chang fast and corresponded well with experimental data. net amount of heat absorbed Ayzvastryk using model isotherms Henderson and relations Klasyvs Klapyrvn in different moisture contents were obtained. This increases the amount of moisture content 0.02 to 0.20) kg water kg dry solid (33.34 value to 2.98) J mol kg (decreased.

Separation issue Fyshrtrvpsh catalytic process of the liquid products) Wax (, Now as one of the main challenges posed Vaknshgrhay slurry bubble. It really isolated because of the high viscosity of the reactive output of wax, and other undesirable properties with low rates and numerous problems is associated. Among the various ethods of separation, supercritical extraction process is one of the best techniques proposed in recent years to do this is segregation. Application of these practices mainly due to distinctive features of supercritical fluid and the fluid's ability to improve physical properties such as viscosity wax is density. On the other hand, should know and do modeling process requires access to information for the physical properties of supercritical fluid is in operational condition, although the calculations and physical properties in these critical situations and challenges critical error always great has been associated with. In this research, the review comments and suggested some type of relationship the best mode equations for predicting viscosity, density and thermal conductivity of light and heavy hydrocarbons and their ixtures, using the same equations of state properties for the hexane and Some mixtures of ydrocarbons in the critical area around and above the calculated and the results are compared with experimental values. then the amounts proposed density, viscosity and conductivity for the mixture of wax and hexane in the operational range around the critical point of hexane is presented. Results indicate that adding hexane to wax the operating range) when supercritical hexane phase is done (than adding it in gas or liquid states, more effective in improving the physical properties of wax and thus efficiency, separation of catalyst / wax will.

Sugar syrups containing glucose and fructose concentration range of 60 to 80 grams per 100 ml by the enzyme lucose Isomerase in optimal conditions of temperature, pH and time of enriched fructose syrups sugar transformation. Glucose Isomerase enzyme Tsbytshdh performance liquid from the sugar palm sap, under certain conditions in batch system was reviewed and optimized. Of hydrolysis) hydrolysis (sucrose in palm sap, due to the low amount, was regardless. Hmparshdn process) Ayzvmryzasyvn (the temperature range $ 30-90 ^ {circ} C $ and the range pH8.5-6 in the batch system, for 30 min and temperature range of $ 50-60 ^ {circ} C $ as the optimal temperature range pH7.7-7 as the optimum pH was obtained.

Carbon dioxide gas separation processes in the refining gas main. In order to separate the gas from the gas stream plus most of the chemical absorption method is used by Lkanlamyn solvents. In this study, thermodynamic model, Gas solubility of carbon dioxide in aqueous mixtures of $ MEA $ and $ MDEA $ studied and model parameters are presented. This model to calculate short-range forces of the model $ UNIQUAC-NRF $ form a non-electrolyte model, and to calculate long-range model Pytzr Dbay Hvkl used. With the development of this model at different temperatures, the interaction parameters for mixed systems $ MDEA-MEA-H_ {2} OCO_ {2} $, respectively. The results of this model) compared with the model $ Li-Mather $ (has good accuracy.

Powder detergent for spray drying, hot air with a gas such as food drops Nahmsv contact form is given. During the call transfer torque phenomena, heat and mass basis is performed simultaneously. The simulation model for predicting the operational parameters, time Khshkshdn tower height and provide the desired effect of various parameters on the performance of spray dryer has been studied. For this purpose, mass and energy balance equations and the torque around a small element of the tower and for both gas and particle phase, was written, and the numbers and the dimensionless heat and mass transfer coefficients were calculated. Then write a suitable computer, application and integration of momentum equations and Mvaznhhay mass and energy, and finite difference method to solve system of equations and a mathematical model was presented. The model profiles via a descending trend for temperatures for the gas and particle temperatures were predicted. Moisture profiles of gas and the particles were evaluated for particle reduction process and the process for increasing the gas humidity was obtained. The results indicate that the radial velocity of particles Atmsaz output at a fraction of seconds to zero, and the axial particle velocity also reaches a fixed value. Effect of particle diameter Atmsaz output has also been investigated. For testing the model of the data using a detergent powder dryer tower and a good agreement between theoretical and experimental results is observed. These results can be simulated in optimizing existing units, changing their operating conditions, and also used in the design of new units.

Living in the industrial age to be changing now with the pattern Mlahzhyy different communities has been associated with food. The high volume of juice excellence of these products is consumer-friendly functions. There opacity Bmyvhsazy industries such as women's problems is considered and Research, Transparency juice is faced with the more fortunate. Fruits such as pomegranates that Iran can produce its high, but despite the high quality production of pomegranate, the fruit concentrate due to lack of attention to the Issue of Transparency in the economic cycle is not active. The first study examined the production of pomegranate juice was given and a complete chemical analysis of pomegranate juice was performed. Transparency also impact on the quality of the various methods tested, and the juice was evaluated. Effect of gelatin, Kyzlsl and pectinase enzymes on the properties of pomegranate juice were tested and the optimum amount of each of these factors to achieve transparency transparent, stable juice were determined.

Biological methods in order to improve the performance of activated sludge systems for dairy wastewater treatment plants, the microbial Jmyt aerobic activated sludge treatment system in Iran Milk Industries Company) Pegah (ten bacteria isolated and the performance of each Ryzandamgan reduce the organic load effluent 've studied. After 30 days of sampling, bacteria BP $ _ {3} $ and BP $ _ {4} $ chemical oxygen required) COD (respectively to 70.7 and 69.5 percent decreased. With Optimum temperature conditions imposed on $ ^ {circ} C $ 35-30, pH equal to 10-11, and round mixer) rpm (150 bacterial, chemical oxygen required) COD (by BP $ _ {3} $ dealing fell 84.70 percent. The amount of bacteria from carbohydrates, fats and proteins respectively effluent 98, 45.30, and has declined 53 percent. Mixed BP $ _ {3} $ and BP $ _ {4} $ Bhandaz·hy BP $ _ {3} $ is not just performance. So BP $ _ {3} $ as the best selection of bacteria in the system and increasing the activated sludge aeration tanks and regain mixed microbial activated sludge system performance efficiency can be raised.

Of water resources is the basic human need. May in some areas, surface water resources is limited or no access to them easy. In these wells can be drilled, to the exploitation of groundwater. Due to population growth and Mhdvdbvdn surface water, groundwater control harvest growing in different parts of the country we are. equires continuous and increasing sources of drinking water contaminants, the exact amount of pollutants entering groundwater and Mathematical Modelling how to play them the necessities because reliance on sampling and testing in this context, time consuming and requires high cost. On the other hand, according to Mhdvdbvdn number of sampling points, it should be stated that studies on modeling Mathematical software and convert it to lead to significant savings in time Mlahzhyy, labor and pays. In this paper, modeling the distribution of water soluble pollutants is the case for publishing underground contaminants from pollution sources form continuous period of six months and $ 5000 ppm $ dealing took place and source of pollution has been cut. Based on mathematical modeling, transport phenomena, including infiltration and pollutant transport by underground water flows are in terms of form and solve equations and numerical finite difference method is done. The results of the model, if the emission of pollution frequently persists maximum concentration of pollutants, at the entrance to the underground water and the amount of the entrance), ie $ 5000 ppm $ (is, while if the sixth month source pollution is discontinued, the maximum concentration two months after discontinued pollutants, within 50 meters from leaks and equal to $ 3200 ppm $ will be, and seven months after the cessation of pollutant levels in distance 50 meters from leaks and equivalents $ 370 ppm $ is estimated. necessary noted that seven months after the cessation of emissions, pollution levels within 500 yards of the spill site, approximately equal to $ 50 ppm $ will be.