Sharif Digital Repository

To study the kinetics of the yttria-stabilized zirconia produced by co-precipitation method from the chemical engineering point of view, this process was studied in two parts of hydrolysis and precipitation. the hydrolysis reaction was studied by titration method, and the rate constant and fraction of formation of hydrous zirconia was determined by applying Avrami equation. The results showed that the percentage of zirconia formation until the boiling time of 12 hours was zero and after 48 hours boiling was 2.81%. moment definitions were used In order to study the kinetics of precipitation. changes in precipitated powder concentration with pH of the solution was obtained based on the... 

This work concerns with experimental and modeling investigation of the asphaltene damage removal using ultrasonic wave irradiation. A specific core holder apparatus was designed and utilized for in situ ultrasonic exposure to damaged core plug at different conditions of exposure time, ultrasound power and distances between sound source and plug. Injection of many pore volumes of an asphaltenic crude oil was used for creating asphaltene induced damaged in porous media through permeability measurements. The deposited asphaltene during oil injection as well as asphaltene removal due to ultrasonic exposure was evaluated using IP-143 analysis. The results revealed that ultrasound application... 

Nowadays oil and gas industry has taken the pulse of world energy. Different countries of the world are trying more and more to explore and produce this black gold. To do so these countries has gained many experiences and even gone to seas and oceans to find oil and gas. In the process, they has faced with a new phenomenon called gas hydrate. The phenomenon which was unknown and destructive at first after excessive research, today is even called as the future energy source of the world. But what we discussed in this study is hydrate as a problem in oil and gas industry. Gas hydrates are formed in favorable temperature and pressure condition (low temperature and high pressure) in the... 

Always, understanding the properties of crude oil and related phenomena of that has been noticeable matter. Surface tension is one of the important fluid properties and the evaluation of that is essential in oil industry especially in enhanced oil recovery method (EOR) and transport of crude oil by using emulsions.
In this research, interfacial tension (IFT) was measured via pendant drop method. The effect of three parameters was investigated on IFT for creating of stable oil/water emulsion. These parameters were temperature, concentration of surfactants, and salinity. They were varied between 25-65 ᵒC, 0.05-0.2 gr and 5000ppm respectively. It was used two types of surfactant; acid... 

In this project, combination of PC-SAFT equation of state and friction theory was used for predicting the viscosity of reservoir fluid. Parameters of PC-SAFT and f-theory are available for pure components, but they are not known for oil cuts that are complex hydrocarbon mixtures. To solve this problem, in the first step, existing optimized parameters for PC-SAFT EOS of hydrocarbon mixtures were used and then, parameters of f-theory for mixtures were optimized. To set the parameters, two approaches were studied. The first approach is to obtain a series of empirical correlations that can estimate the parameters of f-theory (in conjunction with PC-SAFT) for oil cuts in terms of their molecular... 

Submerged Membrane Electro-Bioreactor (SMEBR) was invented to increase the efficiency of Membrane Bioreactor (MBR) systems by reducing the fouling amount. The objective of this study was to understand the physical effects of Electrocoagulation (EC) method on membrane fouling and compares the critical flux number by applying electricity under different conditions and without any electrifying. This paper measured the critical flux, that obtained under different process condition including different MLSS concentrations (8000 ppm, 5000 ppm, 2000 ppm), different current densities and electrodes distance. The best result was obtained during highest CD (30 mA/cm2) and lowest distance of electrodes... 

In tis study, 4 approaches were applied for estimating Minimum Miscibility Pressure (MMP). An oil sample from Norooz and Soroosh field has examined by means of association gas of foroozan field and Carbon Dioxide gas in experimental approach.the experimental method used for estimating MMP in Slim-tube. This kind method is applied in industry widely. The results indicate that the MMP of Carbon Dioxide and Norooz field oil is 3538 psi and with Soroosh field oil is 3650psi. the MMP of foroozan associated gas and Norooz field oil is 5643 psi and MMp with this gas and soroosh field oil not estimating  

Economic loss due to wax precipitation in oil exploitation and transportation has reached several billion dollars a year recently. Development of amodel for better understanding of the process of wax precipitation is therefore veryimportant to reduce the loss.Currently, there are two types of soild models. One is the solid-solution model, and the other is the multisolid-phase model.In this work, a new thermodynamic model that combines the two methods mentioned above, has been presented. The PC-SAFT EOS is used to describe the vapor, liquid and wax phase.SAFT equations describe the phase behavior of large molecules accurately. Intermolecular forces in wax phase are caused by London and Van-... 

Reservoir simulation models are profound tools in reservoir management. Number of grid blocks in a simulation model is much less than the number of grid blocks in geological model, therefore geological model must become upscaled in order to construct simulation model with convenient dimensions. This causes loosing of some details and introduces errors due to discretization and homogenization. One method of construction of an efficient computational grid is use of adaptive mesh refinement (AMR) methods. These methods refine computational grid in regions needing further resolution. An error indicator is used for determining regions candidate for refinement or coarsening. In present study... 

This project simulates the absorption of carbon dioxide absorbent on 4A zeolite is carried out using Monte Carlo simulation. VBA is a programming language and software used. Grand Canonical simulations performed on a set of particles (Grand Canonical) intended to present new algorithms and computational simulations are presented. Density fluctuations in the algorithms used and the smallest value of less than 0.2 is considered. In the new method of modeling, simulation node cell packing and moving is done on a given node. Adsorption density results obtained from the simulation carried out shows that the adsorption process is the logical and reasonable. Also, the part of the validation of the... 

Due to their low volatility, negligible flammability, and high regeneration capacity, ionic liquids have attracted a lot of attention in chemical and process engineering fields. Regarding the limited access to the laboratory facilities, developing theoretical methods such as equations of state is important in this research field. Thus, data for density and viscosity of pure ionic liquids and vapor pressure data for binary mixtures of ionic liquids and acidic gas have been collected and validated from the IL Thermo website for 42 ionic liquids. By consideration of theoretical studies and comparison of the performance of different cubic equations of state in predicting the aforementioned... 

Many researchers were interested in gas hydrates because of their especial properties. These researches divided in two fields, thermodynamic and kinetic. The studies on first field began since many years ago, and they provided suitable results. But the investigation of hydrate formation kinetic started for 30 years ago, approximately, and according to its features such as high complexity of crystallization process and severe dependency on system, yet the comprehensive and pervasive model was not presented. At this project, after the presentation and survey of diverse models, in order to kinetic modeling of available data, among different kinetic models a reaction model selected. Then primary... 

In this work, PC-SAFT, an equation of state based on perturbation theory, is applied to predict the phase behavior of the reservoir fluids. PC-SAFT parameters for pure components are available but they cannot be calculated for petroleum fractions with unspecified components and composition. To solve this problem, and make use of the PC-SAFT model in the reservoir fluids simulations, two approaches are studied. In the first approach new correlations are developed which are able to predict the PC-SAFT parameters for plus fractions based on their molecular weight and mass density. The second approach is to use the artificial neural networks (ANNs) for estimation of PC-SAFT parameters for the... 

gas adsorption in porous solids and adsorbent,is the important cases in gas processing industries. Including the removal of compounds such as carbon dioxide, hydrogen sulfide and mercaptans from sour gas in natural gas sweetening industry is of great importance.Also in solving the greenhouse phenomena extraction of gases such as methane and carbon dioxide of important environmental issues.To understand and predict the behavior of the absorption capacity of various adsorbents and thus the possibility of absorption systems, a mathematical model is needed.Library resources available in order to determine the kinetics and thermodynamic processes of gas adsorption on solid absorbents use... 

Serum osmolality is an important physiological quantity that is directly related to health condition of human body. Glucose, urea, and NaCl are the main components which determine the value of serum osmolality. Besides, calcium and potassium are vital inorganic cations for the body. Thus, it is of high importance to investigate the interactions between these physiological solutes in aqueous solution. Thermodynamic quantities like osmotic and activity coefficients contain enthalpic and entropic information and thus are a direct measure of interactions in these complex systems. Thus, theoretical and experimental methods were applied to investigate these thermodynamic parameters in multi-solute... 

Acidizing is one of the most effective techniques to remove the formation damage and restore (or even increase) the permeability of the near wellbore region. Although this technique is widely used to resolve the skin problem, it could initiate new damages itself that hinder the fluid flow and decrease the well production, consequently. Acid-oil emulsion and sludge formation are known as two major induced formation damage and the main reasons for the oil well acid treatment failures.When the HCl is reacted with asphaltenic crude oil during matrix acidizing, it results in unexpected damage at the near wellbore region and hinder the fluid flow through certain mechanisms include:
1- Pore... 

Nowadays, one of the most basic human problem is how to manage energy resources for sustainable development and how to deal with problems caused by growing energy consumption. Various scenarios are being discussd that the most important of them can be considered research on finding alternative energy sources that are renewable and do not have common pollution. Thus, according to researches carried out until now, using sources such as wind, water, solar biomass, etc. have been proposed. However, due to problems in the development of each of these sources, biomass as the primary option has been introduced. because biomass has several subsidiaries, research shows microalgaes (as a subset) are... 

Hydrogen gas is considered as a clean fuel and energy carrier that its storage for future uses is a challenging issue. One of the methods to store it, is adsorption on a group of adsorbents called metal-organic frameworks. In this research, one of these frameworks called ZIF-8, has been selected to study hydrogen storage capability. To evaluate the effect of having two metals, a mixture of two metals was used in the synthesis process. To characterize the structure of the synthesized adsorbents, X-ray powder diffraction (XRD),adsorption and desorption of nitrogen at temperature of 77 K, Field Emission Scanning Electron Microscopy (FESEM), energy-dispersive X-ray Spectroscopy (EDS) and... 

consumption of which (especially azo dyes) have been increasing nowadays, causing the increase of textile wastewaters. Usually, these wastewaters contain an immense number of dyes, and if these dyes release in the environment especially in waters, they cause some problems, such as the change of watercolor as well as taste, and affect creatures' lives severely. Moreover, If the dyes are left untreated in aquatic ecosystems, they can remain in the environment for a very long time, resulting in harmful and irreversible effects. Azo dyes are classified as mono, di-, three, azo dyes due to their bonds. Because dyes are increasingly used, nowadays, different methods are developed for the treatment... 

Crude oil production could cause the thermodynamic equilibrium of the crude oil to be disturbed in the well column which results in asphaltene precipitation and deposition. The thickness of the deposited material grows over time until it completely blocks the well column.Due to the hard and insoluble nature of deposited asphaltene, the two main chemical and mechanical methods are found to be more effective. It should be noted that the actual organic sediments in the piping are not pure and consist of three components: asphaltene, resin and paraffin. Therefore, it is very important to know the composition of the deposited material before selecting the appropriate chemical solvent.The samples...