فهرست مطالب

Chemical Engineering - Volume:9 Issue: 4, Autumn 2012

Iranian journal of chemical engineering
Volume:9 Issue: 4, Autumn 2012

  • تاریخ انتشار: 1391/10/11
  • تعداد عناوین: 7
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  • A. R. Bastami, M. Delshad, P. Pourafshary Page 3
    Water flooding, the oldest and most common EOR method, increases the displacement efficiency in a reservoir and also maintains the reservoir pressure for a long period of time. In Iran, water injection is widely used as a method to enhance recovery from oil reservoirs. Defining the optimized injection rates and injection patterns, dependent on the geological structure of the reservoir, is essential in operational and economical decisions for reservoir management. In this paper, the Capacitance-Resistive Model is used to find interwell connectivity, and optimized injection rates in a synthetic field. In this approach, the reservoir receives injector rate variations as an input signal, while the producer responses determine the injector/producer pair connectivity quantitatively. This model is used to predict oil production for a specific reservoir, if the production/injection rate and bottomhole pressure data are available. The results show that the Capacitance-Resistive model has the capability to be used for the production history matching and to optimize the injection rate in different wells of a reservoir during the immiscible flooding to maximize the oil production. Moreover, they show that any change in oil and water prices can significantly influence the optimized water injection rates.
    Keywords: Waterflooding, Water Injection, Production Forecast, Optimization, Capacitance Resistive Model
  • J. Shayegan, A. Babaee Page 16
    In recent decades, large amounts of hydrocarbon derivations have contaminated the environment due to industrial developments and neglecting the environmental issues. In this study, the ability of biological removal of hydrocarbon pollution from contaminated soil around Sarkhun gas refinery was investigated. This study was done for seven samples with three different nutrient ratios and by moisture controlling and continuous aeration. During experiments, concentration of Total Petroleum Hydrocarbon (TPH) was measured. Results showed that with a nutrient ratio of 100:5:1 for C:N:P during an 18-day remediation period, the mean contaminant removal was about 50%. By using these results a practical plan was suggested for running in real scale situations. Developing a model was done by considering the Monod model as microbial growth model. Results showed good accordance to empirical data.
    Keywords: Enhanced Bioremediation, Contaminated Soil, TPH, Gas Condensates, Sarkhun Gas Refinery, Monod model
  • M. R. Shahnazari, F. Eslami, Sh. Rezazadeh Page 25
    Stability analysis of miscible displacement has several applications in industries such as oil recovering and ground water tables. In this article an analytical solution is presented based on Tan and Homsy’s results for stability analysis in t = 0. Moreover, a novel semi analytical solution is used, based on weighted residual method, to solve the Fourier space equations. The results are shown as  (disturbance growth rate) – k (wave number); profiles for different values of mobility ratios and times. A comparison with the results of the other researches is also presented. Stability Analysis, Displacement, Miscible Fluid, Porous Medium
    Keywords: Stability Analysis, Displacement, Miscible Fluid, Porous Medium
  • M. Sheikhabbasi, F. Feyzi Page 33
    In direct molecular dynamics simulations (MD) of inhomogeneous systems the density is distributed across the interface and, as a result, the conventional long range corrections cannot be used for these systems. In this work, to correct the results of MD simulations for vapor-liquid equilibrium of methane, we have used the slab based corrections to the direction perpendicular to the interface(z-direction) of the force affecting on each particle. All the particles in each slab are considered to have the same coordinate in the z-direction. The density profiles from preliminary simulations with large cut-off distance values were used for the calculation of long range correction terms. New sets of simulation runs, including long range corrections, were then executed with smaller values of cut-off distance. By employing this approach, more accurate results by the cut-off radiusRc=2.5σ in comparison with those produced with the cut-off distance Rc=5.5σ without applying the long range corrections, are observed for the values of the coexisting densities and the surface tension.
    Keywords: Molecular Dynamic Simulations, Inhomogeneous Systems, Long Range Corrections
  • A. A. Amooey Page 49
    In this study, adsorption data for the case of energetically heterogeneous solid surface are modeled using artificial neural network. A neural network with three hidden neurons, including the bias, was able to predict very accurately the temperature dependency of adsorption data. The results were compared with experimental data (over temperature range 273-313 K and 0-2 MPa pressure) and it was found that the predictions of the artificial neural network model fit the experimental data very accurately.
    Keywords: Artificial Neural Networks, Heterogeneous Solid Surfaces, Adsorption
  • M. Malekydozzadeh, P. Khadiv, Parsi, Sh. Rezazadeh, H. Abolghasemi, Z. Salehi, Q. Li Page 54
    In this work, a new process design and clean production to increase the yield of steam distillation of rosemary essential oil was studied. For extraction of essential oil, a packed bed of rosemary was exposed to the steam flow. For improving the total yield, multistage bed column was used. The effects of steam flow rate, height of plant bed, multistage beds and time of extraction on yield and composition of the oil were studied. Also, trend of three major components of the oil during different extraction times and conditions were observed. We determined minimum steam to be passed through the packed bed so that there is minimum water in the distillation and hence, steam channeling phenomenon was overcome. Furthermore, we obtained optimum steam flow rate and time for extraction of the oil. Using a multistage column with suitable steam redistributors results in reduction of pressure drop, and steam channeling in the column, hence, increacing the yield of extraction. This research revealed different behaviors of the main components of rosemary oil; α-pinene, 1,8-cineole and camphor in treating with amount of steam flow rate.
    Keywords: Multistage Column, Rosemary Plant, Essential Oil, Steam Distillation
  • A. Chackoshian Khorasani, S. Yaghmaei Page 65
    Soil bioremediation, especially in the rhizosphere area, is the result of interaction between plant roots and microorganisms. It can be considered as one of the remarkable ways to eliminate pollutants. Various factors control the process with special relationships in the rhizosphere environment; changing each of them can impress on the system destination. With mathematical modeling, behavior of the process can be predicted and controlled, and improved by appropriate changes in the model. In this study, the effects of different parameters of a simple mathematical model, represented to predict microbial growth and necessary substrate changes in the rhizosphere have been studied using numerical finite difference method. Influences of the parameters on biomass and substrate concentrations were evaluated at different times. A number of variables directly, some negatively, and others neutrally impacted on the biomass and substrate concentrations. Investigating variables differently affecting on a model is important since perfectly tuning them can optimize the system performance, and achieve higher efficiency.
    Keywords: Mathematical Model, Numerical Solution, Soil Bioremediation, Rhizosphere