Sharif Digital Repository

In an increasingly environmentally conscious world, the petroleum industry is faced with the requirements of sustainable development. Petroleum refining is a capital intensive industry consuming much energy that it's cost rises sharply due to high oil price recently. Furthermore, Because the primary source of carbon dioxide discharge is energy use, the regulation requires reduction of energy use. Heat exchanger network synthesis problems (HENs), as a standard problem in process design , have attracted significant research because of the large saving that can be achieved in energy costs. In this work, Heat exchanger network of distillation unit is used as a case study to reduce energy... 

Hydrocracking is one of the most versatile petroleum refining processes for production of valuable products including gasoline, gas oil, and jet fuel. In this paper, a five-parameter continuous lumping model was used for kinetic modeling of hydrocracking of vacuum gas oil (VGO). The model parameters were estimated from industrial data obtained from a fixed bed reactor operating at an average temperature of 400°C and residence time of 0.3 h. Product distributions were obtained in terms of the weight fraction of various boiling point cuts. The model parameters were estimated using the Nelder-Mead optimization procedure and were correlated with temperature. Comparison of experimental and... 

Petroleum production often involves simultaneous flow of three immiscible fluids through porous rock formations. The objective of this work is to experimentally measure two and three phase relative permeabilities and to evaluate the existing relative permeability prediction models. We used typical Berea sandstone with refined mineral oil, distilled water and nitrogen gas. The measurements were carried out at temperature of 23°C and pressure of 800 psi. Two and three phase relative permeability measurements were obtained using the steady state technique. The three-phase experiments are conducted in the imbibition mode. The flow rates of brine and gas were increased gradually and the oil rate... 

Background: To meet stringent emission standards stipulated by regulatory agencies, the oil industry is required to bring down the sulfur content in fuels. As some compounds cannot be desulfurized by existing desulfurizing processes (such as hydrodesulfurization, HDS) biodesulfurization has become an interesting topic for researchers. Most of the isolated biodesulfurizing microorganisms are capable of desulfurization of refined products whose predominant sulfur species are dibenzothiophenes so biocatalyst development is still needed to desulfurize the spectrum of sulfur-bearing compounds present in whole crude. Results: The first desulfurizing bacterium active at 60 °C has been isolated,... 

After a brief review of the global gas flaring and venting in oil industries including the emission of air pollutants and greenhouse gases and the amount of energy resources wasted, the focus is on Iran as a major oil producing and the world's third largest gas flaring country. Gas flaring is also practiced in natural gas industries, petroleum refining and petrochemical plants, although the level of emission is very low compared with emissions from oil production. The historical emission of these gases globally and Iran specifically, geographic location of emission sources, composition of gases, environmental impacts of gas flaring and the current and future projects to mitigate emissions... 

An experimental investigation was conducted on the oxidative desulfurization of model sulfur compounds such as dibenzothiophene and benzothiophene in toluene as a simulated light fuel oil with a mixture of hydrogen peroxide as the oxidant and various acids as the catalyst. The influences of various parameters including reaction temperature (T), acid to sulfur molar ratio (Acid/S), oxidant to sulfur molar ratio (O/S), type of acid, and the presence of sodium tungstate and commercial activated carbon as a co-catalyst on the fractional conversion of the model sulfur compounds were investigated. The experimental data obtained were used to determine the reaction rate constant of the model sulfur... 

The aim of this work is to study the effect of cooling rate and subsequent hot consolidation on the microstructural features and mechanical strength of Al-20Si-5Fe-2X (X = Cu, Ni and Cr) alloys. Powder and ribbons were produced by gas atomization and melt spinning processes at two different cooling rates of 1 × 105 K/s and 5 × 107 K/s. The microstructure of the products was examined using optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The particles were consolidated by hot pressing at 400 °C/250 MPa/1 h under a high purity argon atmosphere and the microstructure, hardness and compressive strength of the compacts were evaluated....