Current Issue : January - March Volume : 2015 Issue Number : 1 Articles : 5 Articles
The metal surface effects produced with various blasting abrasives can range from deep cutting to gentle scouring of the surface. Important factors to consider in selecting an abrasive include: type of surface to be cleaned, shape of the structure, type of material to be removed, surface finish desired, profile, breakdown rate of the abrasive, reclamation of the abrasive, hazards associated with the use of the abrasive. The types of available abrasives vary from one part of the country or the world to another. The general categories are: steel shot, metal grit and mineral abrasives. Naturally occurring ores includes; sand, garnet, ilmenite and white sand are probably the most commonly used for blast cleaning of metallic surfaces before applying protective painting. This study covers the specification and the quality of some nonmetallic ores (sand, garnet, ilmenite, white sand), utilized as abrasive materials used in the blast cleaning of metal surface such as petroleum construction projects, ships, hulls and tanks to remove rust, scale, old paint and marine growth, also to provide the required anchor “profile” necessary for bonding of paint layers with metal substrate. The study program shall compare between the physical, chemical and mechanical properties of Egyptian, Indian, Chinese and Austrian ores to demonstrate the complete figure for the proper abrasive media can achieve the standard metal surface preparation before applying protective coatings in the oil, gas, petrochemical construction projects. The evaluation techniques to evaluate the quality of the various nonmetallic abrasive ores incorporated laboratory and field testing including physical properties (specific gravity, moisture content, pH value, Particle size distribution, free flow, Conductivity, oil content, Hardness), chemical analysis and field particle testing. The study indicates that the GMA Australia garnet, Egyptian Garnet, China and Indian garnet gives a very good result for steel surfaces cleaning, profile, no dust contamination and very low level of slat contamination in comparison with other non metallic ores....
The geochemical composition, API gravity, sulfur content and asphaltene content were determined for the crude oil samples collected from Gharib-164, Gharib-163, Gharib-106, Gharib-116 wells within the Ras Gharib oilfield located in the central Gulf of Suez. Saturated hydrocarbon fractions were subjected to gas chromatography and gas chromatography–mass spectroscopy in order to characterize the type of organo-facies, oil classes and depositional environments, as well as, to assess the thermal maturity level for oil generation. The results showed that the studied oils are belonging to normal oils classes with no heavy biodegradation. Also, the crude oils are more mature and sources derived mainly from mixed organic sources from terrestrial and marine inputs contribution to the biomass from algae and plankton in different saline environments....
Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired\nproduct. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the\nmechanism of the reaction and rate constants.Theobjectives of this research are to develop the kinetic parameters for determination\nof methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine\nthe influence of reaction characteristics (reaction temperature,methanol to oilmolar ratio, and the amount of catalyst) on selectivity.\nFor this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for\nselectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were\nestablished. An enhanced selectivity was found in the base case of transesterification reaction.The selectivity was greatly improved\nat optimum reaction temperature (60?C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock.\nFurther research might explore the application of selectivity for specifying reactor configurations....
The production of synthetic or substitute natural gas (SNG) from coal is a process of interest in Colombia where the reserves-toproduction\nratio (R/P) for natural gas is expected to be between 7 and 10 years, while the R/P for coal is forecasted to be around\n90 years. In this work, the process to produce SNG by means of coal-entrained flow gasifiers is modeled under thermochemical\nequilibriumwith the Gibbs free energy approach.Themodel was developed using a complete and comprehensiveAspen Plusmodel.\nTwo typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated. Emphasis\nis put on interactions between the fuel feeding technology and selected energy output parameters of coal-SNG process, that is,\nenergy efficiencies, power, and SNG quality. It was found that coal rank does not significantly affect energy indicators such as cold\ngas, process, and global efficiencies. However, feeding technology clearly has an effect on the process due to the gasifying agent.\nSimulations results are compared against available technical data with good accuracy.Thus, the proposed model is considered as a\nversatile and useful computational tool to study and optimize the coal to SNG process....
This study investigates the unsteady natural convection and mass transfer flow of viscous reactive, heat generating/absorbing\nfluid in a vertical channel formed by two infinite parallel porous plates having temperature dependent thermal conductivity.The\nmotion of the fluid is induced due to natural convection caused by the reactive property as well as the heat generating/absorbing\nnature of the fluid. The solutions for unsteady state temperature, concentration, and velocity fields are obtained using semi-implicit\nfinite difference schemes. Perturbation techniques are used to get steady state expressions of velocity, concentration, temperature,\nskin friction, Nusselt number, and Sherwood number. The effects of various flow parameters such as suction/injection (?), heat\nsource/sinks (S), Soret number (Sr), variable thermal conductivity (?), Frank-Kamenetskii parameter (?), Prandtl number (Pr),\nand nondimensional time (t) on the dynamics are analyzed.The skin friction, heat transfer coefficients, and Sherwood number are\ngraphically presented for a range of values of the said parameters....
Loading....