فهرست مطالب امین شفقت

Reducing environmental pollution via elimination of sulfur compounds from gas condensate was the aim of this research. Whereby oxidative desulfurization from gas condensate with 3200 ppm initial sulfur was accomplished by hydrogen peroxide (30%wt) as oxidant and formic acid as catalyst. The sulfones after generation in the oxidation step were extracted through a method of liquid-liquid extraction by acetone as a polar solvent. The effects of variables: coefficient of oxidant to sulfur molar ratio (O/S), temperature (T), and coefficient of catalyst to oxidant molar ratio (C/O) were investigated. The experiments were designed with response surface methodology based on central composite design (CCD). The results of experiments demonstrated that none of these variables (O/S, T, and C/O) have any interaction, and among these variables, O/S plays a significant role with the most influence on desulfurization and C/O and T are of the second and third primary of importance, respectively. In addition, 86% desulfurization was obtained in the optimum conditions.

The coke used in aluminum production should possess certain sulfur content (below 3 wt. %). The application of sulfur rich coke will have detrimental effects on the environment. In the aluminum production industry, high sulfur anodes have a lower life span and higher energy consumption, as well as high environmental effects during electrolysis, which are unfavorable to aluminum industry. Therefore, desulfurization of coke is very essential. There are several petroleum coke desulfurization methods. The main objective of this research is the investigation of different petroleum coke desulfurization methods in order to obtain low sulfur coke. The reduction of petroleum coke sulfur not only provides the feed for aluminum production units, but it also protects the environment. This doubles the importance of petroleum coke desulfurization. Different desulfurization methods such as solvent extraction, calcination, separation with molten compounds and hydrogen purification are used in order to remove C-S bonds in petroleum coke. Studies have shown that coke desulfurization by solvent extraction of 35%, calcination of 90%, separation with molten materials 93%, and hydrogenation of 90% have been achieved, which according to the operational conditions of the processes and changes in the coke eventually The desulfurization method is used industrially by calcination.

Environmental restrictions on emission due to fossil fuel combustion have pushed refiners to decrease the sulfur content of products like gasoil and gasoline. The simple concept of ODS method has drawn the attention of many research groups in last few years. Some advantages of this method comparing to other new ones include its simplicity, mild operation condition, low investment cost, and no hydrogen consumption. Many aspects of this process have been investigated; therefore, some different reaction systems are developed. The basis of ODS is oxidizing the organo-sulfur compounds to their sulfones and then removing sulfones from hydrocarbon media. The combination of new technical facilities and traditional chemical processes tend to improve the chemical reaction systems. In this study, by using the ultrasonic waves, the sulfur content of a gasoil sample is decreased to an acceptable limit by Euro environmental laws. Optimum parameters for maximum desulfurization are determined by the analysis of experimental design results. Applying the ultrasonic waves and using optimized parameters, more than 90 percent desulfurization and less than 5 percent hydrocarbon losses are achieved.