الفهرس | Only 14 pages are availabe for public view |
Abstract An investigation has been carried out to evaluate the extent of adsorption of the different solid materials; acid-treated kaolinite clay (El Tih plateau- Sinai peninsula), acid-treated bentonite clay (El Fayoum district), charcoal, petroleum coke and cement-kiln dust (by-product generated in the production of Portland cement clinker). These solid materials have been characterized by applying different techniques; x-ray analysis, differential thermal analysis and thermo-gravimetric analysis, acidity and pore size distribution. X-ray analyses were carried out to investigate the crystalline structure (x-ray diffraction) and the constituents of the solid materials (x-ray fluorescence). Differential thermal analysis and thermo-gravimetric analysis were carried to trace the structural changes accompanying the thermal treatment. The acidity was measured to study the effect of acid treatment on the acidity of the produced protonated materials as well as the effect of impregnating nickel on the acidity of the produced guard bed material. Pore size distribution has been also made to exhibit the change in the porosity of the parent material along with the impregnation of nickel to prepare the guard bed catalyst. Since sulfur compounds are the main cause of the color and color instability of petroleum products. The removal of sulfur compounds from their solutions was the general trend of this work. The adsorption of dimethyldisulfide from its solution in cyclohexane was taken as a measure of solid materials efficiency. Preliminary tests were performed in a batch, usmg investigated volume of dimethyldisulfide in cyclohexane solution (with concentration varying from 0.05 to 0.42 vol.%) and two grams portions of the solid samples at reaction temperature 30°C for six hours to measure the extent of adsorption of the various solid materials used. According to the data obtained under the experimental conditions, the most suitable adsorbent was evaluated, and from which the guard bed adsorbent was prepared. The catalytic activity of the guard bed adsorbent towards hydrodesulfurization reaction was performed in a flow system operated under atmospheric pressure. The hydrodesulfurization reaction of dimethyldisulfide from its solution in cyclohexane, as well as the catalytic gasoline hydrodesulfurization were carried out at a temperature ranging from 200-350°C and at space velocities 3.1 and 1.4 hr-1. |