اسم المؤلف:
هالة حسين حسن ابو نايلة
اسم المشرف:
محمد فاضل عبد
شاكر محمود احمد
المستخلص:
ان النمو المضطرد في انتاج النفوط الثقيلة والطلب المتزايد على المقطرات الوسطيه اعطى اهمية قصوى لعمليات التكسير في المصافي النفطية، وتعتبر طريقة (H - Oil) باستخدام مفاعلات الطبقة الفوارة واحدة من اهم عمليات التكسير المحفز والتي تهدف الى تكسير النفوط الثقيل | The present work was devoted to study the hydrodynamic characteristics of a lab - scale cold - flow ebullated bed three phase column. It was also to investigate the kinetic behavior of an industrial - scale ebullated bed reactor, licensed by Axens Co., installed and operated in Lukoil refinery at Bourgas - Bulgaria.For the design of experiments in the lab - scale cold - flow column, factorial method was introduced to study the influence of the operating variables (i.e., gas and liquid superficial velocities and the liquid internal reflux ratio) on the objective functions (i.e., individual holdups and bubble characteristics).Pressure gradient method was used to estimate the individual holdups and bed porosity along the column, while photographic method was utilized to obtain images of the moving gas bubble which analyzed using Ai Adobe Illustrator CC (64 Bit) software to determine the geometric characteristics of bubbles.The results showed that liquid internal reflux ratio, which characterized the ebullated bed three phase bubble column, has a predominant effect on the individual holdups and bubble sizes.The operating and geometric variables of the lab - scale cold - flow ebullated bed were carefully selected to simulate the hydrodynamic characteristic of the industrial unit through matching five dimensionless groups (M - group, E?tv?s number, Reynolds number, density ratio and velocity ratio) of the cold - flowlab - scale and industrial systems.The percentage average deviations between each two particular groups of the two systems were (14.7%, 25%, 13.14%, 15.2%, and 20%), respectively. Although this did not result in a perfect match, considering the uncertainty in the industrial units exact operating properties, the match was considered to be sufficiently close.A five - lump kinetic model was selected, to describe the catalytic hydrocracking of heavy oil, to formulate the reaction rate equations of vacuum residue, vacuum gas oil, middle distillate, naphtha, and gases. These equations were inserted into the individual mass balance equation of each lump and then utilized in a program of MATLAB based on the nonlinear least square method to estimate the kinetic parameters (rate constants and activation energies of the proposed reaction pathways), to investigate the effect of the operating variables (e.g., operating temperature, WHSV, and reaction time ) on the kinetic parameters and performance of the industrial ebullated bed reactor. It was found that, - The intra - pellet (internal) diffusion was the rate - limiting step in the H - Oil reaction system. - The effectiveness factor decreases with increasing reaction temperature and WHSV. - The outcomes of the mathematical model confirmed the reaction orders of hydrocracking of vacuum residue and catalyst deactivation to be 2.1 and 0.18, respectively. - Activation and deactivation energies resulted to be quite similar of 48.87 and 50.68 kcal/mole, respectively, meaning that there is no strong effect of the deactivation process over the global hydrocracking reaction. - The hydrocracking of vacuum residue has a higher selectivity toward VGO production than toward other lumps in the following order : VGO < Middle Distillate < Naphtha <Gases. - WHSV has a negative impact on yield fractions of the industrial ebullated bed reactor while the images were different with the operating temperature. The formulated model was validated by comparing its outcomes with the findings of other related model (e.g Sa´nchez and Ancheyta, 2007) from literature. The results of comparison confirmed the reliability of the present model.Key words : Hydrodynamic, Kinetic Parameters, Heavy Oil, Ebullated Bed, Reactor.
اسم المؤلف:
هدى كاظم حسن
اسم المشرف:
ثامر جاسم محمد
قصي فاضل عبد الحميد
المستخلص:
يتم انتاج كميات كبيره من الماء المصاحب النفطي من قبل شركة نفط الجنوب.يعتبر محتوى النفطي oil - water والاملاح الذائبه TDS من اخطر الملوثات والتي تتم معالجتها باحدث التكنلوجيا في السنوات الاخيره تم استخدام تقنية الاغشية لمعالجة الماء المصاحب النفطي.الهدف م | A large amount of oil field produced water is generated by South Oil Company. Oil - in - Water and TDS are the most serious pollutants for which current treatment technologies are often costly and ineffective in order to reuse water. In recent years, membrane process has been applied for produced water treatment.The aim of the present work is to treat produced water from oil well before being disposed in environment or reused as re - injection to oil well or agriculture water. Oil field produced water is very difficult wastewater to treat and its characteristics change as well to well. The sample test of this study was taken from dehydrator in the DSI/North Rumila/Southern Oil Company in Basrah /Iraq. The treatment process of produced water consists of two stages. The first stage as pre - treatment is achieved by continuous dissolved air flotation (DAF) to reduce the oil content. The second stages, as advanced treatment processes, are accomplished by microfiltration (MF) to reduce the turbidity and nanofiltration (NF) to reduce the salt content as TDS of produced water. The experimental work was carried out using dissolved flotation column is of Perspex glass (0.1 m I.D, 1.5 m height). The bottom of the column connected to a conical joint of QVF glass with a Teflon distributer. The effect of operating parameters (flow rate of produced water, pH, initial oil concentration, flotation time, alum dosage and surfactant of SLS) saturated pressure=5 Atm on the oil content or oil removal efficiency was investigated. The results showed that the oil removal efficiency increases with increasing the flow rate of produced water, the flotation time and coagulants dosage. The oil removal efficiency in DAF unit without coagulants is equal to (80, 94, 95%) for initial oil concentration (30, 50, 70 ppm), respectively at a flow rate 0.03 m3/h and pH=6. While flotation with coagulation, the results indicated that the removal efficiency is equal to 94% (residual oil content <10 ppm) at pH=5, alum dosage=560 ppm, and initial oil concentration=50 ppm, and the removal efficiency is equal to 89.6 at pH=6, alum+SLS dosage=80 ppm, and initial oil concentration=50 ppm. The kinetics of flotation column was studied and it was found that the order of the reaction is changing between zero to first order.The treatment of produced water by membrane technique was carried out by cross flow mode in hallow fiber microfiltration (MF) and nanofiltration (NF). The effect of operating parameter such as transmembrane pressure (TMP) (1, 1.5, 2 bars) with cross flow 20 mL/min, at room temperature, on the flux, rejection, and turbidity and TDS removal was studied. The experimental results by MF manifested that the permeation flux is (108, 156, 611 l/m2.h) and transemembrane pressure is 2 bar at initial turbidity (100, 200, 300 NTU), respectively. But NF, as a final treatment of produced water to reuse, was studied at different feed concentrations (82950, 75050, 67150 ppm) with different TMPS. According to the experimental results, the higher permeation of flux =15 (l/m2.h) at 82950 ppm and 2 bar, was obtained.The experimental results of the removal efficiency were represented in two and three dimensional graphs. An empirical correlation for R% as a function of different parameters (flow rate, pH, and oil concentration) was developed by aided computer using the following formula %R= a + c1*x1n1 + c2*x2n2 + c3*x3n3.
