Abstract This research was an attempt to use the currently available activity coefficient methods with universal sets of parameters to simultaneously predict ternary liquid-liquid equilibrium data. The focus of this research was to calculate phase equilibrium data within fair error using set of Parameters obtained from the above-mentioned models. The significance of this work is to study the liquid-liquid phase equilibrium of the ternary system at several temperatures and to test the capability of the various equilibrium models to correlate these data. A series of liquid-liquid equilibrium measurements were performed by changing the composition of the mixture.The prepared mixtures were placed in the extraction vessel and stirred for 2 h and then left to settle for 4 h. Samples were taken by a syringe from both the upper phase and lower layers. Both phases were analyzed using gas chromatography equipped. Liquid-liquid equilibrium for the ternary system acetonitrile + benzene + n-heptane was measured at 298,313,333 K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models. The UNIQUAC equation was the most accurate model in correlating the overall equilibrium compositions of the studied system. NRTL models satisfactorily predicted the equilibrium compositions. In each of the mentioned the ternary system, the calculated and experimental data were compared. The root mean square deviation (RMSD) between the observed and calculated mole percent for NRTL, UNIQUAC was 1.44%, 1.35% for acetonitrile + benzene + n-heptane
عماد الدين محمد الزغداني (2014)

Abstract Deposition of undesirable materials on water wall side of boiler tube that are operated under forced circulation boiling conditions can cause serious trouble in steam boilers. The present study is concerned with the scaling characteristics of water in the boilers. The effects of heat flux and water velocity were evaluated for water having a total hardness and calcium hardness in the range (TH= 380 to 390 ppm asCaCO3 ) and(CaH= 250 to 298 ppm asCaCO3) respectively. The heat flux ranged from (1.05 x 105) to and water velocity in a vertical annular test section range from 0.51 to 0.75 m/sec (1.67 to 2.5 ft/sec) . The test section consisted of an annular duct 0.050 m (2.0-in) O.D. and 0.033 m (1.33-in ) I.D. A 0.30 m (12-in) section of the concentric core of the annulus was electrically heated. Hot water at 97.0 (370.1) was circulated through the annulus where boiling occurred on the heated section. The temperature range at the Surface of heated section in the annulus was from (105 - 118 ). The results of five tests are reported in this study. The fouling resistance vr. time curves reached an asymptotic value and the average of fouling resistance for Runs (1-5) had been plotted. Chemical analysis of scale deposits indcated that Calcium carbonate and Silica were the man Constituents. At constant surface temperature an increase in velocity from 0.51 to 0.75 m/sec (1.67 -2.5 ft/sec), caused about a 20 percent reduction in the asymptotic fouling resistance.
عادل محمد شنقير (2008)

دراسة ضمان التدفق هو احدي أهم العمليات التحليلية لمرور الزيت والغاز خلال الأنابيب والمعدات البتروكيميائية. هذه الدراسة تساعدنا فى تصميم وتشغيل وصيانة خطوط الزيت و الغازوخاصة الخطوط الموجودة في أعماق البحار. يعتبر الشمع والهيدريت من أهم المشاكل التى تواجه نقل الزيت والغاز عبر الأنابيب هذه المشاكل تكلف خسائر مالية كبيرة عن طريق اغلاق جزء من انابيب نقل الزيت والغاز. ولتجنب الوقوع فى خطر الهيدريت والشمع يجب ان تكون كل من درجة الحرارة والضغط بعيدة عن تكون الشمع والهيدريت. تضمنت هذه الدراسة تضمنت فحص تأتير كل من اللزوجة, متوسط الوزن الجزئ, نسبة الشمع, سمك العازل, الزمن ودرجة الحرارة الخارجية على ترسب الشمع على جدار أنابيب النقل. وكذلك قمنا بدراسة متى وأين يتكون الهيدريت باختيار زيوت وغازات مختلفة. من أهم النتائج التى تحصلنا عليها من خلال دراسة ترسب الشمع على الأنابيب وتكون الهيدريت كالأتي :أقل لزوجة في الزيوت الشمعية كانت عنده أعلى قيمة ترسب الشمغ علي الأنبوب .زيادة سمك العازل ودرجة الحرارة المحيطة تقلل ترسب الشمع على الأنابيب .زيادة زمن التشغيل تزيد من ترسب الشمع علي الأنابيب .دراسة تكون الهيدريت باستخدام برنامج كمبيوتر (HYSYS وPVTSIM) كانت النتائج المعملية قريبة من النتائج المعملية عند درجة حرارة وضغط منخفض. اضافة مواد كيميائية احدى الطرق التى تبعدنا عن خطر تكون الهيدريت. Abstract Flow assurance is the analysis of thermal, hydraulic and production chemistry issues during the flow of fluids through pipelines and process equipments in the oil and gas industry. These issues arise during the design, operation and maintenance of Gas/oil supply systems, which are often in deep water or challenging environments. Flow assurance studies are usually carried out at design and production stages to insure oil and gas flow in pipe lines and process equipment without any problems. Wax and hydrates are problems associated while gas and oil are transported. Wax deposition is a serious field problem encountered during crude oil production that causes plugging of pipe line, well tubing and process equipment. Wax crystals lead to oil high viscosity and decreased pumping capacity. Gas hydrates are a well-known problem in the oil and gas industry and cost millions of dollars in production and transmission pipelines. To prevent this problem, it is important to predict the temperature and pressure under which gas hydrates will form. This work aims to investigate the major flow assurance aspect (wax deposition and hydrates formation) in flow lines. This may include; Effect of oil viscosity, oil wax percent, average moleculer weight of oil, ambient temperature, insulation thickness and time duration on wax deposition rate in pipelines. In addition concerning hydrates, the main important issue is when and where hydrates will form in flow lines and gas pipelines. five different oils and different gases from literature where selected and utilized as working examples.The important results of wax deposition and hydrate formation are as the following: The lowest viscosity of five crude oils give us the maximum total volume deposition.Increasing of insulation thickness and ambient temperature causes decreasing wax layer deposition.Increasing of time duration causes increasing of wax layer thickness. Hydrate formation by using HYSYS and PVTSIM at law temperature and law pressure is closed to the hydrate formation by experimentally. Adding chemicals (inhibitors) saved the gas through a pipeline from the risk of hydrate formation. The obtained results show that wax deposition and hydrates formation can be predicted with good accuracy with computer soft ware.
المبروك فرحات المسلاتي (2014)