البحث — المستودع الرقمي العراقي

نتائج البحث: 15 من أصل 40

ازالة الكبريت من زيت الوقود باستخدام الاكسدة المعززة بالموجات الفوق الصوتية == Ultrasound - Assisted Oxidative Desulfurization of Fuel Oil

اسم المؤلف: جعفر مازن جعفر

اسم المشرف: نيران خليل ابراهيم | ولاء عبد الهادي نوري

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: ماجستير

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: Due to the dramatic environmental impact of sulfur emissions associated with the exhaust of engines, sulfur content specification for diesel fuels became more and more stringent worldwide. Last environmental regulations for ultralow sulfur diesel require very deep desulfurization processing, which cannot be met by the conventional hydrodesulfurization process (HDS).The present work focuses on benefiting from integrating an ultrasoundassisted oxidative desulfurization process (UAODS) with the conventional HDS process to produce ultra - low sulfur fuels. The proposed method involves a batch ultrasound - assisted oxidative desulfurization process to desulfurize a previously hydrotreated diesel containing 480 ppm sulfur. The oxidizing system used was H2O2/CH3COOH with FeSO4 being used as a catalyst. An ultrasonic probe system was used to enhance the conversion of sulfur - bearing compounds that exist in diesel to sulfones and sulfoxides to affect their removal by a certain separation method, such as extraction or adsorption.The major influential parameters related to UAODS process have been investigated, namely : ratio of oxidant/fuel, ratio of the promoter/oxidant, dose of catalyst, reaction temperature, intensity of ultrasonic waves. A set of comparative studies were also carried out including type of extraction solvent, effect of initial sulfur content, and type of sulfur separation method. Total evaluation for the treated diesel was performed, including GC - MS analysis which has been used to monitor the change of organic sulfur compounds andhydrocarbons in diesel during the desulfurization process.The oxidation treatment, in combination with ultrasonic irradiation, revealed a synergistic effect for diesel desulfurization. The experimental results showed that the removal efficiency for sulfur compounds could amount to 98%, and sulfur level can be reduced to 12 ppm at mild operating conditions (70 and 1 bar). This indicates that this process is so efficient and promising for the production of ultra - low sulfur diesel fuels.The kinetics of the reaction has been also studied. It was observed that the UAODS of diesel fuels fitted pseudo - first - order kinetics under the studied experimental conditions. During this process, values of the apparent rate constant and activation energy were 0.373 min - 1 and 24 kJ/mol, respectively.

تخمين حركية تفاعل ازالة الكبريت للنفثا الثقيلة العراقية == Prediction of Kinetic Reaction of Iragi Heavy Naphtha Desulferization

اسم المؤلف: سها سامي قاسم

اسم المشرف: زيدون محسن شكور

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: دبلوم عالي

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: واحدة من التحديات في مصافي تكرير النفط الخام في الاونة الاخيرة هو الحد من محتوى الكبريت من النفثا الثقيلة الى الحدود الدنيا. في هذا البحث تم اخذ مواصفات محتوى الكبريت للنفثا الثقيلة بمعدل 632 جزء في المليون الى 2.5 جزء في المليون، في درجات حرارة التفاعل ( | One of the recent challenges in the petroleum refineries is the reduction of sulfur content of heavy naphtha to the new lower limits. In this reaserch, was taken the specification of the sulfur content of heavy naphtha at arrange 632 ppm to 2.5 ppm, The range of reaction temperatures is (35 - 175) oC and liquid hourly space velocity (LHSV) at range of (1.3 - 1.4) hr - 1 and hydrogen pressure is 35 bars.The simulators are useful tools to manage operation and to improve the profitability of the process. In this study, excel and Matlab program were developed to simulate hydrodesulferization process (HDS) in vapor phase reactor of heavy naphtha hydrotreating unit of Daura refinery, the comparison between the plan results with HDS reactor model results was made.. Based on the model results the optimum operating conditions were determined. Acomputer program MATLAB (Matrix Laborator) it is software for developed code of kinetic parameter estimation problem using the estimation method and least square as objective function and new GA as solving method. The code was implemented on personal computer (intel (R) Core (TM) i3 CPU, 2.39 GHz processor, 2 GB RAM). The function to be minimized was the sum of squares of the differences between calculated and measured concentration.Genetic optimization method was used to define the parameters of desulfurization reaction kinetic. This hydrotreating reaction kinetic model for desulfurization of Daura heavy naphtha was determined for heavy naphtha boiling point range of (35 - 175) C and using a commercial (HDS) catalyst cobalt - molybdenum (Co - Mo) supported of alumina.The result showed that the order of kinetic reaction was first order for heavy naphtha hydrotreating with (Co - Mo) supported of alumina, and the graphically method is more suitable and less error than optimization method for represent the kinetic reaction for heavy naphtha hydrotreating in Daura refinery.

فعالية عامل مساعد محضر ومحفز بمعادن مختلفة لعملية ازالة الكبريت بالهدرجة لزيت الغاز العراقي == Activity of A Prepared Catalyst Promoted By Different Metals For The Hydrodesulfurization of Iraqi Gas Oil

اسم المؤلف: طارق محمد نايف

اسم المشرف: Abdul | Halim A.K. Mohammed | Hussein K. Hussein

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: دكتوراه

الجامعة: جامعة بغداد - كلية الهندسة - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: The present work deals with the improvement of Iraqi gas oil containing 1.402 wt. % sulfur by hydrotreating process using different prepared hydrodesulfurization catalysts (Ni - Mo/? - Al2O3, Co - Mo/? - Al2O3, Co - Ni - Mo/? - Al2O3, Ti - Ni - Mo/? - Al2O3 and Re - Ni - Mo/? - Al2O3). All catalysts were prepared under vacuum impregnation to ensure efficient precipitation of metals within the carrier ? - Al2O3. Physical adsorption by nitrogen was investigated, and used for determination of the surface area and pore size distribution of prepared catalysts.The results showed that modified catalysts Ti - Ni - Mo/? - Al2O3 and Re - Ni - Mo/? - Al2O3 have a high surface area 225.1 and 235.23 m2/g respectively, as compered with conventional prepared catalysts Ni - Mo/? - Al2O3 and Co - Mo/? - Al2O3 which their have surface area 178.5 and 191.4 m2/g respectively, and exhibits behavior of type four according to Brunauer, Emmett and Teller (BET) classification, and type H1 according to de Boer classification for hysteresis loop, so, it was concluded that the pores of these catalysts are cylindrical. The performances of all the synthesized catalysts for removal of sulfur and aromatic saturation gas oil were tested at different LHSV (1 to 4 h - 1), temperatures ( 275 to 350 °C), constant pressure 40 bar, and H2/HC ratio 500 ml/ml. The results showed that the sulfur and aromatic content were decresed at all operating conditions for all prepared catalysts. It was found that the sulfur removal from gas oil increases with temperature and decreasing with the space velocity, and the temperature has higher effect on the process of sulfur removal than the space velocity. It was found also that Ni - Mo/? - Al2O3 catalyst is slightly better in sulfur removal (61.5 wt. % ) with than Co - Mo/? - Al2O3 (59.2 wt. %) at the same operation conditions (350 °C and LHSV 1 h - 1), and hydrodesulfurization over Ni - Mo/Al2O3 was improved remarkly by adding Ti and Re promoters. Maximam sulfur removal was 76.81 wt. % using Re - Ni - Mo/? - Al2O3 at temperature 350?C, LHSV 1 h - 1, while minumum aromatic content value is 15.44 wt. % for Ni - Mo/ ? - Al2O3. Calculations showed that the hydrodesulfurization rate expressions fitted with second order reaction kinetics model.The rate constant varied from 0.005 to 0.144 liter/kg.h and the values of activation energy varied from 50.0 to 93.59 kJ/mole for all prepared catalysts. Thiele modulus, for all prepared catalysts was calculated.The lower values of the Thiele modulus (> 0.4) gives strong evidence of negligible pore diffusion limitation.

ازالة المحتوى الكبريتي من وقود الديزل بواسطة الاكسدة والاستخلاص بالمذيب == Desulfurization of Diesel Fuel By Oxidation And Solvent Extraction

اسم المؤلف: شيم بهجت عبد الكريم

اسم المشرف: ودود طاهر محمد | رغد فريد

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: ماجستير

الجامعة: جامعة بغداد - كلية الهندسة - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: يهدف البحث الى ازالة المحتوى الكبريتي من مقطع الديزل المهدرج للتخلص من المركبات الكبريتية الثايوفينية التي تتعذر ازالتها بواسطة عملية الهدرجة المعتمدة في المصافي النفطية. ودراسة افضل الظروف للحصول على اعلى نسبة ازالة.رست الظروف التشغيلية التالية : سرعة ال | Removal of sulfur species from fuels is an increasingly critical environmental issue. Hydrodesulfurization (HDS) removes sulfur compounds, such as mercaptans and sulfides from hydrocarbons; however, some sulfur - containing compounds (such as diebenzothiophene) are very difficult to remove and need deep desulfurization processes.This work was applied to the desulfurized diesel fuel produced from the conventional HDS process for ultra - desulfurization. The used fuel types in this investigation were either real diesel fuel or simulated diesel fuel, where sulfur - containing compound ( dibenzothiophene DBT) converted to its corresponding sulfone by oxidation using hydrogen peroxide as an oxidant and acetic acid as homogenous catalyst, and solvent extraction by using acetonitrile (ACN) or N - methyl - 2 - pyrrolidone (NMP) as extractants.Simulated diesel fuel according to British Petroleum 200B doped with dibenzothiophene (DBT) was prepared, the effect of stirring speed (150, 250, 350 and 450) rpm, temperature (30, 40, 45 and 50) ?C, oxidant/simulated diesel fuel ratio (0.5, 0.75,1 and 1.5) (v/v), catalyst/oxidant ratio (0.125, 0.25, 0.5 and 0.75) (v/v), solvent type, and solvent/simulated diesel fuel ratio (0.5, 0.6, 0.75 and 1) (v/v) were examined in order to obtain the maximum sulfur removal. The results of this work exhibit that the highest removal of sulfur 98.5% for N - methyl - 2 - pyrrolidone and 95.8% for acetonitrile were obtained under the conditions of operating in table below : Stirring Speed (rpm) 350 Temperature (?C) 50 Oxidant (hydrogen peroxide)/simulated diesel fuel ratio 1 Catalyst (acetic acid)/oxidant ratio 0.5 Solvent (ACN or NMP)/simulated diesel fuel ratio 1 Experiments with the above best conditions were carried out on Real diesel fuel obtained from Al - Dora refinery with 1000 ppm sulfur containing compounds. It was found that sulfur removal from real diesel fuel was 62.5% for acetonitrile and 75% for N - methyl - 2 - pyrrolidone.

استخلاص الزيوت العطرية من قشور الحمضيات باستعمال التقطير البخاري بمساعدة المايكرويف == Extraction of Essential Oils From Citrus By - Products Using Microwave Steam Distillation

اسم المؤلف: سارة جبير صالح

اسم المشرف: ابتهال كريم شاكر

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: ماجستير

الجامعة: جامعة بغداد - كلية الهندسة - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: يهدف هذا البحث الى استخلاص الزيت العطري من ثلاثة انواع من قشور الحمضيات (البرتقال, الليمون, اللالنكي) بطريقتين : التقطير البخاري والتقطير البخاري بمساعدة المايكرويف.ودراسة تاثير عوامل الاستخلاص : (وزن القشور, وقت الاستخلاص,طاقة المايكرويف ونوع قشور الحمضي | The main objectives of this research is to extract essential oil from : orange( citrus sinensis), lemon( citrus limon) and mandarin( citrus reticulata) peels by two methods : steam distillation (SD) and microwave assisted steam distillation (MASD), study the effect of extraction conditions : weight of the sample( 398.56g, 281.8g, 116.76g), extraction time, microwave power( 135W, 265W, 445W) and citrus peel type( orange, lemon, mandarin) on oil yield and compare the results of the two methods, the resulting essential oil was analyzed by Gas Chromatography (GC).Essential oils are highly concentrated substances used for their flavor and therapeutic or odoriferous properties, in a wide selection of products such as foods, medicines and cosmetics. Extraction of essential oil is one of the most time and effort consuming process. Microwave - assisted extraction is a green technique for the extraction of natural products. (MASD) was better than (SD) in terms of rapidity, energy saving and yield. (MASD) gave higher yield than (SD) with shorter extraction time, yield of orange oil extracted by (MASD) was (1.150%) in (35min.) compared to (1.095%) in (45min.) by (SD) process, same results obtained for lemon and mandarin. It was found that the optimal microwave power was (135W) and the yield was : (1.150%, 1.115%, 0.940%) for orange, lemon and mandarin respectively, (MASD) increased extraction temperature in short time and to a higher level compared to (SD).It was found that the optimal weight was (398.56g) and the yield in (SD) was : (1.095%) and MASD (1.091%) for orange oil, same results obtained for lemon and mandarin.The best citrus peel type which gave the highest yield was orange followed by lemon then mandarin in both processes.Limonene is the most abundant component in citrus essential oil, (GC) analysis showed that the amount of limonene increased in low microwave power with long extraction time for mandarin oil it was (84.3891% at 135W in 60min.), while for (SD) it was (83.0271% in 75min.) and decreased with increasing microwave power for orange oil it was (80.9661% at 265W in 35min.) while for (SD) it was (83.2189% in 45min.), (SD) was more convenient to give high amount of limonene because of the graduate temperature rise, while in microwave extraction exposure to low microwave power for long time would give complete recovery and better quality of essential oil.

تاثير الحماية من التاكل بواسطة الليزر على سبائك الالمنيوم == The Effect of Laser Surface Melting Corrosion Protection On Al Alloys

اسم المؤلف: هبة خميس اسماعيل

اسم المشرف: شذى احمد سامح

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: ماجستير

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: يهدف هذا البحث الى دراسة تاثير المعاملة بالليزر على تاكل سبائك الالومنيوم (7075, 6061, 5083) المغمورة في محلول ملحي (كلوريد الصوديوم) بمختلف التراكيز. وقد تم اعداد عينات من سبائك الالومنيوم ذات ابعاد (2 ملم) سمك وقطر (25 ملم)، وكانت تجارب الاستقطاب في مح | The objectives of the present project are to generate uniform melted layers, free of large second phases to assess the corrosion resistance of the laser treated surface in comparison with the untreated alloy. So disc samples of (7075, 6061 and 5083) aluminum alloys of 2 mm thickness and 25 mm diameter, have been prepared. Polarization tests were carried out in (M lab potentiostat / galvanostat) (Germany) at 298K temperature and (1.5, 2.5 and 3.5) % wt of NaCl solution. The experiments were carried out before and after laser surface melting by (Nd : YAG, MED - 810) pulse laser, system (Q - Switched Nd : YAG 1064/532nm). Before laser surface melting the results showed that the value of the corrosion current density obviously increases with increasing the concentration of NaCl from 1.5% to 3.5%. As well as higher Cl - ions concentration more negative pitting potential (Epit) of aluminum alloys and decrease in the electrochemical stability of aluminum. The corrosion rate for the specimen 7075 is larger than that of 6061 and 5083 aluminum alloys under the same conditions. So it means that the specimens 6061 and 5083 have high resistance to corrosion in NaCl solution After laser surface melting the results showed that the surface of aluminum alloys became more homogenous and pure after treatment.It was found that the corrosion current density decreases after Laser Surface melting at about three orders than that of untreated samples, therefore, the value of the corrosion rate of laser - treated alloy is smaller than that of the untreated. As well as the pitting corrosion potential after Laser Surface melting obviously shifted to more positive direction for all aluminum alloys in different concentrations of the NaCl solution.

تثبيط تاكل الحديد الكاربوني الواطئ في حامض الكبريتيك باستعمال كحول البولي فينيل ومستخلص نبات PIPER LONGUM == Corrosion Inhibition of Low Carbon Steel In Sulfuric Acid By PVA And Piper Longum Extracts

اسم المؤلف: اياد بهاء الدين احمد

اسم المشرف: ماجد ابراهيم عبد الوهاب | ابرائيل سركيس يارو

الموضوع العام: الهندسة الكيمياوية

السنة: 2014

الموضوع الدقيق: الهندسة الكيمياوية

الدرجة: دكتوراه

الجامعة: جامعة بغداد - كلية الهندسة - قسم الهندسة الكيمياوية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: The inhibitive power of Polyvinyl Alcohol (PVA) and the synergistic effects added on the inhibition power of PVA by two types of Piper Longum (PL) Ethanol Extracts (PLEXT) were investigated toward the corrosion of carbon steel in (0.2N) H2SO4 solution in the temperature range (30 - 60?C) and PVA concentration range (150 - 2000 PPM).The corrosion rate measurements were carried out using the following two standard corrosion measurements techniques.1. Weight loss technique was applied on carbon steel plates to evaluate inhibition efficiency in presence and absence of these inhibitors.2. Electrochemical Techniques were used to validate and support inhibition efficiencies found in weight loss techniques.A detailed study of the experimental methods and results is reported for each test conducted.The weight loss results showed that PVA could serve as a corrosion inhibitor but its inhibition power was found to be low for the corrosion of carbon steel in the acidic media.It was shown that the inhibition efficiency for (PVA) decreased with increasing temperature at a given PVA concentration. On the other hand it was shown that at given temperature the inhibition efficiency of (PVA) was increased with increasing of PVA concentration until a PVA concentration of 2000 ppm PVA was reached then only a slight decrease in inhibition efficiency was observed when increasing PVA concentration further.The Maximum inhibition efficiency reached was about 71 % at 30?C & 2000 ppm (PVA) concentration, calculated by the weight loss techniques.In order to improve the inhibition efficiency of PVA, by adding 6 ml/l of ethanol extracts of piper longum (PL) to a liter of the acid solution in presence of concentrations of PVA 150,500,1000.1500, and 2000 ppm at temperatures (30,40,50, and 60?C) was investigated.Weight loss results showed a jump in inhibition efficiency (% IE) value of the modified inhibitor mixture compared with the presence of PVA alone at all (PVA) concentrations for temperature range considered in this investigation.This study demonstrated the extra inhibition power added by the (PL) fruit extracts to the organic polymer (PVA) used. Maximum inhibition efficiencies recorded were approximately 95% for Piper Longum Extract Number two (PLEXT2) at 30?C and 2000 ppm PVA.The kinetic and thermodynamic parameters regarding the adsorption process of inhibitors used was calculated.It was found that the changes corrosion rates correlates well with the Arrhenius equation in absence and presence of inhibitors.The Results showed that the adsorption of the polymer and the plant extract follows Langmuir adsorption isotherms and the adsorption of the inhibitor molecules on the metal surface is mainly physical, nevertheless the adsorption is believed to be slightly deviated from the Langmuir model at 30?C.Electrochemical analysis of the corrosion process of carbon steel in an electrochemical corrosion cell was investigated using 3 - Electrode corrosion cell coupled with a potentiostat interfaced with a computer which assisted polarization data interception and interpretation.Polarization technique was used to obtain polarization data which was recorded for carbon steel in 0.2N H2SO4 solutions in presence and absence of the inhibitors investigated. Electrochemical runs were done in the (PVA) concentrations of 150, 1000, and 2000 PPM and a temperatures of 30, 40, 50, and 60?C.Tafel slopes, Corrosion currents, and corrosion rates were calculated from polarization curves by Tafel extrapolation method. Results showed corrosion rate trends similar to findings by the weight loss method. It was indicated also that the corrosion of carbon steel in 0.2N H2SO4 is highly activity controlled.Results revealed that the inhibition action is occurring at both anodic and cathodic sites on the metal surface so that both corrosion reactions were affected, so that the composite inhibitor could be considered as mixed - type inhibitor.Electrochemical results confirmed that (PLEXT2) was more efficient as inhibition improvement additive to (PVA) than (PLEXT1) at all experimental conditions range encountered in this study.The highest inhibition efficiency recorded using Tafel polarization method was 83% obtained at 30?C and 2000 ppm of PVA with 6 ml/l PLEXT2.