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Article
Kinetic Study of the Leaching of Iraqi Akashat Phosphate Ore Using Lactic Acid
دراسة حركية استخلاص خام فوسفات عكاشات العراقي باستخدام حمض اللبنيك

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Abstract

In the present work, a kinetic study was performed to the extraction of phosphate from Iraqi Akashat phosphate ore using organic acid. Leaching was studied using lactic acid for the separation of calcareous materials (mainly calcite). Reaction conditions were 2% by weight acid concentration and 5ml/gm of acid volume to ore weight ratio. Reaction time was taken in the range 2 to 30 minutes (step 2 minutes) to determine the reaction rate constant k based on the change in calcite concentration. To determine value of activation energy when reaction temperature is varied from 25 to 65℃, another investigation was accomplished. Through the kinetic data, it was found that selective leaching was controlled by surface chemical reaction. The study showed that the reaction kinetics was specifically described by the shrinking core model (SCM). Regression analyses gave values of activation energy (Ea) and Arrhenius constant (ko) as 40.108 KJ/mole and (2.256×103 sec-1) respectively.

في هذا البحث تم إجراء دراسة حركية لأستخلاص الفوسفات من خام فوسفات عكاشات العراقي باستخدام حامض عضوي. تم دراسة عملية الاستخلاص باستخدام حمض اللبنيك لفصل المواد الكلسية. وكانت ظروف التفاعل 2٪ نسبة وزنية من تركيز الحامض و 5 مل/غم من نسبة حجم الحامض إلى وزن خام. تم دراسة زمن التفاعل في المدى من 2 إلى 30 دقيقة (الخطوة 2 دقيقة) لتحديد قيمة ثابت سرعة التفاعل k استنادا إلى التغير في تركيز الكالسايت. تم ايضا اجراء دراسة لتحديد قيمة طاقة التنشيط عند درجات حرارة التفاعل للمدى من 25 إلى 65 درجة مئوية. من خلال البيانات الحركية، وجد أن الخطوة المسيطرة على تفاعل الاستخلاص الانتقائي هو التفاعل الكيميائي السطحي. وأظهرت الدراسة أن حركية التفاعل وصفت على وجه التحديد من قبل نموذج الأساسية تقلص (سم). أعطى تحليل الانحدار قيم طاقة التنشيط (Ea) وثابت أرهينيوس (ko) بقيم 40.108 كيلو جول / مول و (2.256 × 103 ثانية -1) على التوالي.


Article
Parametric Study on Intrinsic Reaction for Straight Run Heavy Naphtha Hydrodesulfurization over CoMo/Al2O3 Catalyst

Authors: Mohammad F. Abid --- Mohammed K. Abdullah --- Salah M. Ali
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 2 Part (A) Engineering Pages: 146-153
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The present study aimed to investigate the intrinsic reaction of hydrodesulfurization (HDS) for a real Straight Run Heavy Naphtha (SRHN) over CoMo-S/Al2O3 catalyst in a fixed- bed reactor. Influence of the process parameters on sulfur removal was investigated by regulating the temperature (T = 320-380 oC), pressure (P = 20 to 35 bar), weight hour space velocity (WHSV = 2.5 to 5.0 h-1) and catalyst average particle size (dp =361 to 3950 μm). Mears and Weisz-Prater criteria were estimated and utilized to validate the intrinsic reaction condition. Operating variables were optimized at (T = 360 oC, P = 30 bars, WHSV = 2.5 h-1, dp= 361 μm) to obtain an optimum sulfur removal of 93.4% under intrinsic reaction conditions. Experimental results showed that % activity of sulfur removal increases to 93.4% as temperature increased to 360oC but it reduces to 90.3% as space velocity increased to 5.0 h-1. Kinetic parameters of the intrinsic reaction rate were estimated and compared with published data. Long-time test was performed on the sulfided catalyst to investigate its activity.


Article
Removal of Cr (VI) and Cu (II) Ions from Synthetic Wastewater by Solar Photocatalytic Reactor

Authors: Mohammad F. Abid --- Luma H. Mahmood --- Noor H. Hamza --- Sukaine J. Mohamed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 4 Part (A) Engineering Pages: 417-423
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Heavy metal ions in wastewater have promoted increasing concern on environmental and health risks. The present work was devoted to investigate the feasibility of utilizing solar light to degrade Cr (VI) and Cu (II) ions in synthetic wastewater. The effect of the key process parameters on the quality of product was studied by varying the pH (3, 5, 7, 9, and 11), H2O2 (50, 100, 200, and 300 mg/L) and TiO2 loading (0.9, 1.3, and 1.7 g/L). Experimental results revealed that after 120 min of solar illumination the highest reduction of Cr (VI) ions was 97.0% obtained under (pH = 3, catalyst loading = 1.3 g TiO2/L, and H2O2 =100 mg/L) and for Cu (II) ions the highest reduction was 97.7% at (pH = 11, catalyst loading = 1.3 g TiO2/L, and H2O2 =200 mg/L). Empirical correlations were suggested for the photoreduction of Cr (VI) and Cu (II) ions as functions of the studied operating parameters with correlation coefficients of 0.946 and 0.948, respectively.


Article
Applying Modern Optimization Techniques for Prediction Reaction Kinetics of Iraqi Heavy Naphtha Hydrodesulferization

Authors: Zaidoon M. Shakor --- Anfal H. Sadeiq
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 11 Part (A) Engineering Pages: 1171-1175
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, a powerful modern optimization techniques such as GeneticAlgorithm (GA), Particle Swarm Optimization (PSO) and Artificial neural network (ANN)were applied to estimate the optimal reaction kinetic parameters for Heavy naphthaHydrodesulferization (HDS), the hydrodesulferization unit located in AL-Daura refineryBaghdad/Iraq.The reactions was carried out in a fixed-bed reactor packed with Co-Mo/γAl2O3catalyst and the operatingwas 315-400 °C temperature 35 bar Pressure and 0.5-2.1hr-1 liquid hourly space velocity. The result showed that hydrodesulferization of heavynaphtha follows the pseudo-first order reaction kinetics. This study signifies that thereaction kinetic parameters calculated by Genetic Algorithm was found to be moreaccurate and gives the highest correlation coefficient (R2= 0.9507) than the other twomethods. ANN technology by using the topology of (3-3-1-1) provides an effective tool tosimulate and understand the non-linear behavior of the process. The modelresult showedvery good agreement with the experimental data with less than 5%. mean absolute error.

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