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Article
Sorption Study of Methyl Orange on the Iraqi Kaolinite Clay

Author: Ali A. Al-Ma'amar
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2012 Volume: 15 Issue: 4 Pages: 98-103
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

The sorption of methyl orange on the kaolinite clay was studied thermodynamically and kinetically, the sorption was of Freundlich type and the multi-layers were formed, and the sorption was a combination of adsorption and absorption, but in some cases the desorption was occurred. The Freundlich constants were calculated to specify the sorption capacity, and sorption intensity. The calculation of thermodynamic parameters revealed that the process was exothermic, ordered, and non-spontaneous at the temperature range(298-328K). Three kinetic models were exploited to calculate the rate constant, diffusion constant, rate of adsorption, and desorption parameter.

تمت دراسة امتزاز المثيل البرتقالي على طين الكاؤلين دراسة حركية وثرموديناميكية, ولقد كان الامتزاز من نوع فرويندلش وتكونت عدة طبقات للامتزاز على سطح المادة المازة, وقد كانت العملية عبارة عن خليط بين الامتزاز والامتصاص, ولكن في بعض الحالات حصلت عملية الابتزاز. تم حساب ثوابت فرويندلش لغرض تحديد سعة الامتزاز وشدتة على السطح, وايضا تم حساب المعاملات الثرموديناميكية وقد بينت ان عملية الامتزاز كانت باعثة للحرارة, ومنظمة, وغير تلقائية ضمن المدى الحراري (298-328 كلفن). تم استخدام ثلاث اشكال حركية لغرض حساب ثابت سرعة العملية, وثابت الانتشار, معدل عملية الامتزاز, ومعامل الابتزاز.


Article
Kinetic Study and Simulation of Oleic Acid Esterification in Different Type of Reactors

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Abstract

Esterification reaction is most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock to study and simulate production of biodiesel. Batch esterification of oleic acid was carried out at operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 1/1 to 6/1, H2SO4 as the catalyst 1 and 5% wt of oleic acid, reaction time up to 180 min. The optimum conditions for the esterification reaction were molar ratio of ethanol/oleic acid 6/1, 5%wt H2SO4 relative to oleic acid, 70 °C, 90 min and conversion of oleic 0.92. The activation energy for the suggested model was 26625 J/mole for forward reaction and 42189 J/mole for equilibrium constant. The obtained results simulated to other types of reactors with different operating conditions using reactop cascade package. The conversion of oleic acid of simulation results at optimum operating conditions was 0.97 for isothermal batch and plug flow reactors, 0.67 for isothermal CSTR, while the conversions of oleic acid in the adiabatic mode were 0.82, 0.40, 0.74 for batch, CSTR, PFR reactors respectively.


Article
Synthesis, Characterization and Kinetic Study of Monomeric Complexes of Cyclohexane-1, 2- bis (Thiosemicarbazone) with Cobalt (II), Nickel (II) and Copper (II)

Author: Al-Ameen Bariz Omar Ali
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2017 Volume: 28 Issue: 2 Pages: 48-54
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Cyclohexane-1,2-bis(thiosemicarbazone) (CHTSC) was synthesized via the condensation reactionof cyclohexane-1,2-dione and thiosemicarbazide. Series of metal complexes of the prepared ligand,of general formula [M(CHTSC)(NO3)2], were reported. The prepared coordination complexeswere characterized and their structures elucidated using different techniques. These showedthat all complexes are octahedral geometries. The kinetics of the formation of these complexeshave been investigated using stopped-flow spectrophotometry. These studies revealed that thereactions are completed on the second’s timescale with 1st-order dependence (either on the concentrationof metal salt or on the concentration of CHTSC)


Article
Kinetic Study of Adsorption Processes of Some Azo Dyes on Activated Carbon
دراسة حركية امتزاز بعض اصباغ الازو على الفحم المنشط

Author: Emad A.S. Al-Hyali عماد عبدالاله صالح الحيالي
Journal: Tikrit Journal of Pure Science مجلة تكريت للعلوم الصرفة ISSN: 18131662 Year: 2007 Volume: 12 Issue: 1 Pages: 48-54
Publisher: Tikrit University جامعة تكريت

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Abstract

The adsorption of a number of azo dyes on activated carbon have been studied. Factors affecting adsorption such as time, concentration, pH and temperature variation have been investigated. The equilibrium constants are calculated from the ratio between the adsorbed and unbound concentration at different temperatures. The enthalpy of adsorption (H) is estimated.The kinetic of adsorption and desorption processes of the studied dyes have been conducted by using the integrated rate equation of the reversible first order reaction. The rate constants of both were determined at various temperatures. The activation energies and thermodynamic parameters of activation of the forward and backward are calculated.The values of the (H) revealed that, the adsorption process for all the studied dyes are exothermic and the forces control the adsorption are physical in nature. The values of activation energies indicated that, the process occurs in favor of the adsorption direction. The activation energies and other parameters of activation are in good agreement with the thermodynamically calculated

تضمن هذا البحث دراسة العوامل المؤثرة على امتزاز عدد من أصباغ الازو على الفحم المنشط مثل زمن التماس والتركيز والدالة الحامضية لوسط الامتزاز فضلا عن التغير في درجة الحرارة. حسبت قيم ثابت توازن الامتزاز عند درجات حرارية مختلفة من النسبة بين كمية المادة الممتزة والمتبقية في المحلول عند التوازن والتي استخدمت لاحقا لحساب انثالبي الامتزاز.اشتمل البحث أيضا على دراسة حركية عمليتي الامتزاز والابتزاز للأصباغ المدروسة على الفحم المنشط من خلال تطبيق المعادلة المتكاملة لمعدل سرعة التفاعل للتفاعلات العكسية من المرتبة الأولى. وحسبت قيم طاقة التنشيط والدوال الثرموداينميكية للتنشيط لكلا العمليتين من خلال حساب قيم ثوابت السرعة عند درجات حرارية مختلفة. أظهرت قيم انثالبي الامتزاز إن عملية الامتزاز لجميع الأصباغ المدروسة هي باعثة للحرارة وان القوى المسؤولة عن الامتزاز هي ذات طبيعة فيزيائية، فيما أظهرت قيم طاقة التنشيط إن عملية الامتزاز تحدث بالأفضلية بالاتجاه الأمامي. وبصورة عامة تتفق قيم الدوال الثرموداينميكية للتنشيط مع قيم انثالبي الامتزاز.


Article
Kinetic and Thermodynamic Study of the Adsorption of some Organic Acids by MnO2
دراسة حركية وثرموداينمكية لامتزاز بعض الحوامض العضوية باستخدام MnO2

Authors: Emad A. S .Al-Hyali --- Khalil I . Al – Niemi --- Safwan A Al-Dubunee
Journal: Tikrit Journal of Pure Science مجلة تكريت للعلوم الصرفة ISSN: 18131662 Year: 2012 Volume: 17 Issue: 2 Pages: 105-111
Publisher: Tikrit University جامعة تكريت

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Abstract

In this research work, the adsorption efficiency of three structurally related acids namely, glycolic, mandelic and benzylic acids by MnO2 from their aqueous solutions is investigated.The study is aimed at developing a better understanding of the adsorption mechanism regarding the molecular level. The experiments were achieved as batch methods.The factors affecting the adsorption efficiency such as; contact time, initial concentration, initial pH of the acid medium and temperature are studied. The results obtained showed that, the increase of initial concentration increases the adsorption efficiency. The initial pH of the medium plays an important role in controlling the attachment of acid molecules on the solid surface of MnO2. The highest adsorption efficiency is observed in the acid medium (natural pH of the acid solutions).This study proved that, the acid is connected to the solid surface of absorbent in its anion form.The thermodynamic functions of adsorption are estimated at different initial concentrations (0.005-0.05 N). The study also included the application of the two kinetic models on the adsorption data namely; the pseudo first order and pseudo second order equations. The investigation is performed at certain concentration and various temperatures. The results denoted that, the studied systems are better fit the second order model.

تضمن هذا البحث دراسة كفاءة امتزاز بعض الأحماض العضوية ( الكلايكوليك و المندليك و البنزيليك) والتي تتفاوت بصيغها التركيبية من محاليلها المائية.وقد هدفت الدراسة التوصل إلى فهم عميق وواضح لميكانيكية امتزاز هذه الأحماض وعلاقتها بالتركيب ألجزيئي لها. وقد أنجزت التجارب العملية باستخدام طريقة الدفعة الواحدة. لقد أشتمل البحث على دراسة العوامل المؤثرة على الامتزاز مثل زمن التماس والتركيز الابتدائي والدالة الحامضية والامتزاز ودرجة الحرارة.أظهرت النتائج إن زيادة التركيز الابتدائي يزيد من كفاءة الامتزاز وان الدالة الحامضية الابتدائية لوسط الامتزاز تلعب دورا أساسي في التحكم بطريقة ارتباط الجزيئات الممتزة بالسطح ألماز . وتبين النتائج إن أعلى كفاءة امتزاز تم ملاحظتها في الوسط ألحامضي (عند الدالة الطبيعية لمحاليل الحوامض) .وقد أثبتت الدراسة إن الأحماض العضوية المدروسة ترتبط مع سطح الـ MnO2 بشكلها ألايوني السالب . وقد حسبت الدوال الثرموداينميكية لنظام الامتزاز بالاعتماد على النتائج المحصل عليها من دراسة تأثير درجة الحرارة عند مدى من التراكيز (0.005-0.05)N.أشتمل البحث أيضا على دراسة حركية امتزاز هذه الأحماض على سطح الـ MnO2 وذلك من خلال تطبيق نموذجي معادلتي المرتبة الأولى الكاذبة والثانية الكاذبة في عدد من درجات الحرارة وعند تركيز ثابت . أظهرت النتائج إن النظام المدروس يتبع نموذج المرتبة الثانية الكاذبة.


Article
Kinetic Study and Simulation of Oleic Acid Esterification over Prepared NaY Zeolite Catalyst

Authors: Rowaida N. Abbas رويدة نزيه --- Ammar S. Abbas عمار صالح عباس
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2013 Volume: 14 Issue: 4 Pages: 35-43
Publisher: Baghdad University جامعة بغداد

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Abstract

Esterification considers the most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock in order to study and simulate production of biodiesel. The batch esterification reaction of oleic acid was carried out at various operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 3/1 and 6/1 and a reaction time up to 180 min. The catalyst used was prepared NaY zeolite, which is added to the reaction mixture as 2, 5 and 10 wt.% of oleic acid. The results show that the optimum conditions, gives 0.81 conversion of oleic acid, were 6/1 molar ratio of ethanol/oleic acid, 5 wt.% NaY relative to initial oleic acid, 70°C and 60 minutes. The activation energy of the suggested model was 42692 J/mole for forward reaction and 17218 J/mole for backward reaction.


Article
Production and Evaluation of Liquid Hydrocarbon Fuel from Thermal Pyrolysis of Virgin Polyethylene Plastics

Authors: Fahmi Abuelgasim Mohamed --- Ammar S. Abbas
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2015 Volume: 16 Issue: 1 Pages: 21-33
Publisher: Baghdad University جامعة بغداد

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Abstract

Pyrolysis of virgin polyethylene plastics was studied in order to produce hydrocarbon liquid fuel. The pyrolysis process carried out for low and high-density polyethylene plastics in open system batch reactor in temperature range of 370 to 450°C. Thermo-gravimetric analysis of the virgin plastics showed that the degradation ranges were between 326 and 495 °C. The results showed that the optimum temperature range of pyrolysis of polyethylene plastics that gives highest liquid yield (with specific gravity between 0.7844 and 0.7865) was 390 to 410 °C with reaction time of about 35 minutes. Fourier Transform Infrared spectroscopy gave a quite evidence that the produced hydrocarbon liquid fuel consisted mainly alkanes and the x-ray diffraction showed no sulfur in the produced hydrocarbon liquids.


Article
Study in Kinetics of Saponification Reaction of Diethyl Adipate with Sodium Hydroxide Solution under Reactive Distillation

Authors: Raghad fareed kasim --- rouaa ali shokorr
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2016 Volume: 17 Issue: 1 Pages: 99-108
Publisher: Baghdad University جامعة بغداد

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Abstract

This research presents a new study in kinetics under reactive distillation by using consecutive two – step reaction : the saponification reaction of diethyl adipate with sodium hydroxide solution . The distillation process takes the role of withdrawing the intermediate product (sodium monoethyladipate SMA) which otherwise converts to the final product of low purity.The effect of three parameters were studied through a design of experiments applying 23 factorial design. These parameters were : the mole ratio of DA to NaOH solution (0.1 and 1) , NaOH solution concentration (3 N and 8 N) , and batch time (1.5 hr. and 3.5 hr.) . The conversion of DA to sodium monoethyladipate(SMA)(intermediate product) was the effect of these parameters which was detected .The results showed that increasing mole ratio of DA to NaOHsolution increases the conversionto a maximum value within the range of study.The effect of NaOH solution concentration decreases the conversion to a specified value within the range of study . The effect of batch time on conversion was decreasing the conversion to a specified value within the range of study . The maximum attainable conversion within the studied range of parameters was eighteen fold of thebase case.Reaction rate constant k and the order of reaction n of first reaction weredetrminedusing the differential method . The study attempted to determine n and k under the maximum conversion condition obtained in this system which corresponds to : feed mole ratio of diethyl adipateDA to NaOH solution of 0.3,NaOH solution concentration of3 Nandtime of1.5 hr.The study showed that the reaction order was 1.5and reaction rate constant was 0.8m3/kmol.s at a temperature of 100 ℃ .


Article
Kinetic study and Modeling of heavy Naphtha Catalytic Reforming process in AL-Daura Refinery

Authors: Mohammad Fadhil Abid --- Haider Majeed Khother
Journal: Journal of Petroleum Research & Studies مجلة البحوث والدراسات النفطية ISSN: 22205381 Year: 2017 Issue: 15 Pages: 1-27
Publisher: Ministry of Oil وزارة النفط

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Abstract

In the present work, kinetics and modeling of heavy naphtha catalytic reforming process in Al-Daura refinery-Midland refineries Company were studied. A proposed reaction scheme involving (15 pseudo components) connected together by a network of 30 reactions for components in the C6-C8+ range have been modeled. In the present work, kinetics and modeling of heavy naphtha catalytic reforming process in AL-Daura refinery-Midland refineries Company were studied. A proposed reaction scheme involving (15 pseudo components) connected together by a network of 30 reactions for components in the C6-C8+ range have been modeled. The proposed model has been solved numerically using the 4th order Runge–Kutta approach. Alteration of components and temperature, with time and reactor length was evaluated. Results showed that the rate of formation of aromatics is becoming slower as the reactants proceed to the third reactor. The catalytic reaction rates in the reformer are well represented by the Hougen-Watson Langmur-Hinshelwood (HWLH) type form. The deactivation of catalyst causes the reactor behavior to continue changing over a longer period of time. This clearly seems to pay off in the scenario where coke deposition plays such a major role. It was also found that the rate of coke formation increases with the progress from first to the last bed, so keeping a decreasing inlet temperature profile from first to the last bed would lead to more uniform coke content in each bed. The production rate of reformate has a negative impact on the octane number. Temperature drop across the first reactor (~ 45oC) is larger than the temperature drops across the other two reactors (10-12oC). This could be related to the endothermic reaction rate which is faster in the first reactor. The results show that perfect agreement of temperatures, compositions, and fractions molar flow rate at the exit of the third reactor is obtained between predicted values and industrial values.This confirmed the reliability of the present model.


Article
Synthesis ,characterization and kinetic studies of the formation of a new chromium( III) complex of mixed ligands L-cysteine and picolinic acid.

Authors: M.A.Abdullah محمد علي عبد الله --- Diary I. Tofiq دياري توفيق
Journal: Iraqi National Journal Of Chemistry المجلة العراقية الوطنية لعلوم الكيمياء ISSN: 22236686 Year: 2010 Issue: 38 Pages: 265-278
Publisher: Babylon University جامعة بابل

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Abstract

Abstract A new Cr(III) complex of mixed ligands of picolinic acid (Hpic) and L-cysteine has been synthesized from acid catalyzed hydrolysis of the blue colored solution of sodium salt of bis L-cysteinato(N,O,S) chromateIII complex with solution of Hpic restrictive acidic media of pH=3-4 with gentle heating. The red-brown color product complex of sodium bis L- cysteinato(N,O) monohydroxy picolinato(N)chromateIII have been characterized by element analysis ,electronic and i.r spectroscopy comparison to the properties of some well known related Cr(III) complexes leads to the conclusion that Hpic binds to Cr(III) center via its nitrogen donor atom. The kinetics and mechanism of the formation of this complex, from the acid catalyzed cleavage of Cr—S bond and subsequent Hpic substitution, have been studied spectrophotometrically in a limited pH 3-4.5 range, which was adjusted by HClO4 (μ =0.2M).The rate of the production shows two reaction paths ;one for mono protic thiol,[ Cr(III) (L-cysH)(L-cysN,O,S) (H2O)] and other for diprotic both thiol, [Cr (L-CysH)2 (H2O)2]+2,with Hpic ligand substitution on Cr(III) through N atom.The speices of monoprotic reacts faster with an acid dependent than the diprotic species reaction .The pseudo first order rate constant equation is of the form; k = k1Ka2 [H+]-1 + k2 (where k1 represents the rate constant for first step, k2 for second step reactions and Ka2 is acid dissociation constant for diprotic species) was obtained with ΔH# and ΔS# for both paths are 67.195 kJ mol-1,- 25.41JK-1mol-1 and 68.96 kJ mol-1,-93.64 JK-1 mol-1 respectively.

الخلاصةتم تحضير و تكوين معقد جديد ال Na[Cr(L-CysH)2(Hpic)(H2O)] للكروم (III) مع الليكندات المختلطة لحامض البيكولينيك (Hpic) مع سيستين من عملية التحلل المائى التحفيزى الحامضى للمعقد الازرق اللون: {Na [Cr (L-cys) 2]. 2H2O} مع محلول الليكاندات (Hipc) فى وسط حامضى (pH =3 - 4.5) مع التسخين الهادىء . المعقد الناتج القهوائى المحمر اللون (Na[Cr(L-CysH)2(Hpic)(H2O)]) تم تشخيصها بالتحليل الدقيق للعناصر والاطياف الالكترونية وتحت الحمراء وكروموتوغرافيا التبادل الايونى وبواسطة مقارنة صفاتهم مع معقدات كروم (III) المعروفة. تبين من تشخيص ناتج التفاعل ان حامض البيكولينيك مرتبطة باصرة تناسقية مع الكروم فى المركز من خلال النايتروجين الواهب للالكترونات .ان ميكانيكية وحركية تكوين المعقد من التفكك الحامضى للاصرة (Cr-S) والحامض بيكولينيك المرتبط, قد تم دراستها فى وسط الحامضى =pH 3-4.5 التي تم ضبطه بالحامض HClO4 وكذلك الشدة الايونية (µ=0.2M NaClO4) .تم ايجاد ثابت سرعة التفاعل من الدرجة الاولى الكاذبة وفق المعادلة: k = k1Ka2[H+]-1+ k2 حيث k1 يمثل ثابت سرعة التفاعل للخطوة الاولى و k2 يمثل ثابت سرعة التفاعل للخطوة الثانية ، اما Ka2 يمثل ثابت تحلل الحامض البيكولينك .H2pic باراميترات المنشطة المحصل عليها كانت لتكوين المعقد في الخطوتين كالاتى :( , ( ∆H*=68.96 kJ mol-1 ( 93.64JK-1mol-1 (∆S*=- و) (∆H*=67kJ mol -1 و (∆S*=-25.41JK-1mol-1 .

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