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Article
Effect of Temperature on Pectin Extraction and Degree of Esterification from Quince and its Pomace (Cydonia oblonga )
أثر درجة الح ا ررة في استخلاص البكتين ودرجة الأسترة لاككةة وبث السارج ( (Cydonia oblong

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Abstract

Pectin was extracted from quince and its pomace by acidified solution water with nitric acid. PH (1.5) time 1 hr and temperatures degrees were 85, 90, 95 and 100 °C. The effects of variable temperatures on the pectin extraction and degree of esterification were investigated .Quince fruit contained 9.14, 11.2, 9.00 and 6.96% respectively, while in pomace the corresponding values were 10.38, 11.92, 9.75 and 8.28% respectively. The maximum values were 11.2 and 11.92% at 90 °C for quince fruit and its pomace respectively, while slight inconstant changes were shown in degree )High) of esterification.

تػ اخػت ص البكتػيف ػف فاكهػو وب ػؿ الخػجرجؿ ب ومػوؿ ال ػا ال و ػض بوػا ض النتتريػؾ بػذ اس ويػدروجيني ) 1.5 ( بوقػتخػاةو وبػدرجات و ا رريػو 85 و 90 و 95 و 100 ئػو تػ د ا رخػو ال خػتويات الأربعػو ػف درجػات الوػ ا ررة فػي نخػبو الأخػت ص ال ئويػولمبكتػيف ودرجػو الأخػترة وبينػت نتػائ التوميػؿ الكي يػائي اف نخبوالأخػت ص ال ئويػو لجاكهػو الخػجرجؿ كانػت 9.14 و 11.12 و 9.00و 6.96 ةمػػػ التػػػ والي، فػػػي وػػػيف كانػػػت وػػػذ النخػػػب لمب ػػػؿ 10.38 و 11.92 و 9.75 و 8.28 ةمػػػ التػػػ والي وبمػػػص اقسػػػ نخػػػبواخت ص ئويو في درجو 90 ئو 11.12 لجاكهو الخجرجؿ في ويف بمغػت لمب ػؿ لقػد وجػد تغييػ ا رت طجيجػو فػي درجػو الأخػترة )العاليػو(غير اف وذ التغيي ا رت غير ابتو

Keywords

pctine --- esterification --- quince --- pumice


Article
Preparation and Characterization of Nay Zeolite for Biodiesel Production

Authors: Rowaida N. Abbas --- 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: 2 Pages: 19-29
Publisher: Baghdad University جامعة بغداد

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Abstract

Iraqi kaolin was used for the preparation and characterization of NaY zeolite for biodiesel production via esterification reaction. Oleic acid was used usually as a typical simulated feedstock of high acid number for the esterification reaction. The chemical composition for the prepared Nay zeolite is as following: (Ca2.6Na1.K0.1)(Al6.3Si17.7)O48.16H2O, the silica to alumina ratio in the prepared catalyst was found equal to 2.6 and Na2O content was 12.26 wt. %, with relative crystallinity equal to 147.4 % obtained by the X-ray diffraction. The surface area result shows that the prepared catalyst has 330 m2/g. While, the measured pore volume by nitrogen adsorption was equal to 0.35 cm3/ g. SEM images show notable differences between the kaolin crystal and prepared NaY crystal. The effect of NaY zeolite, as a loaded catalyst in the esterification of oleic acid reaction did not show any significant change of oleic acid conversion for catalyst load more than 5 wt. %. The reused NaY zeolite is loses 31 % of its activity because of that the pores are filled with water and other organic molecules and that may cause poisoning the catalyst.


Article
Hydrodynamics, Mass and Heat Transferin Reactive Distillation
دراســــة سلوكيــــة وانتقال الكتلة والحرارة في أعمدة التقطـــير ذات المفاعـــل

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Abstract

The ethyl acetate synthesis via heterogeneous reactive distillation is studied experimentally using ethanol and acetic acid. Three types of cation exchanging resins were used as catalysts: Zerolit 225, Zerolit 226 and Ambylite 400. Experiments were carried out in two units of the same dimensions. Each unit consisted of three sections: rectifying, reactive and stripping sections of heights (60+25+20) cm respectively and 2.5cm column diameter. The first unit (column-A-) was a fractionation type and the second unit (column-B-) was packed column. The packing type was hollow glass cylinders with 10 mm height, and 4, 5 mm inner and outer diameter respectively.
The experiments were carried out by using two operation modes. The semi-batch and continuous operation mode. In the first part of present investigation, the semi-batch mode was used to evaluate the catalyst type and to evaluate the performance of reactive distillation unit configuration (Fractionation and packed column). Results show that, the column-B- gave higher conversion rates than column-A-. This is attributed to the high surface area available for liquid vapour contact in packed type column, which leads to increasing mass transfer rates. On the other hand, Ambylite 400 catalyst showed higher activity for esterification reaction than other two types of catalysts.
The second part of work continued with column -B- only. It is well known that, the esterification process is regarded one of exothermic reactions. Therefore, the monitoring of the temperature distribution along column axial for all three types of catalysts showed that the temperature distribution was essentially the same due to steady state operation in continuous operation mode. On the other hand, the effect of reflux ratio on temperature distribution was clearly noted, that is as the reflux ratio increased the temperature distribution along the column was reduced for each type of catalysts.
On the other hand, the experimental results point that, as a reflux ratio increases the conversion rates of acetic acid is increased too because such increasing is related to high mass transfer rates between vapour and liquid along reactive distillation column.

في هذا البحث تم دراسة عملية تحضير خلات الاثيل Ethyl Acetate باستخدام تقنية المفاعل ذو التقطير Reactive Distillation باستخدام الايثانول وحامض ألخليك كمواد أولية للتفاعل واستخدام العوامل المساعدة الصلبة. حيث تم استخدام ثلاثة أنواع مـن العـوامل المساعدة Cation Exchanging Resins والتي هي: Zerolit 225, Zerolit 226 , and Ambylite 400. خلال البحث تم بناء منظومتين رياديتين بأبعاد موحدة لإجراء التجارب. كل منظومة تتكون من ثلاث مناطق هي Rectifying, Reactive and Stripping section بأرتفاعات (60+25+20) سم على التوالي و2,5 سم قطر للعمود. اعتمدت المنظومة الأولى (Column-A-) في تصميمها كونها تحتوي على صواني نوع (Trays (Fractionation, أما المنظومة الثانية (Column-B-)فصممت على أنها عمود تقطير محشو ((Packed Distillation Column تحتوي على حشوات زجاجية اسطوانية الشكل بطول 10ملم وقطر داخلي 4 ملم وقطر خارجي 5 ملم. أجريت التجارب باستخدام نمطين من التشغيل على أساس مرور المواد الأولية: النمط الأول هو عمل نصف الوجــــبةSemi-batch والنمط الثاني هو الأسلوب المستمرContinuous . حيث استخدم النمط الأول لغرض تقييم كفاءة العوامل المساعدة المستخدمة وتحليل وتقييم أداء التصميمين للمنظومتين (Fractionation and packed column) الأتي استخدمن في البحث. حيث أظهرت النتائج أن المنظومة الثانية Column-B- أعطت معدلات كفاءة وتحول عالية نحو النواتج المرغوب بها أكثر من المنظومة الأولى Column-A-. وهذا في حقيقة الأمر يعود إلى المساحة السطحية العالية للحشوات والتي توفر مساحة تلامس جيدة بين البخار الصاعد والسائل الذي ينزل من أعلى البرج, والذي يؤدي بطبيعة إلى زيادة معدلات انتقال الكتلة. من ناحية أخرى أظهرت النتائج أن العامل المساعد نوع Ambylite 400 أعطى فعالية أعلى في تفاعل الاسترة من النوعين الآخرين. من ناحية أخرى تم اعتماد العمل باستخدام المنظومة Column-B-فقط وبالأسلوب التشغيلي المستمر. حيث تعد تفاعلات الاسترة من التفاعلات الباعثة للحرارة, ولهذا متابعة توزيع درجات الحرارة على طـــول البرج وللأنواع الثلاثة من العوامل المساعدة أظهرت النتائج بان التوزيع الحراري تقريباً متساوي لجميع العوامل المساعدة, وهذا يعزى إلى حالة الاستقرار التشغيلي في أسلوب التشغيل المستمر. ومن خلال دراسة تأثير نسبة الراجع Reflux Ratio على توزيع درجات الحرارة في البرج, أظهرت النتائج انه كلما زادت معدلات الراجع كلما انخفضت معدلات توزيع الحرارة داخل البرج ولجميع الأنواع من العوامل المساعدة. أشارت النتائج العملية إلى لا انه بزيادة قيم الراجع فان معدلات تحول حمض ألخليك سوف تزداد , حيث يمكن تفسير مثل هذه الزيادة على أساس التحسن الحاصل بمعدلات انتقال الكتلة بين البخار الصاعد والسائل النازل في برج التقطير ذو المفاعل.


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
Heterogeneously Catalyzed Esterification Reaction: Experimental and Modeling Using Langmuir- Hinshelwood Approach

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Abstract

The esterification reaction of ethyl alcohol and acetic acid catalyzed by the ion exchange resin, Amberlyst 15, was investigated. The experimental study was implemented in an isothermal batch reactor. Catalyst loading, initial molar ratio, mixing time and temperature as being the most effective parameters, were extensively studied and discussed. A maximum final conversion of 75% was obtained at 70°C, acid to ethyl alcohol mole ratio of 1/2 and 10 g catalyst loading. Kinetic of the reaction was correlated with Langmuir-Hanshelwood model (LHM). The total rate constant and the adsorption equilibrium of water as a function of the temperature was calculated. The activation energies were found to be as 113876.9 and -49474.95 KJ per Kmol of acetic acid for the esterification reaction and the heat of adsorption of water. These results agreed well with the previous published data.


Article
Esterification of Free Fatty Acid with High Chain Alcohol for Biodiesel Production Using Semi-Batch Reactive Distillation

Authors: Wadood T. Mohammed --- Marwa F. Abdul Jabbar
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2015 Volume: 16 Issue: 4 Pages: 11-19
Publisher: Baghdad University جامعة بغداد

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Abstract

The esterification of oleic acid with 2-ethylhexanol in presence of sulfuric acid as homogeneous catalyst was investigated in this work to produce 2-ethylhexyl oleate (biodiesel) by using semi batch reactive distillation. The effect of reaction temperature (100 to 130°C), 2-ethylhexanol:oleic acid molar ratio (1:1 to 1:3) and catalysts concentration (0.2 to 1wt%) were studied. Higher conversion of 97% was achieved with operating conditions of reaction temperature of 130°C, molar ratio of free fatty acid to alcohol of 1:2 and catalyst concentration of 1wt%. A simulation was adopted from basic principles of the reactive distillation using MATLAB to describe the process. Good agreement was achieved.


Article
Kinetic Study of Esterification Reaction
دراسة حركية تفاعل الاسترة

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Abstract

The Esterification kinetics of acetic acid with ethanol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 50-60°C and at a different molar ratio of ethanol to acetic acid [EtOH/Ac]. Investigation of kinetics of the reaction indicated that the low of [EtOH/Ac] molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 80% was obtained at 60°C for molar ratio of 10 EtOH/Ac. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. Activity coefficients were calculated using UNIFAC program. Results showed deviation in activation energy in the non-ideal system of about 20% this is due to the polarities of water and ethanol compared to the non-polar ethyl acetate this dissimilarity leading to strong non- ideal behavior. The homogenous reaction has been described with simple power-law model. The chemical equilibrium combustion calculated form the kinetic model in agreement with the measured chemical equilibrium.

تمت دراسة حركية تفاعل استرة حامض الخليك والكحول الاثيلي باستعمال حامض الكبريتيك كعامل مساعد في مفاعل ذو الدفعات. اجري التفاعل في درجات حرارة مختلفة تتراوح بين 50-60°م عند نسب مولية مختلفة للكحول الى حامض الخليك. فقد وجد انه كلما قلت نسبة الكحول الى حامض الخليك يزداد التحول وذلك بسبب ان التفاعل حامضي ولقد تم الحصول على تحول 80% بدرجة حرارة 60°م ونسبة مولية 10 كحول اثيلي/ حامض الخليك. لقد لوحظ ان زيادة درجة الحرارة تؤدي الى زيادة ثابت التفاعل والتحول عند نسبة معينة من الايثانول وحامض الخليك وهذا لكون التفاعل باعث للحرارة. تمت الدراسة من زاوية النظام الغير مثالي. تم حساب معامل الفعالية باستعمال برنامج (UNIFAC). اوضحت النتائج وجود انحراف في طاقة التنشيط للنظام الغير مثالي بمقدار 20% تقريبا. تم الحصول على اعلى تحول, تقريبا 80%, باستعمال نسبة مولية 10 ايثانول/ حامض الخليك وهذا سببه كون الماء والكحول الاثيلي مواد ذات قطبية عالية مقارنة بالاستر الناتج وهذا الاختلاف يؤدي الى السلوك الغير مثالي.


Article
Dynamic Simulation of Semi-Batch Catalytic Distillation Used for Esterfication Reaction

Authors: Ziadoon M. Shakor --- Khalid A. Sukkar
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2008 Volume: 26 Issue: 7 Pages: 777-796
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this paper the detailed mathematical dynamic model of semi-batch reactivedistillation is formulated for ethyl acetate synthesis (estrefication reaction).The model is composed of material balance, heat balance, and equilibriumequations. The set of nonlinear ordinary differential equations governing theunsteady state composition profile in a semi-batch reactive distillation columnwere solved by using fourth order Runge-Kutta integration method with the aid ofthe powerful MATLAB 6.5 program which used to simulate and optimize thesemi-batch reactive distillation column.The simulation provides compositions, temperatures and holdups profilesalong the column as a function of time. Also the reactant conversion and ethylacetate purity in distillate are calculated.Finally, the simulation results are analyzed to find the optimum operatingpolicy of reflux ratio, Ethanol/Acetic acid and catalyst weight.

من المعدات الحديثة التي تجمع (Reactive Distillation) تعتبر معدات التقطيرذات المفاعلعملتي التقطير والتفاعل في نفس المعدة . في هذا البحث تم التوصيف والتمثيل الرياضي لهذاالنوع من المعدات في تفاعل الاسترة لانتاج خلات الاثيل .حيث تمت النمذجة الرياضية على اساس منظومة ريادية سابقة والتي تعمل باسلوب نصفوكان الموديل الرياضي مبنيًا على اساس اعتماد موازنة الكتلة (Semi-batch) الوجبةوالحرارة وخصائص الاتزان بين الطورين. وعليه فان مجموعة المعادلات التفاضلية اللاخطيةتم حلها بطريقة التكامل بواسطة (Unsteady state) التي توصف الحالة غير الستقرةللحل MATLAB ومن خلال استخدام برنامج 6.5 Fourth Order Runge-Kuttaواستحصال النتائج الخاصة بالمنمذ جة الرياضية لها النوع من المعدات .من خلال الموديل تم استحصال نتائج التركيز ودرجة الحرارة ومعدلات الجريان لكل اجزاء برجكدالة للزمن . كما تم حساب نسبة (Reboiler, Column and condenser ) التقطير التفاعلي.(Ethyl Acetate) التحول للمواد المتفاعلة وحساب نقاوة المادة الناتجة والتي هي خلات الاثيلومن خلال التحليل الرياضي تم استحصال نتائج من الموديل تمثل افضل قيم لنسبة.(Reflux Ratio) (Catalyst Weight) and , (Ethanol/Acetic acid ratio) الراجع


Article
Reaction Kinetics of Acetic Acid and n-Butanol Esterification Catalyzed by Dowex 50 Catalyst

Authors: Zaidoon M. Shakoor --- Khalid A. Sukkar --- Mohammed S. Baqer
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 10 Pages: 2060-2072
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The reaction kinetics of the n-butanol esterification and acetic acid on acidic solid catalyst named Dowex 50 under atmospheric pressure was investagated in this work. Reaction experiments were carried out in a stirred batch reactor at temperature range of 343 to 363 K, under various catalyst loads and various starting reactants feedratios. The experimental data were fitted to estimate the kinetic parameters for reaction mechanisms by using MATLAB 7 software. The chemical equilibrium composition was measured and kinetic information was obtained at the same temperature range. The results show that the activation energy of n-butanol esterification reaction was found to be 39.975 kJ/mol. Finally the results of produced reaction mechanisms were compared with experimental results to validate the reaction mechanism. Then it was conclud that the model results with the regressed kinetic parameters are in excellent agreement with the experimental results.


Article
Production and Evaluation of Biodiesel from Sheep Fats Waste

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Abstract

Animal fats are a good, promising and ethical alternative source for biodiesel production, but they need more complex treatments than vegetable oils. Iraqi butchery plants waste fats (sheep fat) which are suggested as feedstock to produce biodiesel. This type of fat contains a large quantity of free fatty acids (FFAs) (acid number 49.13 mg KOH/g of fat). The direct transesterification of such fats produce high amount of soap instead of desired biodiesel, so a pre-treatment step (to reduce FFAs) is necessary before transesterification. This step was done by esterification of the free fatty acids in the fat by adding ethanol and using 1% acid catalyst (H2SO4) for 30 minutes. The results showed that the acid number of sheep fat after pre-treatment step reduced to 0.97 mg KOH/g of fat at esterification step. Transesterification of treated fats (produce from esterification) used to convert biodiesel. The maximum yield of biodiesel was about 85 vol. % for treated fats obtained with 25/100 ethanol/fat wt. ratio, 70° C reaction temperature and 50 minutes total treatment period (pre-treatment step and transesterification reaction). The suggested model of the production rate kinetic of transesterification reaction, found that the production rate is inversely proportional with the volume of biodiesel produced with activation energy of 25320 J/mole.

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