بررسي آزمايشگاهي و مدلسازي استخراج فوق بحراني اسانس روغني از بذر گياه جاتروفا و تبديل كاتاليستي آن به بيوديزل

چكيده انگليسي :

Experimental and Modeling Investigation of Supercritical Extraction of Essential Oil from Jatropha Seed and its Catalytic Conversion to Biodiesel Maliheh Mir m mir@ce iut ac ir March 3 2012 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Seyyed Mohammad Ghoreishi ghoreshi@cc iut ac irAbstractThe increasing demand of petroleum products and finite fuel sources in certain regions of the world has causedthe need for alternative fuels with vegetarian basis to be the focus of research attention of scientists Jatrophaseeds are non edible sources to produce biodiesel with 35 60 oil content The oil composition consists ofmainly palmitic stearic oleic and linoleic fatty acids which can be changed to biodiesel One of the usualmethods for oil extraction is Soxhlet But due to liquid solvent toxicity very high amount of usage and processinability for complete recovery its application is not recommended Employing novel method of extraction viasupercritical fluid because of different environmental scientific and economical advantages has attracted theinterest of researchers investigating different separation processes Therefore supercritical carbon dioxide wasused for extraction of Jatropha seeds oil In this study the experimental design was applied to carry outextraction process at different operating conditions by response surface methodology RSM and centralcomposite design So the effect of four main extraction variables of temperature pressure SC CO2 flow rate anddynamic time were investigated on the extraction recovery and yield in the range of 40 60 C 200 300 bar 1 2ml min and 40 160 min respectively For production of biodiesel from extracted oil transesterification methodwas used in which fatty acids were converted to fatty acid methyl esters FAMEs by using a catalyst In thisstudy two certain acidic and alkali catalysts were employed that higher yield for transesterification reaction wasobtained via alkali catalyst in contrast to acidic catalyst The results of extraction and esterification processes aredemonstrated in response variables such as extraction yield oil and biodiesel the total combination of FAMEs recovery Adjusted R2 for quadratic model of oil recovery was calculated to be 97 6 Moreover this value formodel of palmitic stearic oleic linoleic methyl esters recovery and biodiesel recovery were obtained to be 90 5 92 4 92 0 92 5 and 95 2 respectively In addition to design and data analysis optimization of operatingconditions was also carried out by RSM Accordingly optimum temperature pressure SC CO2 flow rate anddynamic time were obtained to be 55 C 300 bar 1 74 ml min and 160 min respectively At the aforementionedoptimum conditions maximum oil recovery of 82 7 was achieved Additionally at the optimum conditions of52 C 300 bar 1 64 ml min and 160 min the maximum recovery of FAMEs palmitic stearic oleic andlinoleic and biodiesel were determined to be 94 7 75 9 75 9 77 7 and 79 4 respectively In addition to RSManalysis mathematical modeling based on differential mass balance for stationery Jatropha and mobile SC CO2 phases was derived and solved using backward central and forward finite difference method Thedeveloped model contained a linear equilibrium relationship in Jatropha pores and three parameters such as filmmass transfer coefficient effective diffusivity and axial dispersion coefficient The modeling predictions werecompared with experimental data in which the model was validated due to a very close compatibility R2 0 967 Furthermore the aforementioned validated model was utilized for analysis of important extractionvariables In this study the effect of variables such as dynamic extraction time temperature pressure and flowrate of SC CO2 on recovery of biodiesel was investigated using the validated model The experimental andmodeling data indicated that higher pressure led to increased recovery This observation and prediction is due tohigher

مير، مليحه

بررسي آزمايشگاهي و مدلسازي استخراج فوق بحراني اسانس روغني از بذر گياه جاتروفا و تبديل كاتاليستي آن به بيوديزل

روش رويه , پاسخ , مدل رياضي