T. Sathya, A. Manivannan / International Journal of Engineering Research and Applications(IJERA) ISSN: 2248-9622 www.ijera.comVol. 3, Issue 3, May-Jun 2013, pp.488-492488 | P a g eBiodiesel production from neem oil using two steptransesterificationT. Sathya1, A. Manivannan21M.E Student ,2Assistant Professor, Dept. of Mechanical Engineering, Anna university, Tirunelvel Region,Tamilnadu, IndiaABSTRACTCurrently, most of the biodiesel isproduced from the edible/refined type oil usingmethanol and alkaline catalyst. However, largeamount of non-edible type oils and fats areavailable in our country. In this study, crudeneem oil is used as alternative fuel for biodieselproduction. The difficulty with alkalinetransesterification of these oils have containedlarge amounts of free fatty acids (FFA). Thesefree fatty acids quickly react with the alkalinecatalyst to produce soaps that inhibit theseparation of the ester and glycerin. A two-steptransesterification process is developed toconvert the high FFA oils to its mono-esters.Using 100 ml of oil,the optimum combination ofparameters for pretreatment were found to be.45 v/v methanol-oil-ratio,0.5%v/w H2SO4 acidcatalyst, 50˚C and 45 min reaction time. Afterpretreatment of neem oil,transesterificationreaction was carried out with 0.3:1 methanol-to-oil ratio, 1%KOH as alkaline catalyst,1hrreaction time and 55˚C reaction temperature toproduce the fatty acid methyl ester. This two stepprocess gave maximum average yield of 90±2%.Keywords: Biodiesel, free fatty acid, Neem oil,pretreatment, transesterification.1.INTRODUCTIONThe tremendous increase in number ofautomobiles in recent years have resulted in greaterdemand of petroleum products.The depletion ofcrude oil reserves are estimated for few decades,therefore, effort are on way to research nowalternatives to diesel. Due to increasing price ofpetroleum product and environment concern aboutemission from the car exhaust,the biodiesel hasbecome an area of high concern.The biodiesel isan alternative feedstock for depletion of fossile fuel.It has drived from renewable resources such asvegetable oil, which could either be fresh or wastevegetable oil are find useful in Europe, America andAsia as a feedstock in production of biodiesel, as aconsequently, biodiesel derived from a wide varietyof sources can be used as a direct substitute forpetro-diesel fuels. They are several non-edible oilseed such as thevetia(thevetia peruviana), karanja(pongomia pinnate), jatropha (jatropha curca), neem(azadirachta india) etc.Among these, azadirachtaindica seed which contain 25%-45% oil on drymatter basis is non edible oil that can be use inbiodiesel production .Neem tree is evergreen treegrowing in almost every state of India. It is native toIndian subcontinent, South_East Asian countriesand it grows all over India.It grows in all kinds ofsoil and in drier areas .The oil contain three bitter compound thatcan be extracted from it which are nimbin, nimbininand nimbidin which are mostly responsible for itmedicinal value, it can also be use in cosmeticspreparation and act as an effective mosquitorepellent. Neem oil have high free fatty acid valuewhich is accompanied with moisture content andsome other impuritiest, this two have prime effecton the trans-esterification of glycerides with alcoholusing catalyst. However most non-edible oil havehigh free fatty acid content which it leads to highproduction cost through trans- esterification, an FFAcontent more than 2% will form soap and theseparation of the product will be very difficult, itproduces low yield fatty acids methyl esters.This present investigation is intended toconsider aspects related to the feasibility of theproduction of biodiesel from neem oil. The variablesaffecting the yield and characteristics of thebiodiesel made were studied. The obtained resultswere analyzed and compared with conventionaldiesel fuels.2. MATERIALS AND METHODOLOGY2.1 MaterialsCrude neem oil was purchased from localmarket . The magnetic stirrer with hot pte waspurchased from Taleco Chemicals Pvt. Ltd atTirunelveli. Chemicals are used intransesterification process like Pottassium hydroxidepellet(88% purity) ,Methanol (99%purity),Concentrated sulphuric acid and Sodiumsulphate.All the chemicals are purchased fromHimedia and Nice chemicals Pvt Ltd and itsanalytical reagent grade.2.2 EquipmentA round bottom conical flask is used asreactor for these experimental purposes. A magneticstirrer with hot plate arrangement is used for heatingthe mixture in the flask. The mixture is stirred at the
T. Sathya, A. Manivannan / International Journal of Engineering Research and Applications(IJERA) ISSN: 2248-9622 www.ijera.comVol. 3, Issue 3, May-Jun 2013, pp.488-492489 | P a g esame speed for all test runs. The temperature rangeof 40–60˚C is maintained during this experimentand its monitored by thermometer.The separatingfunnel is used to separate the methanol-watermixture after acid pretreatment and the glycerolafter transesterfication.Four set of trail runs arecarried out for each combination of parameter.2.3 MethodologyThe aim of this study is to improve theprocess for producing biodiesel from crude neemoil.There are three process such as oil filtration, acidesterification and alkaline transesterification2.3.1 Oil filtrationNeem oil have higher moiture content andsome other impurities.So, in order to remove themoisture and impurities from the neem oil it shouldbe refined.The purification can be done by boilingoil with about 20% of water.The boiling shouldcontinue until no bubbles of water vapor anymore.After one hours the oil then becomes clear. Thisrefined neem oil is taken as raw material fortransesterification process.2.3.2 Acid esterification100 ml of refined neem oil is poured intothe flask and heated upto 60˚C. The 45% v/vmethanol is added with the preheated neem oil andstirred for a few minutes. 0.5% of sulphuric acid isadded with the mixture. Heating and stirring shouldcontinue about 45min at atmospheric pressure. Aftercompletion of this reaction, the mixture is pouredinto a separating funnel for separating the excessalcohol,impurities and sulphuric acid. The excessalcohol, sulphuric acid and impurities moves to thetop layer and its discarded. The lower layer isseparated for further processing of transesterifiedinto methyl ester. This process reduces the acidvalue of refined neem oil to less than 1% of FFA.2.2.3 Alkaline transesterificationAfter acid pretreatment the esterified oil istaken in flask and heated upto 60˚C.1% of KOH isdissolved in 30% (6:1 M) methanol.The dissolvedsolution is poured into flask.The mixture is heatedand stirred for 1hr.On completion of reaction ,themixture is poured into separating funnel over 12hr.The glycerol and impurities are settled in lowerlayer and its discarded. The impure biodieselremain in upper layer.It contains some trace ofcatalyst ,glycerol and methanol.The washingprocess can be done by the 3/4 th of hot distilledwater added with methyl ester and gentlystirred.The upper layer is pure biodiesel and lowerlayer is drawn off.3. RESULTS AND DISCUSSION3.1. Acid esterification3.1.1 Effect of methanol-to-oil ratioTwo important parameter significantlyaffected the acid value. These are sulphuric acidconcentration and methanol quantities. Molar ratiois defined as the ratio of number of moles ofalcohol to number of moles of vegetable oil.Theoritically , transesterification reaction requires 3moles of alcohol for each mole of oil.However, inpractically molar ratio should be higher thanstoichiometric ratio. By varying methanolpropotion such as 0.35:1, 0.40:1,45, 0.50:1,0.55:1methanol-to-oil ratio, among these 0.45:1 gavehigher yied.The last two 0.50:1, 0.55:1 have onlyslight variation. In economic view 0.45:1 M isselected for reaction condition. The effect ofmethanol variation is shown in fig.1. From thefigure conversion efficiency is slightly increaseupto 0.45:1 methanol-to-oil ratior.After thatconversion efficiency is decreased with increase inmethanol-to oil ratio because it leads to increasingthe acid value. It has been determined that inviscosity reduction increases with increase inmethanol-to-oil ratioFig.1. Effect of methanol on conversion efficiencyFig.2 Effect of acid catalyst amount on conversionefficiency75808590951001050.35:1 0.40:1 0.45:1 0.5:1 0.55:1Conversionefficiency(%)Methanol-to-oil ratio,(v/v)
T. Sathya, A. Manivannan / International Journal of Engineering Research and Applications(IJERA) ISSN: 2248-9622 www.ijera.comVol. 3, Issue 3, May-Jun 2013, pp.488-492490 | P a g e3.1.2 Effect of acid catalyst amountAmount of acid catalyst variation is affectthe conversion efficiency.By varying sulphuric acidpropotion such as .25,.5,.75 and 1% v/v. Maximumconversion efficiency is achieved in 0 .5 % v/vH2SO4. Effect of acid catalyst variation is shown infig. 2. From the figure more than 0.5% v/v H2SO4,the product color is become black. Lower amountof sulphuric acid addition affects the final productyield.3.1.3 Effect of reaction temperatureThe conversion efficiency is very low atroom temperature even after 2 hr reaction .Ifincrease in temperature the conversion takes placeat higher rate. The optimum temperature isachieved at 50˚C.At high reaction temperature, themethanol is lost because melting point of methanolis 65˚C.Above 50˚C product color become black.3.2. Alkaline transesterification3.2.1 Effect of methanol-to-oil ratioMolar ratio is very important factor fortransesterificatin reaction. Theoritically,transesterification reaction requires 3 moles ofalcohol for each mole of oil.However, in practicallymolar ratio should be higher than stoichiometricratio.The higher molar ratio is required forcomplete the reaction at higher rate. In lower molarratio,it takes longer duration for complete thereaction.The effect of methano-to-oil ratio onconversion efficiency is shown in fig. 3. It has beenseen that yield is slightly increase upto 0.3:1methanol-to-oil ratio. The maximum methyl esteryield is achieved at 0.30:1M. With further increasein methanol-to oil ratio the conversion efficiency isdecreases.3.2.2 Effect of alkaline catalystThe amount of catalyst variation is affectthe conversion efficiency. The catalyst propotion isvaried from 0.5- 2% KOH . The effect of catalystvariation on conversion efficiency is shown in fig.4. From the figure yield is slightly increased upto1% KOH and after that yield is decreased due toreverse reaction is take place (emulsionformation).The maximum yield is achieved of 88%at 1% KOH.Fig.3. Effect of methanol on conversion efficiencyFig.4. Effect of alkaline catalyst amount onconversion efficiency4.3. Effect of reaction temperatureThe reaction temperature has importantrole in alkaline-catalyst transesterification .At roomtemperature no significant yield is notified foreven 2hr reaction. The yield is increased withincrease in reaction temperature. The effect oftemperature variation on conversion efficiency isshown in fig.5. By varying temperature in fourdifferent level such as 45,50,55 and 60˚C amongthese 55˚C gave maximum methyl ester yield. Ifgreater than 60˚C,chance for loss the methanol.The maximum ester efficiency is achieved at 55˚C.
T. Sathya, A. Manivannan / International Journal of Engineering Research and Applications(IJERA) ISSN: 2248-9622 www.ijera.comVol. 3, Issue 3, May-Jun 2013, pp.488-492491 | P a g eFig.5. Effect of reaction temperature on conversionefficiency4.4 Effect of reaction timeThe conversion rate is increased withincrease in reaction time. In this experiment,reaction time varying from 0.5-2 hr. The effect ofreaction time variation on the conversion efficiencyis shown fig. 6. From the figure yield was slightlyincreased upto 1hr reaction and after that yield isdecreased. The maximum efficiency is achieved of90% for 1 hr reaction. From these experiment theoptimum yield is obtained at 1 hr reaction.Fig.6. Effect of reaction time on conversionefficiency5. ConclusionThe high FFA (6%) content neem oil hasbeen investigated for the biodiesel production .Ithas been found that the feedstock with high FFA itscouldnot be transesterified with alkaline catalystbecause the alkaline catalyst react with FFA toform soap.So in this study,two step process wasdeveloped to convert FFA to its methyl ester. Thefirst step is acid treatment it reduces the FFAcontent of oil to less than 1% using acid catalyzed(0.5 % v/v H2SO4) reaction with methanol (0.45v/v) at 50˚C temperature and 45 min reaction time.After acid treatment alkaline transesterficationreaction was carried out at 1% KOH ,30%methanol,55˚C and 60 min.The maximum yield is90±2%.The effect of molar ratio, catalyst,reactiontemperature and reaction time are analyzed in eachstep process. Excess addition of sulphuric aciddarkens the product it leads to more productioncost.REFRENCES[1 ] K. Anbumani and Ajit Pal Singh (2010)“Performance of mustard and neem oilblends with diesel fuel in c.i. engine”,ARPN Journal of Engineering and AppliedSciences, VOL. 5(4), 1819-6608 S.S. Ragit et.al.,(2011)„„Optimization ofneem methyl ester from transesterificationprocess and fuel characterization as adiesel substitute”, b i o m a s s and b i oenergy,vol. 3 5, 1 1 3 8-1 1 4 4. Anya Uzo Anya, Nwobia Noelle Chioma,and Ofoegbu Obinna (2012) “Optimizedreduction of free fatty acid content onneem seed oil, for biodiesel production”Journal of Basic and Applied Chemistry,vol.2(4), 21-28. Anindita Karmakar, Prasanta KumarBiswas, Souti Mukherjee (2012),“Environment-Congenial BiodieselProduction from non-edible neemoil”,Environmental engineering research,S27-S32. K.V.Radha, G.Manikandan (2011) “NovelProduction Of Biofuels From Neem Oil”,Bioenergytechnology, 8-11. H. Muthu et.al (2010), “Synthesis ofbiodiesel from neem oil using sulfatedzirconia via tranesterification”, BrazilianJournal of Chemical Engineering , Vol.27, No. 04, 601 - 608, Khandelwal Shikha and Chauhan. Y. Rita(2012), “ Biodiesel production from nonedible-oils : A Review”, Journal ofChemical and Pharmaceutical Research,vol. 4 (9),4219-4230. Emad A. Shalaby1* and Nour Sh. El-Gendy (2012), “Two steps alkalinetransesterification of waste cooking oiland quality assessment of producedbiodiesel”, International Journal ofChemical and Biochemical Sciences, 30-35.
T. Sathya, A. Manivannan / International Journal of Engineering Research and Applications(IJERA) ISSN: 2248-9622 www.ijera.comVol. 3, Issue 3, May-Jun 2013, pp.488-492492 | P a g e Hanumanth Mulimani, Dr. O D Hebbal,M. C. Navindgi (2012), “Extraction ofbiodiesel from vegetable oils and theircomparisons”, International Journal ofAdvanced Scientific Research andTechnology, vol.2(2), 2249-9954. Shashikant Vilas Ghadge, Hifjur Raheman(2005), “Biodiesel production from mahua(Madhuca indica) oil having high freefatty acids”, Biomass and Bioenergy, 28 ,601–605. V.B. Veljkovic et.al (2006) ,“ Biodieselproduction from tobacco (Nicotianatabacum L.) seed oil with a high content offree fatty acids”, Fuel, 85, 2671–2675. Hanny Johanes Berchmans , ShizukoHirata (2008) ,“Biodiesel production fromcrude Jatropha curcas L. seed oil with ahigh content of free fatty acids”,Bioresource Technology, 99 ,1716–1721 Junhua Zhang , Lifeng Jiang (2008) ,“Acid-catalyzed esterification ofZanthoxylum bungeanum seed oil withhigh free fatty acids for biodieselproduction”, Bioresource Technology ,99 ,8995–8998.