Heterogeneous Catalysis of Babassu Oil Monitored by Thermogravimetric Analysis

6527r 2010 American Chemical Society pubs.acs.org/EF

Energy Fuels 2010, 24, 6527–6532 : DOI:10.1021/ef101228fPublished on Web 11/18/2010

Heterogeneous Catalysis of Babassu Oil Monitored by Thermogravimetric Analysis

Carla Veronica Rodarte de Moura,* Adriano Gomes de Castro, Edmilson Miranda de Moura,Jose Ribeiro dos Santos Jr., and Jose Machado Moita Neto

Department of Chemistry, Universidade Federal do Piauı (UFPI), Teresina, Piauı (PI) CEP 64049-550, Brazil

Received July 4, 2010. Revised Manuscript Received October 29, 2010

This paper investigates the transesterification of babassu oil to biodiesel in a fixed-bed reactor usingstrontium oxide (SrO) as a catalyst. Under room temperature, atmospheric pressure, and 100 g of babassuoil initial feeding, babassu oil conversion reached almost 100% after 3 h using 1.5 g of SrO. This resultshows a promising and commercially viable path to produce biodiesel. In terms of technical quality, it wasfound that the reaction time is a key issue rather than the amount of catalyst in use. In addition, thethermogravimetric analysis (TGA) method was found as accurate as nuclear magnetic resonance (NMR)for measurement of the conversion.

Introduction

Biodiesel has emerged as a promising alternative tomineralfuels. This renewable characteristic makes it an importantsource of energy. It can improve air quality because of thereduction in the emission of greenhouse gases and sulfur,1,2

and it can be used in stationary diesel or automotive engines asan additive, without adaptation.3

Industrially, the main catalyst used to produce biodiesel isNaOH, a homogeneous catalyst. However, NaOH can causesomeproblems in theprocess, such as the formationof soaporemulsion.4 The heterogeneous catalysts have been widelystudied and have advantages in the commercial productionof biodiesel, having a positive impact on the economy and theenvironment.5,6 The literature shows that the alkali metaloxides have been used as catalysts for the transesterificationreaction of oils.5 Liu et al.7 have studied the use of strontiumoxide (SrO) as the catalyst for the biodiesel production fromsoybean and achieved conversions exceeding 95%. The re-searchers say that SrO has an excellent catalytic activity andstability because of its strong basicity and long life andbecause it is insoluble in methanol.7

The use of a fixed-bed reactor offers advantages for theproduction of biodiesel, because it can significantly reduce thenumber of stages of the production process. Requiring limitedancillary equipment, it facilitates adequate contact betweenfluid phases and the catalyst because of fixation of particles in

the bed, and not to mention, the catalyst can be reused manytimes.8,9

The main source of raw material in Brazil for biodieselproduction is soybean oil. However, this oil is also consumedin food products. Therefore, it is necessary to diversify supplyoption rawmaterial for this purpose. Fortunately, Brazil has agreat diversity of plants that can be used to manufacturebiodiesel.One of them is babassu coconut oil, where northeastBrazil has an area of about 12 million planted hectares, withmost concentrated in the states of Maranh~ao and Piauı.10

Monthly, around140000 tonsof almondsare drawn from thisculture, and it is possible to use the entire coconut. Forexample, the mesocarp can be used in the manufacturing ofmedium-density fiberboard (MDF) composite; the core ma-terial can be used as charcoal.10With regard to the productionof fuel oil, babassu oil has excellent characteristics for biodie-sel production because of its composition being predomi-nantly lauric ester.10 This fact facilitates the transesterifica-tion reaction, because the lauric ester is composed of shortchains that interact more effectively with the alcohol andcatalyst to obtain a product with excellent physicochemicalcharacteristics, even though the catalyst is different fromNaOH. The literature11 shows that, when using hetero-geneous catalysts and babassu oil for synthesis of biodiesel,higher yields are obtained in comparison to other oils.

There are many methods for characterization of biodiesel,including gas chromatography (GC),12 high-pressure liquidchromatography,13 nuclear magnetic resonance (NMR)spectroscopy,14,15 and Fourier transform near-infrared (NIR)and infrared (IR) spectroscopy.16 Among such techniques,

*To whom correspondence should be addressed. Telephone:55-86(32155840). Fax: 55-86(32155632). E-mail: [email protected].(1) Omer, A. M. Renewable Sustainable Energy Rev. 2008, 12, 1789–

1821.(2) Rashid, U.; Anwar, F. Fuel 2008, 87, 265–273.(3) Pinto, A. C. J. Braz. Chem. Soc. 2005, 16 (6B), 1313–1330.(4) Mohamad, I.; Ali, O. A. Bioresour. Technol. 2002, 85, 253–256.(5) Liu, X.; He, H.; Wang, Y.; Zhu, S.; Piao, X. Fuel 2008, 87,

216–221.(6) Silva, A. R. B.; Neto, A. F. L.; Santos, L. S. S.; Lima, J. R. O.;

Chaves, M. H.; Santos, J. R., Jr.; Lima, G. M.; Moura, E. M.; Moura,C. V. R. Bioresour. Technol. 2008, 99, 6793–6798.(7) Liu, X.; He, H.; Wang, Y.; Zhu, S.Catal. Commun. 2007, 8, 1107–

1111.(8) Ramaswamy,R.C.; Ramachandran, P.A.;Dudukovic,M. P. Ind.

Eng. Chem. Res. 2007, 46, 8638–8651.(9) Helwani, Z.; Othman, M. R.; Aziz, N.; Fernando, W. J. N.; Kim,

J. Fuel Proces. Technol. 2009, 90, 1502–1514.

(10) Lima, J. R. O.; Silva, R. B.; Silva, C. C. M.; Santos, L. S. S.; dosSantos, J. R., Jr.; Moura, E. M.; Moura, C. V. R.Quim. Nova 2007, 30,600–603.

(11) Barros, S. V. Rev. Amazonia 2010, 20, 25.(12) Abreu, F. R.; Lima, D. G.; Hamu, E. H.; Wolf, C.; Suarez,

P. A. Z. J. Mol. Catal. A: Chem. 2004, 209, 29–33.(13) Plank, C.; Lorbeer, E. J. Chromatogr., A 1995, 697, 461–468.(14) Holcapek,M.; Jandera, P.; Fischer, J.; Proke�s, B. J.Chromatogr.,

A 1999, 858, 13–31.(15) Neto, P. R. C.; Caro, M. S. B.; Mazzuco, L. M.; Nascimento,

M. G. J. Am. Oil Chem. Soc. 2004, 81, 1111–1114.(16) Dube, M. A.; Zheng, S.; McLean, D. D.; Kates, M. J. Am. Oil

Chem. Soc. 2004, 81, 599–603.

6528

Energy Fuels 2010, 24, 6527–6532 : DOI:10.1021/ef101228f de Moura et al.

NMR and GC have been extensively used and are consideredstandard techniques for the characterization of substances bymany researchers.17

Thermogravimetric analysis (TGA) is a technique to mea-sure the thermal stability ofmaterials, whether pure ormixed,expressing the result as a major change with increasingtemperature.18 According to Lima et al.,10 biodiesel is amixture of alkyl esters that exhibit physical properties similarto pure esters; therefore, it tends to show volatility and aboiling range dependent upon the fatty acid composition,especially with the size of the chain and unsaturation number.Thus, the boiling range of biodiesel will be the average of theboiling points of the fatty esters that comprise the mixture. Asdescribed byGoodrum,18 the TGA technique can be used as ascreening method for determining the boiling point andmonitoring the transesterification reaction because the resultsare accurate ((5%), there is no evidence that the sampleundergoes thermal decomposition when the analysis is per-formed at 1 atm, and also, the cost of analysis is low.

The proposed monitoring of transesterification reactionsby TGA does not provide structural information, such asNMR, GC, or IR, based on the properties for use becauseheating and volatilization of the sample is part of theimplementation of fuel. Esters coming into boiling at hightemperatures (such as vegetable oils) are good for use and,therefore, are transformed into esters with lower boilingtemperature (ethyl or methyl esters). The yield of the tran-sesterification reactions can be advantageously obtained byTGA and compared to established techniques for the samepurpose. Therefore, we believe that the biodiesel industry canmake use of this technique to control the production ofbiodiesel, to determine the time of the conversion reaction.Importantly, this technique may be used only to monitor theprogress of the transesterification reaction and not to deter-mine the final quality of product.19

Given the facts presented above, the study in questiondescribes the construction of a fixed-bed reactor, where SrOwas used as the heterogeneous catalyst and babassu oil was asthe feedstock to produce biodiesel. The product was charac-terized by the techniques of GC-mass spectrometry (MS),1H NMR, IR, TGA, and physicochemical characterization.Also described is the possibility of the use of the TGA tech-nique to monitor the yield of biodiesel and compare it to1H NMR and GC results.

Experimental Section

Reagents and Equipments.All reagents used in this work wereanalytical-grade, purchased from Synth, Vetec, and Sigma-Aldrich,and used without prior purification. The refined babassu oil wasa donation from �OleosNilo, an oil company located in Teresina,Piauı (PI), Brazil.

TGA was executed using a differential thermal analysis(DTA)/thermogravimetry (TG) analyzer (SDT 2960, TA Instru-ments) in nitrogen, with a heating rate of 3 �C/min, using analuminum pan of 20 μL with a hole of approximately 0.5 mm indiameter in the lid. All of the analyses were performed intriplicate. IR spectra were obtained using a Fourier transforminfrared (FTIR) spectrometer Bomer MB series B 100 andan attenuated total reflectance (ATR) cell with ZnSe crystaland angle of 45�. It was a technique of transmission (KBr pellet

and NaCl window) and attenuated total reflection cell, withATR with ZnSe crystal in the spectral range from 4000 to400cm-1.TheGC-MSanalysiswasperformed inachromatographVarian CP-3380 column BP 20, 12 m � 0.25 mm (SGE), withCarbowax 20M (polyethylene glycol) as the stationary phase,with a flame ionization detector (FID). Conditions: initialcolumn temperature, 200 �C; increasing the temperature at arate of 10 �C/min to 240 �C; injector temperature, 250 �C;splitting ratio, 1:100; and detector temperature, 260 �C. Thespecific surface area was performed from adsorption-desorptionBrunauer-Emmett-Teller (BET) method isotherms of nitrogenmeasured at 77 K in an ASAP2010 apparatus (Micromeritics,Norcross, GA). The samples were run in an atmosphere of N2

and degassed at 250 �C for 20 h before analysis. The 1H NMRspectra were obtained using a Bruker Avance DPX 250 appa-ratus, at 250 MHz, and a Varian 500, at 500 MHz, with CDCl3as the solvent, which served as the internal standard. Theviscosity, density, sulfur, flash point, cold filter plugging point,free and total glycerol, mono-, di-, and triglyceride, and deter-mination of oxidation stability (accelerated oxidation test) weredetermined in accordance with methods described in ANPresolution 07/2008.20 The neutralization number, saponifica-tion number, and acidity index were determined by analyticalnorms of the Adolfo Lutz Institute.21

Catalyst Preparation. SrO was prepared from calcinations ofSrCO3 in amuffle furnace at 1200 �C for 5 h, as described by Liuet al.,7 and it was characterized by IR and BET analysis.

Fixed-Bed Reactor Construction. The fixed-bed reactor(Figure 1) consists of a catalyst-packed hollow glass tube, abeaker (600 mL), silicone hoses (fluid flow), and an immersionpump, with a discharge flow rate of 360 L/h. The beaker used

Figure 1. Schematic view of the process used in this work.

Table 1. Optimum Reaction Conditionsa

sample time (h) catalyst quantity (g)

BD1 1 0.50BD2 1 1.00BD3 1 1.50BD4 1 2.00BD5 1 2.50BD6 2 0.50BD7 2 1.00BD8 2 1.50BD9 2 2.00BD10 2 2.50BD11 3 0.50BD12 3 1.00BD13 3 1.50BD14 3 2.00BD15 3 2.50

aAll of the samples were run at room temperature.

(17) Knothe, G. J. Am. Oil Chem. Soc. 2000, 77, 489–493.(18) Goodrum, J. W. J. Am. Oil Chem. Soc. 1997, 74, 947–950.(19) Chand, P.; Reddy, V. Ch.; Verkade, J. G.; Wang, T.; Grewell, D.

Energy Fuels 2009, 23, 989–992.

(20) Agencia Nacional de Petr�oleo, G�as Natural e Biocombustıveis(ANP). Resoluc-~ao 07/2008; http://anp.gov.br (acessed on July 2010).

(21) Instituto Adolfo Lutz. Normas Analıticas do Instituto AdolfoLutz, 3rd ed.; InstitutoAdolfo Lutz: Sao Paulo, Brazil, 1985; Vol. 1:M�etodosQuímicos e Físicos para An�alise de Alimentos, pp 245-250.

6529


had no lock; the pressure of the reactor was the same of the fluidcaused by the pump. The hollow glass tube measured 2 cm in

outer diameter, 1.5 cm in inner diameter, and 3.5 cm long.A cotton-cloth filter was used as a bed to pack the catalyst, andthis filter covered the entire area of the reactor, forming an innershirt. The filter was filled with varying amounts of catalyst,because this amount has been optimized for this study, asdescribed in Biodiesel Production, andmethanol was percolatedto package it and avoid the formation of bubbles along the bed.

Biodiesel Production. In Table 1, the reaction conditionsinvestigated and adjusted parameters used in this study aredescribed. The amount of catalyst varied from 0.5 to 2.5%based on themass of vegetable oil. The time ranged from1 to 3 h,and the reactions occurred at room temperature (approximately25 �C). In all of the experiments, 100 g of babassu oil, 20 g ofmethanol, and catalyst (0.5-2.5%) were used. The oil andmethanol were mixed in advance in the beaker, and the catalystwas packed directly into the reactor. Themixture (oil/methanol)was suctioned by the pump to soak up the reactor (where thecatalyst was located) and then place it in the beaker, running acycle. After the reaction time, the mixture was transferred to adecanter funnel, where it settled. Glycerin was drained (heavyphase, higher density), and biodiesel (light phase) was separatedand washed 3 times with warm water (30 mL). Afterward,biodiesel was filtered through anhydrous sodium sulfate.

Results and Discussion

Catalyst Results.Figure 2 shows the IR spectra of strontiumcarbonate (SrCO3) and SrO compounds. It may be noted inthe spectrum of SrO decreased the bands in 1473, 856, and700 cm-1 relating to stretching and deformation of CO bonds.We also observed the appearance of a band at 592 cm-1,which was attributed to the stretching of the Sr-O bond.The surface areas found for SrO and SrCO3 were 2.94 and2.02 m2/g, respectively. With regard to the size of the poresfound for SrO between 20 and 500 A, theywere considered asmesopores.

Biodiesel Results.Tomatch theparameters, suchas the reac-tion time and amount of catalyst, we usedmeasures of viscos-ity and thermal analysis (Table 2).

Statistical analysis of biodiesel viscosity measurementsshowed that the time variation (increase) of the reactionled to a decrease in the viscosity (Figure 3); however, when itincreased the amount of catalyst, no significant change isobserved in the results.

According to ANP resolution 07/2008, biodiesel is con-sidered within the standard if the present viscosity is between

Figure 2. IR spectra of SrCO3 and SrO.

Table 2. TGA and Viscometer Results

TGA

samplestime(h)

catalyst(wt %)

rangetemperature

(�C)

weightloss(%)

viscosity at40 �C

(mm2/s)

OB 315.61-476.10 98.73P98.73

BD1 1 0.5 135.90-330.20 49.38 20.62330.20-489.60 49.76P

99.14BD2 1 1.0 154.20-319.00 51.68 19.81

319.00-483.80 48.08P99.76

BD3 1 1.5 183.60-323.80 52.71 19.12323.8-482.00 47.11P

99.82BD4 1 2.0 182.70-315.80 61.30 16.40

315.8-482.45 38.52P99.82

BD5 1 2.5 182.50-314.76 61.67 16.45314.76-476.78 38.15P

99.82BD6 2 0.5 176.70-311.80 62.43 15.75

311.8-474.48 37.39P99.82

BD7 2 1.0 178.70-319.80 63.75 15.35319.8-476.67 36.07P

99.82BD8 2 1.5 185.60-311.54 63.86 15.16

311.54-476.45 35.96P99.82

BD9 2 2.0 181.70-314.56 63.92 15.15314.56-477.25 35.90P

99.82BD10 2 2.5 182.76-319.23 64.35 11.30

319.23-473.45 35.47P99.82

BD11 3 0.5 150.50-323.40 64.32 11.34323.40-475.80 34.68P

99.00BD12 3 1.0 164.20-323.00 76.78 8.12

323.00-482.80 22.98P99.76

BD13 3 1.5 131.93-340.93 91.37 4.74340.93-430.29 7.38P

99.15BD14 3 2.0 182.68-364.80 89.58 4.81

364.8-437.56 9.41P98.99

BD15 3 2.5 178.70-385.69 90.12 5.10365.69-439.45 8.89P

99.01

Figure 3. Viscosity � reaction time.

6530


3 and 6mm2/s, thereby only samplesBD13, BD14, andBD15were considered suitable.

The samples of TGA curves showed the same profile,as seen in the example shown inFigure 4. In all cases, two thermaleventswereobserved: the first assigned tobiodiesel and the secondattributed to the fresh oil. Using the results of the temperature onsets,whichwerecalculatedbythesoftwareequipmentofTGA,wefound theaverageboilingpoint of biodiesel.Onaverage, the valuewas 261.91 �C (biodiesel) and 400.69 �C (oil).

According to Helwan et al.,9 the conversion degree of theproduct is themost important factor in reactor building. Thekey variables that dictate the conversion and selectivity aretemperature, pressure, reaction time, and degree of mixing.In transesterification, the selectivity of the reaction is notadversely affected by the increase in the temperature. Thepressure in the reactor should be maintained at a sufficientlevel that keeps the alcohol in the liquid phase. The conver-sion rate can be improved by increasing the reaction time.Another important parameter in the reactor design is thedegree of mixing, and for bath reactors, this parameter isdirectly related to the amount of energy introduced throughthe impeller.22 In this study, according to the results obtained,the degree of mixing was controlled by the rotor of the pumpand was efficient.

The methods used for multiple comparisons are containedin the general category of analysis of variance (ANOVA).These methods use a single test to determine whether thereare differences between themeans of populations rather thanpaired comparisons, which aremade with the t test. After theANOVA indicates a potential difference, multiple compari-son procedures can be employed to identify which specificmeans differ from other populations.23 This study evaluatedthe influence of two factors in the conversion of the reaction:

reaction time and amount of catalyst. The values used forstatistical calculation were the percentage of weight lossfound for the first event shown in the TGA curves. Theresults showed that the probability of occurrence of the nullhypothesis <5% (p< 0.05) was considered statistically dif-ferent, using one-way ANOVA followed by multiple com-parisons by Tukey’s test. All tests were performed usingSPSS 15.0 for Windows.

The results showed that the amount of catalyst did notsignificantly affect the conversion, as analyzed separately,because we found a value of p=0.780. For the time variable,the value of pwas found<0.05, showing that this parameterhad a significant influence on conversion. The p value isrelated to the significance of a particular variable analyzed ina regression model. The t test showed that the most signifi-cant difference occurred in the time of 3 h and there were nosignificant differences between the reaction times of 1 and 2 h.

If we consider the influence of the reaction time andamount of catalyst simultaneously, to obtain a generalizedlinear model, the contribution to the statistical model of thereaction time (F = 51.94) is about 5 times greater thanstatistical contribution to the amount of catalyst (F= 9.94).The response surface for the conversion of the reaction wasconstructed by multiple linear regression (R = 0.915), andthe equation found was

C ð%Þ ¼ 29:80þ 13:54tþ 6:84cat ð1Þwhere C is the percentage of conversion, t is the time ofreaction, and cat is the catalyst quantity.

Relying on statistical results, only the samples BD11,BD12, BD13, BD14, and BD15 were analyzed by NMRand GC. The conversion results can be seen in Table 3. The

Figure 4. TGA curve of babassu oil (BO) and BD13.

Table 3. Conversion (%) of Biodiesel Found by TGA, NMR, and GC

BD11 BD12 BD13 BD14 BD15

TGA 64.32 76.78 91.37 88.60 88.87RMN 64.75 77.45 98.32 97.87 97.25CG 64.68 76.78 98.54 97.92 96.87

(22) Harvey, A. P.; Mackley, M. R.; Seliger, T. J. Chem. Technol.Biotechnol. 2003, 78, 338–341.(23) Skoog,D.A.;West,D.M.;Holler,F. J.;Crouch, S.R.Fundamentos

de Quımica Analıtica, 8th ed.; Pioneira Thomson Learning: Sao Paulo, Brazil,2006.

6531


1H NMR spectra of the samples BD11 and BD12 showed asinglet at δ 3.64, corresponding to the methoxyl group, twosignals at δ 4.12 and 4.24, attributed to hydrogen fromglycerol (-CH2O), and a multiplet between δ 5.30 and5.34, referent to hydrogens in the olefinic chain and -CHOfrom the glycerol portion. These results showed that theconversion of these samples into biodesel was partial. The1H NMR spectra of the samples BD13, BD14, and BD15showed an intense signal at δ 3.6, concerning the methoxylgroup, and no signal at δ 4.0-4.3 and 5.3, peculiar to CH2

and CH glycerol hydrogen of the triglycerides (Figure 5).The results of multiple linear regressions confirm that the

time had the biggest influence on the percentage of conver-sion. Besides that, we could see that the highest conversionobtained in this study was 98.54%, where the reaction timeselected was 3 h with a percentage of 1.5 wt %.

According to Meher et al.,24 the ester conversion can bedetermined using eq 2

C ð%Þ ¼ 2AME

3ACH2� 100 ð2Þ

where C is the percentage of conversion of triglycerides tocorresponding methyl ester, AME is the integration value ofthe protons of methyl esters, and ACH2 is the integrationvalue of the protons of R-carbonyl.

The GC results of samples BD11 and BD12 showed pro-nounced peak intensities at high retention time (over 32min),which means that there is a certain amount of oil mixturewith biodiesel, because these peaks are represented by mono-,di-, and triglycerides without conversion. In the samplesBD13, BD14, and BD15, the peaks over 32 min were notintense, showing that, in these cases, the ester conversionwasalmost complete. The conversion results using GC, NMR,and TGA techniques are shown in Table 3.

The percentage of fatty acid esters was calculated on thebasis of chromatogram BD13, and the results are shown in

Table 4. The ester predominance in this biodiesel is methyllaurate,25 which is an excellent feature for the production ofbiodiesel. This fact facilitates the transesterification reaction,because of lauric acid being made up of short chains, whichinteract more efficiently and effectively with the alcohol andthe catalyst, to obtain biodiesel with excellent physical andchemical characteristics.

The conversion results found by the TGA technique wereplotted as a function of conversion results found by NMR(Figure 6a) and GC (Figure 6b). The data are typicallybetween (0.02%, and the greater difference is (0.06%.The linear regressions between TGA and NMR (R2 =0.9998) and TGA and GC (R2 = 0.9991) indicate that theTGA technique can adequately replace NMR and GC formonitoring the transesterification reaction.

The physical and chemical analyses were performed onlyfor sample BD13, because it has shown a higher value forconversion with a smaller amount of catalyst. The resultsfound were viscosity, 4.74 mm2/s; specific weight (15 and20 �C), 0.888 kg/m3 ((0.0014) and 0.890 kg/m3 ((0.006); sulfur,0.0201 mg/kg ((0.0007); flash point, 174 �C ((1.00); coldfilter plugging point (CFPP), -4 �C ((1.00); free glycerin(FG), 0.0146% ((0.001); total glycerol (TG), 0.231%((0.005); monoglycerides, 0.564% ((0.002); diglycerides,

Figure 5.1H NMR spectra of (A) BD11 and (B) BD13 in CDCl3.

Table 4. Chemical Composition of Fatty Acids Present in BabassuOil

percentage (%)

peaks fatty acids found literature24

1 caprilic 2.65 2.5-5.52 capric 5.22 5.5-6.13 lauric 51.86 35.00-55.004 miristic 18.02 17.00-19.005 palmitic 7.18 7.00-10.56 estearic 1.26 1.00-3.007 oleic 9.89 10.00-18.008 linoleic 2.46 2.00-3.00

(24) Meher, L. C.; Sagar, D. V.; Naik, S. N. Renewable SustainableEnergy Rev. 2006, 10, 248–268.

(25) Oliveira, A. L. A.; Gioielli, L. A.; Oliveira, M. N. Cienc. Tecnol.Aliment. (Campinas, Braz.) 1999, 19, 14–18.

6532


0.345% ((0.003); triglycerides, 0.000%; free alkaline (FA),0.006 meq/g ((0.003); combined alkaline (CA), 0.018 meq/g((0.0016); and acidity index (AI), 0.223 mg of KOH/g((0.0034). Those results are in accordance with ANP resolu-tion 07/2008.20

Conclusions

The fixed-bed reactor and the catalyst (SrO) have provensuccessful for the production of biodiesel from babassu oil, inthis study. Statistical analysis showed that the amount ofcatalyst did not show a significant difference in the conversionof the reaction,when analyzed separately.However,when thisparameterwas analyzed in conjunctionwith the reaction time,

the amount of catalyst was slightly significant. The time oftransesterificationwas statistically important,with the longesttime being the one that favors higher catalytic conversion(3 h). The best results were found for BD13, where the conver-sion was 98.54% in 3 h. Furthermore, the results suggest thatTGA is an effective method for monitoring the transesterifi-cation reaction.

Acknowledgment. The authors thank the Brazilian agencies,Coordenac-~ao de Aperfeic-oamento de Pessoal de Nıvel Superior(CAPES), Conselho Nacional de Desenvolvimento Cientıfico eTecnol�ogico (CNPq), Financiadora de Estudos e Projetos(FINEP), and Fundac-~ao de Amparo �a Pesquisa do Estado doPiauı (FAPEPI), for their financial support.

Figure 6. Babassu biodiesel content (wt %) obtained by (A) TGA and 1H NMR and (B) TGA and GC.

Heterogeneous Catalysis of Babassu Oil Monitored by Thermogravimetric Analysis

Documents

Transcript of Heterogeneous Catalysis of Babassu Oil Monitored by Thermogravimetric Analysis