Jurnal Akademika Kimia, 14.
: 40-50.
February 2025 ISSN .
2477-5185 | ISSN .
2302-6030 http://jurnal.
id/index.
php/jak/ OPEN ACCESS Optimization of Palm Bunch Ash-Based Catalysts Transesterification of Waste Cooking Oil into Biodiesel *Fillah M.
Sakhi.
Aman Santoso, & Sumari Program Studi Kimia/FMIPA Ae Universitas Negeri Malang.
Malang Ae Indonesia 94119 Received 09 January 2025.
Revised 30 January 2025.
Accepted 20 February 2025 doi: 10.
22487/j24775185.
Abstract The increasing dependence on fossil fuels to meet fuel needs has caused several problems, such as air pollution, greenhouse effects, unpleasant odors, and loud noises.
This research aims to design an alternative fuel in the form of biodiesel by applying a heterogeneous catalyst based on palm bunch to synthesize biodiesel through transesterification.
The research stages include activating the active sites of palm bunches through calcination at temperatures of 400 AC, 500 AC, and 600 AC.
refining waste cooking oil.
The active components of palm bunch ash (PBA) were characterized using XRF and alkalinity testing.
XRF results indicated that PBA contains active basic compounds such as K CCO and CaO, crucial in catalytic activity.
Physical-chemical property testing revealed that the synthesis achieved the highest yield of 93.
744 %.
The results of the physical-chemical characteristic tests produced the best density with an average of 0.
888 g mLAA, and the lowest viscosity with an average of 3.
79 cSt at 40 AC with an iodine number 116 g ICC 100 gAA, a saponification number of 170.
57 mg KOH gAA, and a refractive index of 1.
The catalyst demonstrated stable performance up to three reuses with yields ranging from 80Ae90 %.
FTIR spectra showed strong absorption bands at 1172Ae1165 cmAA, indicating C-O-CHCE stretching from methyl esters.
GC-MS analysis showed that the biodiesel consists of various fatty acid methyl esters (FAME), with the main component being methyl oleate, which appears at a retention time of 37.
096 minutes with an area of 31 %.
So it is shown that PBA catalysts have an excellent potential for commercial applications as they can reduce dependence on fossil fuels by utilizing household waste.
Keywords: Heterogeneous catalyst, palm bunch ash, waste cooking oil.
FAME Repeated heating of WCO significantly increases the free fatty acid content, much higher than new cooking oil (Widyaningsih et al.
, 2.
According to Aworanti et al.
, the free fatty acid content in waste cooking oil reaches 14.
25 %,
while Suroso .
reports a higher figure of 18 % (Posada et al.
, 2007.
Sujadi et al.
, 2.
The high free fatty acid content can trigger saponification reactions, leading to the formation of soap and emulsions that are difficult to separate.
Therefore, several pretreatment processes, such as esterification, are required to reduce the free fatty acid content, ensuring the resulting biodiesel is high quality (Japir et al.
, 2.
Biodiesel synthesis is processed through transesterification reactions using a heterogeneous base catalyst, palm bunch ash (PBA).
The transesterification reaction is carried out in methanol solvent, with the main product being biodiesel, and the byproduct is glycerol (Attari et al.
Joshi et al.
, 2.
Catalysts play a crucial role in accelerating reactions by reducing the activation energy of the (Berchmans Hirata.
Heterogeneous catalysts have several advantages, including reusability, easy operating procedures.
Introduction The depletion of fossil fuels as the primary energy source has made studying new and renewable energy (EBT) increasingly crucial.
The development of EBT is targeted to reach 23 % by To achieve this, proactive measures are being taken, such as eliminating fossil fuel subsidies, regional market integration, and developing alternative fuels such as biodiesel.
Biodiesel is composed of fatty acid methyl esters (FAME) formed from the transesterification reaction between triglycerides .
egetable oil or animal fa.
with methanol and a base catalyst (Yucel & Turkay, 2.
It contains 75 % paraffin hydrocarbons, aromatic hydrocarbon derivatives, and 25 % alkyl benzene and naphthalene These characteristics resemble petrodiesel, enabling it to be used as a blend in fossil diesel fuel (Galadima & Muraza, 2.
Biodiesel can be synthesized from waste cooking oil (WCO) triglycerides.
WCO is a waste product from repeated frying that has undergone chemical degradation, such as hydrolysis and oxidation (Hambali et al.
, 2007.
Nuryanti et al.
a *Correspondence:
Fillah M.
Sakhi e-mail: fillahmuftisakhi26@gmail.
A2025 the Author.
retain the copyright of this article.
This article is published under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.
0 International, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Volume, 14.
No.
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Jurnal Akademika Kimia easy product separation, and minimal wastewater generation (Zheng et al.
, 2.
Heterogeneous catalysts are developed and processed into ash using waste materials such as eggshells, snail shells, and animal bones (Boey et al.
, 2.
In this study, palm bunches were selected as a heterogeneous catalyst in transesterification reactions to produce biodiesel.
palm bunch contains various minerals, primarily The calcination process converts potassium into potassium oxide (KCCO).
KCCO reacts with methanol to form active methoxide, which converts triglycerides in waste cooking oil into methyl esters and glycerol.
Due to its high potassium content and strong pore structure, this ash has potential as a catalyst.
The highest metal oxide in PBA.
KCCO, is a strong base, providing O2- or OH- ions.
These ions break the ester bonds in triglyceride molecules.
In the reaction mechanism, the base ions from KCCO help form methoxide ions (CH3O-) from methanol, which then attack the carbonyl group of This reaction produces new esters and exchanges fatty acid positions, yielding methyl esters and glycerol (Chi, 1.
This reaction forms methyl esters more quickly than esterification reactions using acid catalysts.
Esterification is necessary to reduce high levels of free fatty acids (FFA) and prevent saponification reactions.
The esterification process also reduces water content, as high water content can cause hydrolysis reactions that reduce biodiesel yield (Patil et al.
, 2.
This study aims to synthesize biodiesel as a renewable alternative to replace fossil fuels using household and palm oil waste, making the research environmentally friendly.
(Smartla.
, 0.
1 N NaCCSCCOCE, starch solution, phenolphthalein indicator (PP), universal indicator, and distilled water.
Activation of the Active Site of Palm Bunch Catalyst A sample of palm bunch waste was obtained from South Blitar plantation.
Sample preparation in this research refers to the procedure by Santoso et .
A sample palm bunch waste was washed with clean water until all dirt and dust were The samples were dried and chopped under the sun for two days, followed by drying in an oven at 110 EE for 24 hours.
The samples are ground using a mortar and sieved using a 100-mesh sieve.
Each sample is calcined at varying temperatures of 400 EE, 500 EE, and 600 EE for 4 hours.
Refining of Waste Cooking Oil (WCO) Waste cooking oil is obtained from snack frying in Malang City.
The first step is to prepare 500 g of waste cooking oil in a 1000 mL beaker.
The oil is mixed with zeolite, which amounts to 50 % of the oil weight, which is 250 g.
The mixture is stirred at 80 EE at 1000 rpm for 3 hours.
The mixture is separated into oil and zeolite.
The acid value and % FFA of the refined oil are tested.
Esterification Refined oil is weighed to a total of 200 grams.
The oil is heated to a temperature of 80 EE.
A 1 %
HCCSOCE catalyst solution .
mL) is mixed with methanol .
to a total of 47.
28 mL.
This mixture is then added to the heated oil.
The mixture is refluxed at 60 EE - 65 EE for 5 hours.
After the reaction process, the upper layer .
rganic phas.
and lower layer .
ater phas.
are separated.
The organic layer is washed with warm water, and the acid number and % FFA are tested.
Methods Tools and materials The tools used in this research were beaker glasses 100 mL (Iwak.
, burettes 50 mL (Iwak.
, volumetric flasks (Iwak.
, stands and clamps, threeneck boiling flasks 50 mL (Iwak.
, erlenmeyer flask (Pyre.
, glass funnel (Pyre.
, porcelain crucible, digital balance (Shimadzu ATX.
, volumetric pipette (Iwak.
, separating funnel (Pyre.
, watch glass (Pyre.
, thermometer 100 EE, condenser (Iwak.
, hot plate, magnetic stirrer, furnace (Therm.
, oven (Memmert.
Type: UN .
, oswald viscometer, pycnometer (Iwak.
, ultrasonic water bath (Branson 1.
, cleveland cup, filter paper, and, universal indicator paper.
The instruments were XRD (PANalytical Type: XAoPert PRO).
XRF (PANalytical Type: Minipal .
GC-MS (Shimadzu QP2010 Plu.
FTIR (Shimadzu Type: IRPrestige .
SEM-EDX (FEI.
Type: Inspect-S.
, and SAA (QuadraSorb Station 2 version .
The materials used in this study were waste cooking oil, palm bunch waste, methanol p.
(Merc.
, 96 % alcohol, 1 N KOH (Merc.
, alcoholic KOH (Merc.
, 0.
N HCl (Smartla.
, 1 % HCCSOCE, demineralized water, 3 M HCl, n-hexane (Smartla.
, acetone (Smartla.
, chloroform (Merc.
KI solution Transesterification with the Reflux Method The esterification oil was weighed at 25 mL and then heated to 80 AC.
The palm bunch ash (PBA) catalysts were weighed at 3 %, 5 %, 7 %, and 9 % respectively.
Methanol .
1 mL was mixed with the ash catalyst.
The mixture is refluxed at 60 AC Ae 65 AC for 2 hours.
After the reaction, the mixture is separated by centrifugation for 30 minutes at 3000 rpm.
The methyl ester is separated from the glycerol using a glass funnel and washed with warm water.
The washed methyl ester is then heated to 150 AC to remove residual catalyst and glycerol, and then added as much as necessary of anhydrous MgSO4 to the methyl ester, followed by centrifugation for 30 minutes at 3000 rpm.
The synthesized methyl ester is weighed for yield and subjected to physical and chemical property testing.
Results and Discussion Activation Characterization Heterogeneous Catalysts from Palm Bunch Waste The catalyst was prepared by thermal calcination of dry palm oil waste ash, as shown in Figure 1.
The Fillah M.
Sakhi et al.
calcination process was carried out in a furnace at temperatures of 400 AC, 500 AC, and 600 AC for four hours to remove volatile organic compounds and convert metal elements into active oxide forms.
The temperature selection was done gradually to study the effect of activation temperature on the formation of basic sites.
Table 2.
Results of alkalinity testing using the acid-base titration method Table 1.
XRF Result Metal Oxide Content in PBA
K2O
CaO SiO2 Other Calcination Temperature 400 AC (%) 500 AC (%) 600 AC (%) Basicity .
The results of the basicity test using the fatty acid titration method showed that the average basicity of palm kernel shell ash catalyst was 15.
mmol/g.
This value indicates many basic sites that transesterification reaction.
For comparison, in Mulyani et al.
, which tested the basicity of CaO metal oxide without doping, the value obtained was 23.
5 mmol/g.
This level of basicity is closely related to the dominant content of CaO and K2O, where K2O contributes as a strong base and CaO as a moderate base, both working synergistically to enhance catalytic activity.
Comparing catalysts calcined at 400 AC, 500 AC, and 600 AC shows that 600 AC produces the highest number of basic sites, consistent with carbonate degradation and the formation of pure metal oxides.
The choice of calcination temperature significantly influences the basicity of the catalyst (Boey et al.
The dominance of strong base oxides such as K2O and CaO is due to the deprotonation process, which directly contributes to forming Lewis base active sites capable of generating strong nucleophiles from methanol, particularly methoxide ions (CHCEO-).
These methoxide ions act as nucleophiles that attack the carbonyl ester groups in triglycerides, leading to transesterification reactions (Khatibi et al.
, 2.
Figure 1.
The palm bunch was heated with Calcination at higher temperatures accelerates the decomposition of carbonate compounds into oxides, while increasing the crystallinity of the catalyst and the availability of active surface area (Jiang et al.
, 2023.
Okoye et al.
Based on analysis using X-ray Fluorescence (XRF) instrumentation, palm bunch ash calcined at temperatures of 400 AC, 500 AC, and 600 AC contains the metal oxide components as shown in Table 1.
Metal Oxide Calcination Temperature (AC) Characterization of Waste Cooking Oil The high K2O and CaO content indicates the potential alkalinity of the catalyst, as both oxides are known to be active centers in transesterification These two oxides can provide OAA and OHA ions that support the mechanism of methoxide formation from methanol (Maneechakr & Karnjanakom, 2.
Other components such as SiO.
Al2O3, and Fe2O3 were detected in significant amounts, which can affect the texture and structural strength of the catalyst.
High levels of SiO2 .
4 %) are generally chemically inert, but they can function as a thermal and mechanical support matrix in heterogeneous catalyst systems.
Other compounds such as Fe2O3.
MnO.
CuO, and ZnO were also found in small They did not contribute significantly to basic activity but could affect the texture, thermal stability, or mechanical strength of the catalyst (Zabeti et al.
, 2.
The number of basic sites on the catalyst is expressed in moles of basic sites per gram.
The basic strength of the catalyst surface refers to the catalyst's ability to convert adsorbed neutral acids into their conjugates electrically.
The basicity value of the catalyst is determined by acid-base titration, as shown in Table 2.
The waste cooking oil used in this study was obtained from household frying residues that had been repeatedly used to fry various types of The cooking oil was characterized to determine its initial quality before further Several parameters were tested, including free fatty acid (FFA) content, acid value, viscosity, density, and constituent compound content based on GC-MS and FT-IR analysis.
The characterization results are presented in Table 3.
Table 3.
Results of characterization of WCO
Characterization Result
FFA (%)
Acid Value .
g KOH/g sampl.
Density .
/mL) Viscosity .
The FFA content test using the alkalimetric titration method yielded a value of 8.
116 %,
indicating that this oil has undergone degradation.
This figure is very high when compared to the recommended content for transesterification raw materials (< 2 %) (Rusdi et al.
, 2.
This is consistent with the acid number, significantly higher than the SNI standard at 16.
911 mg KOH/g oil.
This value indicates that the used cooking oil has Volume, 14.
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Jurnal Akademika Kimia undergone physical-chemical changes due to triglyceride hydrolysis, oxidation, decomposition, and oligomerization caused by repeated frying (Mustafa et al.
, 2023.
Wiege et al.
, 2.
The acid number significantly affects oil quality, as a higher acid number indicates poorer oil quality.
High levels of FFA and acid number can lead to side reactions such as soap formation/saponification when directly reacted with a basic catalyst.
Therefore, pretreatment is required, such as esterification using an acid catalyst to reduce FFA levels (Santoso et al.
Viscosity was calculated using the Poiseuille equation and water as the reference fluid, yielding a value of 50 cST .
AC).
This indicates that the oil experienced increased viscosity due to polar compounds forming from thermal and oxidative This value is influenced by changes in the degree of unsaturation of the fatty acid chain, where the double bonds decrease, making the oil more saturated and flow more difficult (Santos et , 2005.
Wiege et al.
, 2.
Furthermore, the measured density value of 0.
999 g/ml is still within the general range of vegetable oils.
density, kinematic viscosity, acid number, free fatty acid content, refractive index, saponification number, and iodine number.
Each parameter serves a specific function in assessing the chemical stability, combustion performance, and corrosion potential of the fuel on the engine.
The test results are then compared with the SNI quality limits to evaluate the compliance of the produced biodiesel.
The test results are presented in Table 4.
Density indicates the amount or ratio of a substance in a unit volume.
This test is influenced by fatty acid composition, namely the length of the ester carbon chain and the degree of fatty acid The longer the carbon chain, the greater the molecular mass (Verduzco et al.
, 2.
Density measurements were conducted using the pycnometric method at 40 AC.
Based on Table 1, the sample with the highest calcination temperature .
AC) produced biodiesel with a lower density than the other calcination temperatures.
This change in density indicates a more stable and responsive catalyst pore structure as a result of optimal calcination, so the transesterification process runs more smoothly.
In contrast, the biodiesel density at 400 AC showed a fluctuating This indicates that the active sites have not reached their peak and still contain residues or amorphous structures that are not yet uniform, thus affecting the reaction efficiency and composition after producing biodiesel (Verduzco et al.
, 2.
Characterization of Methyl Esters As shown in Figure 2, the synthesis result of FAME must be ensured to meet applicable therefore, physical and chemical properties are tested based on the parameters listed in SNI 7182: 2015.
These parameters include .
Figure 2.
FAME results with PBA catalyst at various temperature variants .
400 AC, .
500 AC, .
600 AC Table 4.
Test Results of Physical and Chemical Properties of FAM Parameter Uji Calcined Temp.
Conc.
SNI 7182:2015
Yield .
Density .
/m.
Viscosity .
Acid Value .
g KOH/.
Max.
FFA
(%)
Index of Bias Max.
445 Ae Saponification Numbers .
g KOH/.
Iod Numbers .
I2/100 Max.
Fillah M.
Sakhi et al.
The following test parameter is viscosity.
Viscosity is important to study because it is related to performance and directly affects injection efficiency, fuel atomization, and the formation of the air-fuel mixture in the combustion chamber.
Viscosity values were calculated using the Poiseuille equation, and water was used to compare fluids.
Test results based on Table 1, at calcination temperatures of 500 AC and 600 AC, show viscosity values within the standard range of SNI 7182: 2015 .
3 - 6.
0 cS.
In contrast, samples at 400 AC with 3 % and 5 % catalyst dosage had viscosity values that exceeded the maximum limit of 7.
04 cSt and 6.
cSt, respectively, indicating an imperfect transesterification reaction or high residual triglyceride content.
Based on thermodynamics, a calcination temperature that is too low limits the active surface area of the catalyst, and imperfect oxide structures are formed, reducing the catalytic base activity.
This can produce products with longer carbon chains, thus increasing the product's viscosity.
Catalysts calcined at 500 AC and 600 AC have more stable and uniformly distributed base sites that can encourage the formation of many double bonds and produce lower viscosity (Knothe & Steidley, 2.
The acid number of the biodiesel produced .
543 - 0.
549 mg KOH g-.
already exceeded SNI 7182: 2015 (O 0.
5 mg KOH g-.
, the deviation was still not too far from the tolerance limit, considering that the method used was manual titration with a minimal titrant volume.
This confirms that the transesterification reaction was effective at all combinations of calcination temperatures .
AC 600 AC) at various doses.
Neither temperature nor dosage variation showed a significant trend.
difference between values was only A 0.
005 mg KOH g-1, because the concentration of active strong bases .
etal oxide.
in the catalyst ash was sufficient even at the lowest temperature to neutralize free fatty acids (FFA).
The remaining FFA content .
261 - 0.
263 %) is still within the practical limits often used in industry, although it slightly exceeds the 0.
20 % figure often used as a reference for raw material quality.
This indicates that a small amount of free fatty acids remains postreaction, but the amount is not significant enough to destabilize the product or cause biodiesel quality degradation (Santoso et al.
The resulting iodine number is considered to meet the saturation criteria.
It is still below the maximum limit of 115 g ICC/100 g according to SNI 7182: 2015, which is in the range of 71 - 107 g ICC/100 g for all changes in calcination temperature and catalyst dose (Sumari et al.
, 2.
The iodine number indicates the degree of unsaturation of compounds in biodiesel, especially the number of double bonds in fatty acids.
With a catalyst dose of 5 - 7 % and calcination temperatures of 400 AC and 500 AC, the highest value .
209 g ICC/100 .
was obtained, close to the maximum limit but still safe.
This indicates that the structure of unsaturated fatty acids is generally maintained during the transesterification process under these conditions.
Overall, the 400 AC - 500 AC condition with a 5 - 7 % dosage is still in the optimal balance and remains safe from the oxidation limit according to SNI.
Analysis of FAME Components with FTIR and GC-MS The results of the FT-IR spectra analysis are shown in Figure 3, which shows several absorption peaks and a variety of characteristic bands presented in Table 5.
The absorption peaks of the biodiesel fingerprint region are 400 - 1500 cmA, indicating the presence of functional groups related to the catalyst from palm bunch ash (Phetrungnapha et al.
, 2.
Figure 3.
FTIR Spectrum of FAME and WCO Table 5.
Analysis IR spectrum Wavenumbers .
Absorption Intensity weak-broad medium-sharp strong-sharp strong-sharp medium-sharp medium-sharp strong-sharp medium-sharp strong-broad Signature Band stretching vibration of O-H .
arboxylic aci.
stretching vibration of C-H sp2 (=C-H) stretching vibration of CAeH spA (AeCHCC/CHCE) stretching vibration of C=O ester rocking vibration of CHCC / CHCE stretching vibration of AeCHCE bend to O (AeOAeCHCE) stretching vibration of C-O ester rocking vibration of (CHCC)n metalAeO stretching vibration AeO / SiAeO Volume, 14.
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Jurnal Akademika Kimia In the WCO spectra at wave number 3479 cm-A, there is a peak with weak intensity and very wide, showing the characteristic O-H bond stretching vibrations for carboxylic acid compounds, which indicates that WCO still contains free fatty acids, which, in the ATS spectra, do not appear.
At wave number 3001 cm-A, there is one peak with medium intensity and sharp, which shows the characteristic of C-H sp2 (=C-H) bond stretching vibrations.
This indicates that both WCO and FAME ATS compounds have unsaturated hydrocarbon groups, namely alkene.
In the wave number region of 2924 cm-A - 2854 cm-A, two peaks with strong and sharp intensity show the characteristic C-H spA (-CHCC/CHCE) bond stretching vibrations, which indicate that there are saturated hydrocarbon groups, namely alkane compounds (Santoso et al.
, 2.
Typical methyl esters display a peak at a wave number of 1740 cm-A with a strong and sharp intensity that shows a typical C=O stretching vibration in ester compounds.
This peak vibrates asymmetrically and is characteristic of FAME.
At wave number 1365 cm-A, which has a medium-sharp intensity, there is symmetrical bending of the (-CHCE) group, which indicates the presence of the -OCHCE methoxy group in FAME.
This indicates the attachment of the alkyl group of the alcohol to the triglyceride fatty acid.
Followed by the appearance of C-O stretching vibrations with strong and sharp intensity that appeared at wave numbers 1172 cm-A - 1165 cm-A.
This shows that the compound has a C-O bond in the ester group.
The peak of 1170 cm-A shows the O-CHCE stretch, characteristic of FAME (Fereidooni et al.
, 2.
GC-MS identified the fatty acid composition of the biodiesel.
Peak identification was done by comparing each peak's retention time and mass band against the mass spectra data in the library (NIST12.
LIB) (Agunbiade & Adewole.
The product analyzed synthesized a five wt% % palm bunch ash catalyst with a calcination temperature of 500 AC.
Figure 4 shows the chromatogram of the synthesized biodiesel along with the FAME distribution.
The GC-MS chromatogram in Figure 4 shows eight peaks, indicating the constituent compounds present in the biodiesel product.
Table 6 shows eight compound peaks with the highest area (Saleem et al.
, 2.
Figure 4.
GC-MS Results Chromatogram of FAME in PBA-500-5% Table 6.
Retention Time and Area of FAME Product PBA-500-5 % Retention Time .
% Area
40,31
The constituent components of biodiesel for each retention time in Table 6 were analyzed for fragmentation to determine the constituent compounds of the biodiesel product.
The mass spectra of biodiesel with the highest area with retention times of 37.
096 and 33.
688 minutes are shown in Figures 5 and 6.
Figure 5.
Mass Spectrum of Biodiesel with a Retention Time of 37.
096 minutes.
Figure 6.
Mass Spectrum of Biodiesel with a Retention Time of 33.
688 minutes.
Fillah M.
Sakhi et al.
Figure 5 is the mass spectrum of the product compound with the highest area at the retention time of 37.
096 minutes, which has a similarity index of 95 % with the NIST12.
LIB
library No.
The suspected compound is methyl oleate (C19H36O.
The mass spectrum was analyzed for fragmentation patterns to support the assumption that the compound was methyl oleate.
Methyl oleate is an ester form of oleic acid with a molecular weight of 296 m/z.
This compound undergoes a fragmentation pattern based on the cleavage rule at the branch point, with a break as seen in Figure 7.
In the mass spectrum of the methyl oleate compound, the molecular ion remains detectable, albeit with low intensity.
The m/z 296 molecular ion of methyl oleate has two fragmentation pathways typical for long-chain The first fragmentation involves the release of the methanol (CH3OH) group from the ester group and produces an ion of mass m/z 264.
-CH3OH
m/z=264 m/z=296 m/z=296 m/z=74 m/z=222 -C3H6
m/z=222 m/z=180 -CH2
-C2H4
m/z=137 -CH2
m/z=166 -C2H4
m/z=123 m/z=97 -CH2
-CH2
m/z=69 -CH2 m/z=83 -CH2 m/z=55 m/z=41 Figure 7.
Fragmentation pattern of the compound at retention time 37.
096 minutes The second typical fragmentation pattern is through the McLafferty rearrangement mechanism, which produces two main fragments, namely m/z 74 mass ion and m/z 222 mass ion, which are the remaining unsaturated hydrocarbon chain of methyl oleate (Ismiyarto et al.
, 2.
Furthermore, the series of fragments m/z = 137, 123, 97, 83, 69, 55, and 41 shows a typical fragmentation pattern, where each peak has a Volume, 14.
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Jurnal Akademika Kimia difference of 14, which indicates the sequential release of the -CHCC group.
Based on the fragmentation pattern in the mass spectrum, it can be proved that the compound formed is methyl oleate with the structure shown in Figure 8.
is also consistent with the characteristics of methyl esters of saturated fatty acids, including the appearance of typical fragmentation peaks such as m/z 239 due to the release of methanol (CH3OH), as well as fragment m/z 74, which shows typical ester rearrangement (Hydeler, 2.
The mass spectrum was analyzed for fragmentation patterns based on the cleavage rules listed in Figure 9.
Fragmentation of methyl palmitate shows typical ester identification characteristics, starting with the McLafferty rearrangement mechanism, which produces a stable fragment m/z 74 through -hydrogen transfer and - bond breaking.
This fragment then undergoes the release of the -OCH3 group, producing ion m/z 43, an acylium ion (CH2=COA).
This pattern confirms the presence of long-chain saturated ester groups in the compound structure (Torres et al.
, 2.
Other chromatogram peaks were identified similarly, resulting in the biodiesel product compound components, retention times, and concentrations shown in Table 7.
Figure 8.
Methyl oleate structure (C19H36O.
The second highest peak at a retention time 688 minutes, shown in Figure 6, shows a reasonably high intensity and indicates the presence of methyl palmitate compounds (C17H34O.
It has a similarity index of 95 % with the NIST12.
LIB
library No.
The fragmentation pattern formed -CH3(CH.
11CH=CH2 m/z=270 m/z=74 -OCH3 m/z=74 m/z=74 m/z=43 Figure 9.
Fragmentation pattern of the compound at retention time 33.
688 minutes Table 7.
FAME Content of Biodiesel Retention Compund Rumus Molekul Luas Area (%) Methyl dodecanoate .
ethyl laurat.
Methyl tetradecanoate .
ethyl myristat.
Methyl 9-hexadecenoate .
ethyl palmitoleat.
Methyl hexadecanoate .
ethyl palmitat.
Methyl 9,12-octadecadienoate .
ethyl linoleat.
Methyl 9-octadecenoate .
ethyl oleat.
Methyl octadecanoate .
ethyl stearat.
Methyl eicosanoate .
ethyl arachidat.
C13H26O2
C15H30O2
C17H32O2
C17H34O2
C19H34O2
C19H36O2
C19H38O2
C21H42O2
Catalyst Reusability Test characteristics of biodiesel with reused catalysts are presented in Table 8.
The results show that the catalyst can maintain its catalytic properties in the second and third uses.
The biodiesel yield decreased from A 92 % .
irst cycl.
to 91 % and 90 %, indicating that the catalytic activity remains functionally maintained.
The acid number of the product remained below 55 mg KOH/g.
The results show that the catalyst can maintain its catalytic properties in the second and third uses.
The biodiesel yield decreased from A 92 % .
irst cycl.
to 91 % and 90 %, indicating that the The Heterogeneous base catalytic biodiesel synthesis has the advantage of being reusable.
The palm bunch ash catalyst used in the transesterification reaction cycle was reused with the addition of 5 wt% % catalyst, a methanol: oil ratio of 15:1, and a reaction temperature of 65 AC, with a time of 3 hours.
After each cycle, the solid catalyst was separated from the mixture and washed with n-hexane and acetone.
It was then re-calcined at 500 AC for further use (Niju et al.
, 2.
The results showed that the catalyst could maintain its activity and be reused up to four cycles.
Data on the Fillah M.
Sakhi et al.
Acknowledgment The author would like to express sincere gratitude to Prof.
Dr.
Aman Santoso.
Si.
, the principal supervisor, for his ideas, guidance, and continuous support throughout this research, and to Prof.
Dr.
Sumari.
Si.
, the co-supervisor, for his valuable input and assistance.
catalytic activity remains functionally maintained.
The acid number of the product remained below 55 mg KOH/g.
Table 8.
Physical and chemical properties of reused catalyst FAME Characteristics Yield Density .
/m.
Viscosity .
FFA
(%)
Acid Value .
g KOH/.
Index of Bias Saponification Numbers .
g KOH/.
Iod Numbers .
I2/100 .
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, & Adewole.
Methanolysis of carica papaya seed oil for the production of biodiesel.
Journal of Fuels, 2014.
, 1Ae6.
Attari.
Mayvan.
, & Alisaraie.
Process optimization of ultrasonic-assisted biodiesel production from waste cooking oil using waste chicken eggshell-derived CaO as a green heterogeneous catalyst.
Biomass and Bioenergy, 158(Januar.
Aworanti.
Agbede.
Popoola.
Ogunsola.
Agarry.
Adekunle.
Ogunkunle.
Laseinde.
Odesanmi, , & Alade.
Synthesized heterogeneous nano-catalyst from cow teeth for fatty acid methyl esters production through transesterification of waste vegetable frying oil and methanol: Characterization and optimization studies.
Engineering Reports, 5.
, 1Ae25.
The decrease in yield in the fourth reuse .
060 %) was likely caused by residues such as glycerol, mono-diglycerides, and methanol on the active surface of the catalyst.
In addition, the gradual dissolution of light alkali metals (KA/C.
into the liquid phase also reduced the fundamental strength of the catalyst.
However, catalyst activity can be partially restored through washing with n-hexane and acetone and recalcination at the appropriate temperature for 4 hours.
This treatment removes organic contaminants and reactivates the basic sites, resulting in biodiesel yields nearly equivalent to the initial cycle (A 90 %).
With relatively stable performance and simple recovery, this catalyst shows excellent potential for application in biodiesel production, requiring cost efficiency and minimal waste.
Berchmans.
, & Hirata.
Biodiesel production from crude Jatropha curcas L.
seed oil has a high content of free fatty acids.
Bioresource Technology, 99.
, 1716Ae1721.
Boey.
Maniam.
, & Hamid.
Biodiesel production via transesterification of palm olein using waste mud crab (Scylla serrat.
shell as a heterogeneous catalyst.
Bioresource Technology, 100.
, 6362Ae6368.
Conclusions The synthesis of biodiesel using calcined palm bunch ash (PBA) catalyst at 600 AC produced the best biodiesel .
onversion rate of 92 % A .
, with an average kinematic viscosity of 3.
79 cSt at 40 AC and a density of 0.
888 g mLAA, both within the limits specified by SNI/EN 14214.
In contrast, the iodine number of 80.
116 g I2 100 gAA ensures oxidative stability, and the saponification number of 57 mg KOH gAA confirms the dominance of the C16 AeC18 chain, as well as a refractive index of GC-MS analysis shows the central peak of methyl oleate at tR OO 37.
096 minutes with an area 31 %, indicating unsaturated components as the most significant fraction, while FT - IR shows a single peak of CAeOAeCH3 (OO 1172 Ae 1165 cmAA) characteristic of ester compounds.
These results confirm that the transesterification process at the highest calcination temperature produces highquality biodiesel suitable for use as fuel.
Chi.
The production of methyl esters from vegetable oil/fatty acid mixtures.
Thesis.
University Of Toronto.
Ontario.
Canada.
Fereidooni.
Abbaspourrad.
, & Enayati.
Electrolytic transesterification of waste frying oil using Na /zeoliteAechitosan biocomposite for biodiesel production.
Waste Management, 127(Ma.
, 48Ae62.
Galadima.
, & Muraza.
Waste materials for production of biodiesel catalysts:
Technological status and prospects.
Journal of Cleaner Production, 263(Augus.
, 121358.
Hydeler.
Natural abiotic iron-mediated formation of C1 and C2 compounds from environmentally important methyl-substituted substrates and their implication for nature.
Dissertation.
Ruprecht Karls University Volume, 10.
No.
1, 2021, pp-pp Jurnal Akademika Kimia Heidelberg.
Heidelberg.
Germany.
Modification of egg shell and its application in biodiesel production.
Journal of Saudi Chemical Society, 18.
, 702Ae706.
Hambali.
Mujdalifah.
Tambunan.
Prattiwiri.
, & Hendroko.
Teknologi Bioenergi.
Tangerang: PT AgroMedia Pustaka.