Communications in Science and Technology 10.
87Ae97
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Cobalt-nickel supported on desilicated HZSM-5 for the conversion of Reutealis trisperma .
airy shaw oil to liquid hydrocarbon products Lenny Marlindaa,*.
Rahmib.
Abdul Azizb.
Achmad Roesyadic.
Danawati Hari Prajitnod.
Yustia Wulandari Mirzayantie.
Muhammad Al Muttaqiif Department of Industrial Chemistry.
University of Jambi.
Jambi 36361.
Indonesia Department of Chemistry.
University of Jambi.
Jambi 36361.
Indonesia Department of Chemical Engineering.
Sepuluh Nopember Institute of Technology.
Surabaya 60111.
Indonesia Department of Industrial Chemical Engineering.
Sepuluh Nopember Institute of Technology.
Surabaya 60111.
Indonesia Adhi Tama Institute of Technology.
Department of Chemical Engineering.
Surabaya, 60111.
Indonesia Research Center for Chemistry-National Research and Innovation Agency.
Science and Technology Research Center (PUSPITEK) Area.
Tangerang 15310.
Indonesia Article history:
Received: 20 October 2024 / Received in revised form: 25 May 2025 / Accepted: 25 May 2025 Abstract Desilication/alkaline treatment and metal impregnation were used to create the HZSM-5 catalyst supported by Co-Ni.
These catalysts' isotherm patterns combined type I and type IV isotherms.
This isotherm pattern showed a hysteresis loop at comparatively higher pressures.
The pore size distribution of the mesoporous HZSM-5 catalysts was situated between 6 and 12 nm in size.
Its use in the hydrocracking of Reutealis trisperma (Blanc.
airy shaw oil (RTO) to produce biofuel was investigated.
The results of the catalytic test showed that the hydrocarbon makeup of the biofuel was comparable to that of fuel.
In comparison to HZSM-5, the mesoporous Co-Ni/HZSM-5 catalyst enhanced n-paraffin 32 area% and aromatic by 34.
18 area% in the hydrocracking of RTO.
Keywords: Desilication.
HZSM-5.
liquid hydrocarbon.
Reutealis trisperma (Blanc.
airy shaw Introduction Biofuels are renewable energy sources that can be produced from plant oils without interfering with food production and provide performance on par with fossil fuels.
In view of their high oil content, low extraction costs, adaptability to nutrientpoor soils, and ability to produce by-products such as husks, shells, and cakes that can be turned into organic fertilizers, nonedible vegetable oils like Cerbera manghas oil.
Calophyllum inophyllum oil.
Reutealis trisperma (Blanc.
airy shaw oil (RTO), and Kapok seed oil become all promising options.
Additionally, these plants have dense canopies and broad leaves, which enhance their capacity for CO2 absorption and O2 production .
Non-edible oils hold a substantial promise as reliable feedstocks for biodiesel production due to their abundance, cost-efficiency, and high oil yields.
Their utilization in biodiesel production mitigates the limitations associated with conventional feedstocks, providing a sustainable alternative .
These non-edible vegetable oils * Corresponding author.
Email: marlindalenny@unja.
https://doi.
org/10.
21924/cst.
can be used to produce biofuel, which can limit the use of fossil fuels and alleviate environmental issues by lowering greenhouse gas emissions and increasing the amount of arable land required to maintain energy security and sustainability .
Sunan candlenut, or Reutealis trisperma (Blanc.
airy shaw, is a hardy and versatile plant generally easy to grow and can be harvested once a year after about five years of growth.
Dependent upon the species and agroecosystem conditions, an 8-year-old tree is capable of producing 100Ae150kg of dry seeds, which translates to a crude oil production of roughly 6Ae8 tons per hectare per year .
One of the main byproducts of the oil derived from Reutealis trisperma (Blanc.
airy shaw seeds is biodiesel, which is a prospective feedstock for the oleochemical, biofuel, and other chemical industries.
Reutealis trisperma (Blanc.
airy shaw biodiesel is noteworthy for having traits that are comparable to those of fossil diesel, which qualifies it for direct use in diesel engines.
The oil is poisonous and unfit for human consumption in view of its high concentration of a-elaeostearic acid .
%), palmitic acid .
%), stearic acid .
%), oleic acid .
%), and linoleic acid .
%).
As a consequence, it does not compete with food-based biodiesel feedstocks.
Its promise as a sustainable bioenergy This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.
0 license Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 source is confirmed by the fact that its productivity per hectare is on par with that of major biodiesel-producing crops like palm oil .
Based on favorable tax and subsidy policies, the estimated life cycle cost of a biodiesel plant using crude RTO is $710 million, with a competitive production cost of $0.
and a payback period of 4.
34 years .
With a maximum yield of 96.
53%, the study by Shaah et al.
showed that it is feasible to use the non-edible oil from Reutealis trisperma (Blanc.
airy shaw for biodiesel production through the supercritical methanol technique.
Fatty acids and triglycerides in RTO can be deoxygenated and their carbon chains can be broken by hydrocracking.
HZSM-5 is mostly utilized as a catalyst support in the hydrocracking process.
It is altered with metal transitions including nickel, cobalt, iron, molybdenum, zinc, or copper to increase the catalyst's activity .
, 4, 14-.
Every transition metal that is doped into the HZSM-5 catalyst has a distinct function in a cracking process.
The production of certain hydrocarbons, such as aromatics or BTXs .
enzene, toluene, and xylen.
, is enhanced by nickel and cobalt modifications in HZSM-5.
These dopants have an impact on the catalyst's acidic sites and product selectivity, which ultimately affects the cracking reaction's effectiveness and results .
In previous research .
Ae.
, the combination of nickeliron and nickel zinc with HZSM-5 support was prepared for hydrocracking coconut oil to produce biofuel.
Theoretically, the changed ZSM-5 pore size affects the metal impregnation process, allowing hydrated metal ions to permeate into the ZSM-5 pore well .
Furthermore, it is more possible to enhance the diffusion of hydrocarbon products and triglyceride molecules in a modified ZSM-5 pore compared to the prior All of the aforementioned issues are resolved by the presence of the intracrystalline mesopore produced on HZSM5 through desilication and alkaline treatment .
The hydrocracking of Sunan Candlenut oil was examined in the work by Al Muttaqii et al.
to generate aromatic hydrocarbons using a zeolite-based catalyst.
When compared to the ZSM-5 catalyst without metal impregnation, the Fe and La metal-impregnated catalyst produced the greatest aromatic component, reaching 35.
51%, and improved the acidic sites.
Marlinda et al.
stated that cobalt can regulate nickel's capacity for hydrogenation.
The hierarchical Co-Ni/HZSM-5 catalyst's cobalt content increases catalytic activity in the decarboxylation pathway, resulting in the production of pentadecane .
-C.
and heptadecane .
-C.
According to the hierarchical pore structure, the HZSM-5 catalyst has a 15Ae18% selectivity for monocyclic aromatic hydrocarbons.
To produce the mesoporous HZSM-5 catalyst, a hierarchical pore structure was created in HZSM-5 using Additionally, to manufacture cobalt-nickel supported on a mesoporous HZSM-5 catalyst, the incipient wetness impregnation approach was selected.
Certain apparatus and measurement techniques were used to ascertain the characteristics of catalysts.
The hydrocracking of RTO in a pressure batch reactor .
odel: Paar Compan.
was then used to observe the catalyst's performance.
Here, the impact of CoNi metal impregnation and hierarchical pore structure on HZSM-5 and its catalytic characteristics in paraffin .
ormal/isoparaffi.
and aromatic products were then Materials and Methods Materials The RTO was gathered in Indonesia's West Java.
Zeolyst International supplied the Ammonium-ZSM-5 zeolite (CBV 8014, 400 m2/g surface area, 0.
05 weight percent Na2O), which was calcined into HZSM-5 for 5 hours at 550AC.
Merck provided the additional compounds, including Ni(NO.
6H2O
and Co(NO.
6H2O with a 98% purity level.
Preparation and characterization of catalyst The mesoporous HZSM-5 catalyst was obtained by applying desilication, a common alkaline treatment method and its production process was based on patent IDP000092622.
This procedure involved heating 0.
2 M NaOH solution to 65AC in a stainless steel vessel, after which HZSM-5 was gradually added to the solution.
Zeolite in NaOH solution was then stirred at 200 rpm for 2 hours while being maintained at 65AC.
In this experiment, the weight of the HZSM-5 zeolite ratio and the volume of the NaOH solution were 50 cm3/g.
The slurry was then promptly chilled in a water-ice bath, filtered using a vacuum filter, and meticulously cleaned with distilled water until reaching the neutral pH.
The removal of sodium ions as the desilication agent from the HZSM-5 crystallites was indicated by the neutral pH.
The mesoporous Na-ZSM-5 catalyst was thought to have produced the solids obtained.
Furthermore, ion exchange was performed twice using 0.
NH4Cl solution at 80AC to substitute ammonium ions for sodium ions on the mesoporous Na-ZSM-5.
The slurry was cleaned and filtered then.
After being stored at 60AC for the entire night, the residueAithe mesoporous NH4-ZSM-5Aiwas dried for 12 hours at 120AC.
To substitute hydrogen ions for ammonium ions, a mesoporous NH4-ZSM-5 catalyst was calcined in the air for 5 hours at 550AC.
The mesoporous HZSM-5 catalyst is the name given to the solid.
A previous study showed that Co-Ni impregnated on different supports .
uch as HZSM-5 and the mesoporous HZSM-.
was achieved using the incipient wetness impregnation approach .
, 3, .
g of catalyst support was gradually wetted with the intended concentration of Ni(NO.
6H2O and Co(NO.
6H2O aqueous solution while being gently agitated until becoming completely The sample was then reduced with hydrogen at 450AC for 3 hours after being calcined with air for 2 hours at 400AC.
The solid mesoporous Co-Ni/HZSM-5 catalyst was obtained by cooling the sample to room temperature using N2 flow.
Table 1 depicts the physical characteristics of catalysts.
Catalytic hydrocracking tests With a 600 mL pressure batch reactor (Parr USA 4.
fitted with a mechanical stirrer, the hydrocracking procedure was carried out at hydrogen starting pressure.
First, a reactor with 1 g of catalyst was filled with 200 mL of RTO.
eliminate air that had dissolved in the oil or in the reactor twice, the oil was then filtered using nitrogen.
The reaction temperature was set at 375AC, and hydrogen was supplied into the reactor.
The gas flow was halted when the reactor pressure reached a reaction pressure of 15 to 25 bar.
2 hours passed Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 Characterization of catalyst X-ray diffraction (XRD.
PANanytical X'Pert MPD diffractomete.
, scanning electron microscopy with energy dispersive X-ray analysis mapping (SEM-EDX, model EVO MA.
, and N2 physisorption in accordance with BET and BJH methods (Quanta-chrome NovaWin Vernsion 11.
were used to characterize the Co-Ni/HZSM-5 Furthermore, pyridine adsorption was used to analyze surface acidity.
FT-IR spectra of adsorbed pyridine were obtained by means of a Shimadzu IRPrestige-21 FTIR Spectrometer at a resolution of 4 cm-1.
Pyridine adsorption was used to analyze a large number of Bronsted acid sites and Lewis acid sites in HZSM-5 changed into meso pore size.
milligrams of the sample were put on the sample holder and placed in a Pyrex glass cell with a calcium fluoride (CaF.
In addition, the glass cell was heated for 4 hours at 400AC.
After an 1-hour absorption at room temperature, pyridine underwent desorption for 3 hours at 150AC.
At room temperature.
FTIR spectra in the 1800Ae1400 cm-1 range were Lewis acid sites (L) and Bronsted acid sites (B) were quantitatively analyzed using the absorption of 1450 cm-1, and 1545 cm-1, respectively.
Equations 1 and 2 were quantitatively calculated using the Emeis approach, which had also been employed by Wang et al.
yridine on B site.
= 42 y IA(L) y R2 Structural and textural properties Fig.
1 presents the XRD patterns of the catalyst used to hydrocrack RTO.
Fig.
shows the X-ray diffraction pattern of HZSM-5.
The MFI framework type of HZSM-5 was shown by the characteristics' peaks at the 2A of 7.
87A, 8.
74A, 23.
24A, 23.
64A, 23.
91A, and 24.
Meanwhile.
Fig.
demonstrate that the catalysts' XRD patterns matched the distinctive structure of HZSM-5.
According to a few former investigations, desiccation and metal impregnation did not alter the crystal structure of HZSM-5 although they caused a drop in the strength of each diffraction peak .
,23,.
o MFI n NiO a Co3O4 Mesoporous Co-Ni/HZSM-5 n n n .
Co-Ni/HZSM-5 n .
HZSM-5
2A (A)
Fig.
XRD patterns of catalyst where C is the acid side concentration .
IA (B or L) indicates the integrated absorbance of the Lewis and Bronsted bands .
R is the catalyst disk's radius .
and W is the disk's weight .
Strong Bronsted acid sides were seen in zeolites that already contained transition metals.
The biofuel product was examined using gas chromatography-mass spectrometry (GC-MS.
GC: Agilent HP 6890 models 19091S-433.
HP-5MS capillary column 30m y 250m y 0.
and Fourier transformed infrared spectroscopy (FT-IR.
Thermo Scientific Nicolet iS10 FTIR).
18,68
yridine on L site.
= 88 y IA(B) y R2 Characterization of catalyst Intensity .
during the hydrocracking reaction.
Gas chromatography-mass spectrometry and Fourier-transformed infrared spectroscopy were used to examine liquid products.
Biofuel was classified as hydrocarbons that resembled gasoline (C5AeC.
, kerosene (C10AeC.
, and gasoil (C14AeC.
14,85
14,57
HZSM-5
Co-Ni/HZSM-5 Meso Co-Ni/HZSM-5 Fig.
Crystallinity affected by desilication and metal impregnation Results and Discussion Compositions of Reutealis trisperma (Blanc.
airy shaw oil (RTO) RTO obtained from pressed seeds with a screw press machine consisted primarily of linoleic acid and palmitic acid, 91% and 19.
95%, respectively (Table .
It has been argued that the main polyunsaturated fatty acids are present in RTO .
, .
The XRD patterns of the Co-Ni/HZSM-5 catalyst showed the small peak intensity at 2A of 19.
11A and 31.
59A for the diffraction of Co3O4.
As shown in Fig.
Ni was also detected in the catalyst at 2A of 52.
The most intriguing finding in Fig.
is that, following calcination and reduction, numerous new phases of Co3O4 and NiO species with weak peak intensities were identified in the mesoporous CoNi/HZSM-5 catalyst.
The inability of the nickel supported on Co/HZSM-5 to fully convert Co3O4 and CoO particles into the Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 metallic phase of Co was most likely the cause of this.
Shimura et al.
and Qin et al.
, .
stated that nickel supported on Co/HZSM-5 could enhance the Ni Dispersion on HZSM-5 and reduce Co3O4 and CoO into cobalt metal due to their reciprocal Another contributing factor was the hierarchical pore structure of the mesoporous Co-Ni/HZSM-5 catalyst.
a result, obtaining the metallic phase required calcination and a decrease of temperature.
Furthermore, as illustrated in Fig.
Ni metal was found at 37.
38A and 43.
23A in the Mesoporous Co-Ni/HZSM-5 catalyst with very low intensity.
In contrast, as illustrated in Fig.
, no Ni was found at the similar locations for the Co-Ni/HZSM-5 catalyst.
This phenomenon was probably related to the incredibly tiny and evenly distributed Ni particles in the zeolite matrix of CoNi/HZSM-5, providing weak or undetectable Ni signals in the XRD examination.
On the other hand, the mesoporous structure of the Mesoporous Co-Ni/HZSM-5 catalyst promoted the aggregation of Ni metal particles into larger clusters or increased their crystallinity, enabling them to be easier to be .
HZSM-5 identified in XRD examination.
Even though Co was not found in the catalysts, the SEMEDAX measurement results, as shown in Table 1 and Fig.
, demonstrated the metals' existence.
This indicated that the Ni and Co metals were uniformly distributed in extremely insignificant amounts.
this was why their XRD peak intensities were either very low or not apparent .
However, the desilication and metal impregnation processes on HZSM-5 had an effect on the reduction of its crystallinity (Fig.
This was primarily related to the removal of silicon, which could disrupt the structural integrity, causing disorganization within the framework or partial collapse in specific regions .
, .
Meanwhile, the decrease in crystallinity resulting from metal impregnation indicated that metal ions was successfully incorporated into the structural framework without any significant disruptions.
This reduction is more appropriately attributed to the dispersion of metal particles within the structure rather than an overall decline in crystallinity .
mesoporous Co-Ni/HZSM-5 after calcined and .
mesoporous HZSM-5 Fig.
SEM-EDAX image of catalyst.
Table 1.
The physical properties of the catalyst.
Average pore diameter .
Surface area.
S .
Catalyst Total pore volume .
Actual Metal Contentb .
HZSM-5
SBET
Smicro Smeso Mesoporous HZSM-5 Co-Ni/HZSM-5 Mesoporous Co-Ni/HZSM-5 be published by Al-Muttaqii et al.
EDAX measurement d = not determined Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97
0,04
0,03
c/nm/.
Volume Adsorbed (STP) .
0,02 0,01 0,00 Diameter .
0,10 0,08 dV.
c/nm/.
Volume Adsorbed (STP) .
Relative Pressure (P/P.
HZSM-5
0,06
0,04
0,02
0,00
Diameter .
Relative Pressure (P/P.
mesoporous HZSM-5 after calcined 0,04 0,03 dV.
c/nm/.
Volume Adsorbed (STP) .
0,02 0,01 0,00 Diameter .
Relative Pressure (P/P.
mesoporous Co-Ni/HZSM-5 after calcined and reduced Fig.
Nitrogen isotherms and pore size distribution of catalysts Fig.
show the morphology of the catalyst after the desilication process.
The catalyst surface defects caused by desilication showed the extraction of Si.
In essence, desilication involves selectively removing silicon atoms from the zeolite framework and creating additional porosity.
However, in the hydrocracking process, the desilication procedure can increase the catalyst's surface area, mesopore volume, and density, as well as the number of acid sites, catalytic conversion and prolong the catalyst's lifespan .
, 34-.
It can be proven based on EDAX showing Si/Al ratio dropped from 24.
5 wt.
53 wt.
Following metal impregnation, the Si/Al ratio dropped from 14.
53 wt.
% to 13.
49 wt.
Following desilication on HZSM-5.
Table 1 demonstrates that BET surface area and total pore volume significantly increased from 355.
96 m2/g and 0.
22 cm3/g to 447.
77 m2/g and 15 cm3/g, respectively, as reported by Ma et al.
These physical properties, however, remained nearly unchanged for the mesoporous Co-Ni/HZSM-5 catalyst following metals impregnation with final surface area and total pore volume by 23 m2/g and 1.
16 cm3/g, respectively.
This was most likely caused by Co3O4 and NiO particles present in the catalyst's pore and able to provide surface area for themselves, thereby preventing a considerable drop in the overall surface area of On this Co-Ni/HZSM-5 catalyst, various phenomena were observed, including a modest decrease in surface area and total pore volume to 223,14 m2/g and 0.
15 cm3/g, respectively.
By obstructing the microporous area and clogging the mesoporous area, the addition of metals resulted in micropore surface area and micropore volume was decreased .
, 21, 3.
Fig.
4 illustrates the adsorption pore size distribution and nitrogen isotherms obtained from the BJH technique of a HZSM-5-based catalyst.
In accordance to IUPAC's classification of adsorption isotherms, mesoporous HZSM-5 catalyst showed a combined pattern of type I and type IV isotherms, as shown in previous research (Fig.
) .
HZSM-5, as illustrated in Fig.
, possessed the type I isotherm of microporous materials.
At higher relative pressures, the type IV isotherm verified the existence of a hysteresis loop, which was typified by the development of a hierarchical pore structure on HZSM-5 .
Both curves were roughly parallel from P/Po = 0.
5 to P/Po = 0.
7 since nitrogen desorption did not appear to follow the initial adsorption trend.
The hierarchical pore structure in HZSM-5 enhanced the number of active sites.
This was attributed to the introduction of mesopores .
arger pore.
alongside the intrinsic micropores of HZSM-5, providing a greater surface area for reactant molecules to interact and be adsorbed, ultimately resulting in an increased availability of active sites for catalytic reactions .
It can be stated that the hierarchical structure of HZSM-5, characterized by the combination of micro- and mesopores, significantly improved the catalyst's surface area, accessibility, and optimal utilization of active sites.
The enlarged surface area directly contributed to a higher number of potential locations for reactants to bind and engage in catalytic processes.
addition to reduce diffusion restrictions that may otherwise impair catalytic activity, the mesopores in the ZSM-5 structure made it simpler for bigger reactant molecules to reach the microporous channels and active sites.
This improved accessibility ensures that a greater proportion of active sites can participate in the reaction, thereby enhancing overall catalytic The hierarchical pores allowed for more efficient use of the acidic sites during catalytic reactions by providing access to the active sites inside the ZSM-5 structure.
Such a hierarchical architecture is particularly crucial for reactions prone to diffusion limitations due to coke formation, which can significantly reduce catalytic efficiency.
Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 Brondsted site Lewis site Silanol group Meso Co-Ni/HZSM-5 Co-Ni/HZSM-5 Meso HZSM-5 The FT-IR spectra of adsorbed pyridine (Fig.
illustrated how the acidity of HZSM-5 zeolite was determined by alkali treatment and metal addition (Co-N.
The integrated area (IA) of each characteristic band, as listed in Table 2, was used to determine the number of acid sites.
Pyridine was chemically adsorbed on Brynsted and Lewis acid sites, respectively, to form the bands at 1545 and 1445 cm-1.
Separating the impact of HZSM-5's acidic sites from the formation of aromatics was unable to be done.
As shown in Table 2, the addition of metals and the desilication process of the hierarchical structure maker of HZSM-5 resulted in Brynsted acid sites (B) fewer and Lewis acid sites more.
This phenomenon could be linked to the development of lattice defects and dealumination following treatment with NaOH The aforementioned findings concurred with earlier studies .
-23,.
Both Lewis and Brynsted acid sites are crucial for catalysis.
Lewis acid sites take electron pairs, whereas Brynsted acid sites give protons (H ).
In a variety of processes, the combination of Lewis and Brynsted acid sites can result in an improved catalytic activity.
Proton transfer Acidic properties reactions, which are essential for many catalytic processes such as dehydration, isomerization, and cracking reactions, require Brynsted acid sites.
The active site of the electron acceptor is represented by the Lewis acid site.
However, in a zeolitic catalyst, the Brynsted acid site is an active site that donates protons from the Si(OH)-Al bridge.
The proton on the acid side will be swapped out for the impregnated metal.
The creation of carbenium ions, which are intermediate products in the conversion of hydrocarbons that take place in the presence of Brynsted acid (B) and Lewis acid (L) sites, is what determines the selectivity of aromatics and It may also be said that both kinds of acids can be enhanced by the Co-Ni-impregnated hierarchical porestructured support.
Figure 9 illustrates how these two acid types contributed to the production of aromatics during the hydrocracking of RTO using a mesoporous Co-Ni/HZSM5 Cobalt and nickel supported on mesoporous HZSM-5 are crucial for generating mesoporosity in the catalyst, which enables the rapid diffusion of big molecules, as shown in Fig.
Non-uniform pore size can also result from desiccation.
Because silicate anions were randomly extracted, leaving a hole in the zeolite structure, the pore size became not uniform.
While the micropore size distribution was centered at roughly 43 nm and remained nearly constant based on the H-K method, the mesoporosity in the mesoporous HZSM-5 catalyst showed a narrow pore size distribution and a broader pore size distribution centered at 6 nm and 12 nm, respectively, based on the BJH method.
Gou et al.
discovered the same thing, stating that the desilication produced a mesoporous structure in the HZSM-5 crystals while leaving the microporous structure essentially unaltered.
Abs .
Wavenumber .
m ) Fig.
FT-IR spectra of pyridine adsorption on the parent and alkaline-treated HZSM-5 samples Table 2.
Acidic properties of zeolite Catalyst Meso HZSM-5 Co-Ni/HZSM-5 Meso CoNi/HZSM-5 Acid Wavenumber range .
Absorption band .
Acid Analysis of biofuel As illustrated in Fig.
, the spectra investigation of RTO oil revealed that the carboxylic groups' vibrational modes were intense in the absorption bands at wavenumbers of 1159.
66 cm1 90 cm-1, corresponding to COeO and C=O bonds.
The RTO analysis results are shown in Fig.
, where carboxyl group vibrations and long-chain fatty acid ester components were observed clearly visible.
The prominent peak 90 cm-1 in the 1800Ae1700 cm-1 range was determined to be C=O .
ster grou.
The presence of asymmetric Lewis acid area .
Brynsted acid site .
Total acidity .
L/B stretching vibration in =COeH bonding and symmetric stretching vibration in OeCH2 bonding was confirmed by further peaks at 87 cm-1 and 2852.
3 cm-1.
Peaks at 1238.
9, 1159.
66, and 39 showed the anti-symmetric vibrations of COeOOeC bond .
However, as illustrated in Fig.
, the ester of the secondary alcohol band vanished and the FTIR spectra of a liquid product changed to lower frequencies from 1741.
90 cm1 63 cm-1 wavenumbers.
As shown in an earlier research .
Ae.
, the anomaly in the FTIR spectra indicated that oxygen was removed from oxygenated compounds to create alkanes during hydrocracking through the Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 decarboxylation, decarbonylation, and hydrodeoxygenation The creation of aromatic compounds was indicated by the presence of absorption bands in the FTIR spectra at 722 cm-1 and 746 cm-1 for liquid products, described as a shift in the shape of the COeH bond.
Figure 7 presents the GC-MS spectra of biofuel and RTO generated at 375AC.
The chemicals in the RTO with a retention duration of 10Ae14 minutes vanished following the reaction, as seen in Fig.
As the product was retained for 0Ae12 minutes, the quantity of hydrocarbon compounds in it rose.
Table 3 shows that the main components contained in RTO were primarily free fatty acids .
uch as linoleic acid and palmitic aci.
with a minor portion comprising aromatic compounds and alcohols .
is nearly identical to what Veriansyah et al.
has been demonstrated that mesoporous HZSM-5 with intracrystalline mesoporosity and cobalt-nickel had better intracrystalline diffusion and active sites .
, .
The desilication resulted in a reduction of acid sites, consistent with the findings of other research .
, 23, .
Additionally, mesoporous HZSM-5's acidity was decreased by the addition of metal.
Hao et al.
reported that, in mesoporous HZSM5, the metals took the place of the proton.
One could argue that HZSM-5's acidity can enhance C-C bond cracking.
C-O strech .
cid, ester of secendory alcoho.
C=O strech .
Transmittance (%) .
RTO Wavenumber .
RTO C=O (Carboxylic acid.
aliphatic keto.
Transmittance (%) Wavenumber .
the liquid product obtained at 375AC for 2 hours with Co-Ni/HZSM-5 .
liquid product produced at 375AC for 2 hours with mesoporous CoNi/HZSM-5 catalyst Fig.
GC-MS spectra under 20A5 bar in the batch reactor Fig.
Spectra FTIR analysis under 20C5 bar in the batch reactor.
As depicted in Fig.
and Table 4, the monocyclic aromatic hydrocarbons type of aromatic compound that are common in biofuel had chromatograms.
N-paraffin, which includes pentadecane (C.
and heptadecane (C.
, are the other prevalent compounds.
Fig.
8 shows that the liquid product contained high aromatic hydrocarbons of 47% area for Co-Ni catalyst impregnated on mesoporous HZSM-5.
As evidence, the liquid product's nparaffin content rose due to the mesoporous HZSM-5 catalyst.
The carboxylic acid and n-paraffin content of the mesoporous HZSM-5 catalyst both before and after cobalt-nickel metal impregnation showed an intriguing trend.
The area of normal paraffin compounds rose from 12% to 34%, while the area of carboxylic acid dropped dramatically from 60% to 2%.
Pentadecane made up 18% of the n-paraffin's makeup, whereas heptadecane made up 13%.
According to this finding, pentadecane and heptadecane were the most abundant hydrocarbon components in the liquid product.
This outcome Fig.
Effect of hierarchical mesoporous catalyst on hydrocarbon composition in liquid product.
Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 Table 3.
Chemical compounds in RTO before catalytic hydrocracking tests Compound/formula Structure n-Hexadecanoic acid (Palmitic aci.
/C16H32O2 9,12-Octadecanienoic acid (Linoleic aci.
/C18H32O2 RT .
Abundance .
rea%) Table 4.
Aromatic compounds in biofuel produced with HZSM-5 based catalyst at 375oC under 20C5 bar in the batch reactor.
Aromatic compound/formula Structure pentyl-/ C11H16 Abundance .
rea%)b i 1-Methyl-2-N-Hexylbenzene/C13H20 .
-methylhepty.
-/2Phenyloctane/C14H22 .
-methylnony.
-/C16H26 1-methyl-4-.
-methylet.
4-Isopropyltoluene/ C10H14 1-methyl-4-.
-methylpr.
/pIsobutyltoluene / C11H16 hexyl-/ C12H18 1,3-Dimethylbutylbenzene/ C12H18 heptyl-/ C13H20 octyl-/ Phenyloctane/ C14H22 nonyl-/C15H24 Benzene,- RTa.
1-methyl-3-.
-methyletA/ isopropyltoluene/ C10H14 .
-methyldecy.
- /C17H28 -diethyl/C10H14 1-ethyl-3,5-dimethylbenzene.
Ethyl-m-xylene/C10H14 /5- undecyl-/C17H28 tridecyl-/C19H32 dodecyl-/C18H30 RT = retention time for Mesoporous Co-Ni/HZSM5 catalyst I = Mesoporous Co-Ni/HZSM5.
II = Co-Ni/HZSM-5.
i = Mesoporous HZSM-5.
IV = HZSM-5
Table 4 demonstrates that the most of the aromatics generated during hydrocracking were monocyclic aromatic hydrocarbons (MAH.
, such as substituted benzenes.
The most abundant hydrocarbon component in liquid products for all catalysts was benzoene .
-Methyldecy.
A significant amount of n-C17H36 was present, and a significant amount of the equivalent .
-Methyldecy.
benzene was visible.
This indicated that the amount of alkylbenzenes generated was proportionate to n-paraffins with the same number of C atoms.
Filho et al.
also reported a similar phenomenon as found in this work.
In the case of dodecylbenzene and its isomers.
Rabaev et al.
found that the presence of .
-Methyldecy.
benzene exhibited a migrating process of double bond .
onjugated syste.
along chain fatty acids into carboxylic terminal or methyl group prior to aromatization.
There were additional polycyclic aromatic hydrocarbons (PAH.
such butyl and 2methyl naphthalene.
Less than 0.
5% of the area had The creation of the substituted benzenes and naphthalenes was enhanced by the combination of metals and the Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 mesoporous structure.
However, the production of PAHs like phenanthrene and anthracene was not aided by impregnation.
Additionally, aromatic chemicals generated in the C5AeC15 range were identified in gasoline by Vichaphund et al.
Consequently, when Co-Ni metals were impregnated into the HZSM-5 pore, 1,3-dimethylbutylbenzene and 1-ethyl-3,5dimethylbenzene in liquid products were abundant hydrocarbon molecules clustered in gasoline .
By raising the octane value, these aromatic chemicals may raise the heating value of biofuel.
The liquid substance might also be referred to as biofuel.
The incorporation of Co-Ni metals into hierarchical HZSM5 has been shown to significantly improve hydrocarbon yields compared to the unmodified catalyst, as demonstrated by Marlinda et al.
Furthermore.
Rac et al.
reported that the desilication process not only increased the surface area but also enhanced the distribution of Brynsted acid sites.
As reported by Riyanto et al.
, the addition of Co and Ni metals to HZSM-5 resulted in a greater number of Lewis acid sites as opposed to Brynsted acid sites.
When the two metals were successively and independently injected onto the hierarchical zeolite HZSM-5, this was likewise seen.
These findings suggest that while desilication of HZSM-5 may result in fewer acid sites, the quantity of acid sites rises once more after the addition of Co-Ni metals.
Anggoro et al.
claimed that the greater number of Lewis acid sites following metal impregnation than Brynsted acid sites was caused by the presence of vacant d-orbitals in transition metals, which were capable of accepting electrons.
The co-impregnation of Co and Mo metals reported by Riyanto et al.
showed a propensity for a decrease in both Brynsted and Lewis acid sites, as well as total acidity, in contrast to the results observed in our work utilizing the incipient wetness impregnation approach.
This drop was ascribed to metal species obstructing the pores, which reduced the surface area and prevented access to acid sites.
These results imply that the zeolite's acidity is greatly determined by the impregnation technique.
As shown in Table 2, the catalyst generated in this investigation was shown to have a low Brynsted-to-Lewis (B/L) acid site ratio.
In Fig.
9, the combination of these two kinds of acid sites encouraged the synthesis of aromatic Additionally, the C15/C16 ratio showed that the decarboxylation reaction, controlling the RTO hydrocracking process, was efficiently promoted by all catalysts.
consequence, this helped to lower the amount of hydrogen The function of Lewis and Bronsted acid sites in the synthesis of aromatic and paraffin compounds is illustrated in Fig.
Chen et al.
stated that the process of fatty acid deoxygenation is the first step in the reaction mechanism of aromatic synthesis.
This process yields paraffin compounds .
by following the general pathway of hydrocracking .
ecarboxylation/decarbonylation At the Bronsted acid site, alkane compounds with an atomic chain length of C15AeC18 hydrocracked into alkanes (C2-C.
, while some cracked into alkenes (C2-C.
Lewis acid sites and olefins enabled cyclization processes to produce intermediates, subsequently dehydrogenated at the Brounsted acid site to produce aromatic Additionally, these intermediates were hydrogenated to create cyclic molecules.
Fig.
Prediction of the mechanism of aromatic formation from hydrocracking of RTO with Co-Ni/HZSM-5 meso catalyst at a temperature of 375oC Conclusion Through desilication, a mesoporous HZSM-5 catalyst was The meso-microporous hierarchical pore structure of this catalyst was able to decrease the diffusion routes of triglyceride molecules and enhanced the number of active sites.
Co-Ni impregnation on mesoporous HZSM-5 could also enhance the textural characteristics of catalysts.
It has been demonstrated that the combination of desilication and Co-Ni impregnation increased the quantity of hydrocarbon compounds, such as n-paraffins, isoparaffins, cycloparaffins, and aromatics, in the hydrocracking of RTO.
The mesoporous Co-Ni/HZSM-5 catalyst exhibited an aromatic area of 46.
32% and an n-paraffin area of 34.
Marlinda et al.
/ Communications in Science and Technology 10.
87Ae97 Acknowledgements DP2M-DIKTI.
LPPM Skema Penelitian Terapan Universitas Jambi (No.
306/UN21.
11/PT.
05/SPK/2.
RIIM LPDP
Grant, and BRIN (National Research and Innovation Agenc.
with grant numbers B-844/II.
7/FR.
06/5/2023 and B948/i.
10/FR.
06/5/2023 are all acknowledged by the authors for their research grants.
We are grateful to the laboratory crews.
Muhammad Rizki Indra Saputra and Akhmad Ridho, as well as the Head of Chemical Reaction Engineering Laboratory.
Department of Chemical Engineering.
Faculty of Industrial Technology.
Sepuluh Nopember Institute of Technology, for the References