International Conference on Engineering.
Applied Science and Technology Effect of Cu-MOF Catalyst Impregnated with K2O to Enhance Pyrolytic Catalytic Cracking of Waste Cooking Oil for Biofuel Production Tri Widjaja*1.
Ali Altway1.
Shofia Khoirunnisa1.
Dinda Amelia Nurhanifa1.
Hendro Juwono1.
Deliana Dahnum2.
Joni Prasetyo2.
Nadiyah Salsabil Zahidah1.
Citra Yulia Sari1 Chemical Engineering Department.
Sepuluh Nopember Institute of Technology.
Indonesia National Research and Innovation Agency.
Indonesia
ARTICLE INFO
ICEAST use only:
Received date : 2 November 2024 Revised date : 14 November 2024 Accepted date : 28 November 2024 Keywords:
Biofuel Deoxygenation Metal-organic framework Waste cooking oil Pyrolytic catalytic cracking ABSTRACT Waste oil can be converted to fuel through complex processes due to its high impurity level and significant oxygen content.
This research explores the use of pyrolysis together with metal-organic frameworks (MOF.
to enhance the conversion of waste oil.
MOFs, porous crystalline materials formed by linking metal ions with organic linkers, provide moderate surface area and increased active sites for catalytic applications, especially in bioproduction.
In this study, copperbased MOFs (Cu-MOF) were synthesized via a room temperature method using CuSO4-5H2O and 2-methylimidazole, followed by wet impregnation with K2O.
The synthesized catalysts were characterized using FTIR.
SEM, and BET and the biofuel production using GC-MS.
The characterization results showed that K 2O impregnation enhanced the stability of MOF structure and significantly improved thermal stability as well as made it more efficient for the pyrolytic catalytic process for biofuel production.
FTIR analysis confirmed the successful impregnation of K2O.
SEM analysis showed that the Cu-MOF particles did not have a clear crystal From BET analysis, there is a decrease in surface area due to K 2O Gas chromatography-mass spectrometry (GC-MS) confirmed that the pyrolytic reaction occurred by using Cu-MOF/K2O catalyst can significantly increase the hydrocarbon compounds of the waste cooking oil to 39.
25% as well as decrease the oxygen content contained in the oil to 56.
65% according to the reaction in the pyrolytic catalysis cracking process.
Importantly, the catalyst showed regeneration potential after use, proving its feasibility for repeated application in waste oil conversion processes.
A 2024 International Conference on Engineering.
Applied Science and Technology.
All rights reserved IntroductionA Metal-organic frameworks (MOF.
are versatile heterogeneous materials gaining attention due to their wide-ranging applications in energy storage, catalysis, and electromagnetism .
These porous crystalline structures are formed by linking metal ions with organic ligands, offering a significant surface area and active sites suitable for catalysis .
These properties make MOFs particularly promising for biodiesel production.
Specifically, copper-based A Corresponding author.
E-mail address: tri.
widjaja@its.
MOFs have shown great potential as heterogeneous catalysts for alcohol oxidation, which could serve as an effective pathway for achieving more stable biodiesel production.
In biofuel research, numerous catalysts are employed in the transesterification process, including MOF-808.
Mo-MOF.
Zr-based MOFs.
MOF-5.
CuBTc-MOF, as well as copper- and calcium-based MOFs like BZnFMO .
Given the oxygenated hydrocarbons in biofuels and their growing significance in energy, economic, and environmental sectors, biofuel production has International Conference on Engineering.
Applied Science and Technology become increasingly critical.
However, before biofuels can be effectively used, these oxygenated compounds need to be broken down into shorter hydrocarbon chains.
While MOF-based catalysts have shown potential, their application in biodiesel synthesis is still underexplored.
Therefore, this study seeks to investigate the use of MOF-based catalysts, particularly Cu-MOF, for biodiesel production from waste cooking oil (WCO).
Previous research by Buchori et al.
, examined the doping of CaO-ZnO catalysts with varying concentrations of KCCO .
%, 3%, and 5% by weigh.
and found that increased KCCO concentrations enhanced the basicity of the catalyst, leading to better oxygen removal and yielding hydrocarbons like alkanes and alkenes.
Building on these insights, this study explores the doping of KCCO onto Cu-MOF catalysts to optimize the pyrolysis process for biofuel production.
The pyrolysis setup used in this study includes a catalytic bed reactor and an integrated condenser.
The catalytic bed serves as the primary site where waste cooking oil is thermally decomposed into smaller fractions under oxygen-free conditions.
The catalyst within the reactor is critical in accelerating the reaction and improving selectivity towards After pyrolysis, the resulting vapor is directed to the condenser, where it is cooled into a liquid phase.
This integrated system enables efficient separation and collection of biofuel, particularly The reactor-condenser integration is key to achieving an efficient conversion process from waste oil to renewable fuel.
A similar study by Ramli et al .
focused on pyrolysis of plastics using a reactor integrated with a bubble cap distillation column, demonstrating reduced energy consumption through vapor-phase condensation on each tray.
This research aims to explore the catalytic conversion of waste cooking oil into biofuel using Cu-MOF catalysts doped with potassium oxide (KCCO).
The novelty of this study lies in the use of Cu-MOF in the catalytic cracking of WCO, a catalyst that has not been extensively studied for this purpose.
By doping the Cu-MOF with KCCO, the catalystAos performance is expected to improve, particularly by enhancing its Comprehensive characterization of the catalyst was performed to identify optimal conditions for the catalytic cracking Furthermore, a customized pyrolysis system integrated with a condenser was developed for efficient conversion of WCO into valuable biofuel This study hypothesizes that Cu-MOF doped with KCCO will increase catalytic activity, yielding higher hydrocarbon products and reducing oxygen content in the biofuel, thus enhancing its The exploration of Cu-MOF doped with KCCO for pyrolytic catalytic cracking of WCO represents a novel and in-depth contribution to renewable biofuel research, filling a gap in current literature regarding its catalytic efficiency and mechanistic pathways.
Methods All the chemicals such as copper (II) sulphate anhydrous (CuSO4.
5H2O), methanol (MeOH) (Sigma, 99%), 2-Methylimidazole (Sigma, 99%), pottasium acetate (CH3COOK) (Sigma, 99%), and deionized (DI) water were purchased from Sumber Ilmiah Persada (Surabaya.
Indonesi.
and used without further purification.
Waste cooking oil (WCO) as raw materials were collected from street vendors in Surabaya.
Indonesia.
Cu-MOF was synthesized using a room temperature method with a metal-to-organic molar ratio of 1:2 (CuSOCEA5HCCO and 2-Methylimidazol.
To create solution 'A,' CuSOCEA5HCCO was dissolved in distilled water, while solution 'B' was prepared by dissolving 2-Methylimidazole in methanol.
Both solutions were stirred at 300 rpm at ambient temperature overnight, leading to the formation of a precipitate.
This precipitate was then separated by centrifugation at 5000 rpm for 5 minutes and dried at 100AC overnight to produce Cu-MOF.
Potassium loading on the CuMOF catalyst was carried out using the wet impregnation technique.
A potassium solution was prepared by dissolving CHCECOOK in deionized water, based on an incipient wetness volume of 5 mL/g of Cu-MOF.
The solution was added slowly to the catalyst under continuous stirring, followed by drying at 80AC overnight and calcination at 500AC for 5 hours to achieve KCCO-loaded Cu-MOF.
Results and Discussions In order to understand the bonding interaction between Cu and 2-methylimidazole in all samples.
FTIR (Fourier-transform Infrared Spectroscop.
analysis was performed.
Figure 1 displays the FTIR spectra of the synthesized Cu-MOF and pure 2methylimidazole at room temperature.
The analysis was carried out at the Water Technology and Industry Consulting Laboratory (TAKI).
Department of Chemical Engineering.
Sepuluh Nopember Institute of Technology (ITS).
Peaks observed between 650 and 1500 cmAA correspond to the stretching and bending modes of the imidazole ring, characteristic of 2-methylimidazole .
The peak at 1578 cmAA is assigned to the C=N stretching mode of 2methylimidazole, while those at 2920 and 3131 cmAA correspond to C-H bond stretching modes in the Tri Widjaja.
Ali Altway.
Shofia Khoirunnisa.
Dinda Amelia Nurhanifa.
Hendro Juwono.
Deliana Dahnum.
Joni Prasetyo.
Nadiyah Salsabil Zahidah.
Citra Yulia Sari: Effect of Cu-MOF Catalyst Impregnated with K2O to Enhance Pyrolytic Catalytic Cracking of Waste Cooking Oil for Biofuel Production International Conference on Engineering.
Applied Science and Technology aliphatic hydrocarbon chain and the aromatic ring of 2-methylimidazolate .
Distinct peaks at 1116 cmAA and 1250 cmAA are attributed to C-O stretching vibrations, characteristic of the MOF structure .
Additionally, a band around 728 cmAA is indicative of Cu-O stretching vibrations, resulting from the coordination of oxygen atoms with Cu atoms, confirming the successful formation of Cu-MOF .
The pronounced peak near 3400 cmAA suggests O-H stretching vibrations, possibly from hydroxyl groups or adsorbed water .
Figure 1 FTIR spectra of 2-Methylimidazole.
CuMOF.
, and Cu-MOF/K2O.
Following the successful formation of Cu-MOF, the catalyst was impregnated with KCCO to enhance its catalytic efficiency are presented in Figure 1.
shift in the vibration peaks associated with the imidazole ring is observed in the spectral region between 1200 cmAA and 1600 cmAA, with a prominent peak at 1400 cmAA, indicating successful KCCO Brunauer.
Emmett, and Teller (BET) analysis was used to assess the specific surface area, pore volume, and size of the materials.
The physical properties of Cu-MOF and Cu-MOF/ K2O obtained through N2 physisorption analysis, as shown in Table 1.
CuMOFAos surface area decreases to 371.
514 mAgAA after potassium oxide impregnation.
The reduction in surface area is likely due to the blockage of small pores by potassium oxide particles .
and accompanied by a reduction in pore volume after impregnation with potassium oxide particles.
The pore size increases from 3.
7636 nm to 3.
9665 nm after impregnation with 1% potassium oxide.
Cu-MOF restructuring, resulting in an increase in pore diameter .
Table 1.
The nitrogen adsorptionAedesorption method was used to examine catalysts Catalyst Spesific (SABET) .
Pore (Vpor.
Pore (DPor.
Cu-MOF CuMOF/K2O Previous studies on potassium oxide impregnation on dolomite indicated that increasing the concentration of potassium oxide from 15% to 20% led to a decrease in the basic site capacity of the catalyst.
Potassium oxide impregnation leads to a decrease in surface area and indicates a saturation limit, the results still demonstrate that potassium oxide impregnation can enhance catalytic activity due to the introduction of new active sites .
The experimental results show that using imidazole as an organic solvent in the synthesis of Cu-MOF yields a specific surface area of 435 mAgAA, significantly higher than the study .
, which used dimethylformamide (DMF) and reported a surface area of 118 mAgAA.
Figure 2 Nitrogen sorption isotherm For further clarity.
Figure 2 illustrates the adsorption and desorption isotherm peaks of nitrogen from the synthesized catalysts.
Both Cu-MOF and Cu-MOF/ International Conference on Engineering.
Applied Science and Technology K2O exhibit hysteresis, indicating that both catalysts possess mesoporous materials.
The surface morphologies of the Cu-MOF catalyst were examined using Scanning Electron Microscopy (SEM) at 50,000x magnification.
Figure 3a, representing Cu-MOF/K2O, exhibits a more homogeneous and less intricate surface structure.
The particles appear discrete and well-defined, suggesting minimal agglomeration.
This uniformity serves as a baseline morphology for comparative analysis of K2O impregnation effects.
Figures 3b, c, and d demonstrate of K2O impregnation effects, its enhanced surface irregularities and porosity indicate that K2O dopping significantly alters the material's These potentially increase the surface area and number of active sites, which could enhance catalytic activity a beneficial attribute for applications such as gasification or catalysis.
incomplete combustion.
Moreover, the acidity of WCO poses a risk of corrosion to both engines and storage systems .
The pyrolytic cracking of WCO begins at approximately 300AC and is completed around 600AC, with significant hydrocarbon weight loss typically occurring between 300AC and 500AC .
A common operating temperature range is 350AC to 450AC, which optimizes the production of lighter hydrocarbons, including those beneficial for biodiesel synthesis.
According to .
, the biofuel production process from off-grade crude palm oil operates in two stages: an initial reaction at 300AC followed by a second stage at 400AC, at which the cracking of hydrocarbons occurs.
Based on these findings, a reaction temperature of 400AC was selected for this study.
The catalytic pyrolytic cracking process occurs in two stages.
In the first stage, the waste cooking oil undergoes thermal decomposition of triglyceride and fatty acid molecules, resulting in the formation of oxygenated products.
In the second stage, these oxygenated products react through cracking over the catalyst to form hydrocarbon compounds .
Three concurrent reaction mechanisms occur in the gas and liquid phases namely hydrodeoxygenation (HDO), decarbonylation (DCO), and decarboxylation (DCO.
HCC can be produced from the breakdown of tar into gaseous components and through the water-gas shift reaction .
The presence of KCCO in the catalyst introduces more basic sites, which help reduce the oxygen content in the pyrolytic oil.
This is evident from the data, where the oxygenated hydrocarbon compounds decreased from an initial 98.
47% in waste cooking oil to 75% for pyrolytic oil produced with Cu-MOF, and Cu-MOF/K2O.
Hence, it can be concluded that CuMOF/K2O catalysts are more effective and efficient in reducing oxygen content during the catalytic pyrolytic cracking process compared to Cu-MOF Figure 3 SEM images of .
Cu-MOF, .
Cu-MOF/K2O Waste cooking oil from palm oil (WPCO) can be converted into petroleum-like products such as gasoline, kerosene, and diesel through pyrolytic catalytic cracking.
WPCO is rich in fatty acids, primarily palmitic acid (CCACI) and oleic acid (CCACO), which are present in a triglyceride structure derived from palm oil.
Due to its high kinematic viscosity and elevated acid value.
WCO is often considered lowquality oil.
These properties can negatively impact engine performance, leading to problems such as increased smoke emissions, carbon deposition, and The GC-MS chromatogram (Figure 4.
shows that the primary components of the pyrolytic oil are hydrocarbons, including alkanes, cycloalkanes, and aromatic compounds, with significantly reduced concentrations of oxygenated compounds.
contrast, the waste cooking oil is primarily composed 56% carboxylic acids, 0.
37% esters, and 4.
glycerol derivatives, which contribute to its elevated The use of the Cu-MOF/1-KCCO catalyst led to a marked decrease in oxygenated compounds (Figure 4.
23% to 46.
31%, along with an increase in hydrocarbon content to 43.
35%, as compared to 25% when using the Cu-MOF catalyst alone.
Tri Widjaja.
Ali Altway.
Shofia Khoirunnisa.
Dinda Amelia Nurhanifa.
Hendro Juwono.
Deliana Dahnum.
Joni Prasetyo.
Nadiyah Salsabil Zahidah.
Citra Yulia Sari: Effect of Cu-MOF Catalyst Impregnated with K2O to Enhance Pyrolytic Catalytic Cracking of Waste Cooking Oil for Biofuel Production International Conference on Engineering.
Applied Science and Technology These results align with previous studies, such as those by .
, which similarly identified aliphatic and aromatic hydrocarbons as the dominant components in pyrolytic oil.
The superior performance of the CuMOF/KCCO catalyst is likely due to its enhanced basicity, which promotes more efficient catalytic cracking and deoxygenation, making it significantly more effective for pyrolytic catalysis than Cu-MOF .
Figure 4 GCMS Results .
classification based on oxygenated compounds .
components of OLP Conclusions This study investigates the conversion of used cooking oil into biofuel using a Cu-MOF/K2O The physical and chemical properties of the catalyst were characterized through various analytical techniques, demonstrating that K2O was successfully doped onto Cu-MOF, as confirmed by FTIR analysis.
SEM analysis revealed no significant crystalline structures in the catalyst, while the incorporation of K2O increased the surface area and neutralized acid sites.
The used of K2O enhanced catalytic efficiency, contributing to improved biofuel production through pyrolytic catalytic cracking (PCC).
The use of the best catalyst for biofuel production in this study was Cu-MOF/1-K2O as evidenced by the results of GC-MS analysis which showed a reduction of fatty acids from used cooking oil from 89.
56% to 45.
92% and caused hydrocarbons to increase to 43.
35% as well as a decrease in oxygen content from 98.
47% in used cooking oil to 56.
This study shows that Cu-MOF/K2O catalyst is highly effective and efficient for biofuel production via pyrolytic catalysis, although further research is needed to optimize the catalyst composition for maximum performance.
Acknowledgment The authors thank Ministries Of Education And Culture.
Research And Technology through Basis Informasi Penelitian dan Pengabdian kepada Masyarakat (BIMA) Ae Implementation of the State University Operational Assistance Program Regular Fundamental Research (Master Contract Number:
038/E5/PG.
PL/2024, dated 11 June 2024.
Researcher Contract Number: 1782/PKS/ITS/2024, dated June 12 2.
for the financial support of this Funding This research was funded by Ministries of Education And Culture.
Research And Technology through Basis Informasi Penelitian dan Pengabdian kepada Masyarakat (BIMA).
Master Contract Number:
038/E5/PG.
PL/2024
Author Contributions Conceptualization.
Tri Widjaja and Joni Prasetyo.
Ali Altway and Hendro Yuwono.
Deliana Dahnum, and Dinda Amelia Nurhanifa.
formal analysis.
Nadiyah Salsabil Zahidah.
Shofia KhoirunnisaAo resources.
Shofia KhoirunnisaAo.
data curation.
Dinda Amelia Nurhanifa.
writingAioriginal draft preparation.
Tri Widjaja.
writingAireview and editing.
Ali Altway.
Dinda Amelia Nurhanifa.
Nadiyah Salsabil Zahidah.
project administration.
Shofia KhoirunnisaAo.
Tri Widjaja.
All authors have read and agreed to the published version of the manuscript.
Conflicts of Interest The authors declare no conflict of interest and the funders had no role in the design of the study.
in the collection, analyses, or interpretation of data.
in the writing of the manuscript.
or in the decision to publish the results.
References