Synthesis and Application of Deep Eutectic Solvents for the Deacidification of Waste Cooking Oil: A Pathway to High-Quality Biodiesel

Mutiara Putri, Leila Kalsum, Aida Syarif


Abstract


This study investigates the synthesis and application of deep eutectic solvents (DESs) for deacidifying waste cooking oil (WCO) to produce high-quality biodiesel. The research addresses conventional biodiesel production's economic and environmental challenges by using WCO as a cost-effective feedstock and employing DESs as a greener alternative to traditional solvents. DESs are biodegradable, have low toxicity, and can be easily prepared by mixing a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA). The study synthesized DES using Choline Chloride (ChCl) as the HBA and ethylene glycol (EG) as the HBD at a constant temperature of 60° C and variable stirring rates of 150 and 200 rpm. Five different molar ratios of ChCl to EG were tested: 1:1, 1:2, 1:4, 1:6, and 1:8. The effectiveness of the DESs was evaluated based on their ability to remove free fatty acids (FFAs) from WCO, with DES 2 (1:2 molar ratio) and DES 3 (1:4 molar ratio) showing the highest adsorption efficiencies. The research also characterized the resulting biodiesel, comparing key properties such as cetane number, sulfur content, and flash point to established standards. The results show that increasing the DES concentration significantly enhances the removal of FFAs, with DES 2 achieving an 84% efficiency and DES 3 achieving an 83% efficiency at a 1:6 WCO: DES molar ratio. DES treatment consistently improved key fuel properties: the cetane number increased, while sulfur content and total acid number (TAN) were significantly reduced. DES 3 emerged as the most effective solvent, yielding the highest cetane number (56.3), lowest sulfur content (18 ppm), and lowest TAN (0.12 mgKOH/g) at the 1:6 molar ratio. While DES treatment reduced the fuel's flash point, the overall benefits of producing a cleaner, higher-quality fuel outweigh this concern. This research confirms that DESs provide a sustainable and practical pathway for producing high-quality biodiesel from waste cooking oil

Keywords


Biodegradable, Biodiesel, Deacidification, Transesterification, Waste Cooking Oil

Full Text:

PDF

References


Alam, Md Asraful, Liya Deng, Ange Douglas Potchamyou Ngatcha, Aymard Didier Tamafo Fouegue, Jingcheng Wu, Shen Zhang, Anqi Zhao, Wenlong Xiong, and Jingliang Xu. 2023. “Biodiesel Production from Microalgal Biomass by Lewis Acidic Deep Eutectic Solvent Catalysed Direct Transesterification.” Industrial Crops and Products 206(September):117725. doi: 10.1016/j.indcrop.2023.117725.

Andermann, Tessa M., Farnaz Fouladi, Fiona B. Tamburini, Bita Sahaf, Ekaterina Tkachenko, Courtney Greene, Matthew T. Buckley, Erin F. Brooks, Haley Hedlin, Sally Arai, Crystal L. Mackall, David Miklos, Robert S. Negrin, Anthony A. Fodor, Andrew R. Rezvani, and Ami S. Bhatt. 2021. “A Fructo-Oligosaccharide Prebiotic Is Well Tolerated in Adults Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: A Phase I Dose-Escalation Trial.” Transplantation and Cellular Therapy 27(11):932.e1-932.e11. doi: 10.1016/j.jtct.2021.07.009.

Blaschke, Fabio, Richard Hasso, and Viktor Hacker. 2024. “Unlocking Synergistic Effects of Mixed Ionic Electronic Oxygen Carriers in Ceramic-Structured Environments for Efficient Green Hydrogen Storage.” International Journal of Hydrogen Energy (July). doi: 10.1016/j.ijhydene.2024.08.508.

Bow, Yohandri, Abu Hasan, Rusdianasari Rusdianasari, Zakaria Zakaria, Bambang Irawan, and Nedia Sandika. 2022. “Biodiesel from Pyrolysis Fatty Acid Methyl Ester (FAME) Using Fly Ash as a Catalyst.” Proceedings of the 5th FIRST T1 T2 2021 International Conference (FIRST-T1-T2 2021) 9:175–81. doi: 10.2991/ahe.k.220205.030.

Buasri, Achanai, Suthita Lertnimit, Arnon Nisapruksachart, Issara Khunkha, and Vorrada Loryuenyong. 2023. “Box-Behnken Design for Optimization on Esterification of Free Fatty Acids in Waste Cooking Oil Using Modified Smectite Clay Catalyst.” ASEAN Journal of Chemical Engineering 23(1):40–51. doi: 10.22146/ajche.77009.

Burmana, Anggara Dwita, Renita Manurung, Affila, Aga Nugraha, Asri Munawar, and Rondang Tambun. 2025. “Carbon Footprint of Biodiesel Production Using Waste Cooking Oil: Performance and Analysis through Amberlite HPR 9000 SO4 as Catalyst.” Results in Engineering 27(July):106366. doi: 10.1016/j.rineng.2025.106366.

Dou, Zhenlan, Chunyan Zhang, Dongmin Yu, Zihua Ye, Songcen Wang, and Siyuan Fan. 2025. “A New Co-Production (Biogas& Biodiesel) Plant under a Microalgae-to-Biofuel Process Designed under a Hydrothermal Disintegration/ Deep Eutectic Solvent Process.” Process Safety and Environmental Protection 193(November 2024):54–73. doi: 10.1016/j.psep.2024.11.016.

Drogobuzhskaya, Svetlana, Margarita Frolova, Andrey Shishov, and Nikita Tsvetov. 2024. “Comparison of Extraction Abilities of Deep Eutectic Solvents and Aqueous Acid Solutions for Extraction of Rare Earths and Transition Metals.” Journal of Rare Earths 42(6):1157–64. doi: 10.1016/j.jre.2023.06.014.

Foroutan, Rauf, Mahsa Foroughi, Abolfazl Tutunchi, Bahman Ramavandi, Daniel Terrón, and Marta Pazos. 2025. “Production of Biodiesel from Waste Cooking Oil and Non-Edible M. Oleifera Oil Utilizing a CaO/CuFe2O4/LaTiO3Perovskite@Na Bifunctional Heterogeneous Nanocatalyst.” Journal of Environmental Chemical Engineering 13(4). doi: 10.1016/j.jece.2025.117261.

Herman, Indah Thuraya, Khairuddin Md Isa, Naimah Ibrahim, Saiful Azhar Saad, Tuan Amran Tuan Abdullah, Mohd Aizudin Abd Aziz, and Muhammad Auni Hairunnaja. 2024. “Performance of Waste Cooking Oil Esterification for Biodiesel Production Using Various Catalysts.” Pertanika Journal of Science and Technology 32(2):669–84. doi: 10.47836/pjst.32.2.10.

Irawan, Bambang, Rusdianasari, and Abu Hasan. 2021. “Pyrolysis Process of Fatty Acid Methyl Ester (FAME) Conversion into Biodiesel.” International Journal of Research in Vocational Studies (IJRVOCAS) 1(2):01–10. doi: 10.53893/ijrvocas.v1i2.21.

Ishak, Muhamad Iqbal, Asiah Nusaibah Masri, Azad Anugerah Ali Rasol, Izni Mariah Ibrahim, and Hasrinah Hasbullah. 2025. “Optimization of Ternary Glutaric Acid-Based Deep Eutectic Solvents (TGADES) for Oxidative-Extractive Desulfurization of Model Oil Using Response Surface Methodology (RSM).” Sustainable Chemistry and Pharmacy 46(March):102052. doi: 10.1016/j.scp.2025.102052.

Kailas, T. Gopikrishnan, Akash A R, Saikat Dutta, and Vasudeva Madav. 2025. “Novel Adsorption-Based Upgradation of End-of-Life Polypropylene Pyrolysis Oil Using Carbonised Rice Husk.” Energy Conversion and Management: X 25(September 2024):100824. doi: 10.1016/j.ecmx.2024.100824.

Lei, Yang, Lei Du, Xinyan Liu, Haoshui Yu, Xiaodong Liang, Georgios M. Kontogeorgis, and Yuqiu Chen. 2023. “Natural Gas Sweetening Using Tailored Ionic Liquid-Methanol Mixed Solvent with Selective Removal of H2S and CO2.” Chemical Engineering Journal 476(June):146424. doi: 10.1016/j.cej.2023.146424.

Luo, Hongzhen, Tairan Zhou, Rui Zhang, Qianyue Yang, Xinyan You, Shijie Wang, Jiabin Wang, Fang Xie, and Rongling Yang. 2024. “Conversion of Biomass to Biofuels: Integration of a Ternary Deep Eutectic Solvent Pretreatment and Microbial Fermentation for C2-C4 Bioalcohols Production from Lignocellulose.” Industrial Crops and Products 220(June):119271. doi: 10.1016/j.indcrop.2024.119271.

Martins, Denis, Anna Korre, Zhenggang Nie, and Sevket Durucan. 2024. “Carbon Capture Science & Technology Multi-Period , Multi-Objective Optimisation of the Northern Lights and Stella Maris Carbon Capture and Storage Chains.” Carbon Capture Science & Technology 11(December 2023):100190. doi: 10.1016/j.ccst.2024.100190.

Mertsoy, E. Y., E. Sert, S. Atalay, and F. S. Atalay. 2023. “Deep Eutectic Solvent Incorporated AC/MIL-101 Hybrid Material Catalysts for the Production of Fuel Additives (Acetins) from by-Product Glycerol.” Materials Today Sustainability 24:100499. doi: 10.1016/j.mtsust.2023.100499




DOI: https://doi.org/10.30743/best.v9i1.13036

Refbacks

  • There are currently no refbacks.


Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.