Biodiesel production enhanced by ultrasound-assisted esterification and transesterification of inedible olive oil




Biodiesel, Esterification, Olive oil, Transesterification, Ultrasound


In the first phase of this study, inedible olive oil with different initial free fatty acid concentrations (2.5, 5.0, and 10.0%) was processed through acid-catalyzed esterification. Various heating methods were used for this purpose. The ultrasound-assisted esterification and traditional magnetic stirrer-assisted esterification methods were similar to each other in terms of their effects on free fatty acid reduction. However, the ultrasound reaction time was significantly shorter than that of the traditional magnetic stirrer. In the second phase of this study, biodiesel production was carried out through the ultrasound-assisted transesterification of inedible olive oil. Independent variables were, namely, ultrasound power level (30, 90, and 150 W), methanol/oil mole ratio (3, 9, and 15), catalyst concentration (0.5, 1.0, and 1.5%), ultrasound time (15, 30, and 45 min), and reaction temperature (45, 55, and 65 °C), which affected the yield indices and physicochemical constants of the produced biodiesel. The purest biodiesel (98.95%) and the highest amount of yield (92.69%) were observed when using an ultrasound power level of 90 W, a methanol/oil mole ratio of 9, a catalyst concentration of 1.0%, an ultrasound time of 30 min, and a reaction temperature of 55 °C. Optimizing the reaction conditions of the ultrasound operation can effectively increase the biodiesel yield (92.69%), while reducing the energy consumption (4.775 kWh/kg) and shortening the reaction time (30 min), compared to the traditional magnetic stirrer (77.28%, 2.17 kWh/kg, and 120 min, respectively). Therefore, ultrasound-assisted transesterification can serve as an effective alternative because of its fast and economic operation for making biodiesel out of inedible olive oil.


Download data is not yet available.


AOCS. 2000. Official Methods and Recommended Practices of the American Oil Chemists' Society (5th ed.). USA, AOCS Press, Champaign, Illinois.

ASTM. 2013. Standard Specification for Biodiesel Fuel Blend Stock (B100) for Distillate Fuels, ASTM D6751-12

Atapour M, Kariminia HR. 2011. Characterization and transesterification of Iranian bitter almond oil for biodiesel production. Appl. Energy 88, 2377-2381.

Badday AS, Abdullah AZ, Lee K-T. 2013. Ultrasound-assisted transesterification of crude Jatropha oil using alumina-supported heteropolyacid catalyst. Appl. Energ. 105, 380-388.

Chai M, Tu Q, Lu M, Yang YJ. 2014. Esterification pretreatment of free fatty acid in biodiesel production, from laboratory to industry. Fuel Process Technol. 125, 106-113.

Dehghan L, Golmakani M-T, Hosseini SMH. 2019. Optimization of microwave-assisted accelerated transesterification of inedible olive oil for biodiesel production. Renewable Energ. 138, 915-922.

Deshmane VG, Adewuyi YG. 2013. Synthesis and kinetics of biodiesel formation via calcium methoxide base catalyzed transesterification reaction in the absence and presence of ultrasound. Fuel 107, 474-482.

Golmakani M-T, Mendiola JA, Rezaei K, Ibanez E. 2012a. Expanded ethanol with CO2 and pressurized ethyl lactate to obtain fractions enriched in γ-Linolenic Acid from Arthrospira platensis (Spirulina). J. Supercrit. Fluid 62, 109-115.

Golmakani M-T, Rezaei K, Mazidi S, Razavi SH. 2012b. Effect of alternative C2 carbon sources on the growth, lipid, and γ-linolenic acid production of Spirulina (Arthrospira platensis). Food Sci. Biotechnol. 21, 355-363.

Habibi M, Golmakani M-T, Farahnaky A, Mesbahi G, Majzoobi M. 2016. NaOH-free debittering of table olives using power ultrasound. Food Chem. 192, 775-781. PMid:26304410

Ho WWS, Ng HK, Gan S. 2016. Advances in ultrasound-assisted transesterification for biodiesel production. Appl. Therm. Eng. 100, 553-563.

Hsiao MC, Lin CC, Chang YH, Chen LC. 2010. Ultrasonic mixing and closed microwave irradiation-assisted transesterification of soybean oil. Fuel 89, 3618-3622.

Joshi SM, Gogate PR, Suresh Kumar S. 2018. Intensification of ultrasound assisted esterification of karanja oil for production of biodiesel with optimization using response surface methodology. Chem. Eng. Process. 124, 186-198.

Kanitkar A, Balasubramanian S, Lima M, Boldor D. 2011. A critical comparison of methyl and ethyl esters production from soybean and rice bran oil in the presence of microwaves. Bioresour. Technol. 102, 7896-7902. PMid:21715160

Korkut I, Bayramoglu M. 2018. Selection of Catalyst and Reaction Conditions for Ultrasound Assisted Biodiesel Production from Canola Oil. Renewable Energ. 116, 543-551.

Maddikeri GL, Pandit AB, Gogate PR. 2013. Ultrasound assisted interesterification of waste cooking oil and methyl acetate for biodiesel and triacetin production. Fuel Process. Technol. 116, 241-249.

Maneerung T, Kawi S, Dai Y, Wang C. 2016. Sustainable biodiesel production via transesterification of waste cooking oil by using CaO catalysts prepared from chicken manure. Energ. Convers. Manage. 123, 487-497.

Meher LC, Kulkarni MG, Dalai AK, Na S. 2006. Transesterification of karanja (Pongamia pinnata) oil by solid basic catalysts. Eur. J. Lipid Sci. Tech. 108, 389-397.

Motasemi F, Ani FN. 2012. A review on microwave-assisted production of biodiesel. Renew. Sust. Energ. Rev. 16, 4719-4733.

Sharma A, Kodgire P, Surendra Singh Kachhwaha SS. 2020. Investigation of ultrasound-assisted KOH and CaO catalyzed transesterification for biodiesel production from waste cotton-seed cooking oil: Process optimization and conversion rate evaluation. J. Clean. Prod. 259, 1-68.

Talebian-Kiakalaieh A, Amin NAS, Mazaheri H. 2013. A review on novel processes of biodiesel production from waste cooking oil. Appl. Energy 104, 683-710.

Tan YH, Abdullah MO, Nolasco-Hipolito C, Taufiq-Yap YH. 2015. Waste ostrich-and chicken-eggshells as heterogeneous base catalyst for biodiesel production from used cooking oil: Catalyst characterization and biodiesel yield performance. Appl. Energ. 160, 58-70.

Thanh LT, Okitsu K, Sadanaga Y, Takenaka N, Maeda Y, Bandow H. 2010. Ultrasound-assisted production of biodiesel fuel from vegetable oils in a small scale circulation process. Bioresource Technol. 101, 639-645. PMid:19736002

Trinh H, Yusup S, Uemura Y. 2018. Optimization and kinetic study of ultrasonic assisted esterification process from rubber seed oil. Bioresource Technol. 247, 51-57. PMid:28946094

Vicente G, Martinez M, Aracil J. 2004. Integrated biodiesel production: a comparison of different homogeneous catalysts systems. Bioresour. Technol. 92, 297-305. PMid:14766164

Yasvanthrajan N, Sivakumar P, Muthukumar K, Murugesan T, Arunagiri A. 2020. Production of biodiesel from waste bio-oil through ultrasound assisted transesterification using immobilized lipase. Environ. Technol. Innov. In Press.

Yin X, Zhang X, Wan M, Duan X, You Q, Zhang J, Li S. 2017. Intensification of biodiesel production using dual-frequency counter-current pulsed ultrasound. Ultrason. Sonochem. 37, 136-143. PMid:28427616



How to Cite

Golmakani M-T, Dehghan L, Rahimizad N. Biodiesel production enhanced by ultrasound-assisted esterification and transesterification of inedible olive oil. grasasaceites [Internet]. 2022Mar.30 [cited 2022Dec.7];73(1):e447. Available from:




Funding data

Shiraz University
Grant numbers 9261474