Microwave Assisted Continuous Flow Transesterification of Waste Cooking Oil for Biodiesel Production

Document Type : Research Paper

Authors

College of Engineering, Chem. Eng. Dept., University of Baghdad, Baghdad, Iraq.

Abstract

Biodiesel is a major renewable energy source derived from vegetable oils. Modern techniques are now required to produce biofuels, particularly biodiesel, to improve the efficiency and sustainability of the process. This study focuses on continuous biodiesel production from waste cooking oil via microwave-assisted transesterification in a flow process. Calcium oxide prepared from willow leaf extract was used as a catalyst at concentrations ranging from 1% to 4%, with a microwave power of 20% of the total 800W and an irradiation time of 0.5-7 min. The oil-to-methanol ratio was 50wt.%- 80wt.%, and the reaction temperature was 45-75 ℃. The results revealed that the waste cooking oil can be converted to biodiesel with a yield of (93.43%) in 5 min. with a 70wt.% oil/methanol molar ratio and 3wt.% catalyst. Also, the results indicated that the production of high-quality biodiesel, in accordance with ASTM standards, was facilitated under all operational conditions. The results suggest that microwave heating is a viable approach for achieving high biodiesel yields with shorter reaction times, even in continuous reactions. This is attributed to reduced energy activation. This method is promising for industrial-scale production of high-quality biodiesel, with methanol as the preferred alcohol.

Keywords

Main Subjects

References

  1. Al-Yaqoobi AM, Al-Rikabey MN, Al-Mashhadani MKH. Electrochemical harvesting of microalgae꞉ Parametric and cost-effectivity comparative investigation. Chemical Industry and Chemical Engineering Quarterly. 2021;27(2):121–30. https://doi.org/10.2298/CICEQ191213031A.
  2. Abd MF, AL-yaqoobi AM. The potential significance of microwave-assisted catalytic pyrolysis for valuable bio-products driven from Albizia tree. Applied Science and Engineering Progress. 2025;18(1):7454. https://doi.org/10.14416/j.asep.2024.07.016.
  3. Abd MF, Al-yaqoobi AM, Abdul-Majeed WS. Catalytic microwave pyrolysis of albizia branches using iraqi bentonite clays. Iraqi Journal of Chemical and Petroleum Engineering. 2024;25(2):175–86. https://doi.org/10.31699/IJCPE.2024.2.16.
  4. Haryono H, Ishmayana S, Fauziyah I. Synthesis and Characterization of Calcium Oxide Impregnated on Silica from Duck Egg Shells and Rice Husks as Heterogeneous Catalysts for Biodiesel Synthesis. Baghdad Science Journal. 2023;20:1976–84. https://doi.org/10.21123/bsj.2023.7895.
  5. Tippayawong N, Sittisun P. Continuous-flow transesterification of crude jatropha oil with microwave irradiation. Scientia Iranica. 2012;19(5):1324–8. https://doi.org/10.1016/j.scient.2012.08.004.
  6. Kumar R, Ravi Kumar G, Chandrashekar N. Microwave assisted alkali-catalyzed transesterification of Pongamia pinnata seed oil for biodiesel production. Bioresour Technol. 2011 Jun;102(11):6617–20. . https://doi.org/10.1016/j.biortech.2011.03.024.
  7. Sahu S, Saikia K, Gurunathan B, Dhakshinamoorthy A, Rokhum SL. Green synthesis of CaO nanocatalyst using watermelon peels for biodiesel production. Molecular Catalysis. 2023 Aug 1;547. https://doi.org/10.1016/j.mcat.2023.113342.
  8. Abbas AS, Abbas RN. Preparation and characterization of NaY zeolite for biodiesel production. Iraqi Journal of Chemical and Petroleum Engineering. 2015;16(2):19–29. https://doi.org/10.31699/IJCPE.2015.2.3.
  9. Abbas RA, Flayeh HM. Bioethanol (biofuel) production from low grade dates. Iraqi Journal of Chemical and Petroleum Engineering. 2019;20(4):41–7. https://doi.org/10.31699/IJCPE.2019.4.7.
  10. Hussain HK, Kareem A, Jendeel A, Naife TM, Abdul H, Al K, et al. Production of Biodiesel Fuel from Used vegetable Vol. 17, Journal of Engineering. 2011. https://doi.org/10.31026/j.eng.2011.05.25.
  11. Haryono H, Ishmayana S, Fauziyah I. Synthesis and Characterization of Calcium Oxide Impregnated on Silica from Duck Egg Shells and Rice Husks as Heterogeneous Catalysts for Biodiesel Synthesis. Baghdad Science Journal. 2023;20:1976–84. https://doi.org/10.21123/bsj.2023.7895.
  12. Phan AN, Phan TM. Biodiesel production from waste cooking oils. Fuel. 2008;87(17–18):3490–6. https://doi.org/10.1016/j.fuel.2008.07.008.
  13. Meng X, Chen G, Wang Y. Biodiesel production from waste cooking oil via alkali catalyst and its engine test. Fuel processing technology. 2008;89(9):851–7.. https://doi.org/10.1016/j.fuproc.2008.02.006.
  14. Tan KT, Lee KT, Mohamed AR. Potential of waste palm cooking oil for catalyst-free biodiesel production. Energy. 2011;36(4):2085–8. https://doi.org/10.1016/j.energy.2010.05.003.
  15. Ani FN, Said NH, Said MFM. Optimization of biodiesel production using a stirred packed-bed reactor. International Journal of Technology. 2018 Apr 1;9(2):219–28. https://doi.org/10.14716/ijtech.v9i2.1386.
  16. Subramaniam K, Wong KY, Wong KH, Chong CT, Ng JH. Enhancing Biodiesel Production: A Review of Microchannel Reactor Technologies. Vol. 17, Energies. Multidisciplinary Digital Publishing Institute (MDPI); 2024. https://doi.org/10.1007/s12155-021-10333-w.
  17. Marinković DM, Stanković M V., Veličković A V., Avramović JM, Miladinović MR, Stamenković OO, et al. Calcium oxide as a promising heterogeneous catalyst for biodiesel production: Current state and perspectives. Vol. 56, Renewable and Sustainable Energy Reviews. Elsevier Ltd; 2016. p. 1387–408. https://doi.org/10.1016/j.rser.2015.12.007.
  18. Kouzu M, Hidaka JS. Transesterification of vegetable oil into biodiesel catalyzed by CaO: A review. Vol. 93, Fuel. 2012. p. 1–12. https://doi.org/10.1016/j.fuel.2011.09.015.
  19. Almadani EA, Abdelghani KA, Omar FA. Calcium Oxide as an Efficient Heterogeneous Catalyst for Production of Biodiesel. The Scientific Journal of University of Benghazi. 2023 Dec 6;36(2). https://doi.org/10.37376/sjuob.v36i2.4303.
  20. Subramaniam K, Wong KY, Wong KH, Chong CT, Ng JH. Enhancing Biodiesel Production: A Review of Microchannel Reactor Technologies. Vol. 17, Energies. Multidisciplinary Digital Publishing Institute (MDPI); 2024. https://doi.org/10.3390/en17071652.
  21. Abd Maha F, Al-Yaqoobi AM. The feasibility of utilizing microwave-assisted pyrolysis for Albizia branches biomass conversion into biofuel productions. International Journal of Renewable Energy Development. 2023;12(6):1061. https://doi.org/10.14710/ijred.2023.56907.
  22. Gude VG, Patil P, Martinez-Guerra E, Deng S, Nirmalakhandan N. Microwave energy potential for biodiesel Sustainable Chemical Processes. 2013;1:1–31. https://doi.org/10.1186/2043-7129-1-5.
  23. El Sherbiny SA, Refaat AA, El Sheltawy ST. Production of biodiesel using the microwave technique. J Adv Res. 2010 Oct;1(4):309–14. https://doi.org/10.1016/j.jare.2010.07.003.
  24. Abd MF, Al-yaqoobi AM, Abdul-Majeed WS. Catalytic microwave pyrolysis of albizia branches using iraqi bentonite clays. Iraqi Journal of Chemical and Petroleum Engineering. 2024;25(2):175–86. https://doi.org/10.31699/IJCPE.2024.2.16.
  25. Gnaneswar Gude V, Patil P, Martinez-Guerra E, Deng S, Nirmalakhandan N. Microwave energy potential for biodiesel production [Internet]. 2013. Available from: http://www.sustainablechemicalprocesses.com/content/1/5/5.https://doi.org/10.1186/2043-7129-1-5.
  26. Iyyaswami R, Halladi VK, Yarramreddy SR, Malur Bharathaiyengar S. Microwave-assisted batch and continuous transesterification of karanja oil: Process variables optimization and effectiveness of irradiation: Microwave-assisted transesterification of karanja oil. Biomass Convers Biorefin. 2013;3(4):305–17. https://doi.org/10.1007/s13399-013-0080-8.
  27. Acevedo-Quiroz A, Carrera-Avendaño E de J, Acevedo-Quiroz N, Alvarez-Gutiérrez PE, Borunda M, Adam-Medina Experimental Study on Biodiesel Production in a Continuous Tubular Reactor with a Static Mixer. Processes. 2024;12(12):2859. https://doi.org/10.3390/pr12122859.
  28. He BB, Singh AP, Thompson JC. EXPERIMENTAL OPTIMIZATION OF A CONTINUOUS-FLOW REACTIVE DISTILLATION REACTOR FOR BIODIESEL PRODUCTION. Transactions of the ASAE. 48(6):2237–43. https://doi.org/10.13031/2013.20071.
  29. Serhan M, Sprowls M, Jackemeyer D, Long M, Perez ID, Maret W, et al. Total iron measurement in human serum with a smartphone. In: AIChE Annual Meeting, Conference Proceedings. American Institute of Chemical Engineers; 2019. https://doi.org/10.1039/x0xx00000x.
  30. Groisman Y, Gedanken A. Continuous flow, circulating microwave system and its application in nanoparticle fabrication and biodiesel synthesis. Journal of Physical Chemistry C. 2008 Jun 19;112(24):8802–8. https://doi.org/10.1021/jp801409t.
  31. Tran DT, Chang JS, Lee DJ. Recent insights into continuous-flow biodiesel production via catalytic and non-catalytic transesterification processes. Vol. 185, Applied Energy. Elsevier Ltd; 2017. p. 376– https://doi.org/10.1016/j.apenergy.2016.11.006.
  32. Aljendeel H, Borhan E, Al-Ani MJ. Kinetic Study of Transesterification Reaction of Edible Oil Using Heterogenous Iraqi Journal of Chemical and Petroleum Engineering. 2022 Sep 30;23(3):11–6. https://doi.org/10.31699/ijcpe.2022.3.2.
  33. Pauline JMN, Sivaramakrishnan R, Pugazhendhi A, Anbarasan T, Achary A. Transesterification kinetics of waste cooking oil and its diesel engine performance. Fuel. 2021;285:119108. https://doi.org/10.1016/j.fuel.2020.119108.
  34. Encinar JM, Gonzalez JF, Rodriguez JJ, Tejedor A. Biodiesel fuels from vegetable oils: transesterification of Cynara c ardunculus L. oils with ethanol. Energy & fuels. 2002;16(2):443–50. https://doi.org/10.1021/ef010174h.
  35. Gimbun J, Ali S, Kanwal CCSC, Shah LA, Muhamad NH, Cheng CK, et al. Biodiesel production from rubber seed oil using activated cement clinker as catalyst. Procedia Eng. 2013;53:13–9. https://doi.org/10.1016/j.proeng.2013.02.003.
  36. Wang B, Li S, Tian S, Feng R, Meng Y. A new solid base catalyst for the transesterification of rapeseed oil to biodiesel with methanol. Fuel. 2013;104:698–703. https://doi.org/10.1016/j.fuel.2012.08.034.
  37. Azcan N, Yilmaz O. Microwave assisted transesterification of waste frying oil and concentrate methyl ester content of biodiesel by molecular distillation. Fuel. 2013;104:614–9. https://doi.org/10.1016/j.fuel.2012.06.084.
  38. Zhang H, Ding J, Zhao Z. Microwave assisted esterification of acidified oil from waste cooking oil by CERP/PES catalytic membrane for biodiesel production. Bioresour Technol. 2012;123:72–7. https://doi.org/10.1016/j.biortech.2012.06.082.
  39. Uzun BB, Kılıç M, Özbay N, Pütün AE, Pütün E. Biodiesel production from waste frying oils: Optimization of reaction parameters and determination of fuel properties. Energy. 2012;44(1):347–51. https://doi.org/10.1016/j.biortech.2012.06.082.
  40. Jachuck R, Pherwani G, Gorton SM. Green engineering: Continuous production of biodiesel using an alkaline catalyst in an intensified narrow channel reactor. Journal of Environmental Monitoring. 2009;11(3):642–7. https://doi.org/10.1039/b807390m.
  41. Degfie TA, Mamo TT, Mekonnen YS. Optimized biodiesel production from waste cooking oil (WCO) using calcium oxide (CaO) nano-catalyst. Sci Rep. 2019;9(1):18982. https://doi.org/10.1038/s41598-019-55403-4.
  42. Lin CH, Chang YT, Lai MC, Chiou TY, Liao CS. Continuous biodiesel production from waste soybean oil using a nano-Fe3O4 microwave catalysis. Processes. 2021;9(5):756. https://doi.org/10.3390/pr9050756.
  43. Kumar G, Kumar D, Singh S, Kothari S, Bhatt S, Singh CP. Continuous low cost transesterification process for the production of coconut biodiesel. Energies (Basel). 2010;3(1):43–56. https://doi.org/10.3390/en3010043.
  44. Barnard TM, Leadbeater NE, Boucher MB, Stencel LM, Wilhite BA. Continuous-flow preparation of biodiesel using microwave heating. Energy & Fuels. 2007;21(3):1777–81. https://doi.org/10.1021/ef0606207.
  45. Sarvi A, Fogelholm CJ, Zevenhoven R. Emissions from large-scale medium-speed diesel engines: 2. Influence of fuel type and operating mode. Fuel Processing Technology [Internet]. 2008;89(5):520–7. Available from: https://www.sciencedirect.com/science/article/pii/S0378382007002159. https://doi.org/10.1016/j.fuproc.2007.10.005.
Journal of Chemical and Petroleum Engineering
Volume 60, Issue 1
June 2026
Pages 127-140

Files

History

  • Receive Date: 18 October 2025
  • Revise Date: 08 November 2025
  • Accept Date: 15 February 2026

Share

How to cite

Statistics