The growing demand for renewable energy sources encourages the development of technologies for the production of biodiesel from waste, but the high content of free fatty acids in raw materials complicates transesterification, reduces fuel yield, and increases the need for purification. The purpose of the study was to develop and validate a mathematical model of the process of transesterification of used oils into diesel biofuels to optimise technological parameters. The rationalised model described in detail the patterns of triglyceride transformation in the presence of alcohol and a catalyst. It allowed tracking changes in the concentrations of reaction intermediates, in particular, diglycerides, monoglycerides, biodiesel, and glycerol, which is critical for predicting the effectiveness of the process. Stable values of the speed of the transesterification process are indicated using the Arrhenius equation, which helped to estimate the effect of temperature and the ratio of reactants on the overall kinetics of the reaction. As part of the study, numerical modelling and correlation of the model were carried out by systematising the results with the data obtained during the research and obtained from the results of the analysis of literature sources. Catalytic and non-catalytic variants of the process were analysed, which determined the most effective reaction conditions. The simulation results confirmed that an increase in temperature values to 60°C leads to an increase in the yield of diesel biofuels, so excessive heating above the boiling point of methanol causes its evaporation, which leads to a decrease in the efficiency of the process and the loss of raw materials. Optimal technological parameters that ensure the maximum yield of biodiesel with minimal material and energy costs were determined. The proposed mathematical model can be used in industrial settings to optimise the biofuel production process, helping to increase the efficiency of recycling
kinetic model, free fatty acids, parameter optimisation, temperature regime, biofuel yield, energy efficiency
[1] Aghbashlo, M., Peng, W., Tabatabaei, M., Kalogirou, S.A., Soltanian, S., Hosseinzadeh-Bandbafha, H., & Lam, S.S. (2021). Machine learning technology in biodiesel research: A review. Progress in Energy and Combustion Science, 85, article number 100904. doi: 10.1016/j.pecs.2021.100904.
[2] Ahranjani, P.J., Saei, S.F., El-Hiti, G.A., Yadav, K.K., Cho, J., & Rezania, S. (2024). Magnetic carbon nanotubes doped cadmium oxide as heterogeneous catalyst for biodiesel from waste cooking oil. Chemical Engineering Research and Design, 201, 176-184. doi: 10.1016/j.cherd.2023.11.059.
[3] Ali, S., Shafique, O., Mahmood, S., Mahmood, T., Khan, B.A., & Ahmad, I. (2020). Biofuels production from weed biomass using nano catalyst technology. Biomass and Bioenergy, 139, article number 105595. doi: 10.1016/j.biombioe.2020.105595.
[4] Athar, M., & Zaidi, S. (2020). A review of the feedstocks, catalysts, and intensification techniques for sustainable biodiesel production. Journal of Environmental Chemical Engineering, 8(6), article number 104523. doi: 10.1016/j.jece.2020.104523.
[5] Aurtherson, P.B., Nalla, B.T., Srinivasan, K., Mehar, K., & Devarajan, Y. (2023). Biofuel production from novel Prunus domestica kernel oil: process optimization technique. Biomass Conversion and Biorefinery, 13(7), 6249-6255. doi: 10.1007/s13399-021-01551-5.
[6] Babadi, A.A., Rahmati, S., Fakhlaei, R., Barati, B., Wang, S., Doherty, W., & Ostrikov, K.K. (2022). Emerging technologies for biodiesel production: Processes, challenges, and opportunities. Biomass and Bioenergy, 163, article number 106521. doi: 10.1016/j.biombioe.2022.106521.
[7] Cheliadyn, L., Ribun, V., & Cheliadyn, V. (2020). Technological and environmental aspects of improving the biodiesel production from vegetable oils. Ecological Safety and Balanced Use of Resources, 11(2), 83-91. doi: 10.31471/2415-3184-2020-2(22)-83-91.
[8] Chen B., Zheng, D., Xu, R., Leng, S., Han, L., Zhang, Q., Liu, N., Dai, C., Wu, B., Yu, G., & Cheng, J. (2022). Disposal methods for used passenger car tires: One of the fastest growing solid wastes in China. Green Energy & Environment, 7(6), 1298-1309. doi: 10.1016/j.gee.2021.02.003.
[9] Dahiya, A. (2020, January). Cutting-edge biofuel conversion technologies to integrate into petroleum-based infrastructure and integrated biorefineries. In Bioenergy (pp. 649-670). London: Academic Press. doi: 10.1016/b978-0-12-815497-7.00031-2.
[10] Devarajan, Y., Munuswamy, D.B., Subbiah, G., Vellaiyan, S., Nagappan, B., Varuvel, E.G., & Thangaraja, J. (2022). Inedible oil feedstocks for biodiesel production: A review of production technologies and physicochemical properties. Sustainable Chemistry and Pharmacy, 30, article number 100840. doi: 10.1016/j.scp.2022.100840.
[11] Eldiehy, K.S., Daimary, N., Borah, D., Sarmah, D., Bora, U., Mandal, M., & Deka, D. (2022). Towards biodiesel sustainability: Waste sweet potato leaves as a green heterogeneous catalyst for biodiesel production using microalgal oil and waste cooking oil. Industrial Crops and Products, 187, article number 115467. doi: 10.1016/j.indcrop.2022.115467.
[12] Elgharbawy, A.S., Sadik, W., Sadek, O.M., & Kasaby, M.A. (2021). A review on biodiesel feedstocks and production technologies. Journal of the Chilean Chemical Society, 66(1), 5098-5109.
[13] Esmaeili, H. (2022). A critical review on the economic aspects and life cycle assessment of biodiesel production using heterogeneous nanocatalysts. Fuel Processing Technology, 230, article number 107224. doi: 10.1016/j.fuproc.2022.107224.
[14] Gad, M.S., Ağbulut, Ü., Afzal, A., Panchal, H., Jayaraj, S., Qasem, N.A., & El-Shafay, A.S. (2023). A comprehensive review on the usage of the nano-sized particles along with diesel/biofuel blends and their impacts on engine behaviors. Fuel, 339, article number 127364. doi: 10.1016/j.fuel.2022.127364.
[15] Ganesan, R., Manigandan, S., Samuel, M.S., Shanmuganathan, R., Brindhadevi, K., Chi, N.T.L., & Pugazhendhi, A. (2020). A review on prospective production of biofuel from microalgae. Biotechnology Reports, 27, article number e00509. doi: 10.1016/j.btre.2020.e00509.
[16] Hazrat, M.A., Rasul, M.G., Khan, M.M.K., Mofijur, M., Ahmed, S.F., Ong, H.C., & Show, P.L. (2021). Techniques to improve the stability of biodiesel: A review. Environmental Chemistry Letters, 19, 2209-2236. doi: 10.1007/s10311-020-01166-8.
[17] Hosseinzadeh-Bandbafha, H., Li, C., Chen, X., Peng, W., Aghbashlo, M., Lam, S.S., & Tabatabaei, M. (2022). Managing the hazardous waste cooking oil by conversion into bioenergy through the application of waste-derived green catalysts: A review. Journal of Hazardous Materials, 424, article number 127636. doi: 10.1016/j.jhazmat.2021.127636.
[18] Jayaraman, J., Dawn, S.S., Appavu, P., Mariadhas, A., Joy, N., Alshgari, R.A., & Kumar, J.A. (2022). Production of biodiesel from waste cooking oil utilizing zinc oxide nanoparticles combined with tungsto phosphoric acid as a catalyst and its performance on a CI engine. Fuel, 329, article number 125411. doi: 10.1016/j.fuel.2022.125411.
[19] Khan, Z., Javed, F., Shamair, Z., Hafeez, A., Fazal, T., Aslam, A., & Rehman, F. (2021). Current developments in esterification reaction: A review on process and parameters. Journal of Industrial and Engineering Chemistry, 103, 80-101. doi: 10.1016/j.jiec.2021.07.018.
[20] Konur, O. (2021). Biodiesel and petrodiesel fuels: Science, technology, health, and the environment. In Biodiesel fuels (pp. 3-36). Boca Raton: CRC Press. doi: 10.4324/9780367456238-2.
[21] Kukana, R., & Jakhar, O. P. (2022). Performance, combustion and emission characteristics of a diesel engine using composite biodiesel from waste cooking oil – Hibiscus Cannabinus oil. Journal of Cleaner Production, 372, article number 133503. doi: 10.1016/j.jclepro.2022.133503.
[22] Maheshwari, P., Haider, M.B., Yusuf, M., Klemeš, J.J., Bokhari, A., Beg, M., & Jaiswal, A.K. (2022). A review on latest trends in cleaner biodiesel production: Role of feedstock, production methods, and catalysts. Journal of Cleaner Production, 355, article number 131588. doi: 10.1016/j.jclepro.2022.131588.
[23] Mathew, G.M., Raina, D., Narisetty, V., Kumar, V., Saran, S., Pugazhendi, A., & Binod, P. (2021). Recent advances in biodiesel production: Challenges and solutions. Science of the Total Environment, 794, article number 148751. doi: 10.1016/j.scitotenv.2021.148751.
[24] Mushtruk, M., Bal-Prylypko, L., Slobodyanyuk, N., Boyko, Y., & Nikolaienko, M. (2022). Design of reactors with mechanical mixers in biodiesel production. In Lecture notes in mechanical engineering (pp. 197-207). Springer: Springer International Publishing. doi: 10.1007/978-3-031-06044-1_19.
[25] Mushtruk, M., Mushtruk, N., Slobodyanyuk, N., Vasyliv, V., & Zheplinska, M. (2024). Enhanced energy independence: Converting animal fat into biodiesel. International Journal of Environmental Studies, 81(1), 134-144. doi: 10.1080/00207233.2024.2314860.
[26] Pasha, M.K., Dai, L., Liu, D., Guo, M., & Du, W. (2021). An overview to process design, simulation and sustainability evaluation of biodiesel production. Biotechnology for Biofuels, 14, article number 129. doi: 10.1186/s13068-021-01977-z.
[27] Pinheiro, C.T., Quina, M.J., & Gando-Ferreira, L.M. (2021). Management of waste lubricant oil in Europe: A circular economy approach. Critical Reviews in Environmental Science and Technology, 51(18), 2015-2050. doi: 10.1080/10643389.2020.1771887.
[28] Razak, N.H., Hashim, H., Yunus, N.A., & Klemeš, J.J. (2021). Reducing diesel exhaust emissions by optimisation of alcohol oxygenates blend with diesel/biodiesel. Journal of Cleaner Production, 316, article number 128090. doi: 10.1016/j.jclepro.2021.128090.
[29] Subhash, G.V., Rajvanshi, M., Kumar, G.R.K., Sagaram, U.S., Prasad, V., Govindachary, S., & Dasgupta, S. (2022). Challenges in microalgal biofuel production: A perspective on techno economic feasibility under biorefinery stratagem. Bioresource Technology, 343, article number 126155. doi: 10.1016/j.biortech.2021.126155.
[30] Suzihaque, M.U.H., Syazwina, N., Alwi, H., Ibrahim, U.K., Abdullah, S., & Haron, N. (2023). A sustainability study of the processing of kitchen waste as a potential source of biofuel: Biodiesel production from waste cooking oil (WCO). Materials Today: Proceedings, 63, S484-S489. doi: 10.1016/j.matpr.2022.04.526.
[31] Tucki, K., Orynycz, O., Wasiak, A., Świć, A., Mruk, R., & Botwińska, K. (2020). Estimation of carbon dioxide emissions from a diesel engine powered by lignocellulose derived fuel for better management of fuel production. Energies, 13(3), article number 561. doi: 10.3390/en13030561.
[32] Vickram, S., Manikandan, S., Deena, S.R., Mundike, J., Subbaiya, R., Karmegam, N., & Awasthi, M.K. (2023). Advanced biofuel production, policy and technological implementation of nano-additives for sustainable environmental management – a critical review. Bioresource Technology, 387, article number 129660. doi: 10.1016/j.biortech.2023.129660.
[33] Zhao, Y., Wang, C., Zhang, L., Chang, Y., & Hao, Y. (2021). Converting waste cooking oil to biodiesel in China: environmental impacts and economic feasibility. Renewable and Sustainable Energy Reviews, 140, article number 110661. doi: 10.1016/j.rser.2020.110661.
[34] Zulqarnain, M.Y.M.H., Ayoub, M., Ramzan, N., Nazir, M.H., Zahid, I., Butt, T.A. (2021). Overview of feedstocks for sustainable biodiesel production and implementation of the biodiesel program in Pakistan. ACS Omega, 6(29), 19099-19114. doi: 10.1021/acsomega.1c02402.