Energy Efficiency Improvement in Palm Oil Mills through Waste Heat Recovery and Sustainable Process Integration
Keywords:
cogeneration, process integration, waste heat recoveryAbstract
Palm oil mills are energy self-sufficient, and that self-sufficiency has become the principal obstacle to their energy efficiency. Because fibre and shell are burned on site at no accounted cost, thermal losses that would be intolerable in a fuel-purchasing plant persist without scrutiny. This paper reviews the technical basis for energy efficiency improvement in palm oil mills through waste heat recovery and process integration, and establishes where the recoverable losses lie and what determines whether recovery is worth undertaking. A structured review was conducted on peer-reviewed studies indexed in Scopus and SINTA published between 2010 and 2025, covering mill energy and exergy analysis, cogeneration enhancement, waste heat recovery, biogas utilisation, and process integration in agro-industrial plants. Studies were coded for the loss stream addressed, the recovery mechanism proposed, the reported performance, and the analytical method employed. The synthesis identifies four principal loss streams: vented sterilizer exhaust steam, boiler flue gas, engine jacket and exhaust heat from biogas generators, and sterilizer condensate. Mill-scale evidence indicates that recovering these streams within an enhanced cogeneration configuration substantially increases surplus power and, more importantly, extends continuous plant operation. The paper argues that the decisive variable is not thermodynamic recoverability but whether the mill has an accounting framework that assigns a value to internally consumed biomass, and proposes that opportunity-cost pricing of fibre and shell precede technical assessment.
References
Anyaoha, K. E., Sakrabani, R., Patchigolla, K., & Mouazen, A. M. (2018). Critical evaluation of oil palm fresh fruit bunch solid wastes as soil amendments: Prospects and challenges. Resources, Conservation and Recycling, 136, 399–409. https://doi.org/10.1016/j.resconrec.2018.04.022
Booneimsri, P., Kubaha, K., & Chullabodhi, C. (2018). Increasing power generation with enhanced cogeneration using waste energy in palm oil mills. Energy Science & Engineering, 6(3), 154–173. https://doi.org/10.1002/ese3.196
Cheah, W. Y., Siti-Dina, R. P., Leng, S. T. K., Er, A. C., & Show, P. L. (2023). Circular bioeconomy in palm oil industry: Current practices and future perspectives. Environmental Technology & Innovation, 30, 103050. https://doi.org/10.1016/j.eti.2023.103050
Harahap, F., Leduc, S., Mesfun, S., Khatiwada, D., Kraxner, F., & Silveira, S. (2019). Opportunities to optimize the palm oil supply chain in Sumatra, Indonesia. Energies, 12(3), 420. https://doi.org/10.3390/en12030420
Hardianto, T., Wenas, A. A., & Juangsa, F. B. (2023). Upgrading process of palm empty fruit bunches as alternative solid fuel: A review. Clean Energy, 7(6), 1173–1188. https://doi.org/10.1093/ce/zkad059
Rajakal, J. P., Hwang, J. Z. H., Hassim, M. H., Andiappan, V., & Tan, Q. T. (2023). Integration and optimisation of palm oil sector with multiple industries to achieve circular economy. Sustainable Production and Consumption, 40, 318–336. https://doi.org/10.1016/j.spc.2023.06.022
Razman, K. K., Hanafiah, M. M., Mohammad, A. W., & Ang, W. L. (2022). Life cycle assessment of an integrated membrane treatment system of anaerobic-treated palm oil mill effluent (POME). Membranes, 12(2), 246. https://doi.org/10.3390/membranes12020246
Saidur, R., Ahamed, J. U., & Masjuki, H. H. (2010). Energy, exergy and economic analysis of industrial boilers. Energy Policy, 38(5), 2188–2197. https://doi.org/10.1016/j.enpol.2009.11.087
Siagian, U. W. R., Wenten, I. G., & Khoiruddin, K. (2024). Circular economy approaches in the palm oil industry: Enhancing profitability through waste reduction and product diversification. Journal of Engineering and Technological Sciences, 56(1), 25–49. https://doi.org/10.5614/j.eng.technol.sci.2023.56.1.3
Umar, M. S., Urmee, T., & Jennings, P. (2018). A policy framework and industry roadmap model for sustainable oil palm biomass electricity generation in Malaysia. Renewable Energy, 128, 275–284. https://doi.org/10.1016/j.renene.2017.12.060
