Optimization of Flue Gas Energy Exploitation via Organic Rankine Cycle System at Bangkanai Gas Engine Power Plant
DOI:
https://doi.org/10.32497/eksergi.v22i03.7943Keywords:
Organic Rankine Cycle, waste heat recovery, PLTMG, flue gas, thermal efficiency, emissions, Thermodynamics, MATLAB-CoolPropAbstract
Bangkanai Gas Engine Power Plant exhibits a substantial waste heat potential within its exhaust gas, with manifold temperatures post-turbocharger ranging from 386.40 °C to 515.00 °C. Currently, this high temperature thermal energy is underutilized. This study aims to evaluate the technical and financial feasibility of integrating an Organic Rankine Cycle (ORC) bottoming system into the exhaust stack of PLTMG Bangkanai. A dynamic computational model was constructed using the MATLAB R2023a-CoolProp platform. The thermodunamic property pf the mixed flue gas – characterized bt a molecular weight of 28.164 g/mol – were dynamically tarcked across a 24 – hour daily cycle utilizing the JANAF/NIST Shomate Polynomial functions. The simulation evaluated four working fluids (R245fa, Toluene, Benzene, R1233zd(E)) across three optimization scenarios, constrained by an acid dew point stack safety limit (≥ 160.00 °C). The results reveal that R1233zd(E) yields the most superior performance, maintaining an absolute dry vapor phase at the turbine outlet ( ) and completely eliminating turbine blade cavitation risks. The integrated ORC system successfully harvested a peak net clean power output 6,152.40 kW. This addition elevated the overall system thermal efficiency from 38.50 % to 42.10 % and reduced the Specific Gas Comsumption (SGC) by 3.66%. Eviromental assessment utilizing the Higher-Tier Tier 3 IPCC direct stoichiometry approach indicates a greenhouse gas mitigation potential of 1,382.328 Tons of per year. Financial feasibility analysis was conducted over a 20-year Power Purchase Anreement (PPA) horizon, calibrated with a 10.00% Cost Of Capital (CoC) and a flat exchange rate of Rp17,500/USD. The initial Capital Expenditure (CapEx) allocation of Rp236.87 Billion is economically viable, generating a positive Net Present Value (NPV) of +Rp49.72 Billion, an Internal Rate of Return (IRR) of 14.52%, a Benefit-Cost Ratio (B/C) of 1.177, and a Payback Period (PBP) of 8.2 years
References
[1] Sansuadi and N. Mazidah, “Statistik Ketenagalistrikan 2024 (Edisi No. 38),” Jakarta, 2024. [Online]. Available: https://gatrik.esdm.go.id/assets/uploads/download_index/files/91fa8-buku-statistik-ketenagalistrikan-2024.pdf
[2] Direktorat Jenderal Ketenagalistrikan, “RENCANA USAHA PENYEDIAAN TENAGA LISTRIK (RUPTL) 2025 - 2024,” 2025. [Online]. Available: https://gatrik.esdm.go.id/assets/uploads/download_index/files/b967d-ruptl-pln-2025-2034-pub-.pdf
[3] M. A. Sidqi, A. Makkulau, and M. Rizal Oktavian, “Kontibusi Percepatan Net Zero Emission Dengan Pendekatan Strategis Peningkatan Efisiensi Pengelolaan Pembangkit Listrik Melalui Keunggulan Operasional,” ENERGI & KELISTRIKAN, vol. 16, no. 1, pp. 12–20, Sep. 2024, doi: 10.33322/energi.v16i1.2517.
[4] PT PLN (Persero) Pusat Sertifikasi, “Laporan Pengujian No. LKIT/0484/10121235/2025: Pengujian Heat Rate dan DMN PLTMG Bangkanai Engine 5 & 11,” Jakarta, Dec. 2025.
[5] A. Mahmoudi, M. Fazli, and M. R. Morad, “A recent review of waste heat recovery by Organic Rankine Cycle,” Appl. Therm. Eng., vol. 143, pp. 660–675, Oct. 2018, doi: 10.1016/j.applthermaleng.2018.07.136.
[6] I. Salhi, F. ezzahra Sadni, F. Belhora, and A. Hajjaji, “Thermodynamic Analysis of Basic and Regenerative Organic Rankine Cycle Configurations Using Six Working Fluids: A Parametric Study With CoolProp in MATLAB,” Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy, vol. 1, no. 4, Jul. 2025, doi: 10.1115/1.4067544.
[7] PT PLN (Persero) Unit Induk Penyaluran dan Pusat Pengatur Beban Kalimantan, “Evaluasi Operasi Tahunan Sistem Tenaga Listrik (EOT 2025),” 2026.
[8] Wärtsilä Energy, “Wärtsilä 34SG gas engine for power plants,” 2023.
[9] Y. A. . Çengel, M. A. . Boles, and Mehmet. Kanoğlu, Thermodynamics : an engineering approach. McGraw-Hill Education, 2019.
[10] John. Heywood, Internal Combustion Engine Fundamentals 2E. McGraw-Hill Education, 2019.
[11] T. F. Bertrand, G. Papadakis, G. Lambrinos, and A. Frangoudakis, “387-Criteria for working fluids selection in low-temperature solar organic Rankine cycles.”
[12] IPCC, “2006 IPCC Guidelines for National Greenhouse Gas Inventories, Volume 2: Energy,” Geneva, Switzerland: Intergovernmental Panel on Climate Change, 2006. Accessed: Aug. 05, 2026. [Online]. Available: iges.or.jp
[13] S. Quoilin, M. Van Den Broek, S. Declaye, P. Dewallef, and V. Lemort, “Techno-economic survey of organic rankine cycle (ORC) systems,” 2013. doi: 10.1016/j.rser.2013.01.028. [24] E. Tayyeban and M. Deymi-Dashtebayaz, “Optimizing an expansion engine-based organic rankine cycle system for heat recovery from natural gas engines,” Energy Convers. Manag., vol. 343, Nov. 2025, doi: 10.1016/j.enconman.2025.120209.
[14] L. T. . Blank and A. J. . Tarquin, Engineering economy. McGraw-Hill Education, 2018.
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