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Effect of Oxy-hydrogen Enrichment into Water-in-Biodiesel Emulsion Towards Performance and Exhaust Emissions of a Diesel Engine

Frendy Rian Saputro(1), Ahmad Muhsin Ithnin(2), Mohd Fareez Edzuan Abdullah(3), Chungpyo Hong(4), Takeshi Ohtaka(5), Aluyah Sipi(6), Wira Jazair Yahya(7),


(1) Universiti Teknologi Malaysia
(2) Universiti Teknologi Malaysia
(3) Heriot-Watt University Malaysia
(4) Kagoshima University
(5) Kagoshima University
(6) Universiti Teknologi Malaysia
(7) Universiti Teknologi Malaysia
Corresponding Author

Abstract


This study aims to evaluate the combined effect of water-in-biodiesel emulsions (WBE) and oxy-hydrogen (HHO) enrichment on diesel engine performance and emissions. Experiments were conducted on a single-cylinder diesel engine fueled with B35 (35% biodiesel–65% diesel), WBE5 (5% water-in-biodiesel emulsion), and their HHO-enriched blends under 1–4 kW loads. Engine performance was assessed through brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), and exhaust gas temperature (EGT), while emissions of NOx, CO, and CO₂ were measured. Results show that WBE5 reduced NOx emissions by up to 30.2% compared with B35 and improved BSFC by 6.2% and BTE by 8.4% at 2–3 kW loads. However, CO emissions increased by about 18% due to lower combustion temperatures. HHO enrichment improved BSFC and BTE at light loads (1–2 kW) by up to 2% and decreased CO emissions through enhanced oxidation, but its influence on NOx was minimal and diminished at higher loads. Overall, WBE–HHO dual-fuel operation provides partial advantages, particularly under light-to-medium loads, offering a feasible pathway toward cleaner and more efficient diesel engine operation without major modifications.

Keywords


Biodiesel–water emulsion; Brake thermal efficiency; Diesel engine performance; Exhaust emissions; Oxy-hydrogen enrichment

References


Ahmad, M. A., Yahya, W. J., Ithnin, A. M., Hasannuddin, A. K., Bakar, M. A. A., Fatah, A. Y. A., Sidik, N. A. C., and Noge, H. (2018). Combustion performance and exhaust emissions fuelled with non-surfactant water-in-diesel emulsion fuel made from different water sources. Environmental Science and Pollution Research, 25(24), 24266-24280.

Elsanusi, O. A., Roy, M. M., and Sidhu, M. S. (2017). Experimental investigation on a diesel engine fueled by diesel-biodiesel blends and their emulsions at various engine operating conditions. Applied Energy, 203, 582–593.

El-Shafay, A. S., Ağbulut, Ü., Shanmugan, S., and Gad, M. S. (2025). Production of oxy-hydrogen with an alkaline electrolyzer, and its impacts on engine behaviors fuelled with diesel/waste fish biodiesel mixtures supported by graphene nanoparticles. Energy, 314, 133934.

Hamasaki, K., Kinoshita, E., and Matsuo, Y. (2002). Utilization of palm oil for diesel fuel. Transactions of the Japan Society of Mechanical Engineers, Series B, 68(667), 958–963.

Ithnin, A. M., Ahmad, M. A., Bakar, M. A. A., Rajoo, S., and Yahya, W. J. (2015). Combustion performance and emission analysis of diesel engine fuelled with water-in-diesel emulsion fuel made from low-grade diesel fuel. Energy Conversion and Management, 90, 375-382.

Ithnin, A. M., Yahya, W. J., Ahmad, M. A., Ramlan, N. A., Kadir, H. A., Sidik, N. A. C., and Koga, T. (2018). Emulsifier-free Water-in-Diesel emulsion fuel: Its stability behaviour, engine performance and exhaust emission. Fuel, 215, 454-462.

Jazair, W., Harada, T., Kubo, S., Kidoguchi, Y., and Miwa, K. (2007). Improvement of emissions in a DI diesel engine fuelled by biodiesel fuel and waste cooking oil. SAE Technical Paper 2007-01-2029.

Kapadia, H., Brahmbhatt, H., Dabhi, Y., and Chourasia, S. (2019). Investigation of emulsion and effect on emission in CI engine by using diesel and biodiesel fuel: A review. Egyptian Journal of Petroleum, 28(4), 323–337.

Mahdi, W. N. I. W., Ithnin, A. M., Yahya, W. J., Sugeng, D. A., Saputro, F. R., and Rashid, M. A. A. (2025). A comparative review of alternative fuels: Diesel-HHO and diesel-hydrogen via enrichment method in diesel engines application. International Journal of Hydrogen Energy, 120, 444-472.

Masjuki, H. H., Ruhul, A. M., Mustafi, N. N., Kalam, M. A., Arbab, M. I., and Fattah, I. R. (2016). Study of production optimization and effect of hydroxyl gas on a CI engine performance and emission fueled with biodiesel blends. International Journal of Hydrogen Energy, 41(33), 14519-14528.

Mofijur, M., Masjuki, H. H., Kalam, M. A., and Atabani, A. E. (2013). Evaluation of biodiesel blending, engine performance and emissions characteristics of Jatropha curcas methyl ester: Malaysian perspective. Energy, 55, 879-887.

Paparao, J., and Murugan, S. (2022). Dual-fuel diesel engine run with injected pilot biodiesel–diesel fuel blend with inducted oxy-hydrogen (HHO) gas. International Journal of Hydrogen Energy, 47(40), 17788–17807.

Rao, S. S., Paparao, J., Raju, M. V. J., and Kumar, S. (2024). Effect of nanoparticle-doped biofuel in a dual-fuel diesel engine with oxy-hydrogen gas. International Journal of Hydrogen Energy, 70, 146-158.

Reham, S. S., Masjuki, H. H., Kalam, M. A., Shancita, I., Fattah, I. R., and Ruhul, A. M. (2015). Study on stability, fuel properties, engine combustion, performance and emission characteristics of biofuel emulsion. Renewable and Sustainable Energy Reviews, 52, 1566-1579.

Sahoo, P. K., Das, L. M., Babu, M. K. G., Arora, P., Singh, V. P., Kumar, N. R., and Varyani, T. S. (2009). Comparative evaluation of performance and emission characteristics of jatropha, karanja and polanga based biodiesel as fuel in a tractor engine. Fuel, 88(9), 1698-1707.

Saputro, F. R., Ithnin, A. M., Sugeng, D. A., Mahdi, W. N. I. W., Yahya, W. J., Prabowo, W., Anggoro, T., and Rosyadi, E. (2025). Effects of oxyhydrogen enrichment on diesel engine performance and emissions using B35 and its water-in-biodiesel emulsion. International Journal of Hydrogen Energy, 142, 109-121.

Subramanian, B., and Thangavel, V. (2020). Experimental investigations on performance, emission and combustion characteristics of Diesel-Hydrogen and Diesel-HHO gas in a Dual fuel CI engine. International journal of hydrogen energy, 45(46), 25479-25492.

Sugeng, D. A., Ithnin, A. M., Yahya, W. J., and Kadir, H. A. (2020). Emulsifier-free water-in-biodiesel emulsion fuel via steam emulsification: Its physical properties, combustion performance, and exhaust emission. Energies, 13(20), 5406.

Tamam, M. Q. M., Yahya, W. J., Abdul Rahman, H., Ithnin, A. M., Abd Kadir, H., Rahman, M. M., Ithnin, A, M., Kadir, H. A., Rahman, M., Noge, H., Koga, T., and Sugeng, D. A. (2025). Application of an inline mixer to produce surfactant-free biodiesel-diesel/water emulsion fuel: An analysis of water droplets characteristics and drive cycle emissions. Arabian Journal for Science and Engineering, 50(12), 9261-9274..

Vellaiyan, S. (2023). Recent advancements in water emulsion fuel to explore efficient and cleaner production from various biodiesels: A retrospective review. Renewable and Sustainable Energy Reviews, 187, 113704.


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