Abstract
The principal objective of this research is to employ modern machine learning techniques to optimize high-pressure biofuel injection strategies for sustainable energy applications. An engine powered with biofuel and hydrogen (H₂) under dual-fuel (DF) mode was tested under a varied fuel injection pressure range from 180 to 240 bar for optimization and modeling. The results demonstrate that an injection pressure of 220 bar produces enhanced engine performance. At this pressure, enhancements were noted in combustion characteristics, efficiency, and emission levels. The ignition delay (ID) at 220 bar injection pressure was 9.4% longer than at 240 bar injection pressure. The 220 bar IP mix demonstrated reduced peak cylinder pressure (PCP) and heat release rate (HRR) compared to the 240 bar. A 12.4% rise in brake-specific fuel consumption (BSFC) was observed at 220 bar inlet pressure. Nevertheless, although brake thermal efficiency (BTE) increased with increasing injection pressure (IP), the increase at 220 bar was somewhat less than that at 240 bar. Despite elevated nitrogen oxide (NOx) emissions with the 220 bars compared to pure diesel, carbon monoxide (CO) and hydrocarbon (HC) emissions were markedly decreased. Smoke emissions were reduced with the 220 bars in comparison to diesel and other fuel combinations. Three machine learning models were employed to establish a predictive control framework. The decision tree (DT) model had the greatest accuracy, with R² values of 0.9792 for PCP and 0.9710 for HC, alongside near-zero MAPE for BTE and HC This study underscores the potential of AI-driven biofuel optimization for fostering sustainable transportation and renewable fuel strategies, paving the way for large-scale adoption of low-carbon, high-efficiency energy solutions.
Data availability
The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.
Abbreviations
- H2 :
-
Hydrogen
- DF:
-
Dual-fuel
- IP:
-
Injection pressure
- ID:
-
Ignition delay
- PCP:
-
Peak cylinder pressure
- HRR:
-
Heat release rate
- BSFC:
-
Brake-specific fuel consumption
- BTE:
-
Brake thermal efficiency
- EGT:
-
Exhaust gas temperature
- NOx:
-
Nitrogen oxides
- CO:
-
Carbon monoxide
- DT:
-
Decision tree
- R2 :
-
Coefficient of determination
- MAPE:
-
Mean absolute percentage error
- Wi:
-
Wilmott’s index
- LR:
-
Linear regression
- RF:
-
Random forest
- bTDC:
-
Before top dead center
- DI CI:
-
Direct injection compression ignition
- CRDi:
-
Common rail direct injection
- IMEP:
-
Indicated mean effective pressure
- ML:
-
Machine learning
- CV:
-
Calorific value
- ARCNP:
-
Advanced renewable catalytic nano particles
- DTBP:
-
Di-tert-butyl peroxide
- ASTM:
-
American Society for Testing and Materials
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Funding
Open access funding provided by Budapest University of Technology and Economics. The authors sincerely thank the Karpagam Academy of Higher Education (KAHE), Coimbatore, India, for providing facilities to carry out the research to complete the present study. This project has received funding from the Research Council of Lithuania (LMTLT), agreement No S-PD-24-180.
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S.A., D.B., P.P., D.B., K.U., and A.K. wrote the main manuscript text. All authors reviewed the manuscript.
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Aravind, S., Barik, D., Paramasivam, P. et al. AI based optimization of injection pressure for hydrogen and spirogyra biodiesel dual fuel engine to enhance combustion performance and emission characteristics. Sci Rep (2026). https://doi.org/10.1038/s41598-025-34179-w
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DOI: https://doi.org/10.1038/s41598-025-34179-w