Evaluation of performance, combustion and emission characteristics of blends of soybean biodiesel in a single cylinder diesel engine: An experimental approach

Authors

  • Rupesh Lal Karn Department of Mechanical Engineering, Prairie View A&M University, Prairie View, Texas, 77446, USA
  • Shahil Sharma Department of Automobile and Mechanical Engineering, Thapathali Campus, Institute of Engineering, Tribhuvan University, Kathmandu, Nepal
  • Lasata Maharjan Department of Automobile and Mechanical Engineering, Thapathali Campus, Institute of Engineering, Tribhuvan University, Kathmandu, Nepal
  • Gagin Bajagain Department of Automobile and Mechanical Engineering, Thapathali Campus, Institute of Engineering, Tribhuvan University, Kathmandu, Nepal
  • Samjhana Jyakhwo Department of Automobile and Mechanical Engineering, Thapathali Campus, Institute of Engineering, Tribhuvan University, Kathmandu, Nepal
  • Sushila Subedi Department of Automobile and Mechanical Engineering, Thapathali Campus, Institute of Engineering, Tribhuvan University, Kathmandu, Nepal
  • Laxman Palikhel Department of Automobile and Mechanical Engineering, Thapathali Campus, Institute of Engineering, Tribhuvan University, Kathmandu, Nepal

DOI:

https://doi.org/10.70530/kuset.v19i3.690

Keywords:

Soybean biodiesel, Methyl ester blends, Diesel engine performance, Combustion characteristics, Emission reduction

Abstract

This experimental study evaluates the performance, combustion, and emission characteristics of soybean biodiesel blends (10–40% v/v) in a single-cylinder diesel engine. Soybean methyl ester (SME) was produced via single-stage alkaline transesterification due to low free fatty acid content (<2%). Tests were conducted on a variable compression ratio engine (17:1, 1500 rpm) at varying brake power loads. GC-MS analysis confirms a fatty acid methyl ester (FAME) profile dominated by methyl linoleate (48.42%) and methyl oleate (32.35%). Engine testing revealed that B30 optimized performance parameters, increasing brake thermal efficiency by 11.94% and reducing brake-specific fuel consumption by 5.41% relative to diesel. Emission analysis demonstrated that B20 achieved maximal reductions: CO$_2$ (3.5%), NO (19.2 %), HC (18.97 %), and NO$_x$ (18.93 %). Combustion characteristics showed marginal decreases in peak cylinder pressure (≤3.5%) and net heat release (≤6.18%) for most blends, attributable to SME’s lower calorific value (33.54–41.66 MJ/kg vs. 42.5 MJ/kg for B0). The study establishes B20–B30 blends as optimal for balancing engine efficiency with emission mitigation, affirming soybean biodiesel’s viability in conventional diesel engines without modification.

Published

2025-12-31

How to Cite

Karn, R. L. ., Sharma, S. ., Maharjan, L. ., Bajagain, G. ., Jyakhwo, S. ., Subedi, S., & Palikhel, L. . (2025). Evaluation of performance, combustion and emission characteristics of blends of soybean biodiesel in a single cylinder diesel engine: An experimental approach. Kathmandu University Journal of Science Engineering and Technology, 19(3). https://doi.org/10.70530/kuset.v19i3.690

Issue

Vol. 19 No. 3 (2025): Kathmandu University Journal of Science, Engineering and Technology

Section

Original Research Articles
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