Performance and emissions optimization of a dual-fuel diesel engine powered by cashew nut shell oil biodiesel/hydrogen gas using response surface methodology

• Published in: Fuel (Guildford) 2025-03, Vol.384, p.133960, Article 133960
• Main Authors: Lionus Leo, G.M., Jayabal, Ravikumar, Kathapillai, Arun, Sekar, S.
• Format: Article
• Language: English
• Subjects: Biodiesel; Dual fuel; Emissions; Hydrogen; Optimization
• ISSN: 0016-2361
• DOI: 10.1016/j.fuel.2024.133960

[Display omitted] •CNSO biodiesel reduced BTE and reduced CO emissions.•Hydrogen addition improved combustion efficiency and increased BTE.•CO and HC emissions were reduced by addition of hydrogen fumigation.•Adding hydrogen into the biodiesel increased NOx emissions.•RSM method showed a 3 % error, with 5.22 g/kWh CO2 and 12.68 g/kWh NOx emissions. This study investigates the optimization of a dual-fuel diesel engine powered by Cashew Nut Shell Oil (CNSO) biodiesel and hydrogen (H2) using Response Surface Methodology (RSM). The objective is to enhance engine performance while minimizing emissions. Investigations were performed on a single-cylinder diesel engine powered by diesel, CNSO biodiesel and CNSO biodiesel blend (50CNSO50D) without and with H2 fumigation at flow rates of 3 and 6 L per minute (LPM) at varying engine loads (0 % to 100 %). The research findings demonstrated that introducing H2 resulted in a 4.2 % increase in BTE for CNSO biodiesel and a 4.4 % increase for a 50CNSO50D blend, with BTE improving from 31.1 % to 35.5 % for pure diesel. The peak in-cylinder pressure increased by 8.56 % for diesel and 3.25 % for CNSO biodiesel at full load. The heat release rate (HRR) increased by 32.4 % for diesel and 26.13 % for CNSO biodiesel. Emissions analysis showed a reduction in carbon monoxide (CO) by 5.6 %, hydrocarbon (HC) by 22.2 %, and carbon dioxide (CO2) by 7 %, while nitrogen oxide (NOx) emissions increased by 6.7 %. The optimal fuel configuration was achieved at a 50CNSO50D blend, 6 LPM H2 flow, and 80 % engine load. BTE improved by 4.4 %, CO emissions reduced by 5.6 %, HC emissions decreased by 22.2 %, and CO2 emissions dropped by 7 %. The RSM models were validated with an accuracy of within 3 %. This research demonstrates the potential of CNSO biodiesel and hydrogen as a sustainable fuel alternative for diesel engines.