Effect of Gaseous Acetylene Addition on the Characteristics of a CI Engine at Modified Compression Ratios Fuelled with Biodiesel Blends

Abstract

Non-edible vegetable oil seeds and animal fats may be used to make biodiesel. Prosopis juliflora seed oil has the potential to serve as an alternate fuel source. They can be effectively transformed into alternative diesel fuel, lowering the need for crude oil imports. This research aims to develop alternative fuels to combat rising pollution levels and enhance air quality. This research examines the effects of adding acetylene to a dual fuel mode that runs on diesel and a biodiesel blend (B20) at different compression ratios on emissions, combustion and engine performance. The present study utilizes a single-cylinder, four-stroke engine with a variable compression ratio, 1500 rpm was employed to operate at a standard compression ratio (SCR) of 17.5 and a modified compression ratio (MCR) of 15.5, with a constant acetylene flow rate of 2 lpm for diesel and B20. Adding gaseous acetylene to diesel increased both cylinder pressure and heat release rates compared to pure gasoline operation. These resulted in an 11.2% shorter delay period and lower peak pressure than pure diesel operations. The dual fuel mode of C₂H₂ with B20 at a modified compression ratio resulted in a reduced maximum heat release rate and delayed occurrence. The engine's NOX, UBHC and CO emissions dropped by 22.4%, 49.6%, and 18% respectively, but smoke opacity increased considerably. Using C2H2 with B20 at a lower compression ratio reduces NOX emissions compared to diesel.