Performance Investigation of Spark Ignition Engines (SIE) using Biofuel Blended with N-Propanol Fuel Additive

Abstract

This experiment studies the suitability of n-propanol in biofuel for the performance improvement of the Spark Ignition Engine (SIE). Literature reported performance limitations of SIE with Ethanol-Gasoline (EG) blends. N-propanol can be an additive due to its good calorific value and non-separating properties. Various blends such as EG, Propanol-Gasoline (PG), and Propanol-Ethanol-Gasoline (PEG) were tested to assert their best potential in an SIE. Experimentation was conducted on a 4-stroke petrol test engine running at 2800 rpm with low fuel blend concentrations and varying Compression Ratio (CR) to investigate its effects on the performance of SIE. Increasing CR improved PEG-fueled engine performance more than gasoline-fueled engines, such as Brake Thermal Efficiency (BTE) and Brake Specific Fuel Consumption (BSFC), and decreased emissions like Carbon Dioxides (CO2), Carbon Monoxide (CO), and Unburnt Hydrocarbons (HCs). The performance of SIE mainly compared E10 (10% ethanol in gasoline) and E10Pr1.5 (10% ethanol and 1.5% propanol in gasoline) biofuels at different CRs. As compared to E10, E10Pr1.5 reported an increase in BTE from 0.43-0.83%, a significant decrease in BSFC from 0.05-0.37%, a reduction in CO emission from 6.85-9.78%, and a decline in HCs emission from 2.16-3.69%, at different CRs (4.67-7.5) respectively. Results show that a 1.5% addition of propanol in E10 biofuel improves the performance of SIE compared to pure gasoline and EG blend with 10% ethanol in gasoline. E10Pr1.5 shows the highest BTE, lowest BSFC, and lowest emissions of CO and HCs for different CRs. Propanol can be used as a fuel additive in the EG biofuel.