Emission Analysis of Water-Diesel-Butanol Blends on Engine Performance at Variable Loads

Abstract

This study investigates the impact of water-diesel-butanol (WDB) blends on exhaust emissions from diesel engines under varying loads (20%, 35%, and 50%) and engine speeds. Five fuel types were tested: pure diesel (D), water-diesel emulsion (W5D), and WDB blend with 5%, 10%, and 15% butanol (W5DBu5, W5DBu10, W5DBu15). The results revealed that at 20% load, NOx emissions from pure diesel reached the highest average value of 435 ppm, approximately 39% higher than the WDB blends. W5DBu15 recorded the lowest NOx emissions across all load levels due to lower combustion temperature and higher latent heat of vaporization. CO emissions remained below 5% for all fuel types but were consistently lower for WDB blends. At 50% load and 3000 rpm, W5DBu15 showed the lowest CO emission, around 2.1%, compared to 3.6% for pure diesel. Interestingly, CO₂ emissions increased with higher butanol content, with W5DBu15 showing the highest CO₂ emission of 262.5% more than pure diesel at 20% load and 3000 rpm, indicating more complete combustion. These findings suggest that using WDB blends, particularly with higher butanol concentrations, can significantly reduce NOx and CO emissions while improving combustion efficiency. This demonstrates the promising potential of WDB fuels as cleaner alternatives for sustainable diesel engine operations.