Impact of Diesel-butanol Blends on Performance and Emission of Diesel Engine

Abstract

The aim of lowering the pollutants and to enhance the performance of diesel engines has intensified research in diesel engines. The goal of this study was to assess combustion, performance and emission characteristics of diesel engine using diesel-oxygenate blends. In this direction, experimental investigations were carried out on a single cylinder four stroke direct injection water cooled diesel engine using butanol blended fuels in different volume ratios with diesel fuel. The butanol had no solubility or stability problems when blended with diesel fuel. As there was not phase separation in the blends, no additive was added. The experimental investigation was done with four different blends of butanol on volume basis [B0 (0% Butanol and 100% Diesel), B5 (5% Butanol and 95% Diesel), B10 (10% Butanol and 90% Diesel), B15 (15% Butanol and 85% Diesel) and B20 (20% Butanol and 80% Diesel)] to study the impact of using butanol -diesel blends on diesel engine performance, combustion and emissions. The outcome indicates that the brake thermal efficiency increased with an increase in butanol contents in the blended fuels at overall operating conditions. At higher loads, reduced CO emission levels were observed for blends of butanol. HC emissions increased for all blends of butanol compared with diesel fuel due to high fuel consumption and high latent heat of vaporization which lowers cylinder temperatures and causes the emission of unburned hydrocarbons at lower load. NOx emissions with diesel–butanol blends were found to be comparable with neat diesel at low loads due to lower calorific value and high latent heat of vaporization of butanol results in reduced flame temperature and slightly higher NOx at high loads with increased butanol percentage in the blend compared to neat diesel. Butanol showed lowest smoke opacity at high engine loads compared to diesel fuel operation.