Effect of n-Butanol Concentration on Combustion and Emission Phenomenon using Higher Blends of Cotton Seed Biodiesel in a Direct Injection CI Engine

Abstract

This paper experimentally investigates the effect of cottonseed biodiesel at higher blend ratios with mineral diesel on the combustion aspects of a direct injection CI engine. The effect of n -butanol concentration at higher blend ratios were also analysed at all loading conditions. CBD was synthesized by base catalysed trans-esterification with methanol and KOH as catalyst with the molar ratio of 8:1. GCMS analysis exposed the presence of Octadecanoic acid methyl ester as major constituent. D50CBD50 (mineral diesel 50% and CBD 50%) a higher blend test fuel was used with D100 as base reference fuel. The experiments were carried out at constant speed of 1500 rpm and the result indicated higher in-cylinder pressure for D50CBD50 n B10 at all loads. At low and part load, the rate of heat release was higher for D50CBD50 whereas, for D50CBD50 n B20 it increased significantly at full load condition. The peak of D50CBD50nB10 was found to exhibit higher ROPR across all loading conditions. CHR of D100 was found to be highest at full load condition whereas D50CBD50 n B20, exhibited peak values at part load condition. The ignition delay showed a decreasing trend across all fuel blends with biodiesel blends and it was lower than diesel. Emission analysis showcased a notable decrease in UBHC and CO emission with a significant increase in NO x , CO 2 and Smoke emission. Among all the test fuels, D50CBD50 n B10 exhibited better combustion phenomenon with reduced emission characteristics.