Experimental investigation of a novel quaternary blend for CRDI engine: performance, emission, and combustion characteristics

Abstract

ABSTRACT The shortage-inflation of fossil fuels and aggravation of pollution intensity have initiated the search for innovative biofuel blends. Binary and Ternary fuels are studied for a long time. The use of biodiesel/vegetable oil up to 5–20% can replace fossil fuel with little modification in engine. However, to replace fossil fuel dependence up to 30–40% with little or no modification in engines is a challenge to researcher. This can be approached to evaluate a novel biofuel mix pattern called optimum Quaternary Blend by the experimental investigation. The main objective of the present research is to replace conventional Diesel with biofuels 30–40% with innovative fuel mix and lesser NOx-soot emission. In view of this, experimentally investigated combustion, emission, and performance behavior of single cylinder Common Rail Direct Injection (CRDI) engine fueled by quaternary blends combination of diesel (60–70 vol %), vegetable oil (Cotton Seed Oil – 5 vol% fixed), biodiesel (Mahua Biodiesel 5–25 vol %), and bio-alcohol (n-butanol 10–25 vol %). Further, to compare engine characteristics with D100% and D50B50%. Engine performance measures like brake thermal efficiency, specific energy consumption, emissions, and combustion characteristics such as rate of pressure rise (RPRR), combustion duration, CA50, CA90, mean gas temperature, combustion-chamber pressure, and net heat release rate are studied. It is noted that Diesel 60%, cotton seed oil 5% with mahua biodiesel 15–20%, and n-butanol 20–15% showed superior quaternary blend among all fuels. This optimum quaternary blend QB3-QB4 showed relatively higher brake thermal efficiency 8% more at lower specific energy consumption 10 MJ/kg about 29% less compared to other blends. Also, controlled combustion with rate of pressure rise 8.6 bar/deg CA about 14% less compared to other fuels. The NOx 10% less and smoke 2% less reported by optimum quaternary blends QB3 compared to other blends. However, CO emissions are noted least with marginal penalty in HC emissions.