Effect of amyl alcohol addition in a CI engine with Prosopis juliflora oil – an experimental study

Abstract

ABSTRACT This study aims to replace diesel with Prosopis Juliflora seed oil (JPO) in a compression ignition (CI) engine. The high viscosity of JPO promotes inferior performance and combustion. Brake thermal efficiency of JPO is 28.3%, which is less compared to 30.7% for diesel. This also leads to higher brake-specific energy consumption, HC, CO, and smoke emissions. JPO was converted to its biodiesel (Prosopis Juliflora methyl ester) (JPME) through the transesterification process. The physical properties were improved post-transesterification process. Brake thermal efficiency was improved to 29.3% for JPME. Higher NOx emission with reduced HC, CO, and smoke emissions was observed with JPME in comparison with JPO. The test engine employed for the investigations has a single-cylinder configuration with the maximum power of 5.2 kW enabled with water cooling. Furthermore, amyl alcohol was added with JPME in various proportions of 5%, 10%, 15%, and 20% by volume and experiments were conducted. The addition of amyl alcohol in the volume mentioned earlier has improved the thermal efficiency at higher loads; added to this NO and smoke emission were lowered simultaneously for all the loading conditions. Except with the 5% volume of amyl alcohol, HC and CO emissions have increased for all other volume compositions. JPME with 20% volume amyl alcohol exhibits the highest peak pressure and heat release rate. The brake thermal efficiency of JPME + A20 is on par with diesel. NO and smoke were reduced by 7% and 29%, respectively, for JPME + A20 in comparison with diesel. The study shows that the addition of 20% amyl alcohol with JPME has performance and emission characteristics similar to diesel. Further increase in amyl alcohol led to poor cold starting condition and may also lead to knocking. Hence, it was concluded to use only up to 20% of amyl alcohol to avoid any operational complications.