Engine Performance and Emission Analysis of an IDI-Diesel Engine with Rice Bran Methyl Ester and Isopropanol Injection at Suction End

Abstract

The tail pipe emissions of petroleum diesel engines are considerably higher. In view of mandatory instructions from international pollution control board, the tail pipe emissions of the engines of automobiles should come down to lower levels. To comply with the pollution norms, the engines should use alternative fuels like biodiesel fuel and alcohols which have the capability to reduce the emissions from the engine. The choice of biodiesel is also a criterion to replace the petro diesel with the suggested one. In this present context the IDI engine is tested with the conventional petro-diesel and biodiesel along with biodiesel and several additive compositions. The additive used is Isopropanol (C3 H8 O) in various percentages viz. 2%, 3%, 4% and 5% of Isopropyl alcohol (additive) is injected calculated with reference to 1litre/hr. biodiesel and RBME is injected through the regular nozzle in a dual fuel mode. Isopropanol is injected into the air inlet at 3bar  without suffering the volumetric efficiency. The main idea in introducing the additive is to dilute the combustion and thereby to reduce the combustion temperatures to limit the NOx formation. Higher latent of isopropanol and volatility of the additive has its effect in reducing the combustion temperatures. From the investigation conducted 2% additive by volume has yielded encouraging results. Results envisage reduction of 2.63%&3.12% at full load and proximate part load with respect to neat biodiesel.4.3%& 4.9% hike in thermal efficiency at maximum load  w.r.t diesel &biodiesel,4.8% &5.7% at part load  as mentioned above is observed with the designated isopropanol percentage. HC reduction is observed as 5ppm at maximum load w.r.t diesel fuel.CO reduction is nearly 14% w.r.t diesel at maximum load. CO2 has increased by 7.6% with respect to neat diesel. There is a reduction of 36.5% of NO with respect to diesel fuel. Reduction of 27.5 HSU is observed at Maximum load w.r.t diesel, even though, there is an increase in the smoke w.r.t biodiesel.

Abbreviations: HC- Hydrocarbon, CO-Carbon monoxide,  CO2-Carbondioxide,NO- Nitric Oxide, HSU- Hatridge smoke Units, RBME-Rice bran methyl ester, IP-Isopropanol.