An Experimental Investigation on the Combined Effect of Exhaust Gas Recirculation and Cetane Improver on Biodiesel-fueled Diesel Engine

Abstract

Diesel-biodiesel blends increase Nitrogen Oxides (NO_x) emission of engine exhaust. Exhaust Gas Recirculation (EGR) is an effective way of reducing the NO_x emissions. Cetane improvers on the other hand reduce the ignition delay, which in turn reduces the combustion temperatures as a result of which NO_x emissions decrease. A combination of EGR and the cetane improver Di Tertiary Butyl Peroxide (DTBP) is taken up in the present work to investigate experimentally the performance and emissions on a four stroke single cylinder direct injection diesel engine. DTBP is added such as 0.5% and 1% by volume (B30D0.5 and B30D1) to diesel-biodiesel blend B30 (30% by volume of biodiesel). EGR rate is varied from 0 % to 20% (0%, 10%, and 20%). The combined effect of EGR and cetane improver on Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), cylinder pressure and exhaust emissions like Carbon Monoxide (CO), Hydro Carbon (HC), NO_x and smoke opacity is studied. From experimental results it is found that BTE and BSFC increase with both EGR and DTBP while the exhaust gas temperature decreases. It is also found that NO_x decreases significantly while CO, HC and smoke opacity increase slightly with increase in EGR percentage. However at a particular EGR, CO and HC emissions are low for blends with DTBP than that of pure diesel.