Comparative Studies on Exhaust Emissions from a High Grade Low Heat Rejection Diesel Engine with Carbureted Alcohol and Crude Jatropha Oil

Investigations were carried out to study the exhaust emissions from high grade low heat rejection (LHR) diesel engine consisting of air gap insulated piston with 3-mm air gap with superni (an alloy of nickel) crown, air gap insulated liner with superni insert and ceramic coated cylinder head with normal temperature condition of crude jatropha oil and carbureted alcohol (ethanol / methanol) with varied injection timing and injection pressure and compared with methanol operation over ethanol operation and also with pure diesel operation on conventional engine (CE). Exhaust emissions of smoke and oxides of nitrogen (NOx) were recorded by AVL Smoke meter and Netel Chromatograph NOx analyzer respectively at different values of brake mean effective pressure (BMEP). Aldehydes were measured by dinitrophenyl hydrazine (DNPH) method at peak load operation of the engine. Smoke levels and NOx levels decreased by 47% 12% respectively with LHR engine at 27bTDC and at an injection pressure of 190 bar with methanol operation in comparison with pure diesel operation on CE.