Effect of primary and secondary alcohols as oxygenated additives on the performance and emission characteristics of diesel engine

The demand for renewable energy sources is gradually escalating due to the spontaneously growing population and global economic development. The access to fossil fuels is gradually declining due to the limited available reserves. Hence, renewable energy resources, technology choice, and energy policy are always being revised due to the modernization of society. Meanwhile, the liquid energy sources such as methyl ester from locally produced vegetable oils are readily accepted by many countries globally, although it is currently being blended (up to 20%) with diesel. Oxides of nitrogen are the most substantial emissions from diesel engines produced due to high combustion temperature. The addition of alcohol in the fuel reduces the NO_x formation since alcohols have high latent heat of evaporation. The present study's primary purpose is to investigate the effect of different alcohol types on engine performance and emission characteristics. For this purpose, seven test fuels and neat diesel were used. The test fuels P20 (20% palm biodiesel with 70% neat diesel and 10% alcohol on a volume basis), D₇₀P₂₀E₁₀, D₇₀P₂₀Pr₁₀, D₇₀P₂₀B₁₀, D₇₀P₂₀Pe₁₀, D₇₀P₂₀H₁₀ were prepared and tested on a single-cylinder, 4-stroke, DI-diesel engine at different speeds at 100 % load. The P20E10 ternary fuel blend illustrated the most practical combination of all the bioethanol-based blends, which considerably improves the BTE, BSFC and reduces NO_xformation at high speed compared to other types of alcoholic fuel blends. Also, the P20E10 fuel blend improved the cloud point of neat diesel.