Investigation of diesel post injection using diesel/biodisel/methanol/DTBP: a path towards ultra-low smoke emissions and improved fuel economy.

Although post injection (PoI) mode is a prominent technique for attaining lower carbon-based emissions from diesel engines, it offers a disadvantage of higher fuel consumption. In this work, PoI mode was explored with a prime objective of improving fuel consumption while further improving the carbon-based emissions. B30 was considered as a base fuel and M10 blend was formed by adding 10% methanol into base fuel and was used under PoI mode to achieve ultra-low smoke emissions as methanol has highest oxygen content and lowest carbon content among all the alcohol fuels. The usage of methanol blended fuel under PoI mode caused difficulty of burning of PoI fuel due to increased octane number (ON) of the blend and reduced capability of PoI fuel in terms of oxidizing carbon-based emissions. In order to address this problem, 0.5% di-tert-butyl-peroxide (DTBP) which is a cetane booster was added into M10 forming B1 blend. The obtained results demonstrated that Run no. 5 with B1 blend reduced smoke, carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) emissions by 84.62%, 83.33%, 64.86% and 4.93% respectively compared to the single injection mode while improving the brake specific fuel consumption (BSFC) by 4.39%.