Effect of diesel and propanol blends on regulated pollutants and polycyclic aromatic hydrocarbons under lean combustion conditions

Abstract

AbstractAlcohols such as n‐propanol and diesel fuel can be mixed to increase the rate of bioalcohol utilization while reducing harmful pollutants. Examination of exhaust emissions from diesel engines, in terms of both regulated pollutants and unregulated polycyclic aromatic hydrocarbons (PAHs), is very important to the environment, public health, and engine durability. For this purpose, in this study, diesel blends with various n‐propanol concentrations (5%, 20%, and 35% by volume) were evaluated in a diesel engine. Regulated emissions were measured using a standard 5‐gas analyzer and polycyclic aromatic hydrocarbons were detected and quantified using gas chromatography–mass spectrometry (GC–MS). The effect of blended fuels on PAH formation (total PAHs, PAH distribution, and PAH toxicity) was examined in detail and compared with baseline diesel. Nitrogen oxide (NOx) emissions were reduced by 18.30% with higher n‐propanol concentrations. The addition of n‐propanol to diesel decreased total PAHs by as much as 71.20%. The fuel blend with a 20% n‐propanol concentration stood out with a maximum reduction of 91.23% in the toxicity of PAHs. In addition, n‐propanol led to a substantial decrease in the distribution of high ring aromatic compounds. Overall, it was demonstrated that n‐propanol is an effective additive to not only reduce the total PAH emissions and toxicity but also heavier PAHs which are more carcinogenic and cause a greater risk of the wetstacking issues for engines under cold operating or low load conditions.