Emission characteristics of compression ignition (CI) engine using diesel blended with hydrated butanol

The aim of this study was to investigate the emission characteristics of a single cylinder diesel engine using a blended fuel of diesel with hydrated butanol. The characteristics of the combustion and exhaust emissions of two blended fuels (diesel + n-butanol + water) were compared with the results of 100% diesel, according to the operating conditions of the engine. The blended fuels were DB10W2 (diesel + 10 wt% n-butanol + 2 wt% water) and DB10W5 (diesel + 10 wt% n-butanol + 5 wt% water). Four aldehydes (formaldehyde, acetaldehyde, acrolein, and propionaldehyde) and one ketone (acetone) were described mainly by high-performance liquid chromatography (HPLC) and sampled using 2,4-dinitrophenylhydrazine (2,4-DNPH). The engine operating conditions include two engine speeds, one fixed injection quantity, and four different injection timings. It was found that the blended fuel slightly increased the THC and CO with increase in the water content, relative to those with diesel fuel. NOX and PM were simultaneously decreased when blended fuels were used. The number of PM particles decreased by 81% and 67% when blended fuel (DB10W2 and DB10W5, respectively) was used. And use of blended fuels decreased the PM mass by about 89%. Carbonyl compounds increased when the lower exhaust temperature, shorter mixing time for air and fuel and increase of the water content in the blended fuel.