Researchers at Chonnam National University (S. Korea) have investigated the effect of diesel fuel blends with n-butanol (5%, 10%, and 20% by volume) on the individual hydrocarbons and particulate matter (PM) of a turbocharged common rail direct injection diesel engine and compared the results with those from using neat diesel fuel. The emission characteristics were estimated by using of n-butanol blended with conventional diesel fuel.
The team measured emissions of total hydrocarbons (HC) or individual HC, CO, NOx, PM and the non-regulated emission of formaldehyde, which were measured under three different engine loads (25.4, 52.9 and 78.4 N·m) and three different engine speeds (1500, 2000 and 2500 rpm).
The mass of PM for the fuel blended with 10% butanol was decreased by 31.1%. They found that more ethylene and benzene are emitted under low load condition; these amounts increase with increasing n-butanol blend ratio.
The fuels blended with more than 10% butanol produced higher non-regulated formaldehyde (HCHO) emission than the neat diesel fuel under lower engine load conditions. The particle numbers for particles smaller than 50 nm were higher for the fuel blended with 20% butanol in diesel fuel compared to the neat diesel fuel.
From TEM images, they found that a larger number of individual particles with a size of 10–30 nm were stacked on top of each other in a circular pattern.
Byungchul Choi, Xiaolong Jiang (2015) “Individual hydrocarbons and particulate matter emission from a turbocharged CRDI diesel engine fueled with n-butanol/diesel blends,” Fuel, Volume 154, Pages 188-195 doi: 10.1016/j.fuel.2015.03.084