One alternative to fossil fuels is the use of bioethanol in internal combustion
engines. However, the application of this renewable fuel in compression-ignition
engines is limited due to its low cetane number. This barrier, however, can be
overcome by using additives that enhance this property. Consequently, additized
ethanol emerges as a promising option with significant potential for
decarbonization and improved combustion efficiency. In this context, the present
study numerically investigated, using the CONVERGE CFD software, the use of
additized ethanol in a compression-ignition internal combustion engine used in
marine transportation. As a comparative baseline for each investigated setup,
cases involving conventional diesel fuel were also analyzed numerically. The
reaction mechanisms used for modeling the combustion of both additized ethanol
and conventional diesel were validated against experimental data available in
the literature. Di-tert-butyl peroxide (DTBP) was the studied cetane improver
used in this study, blended with ethanol at weight fractions equal to 0%, 5% and
10%. In addition to the additive content in ethanol, the study also evaluated,
through a sensitivity analysis, the impact of fuel injection strategies,
including variations in injection timing (from 6 to 0 degrees before top dead
center) and engine load levels (25%, 50%, 75%, and 100%). Key combustion,
performance, and emission parameters were analyzed, including ignition delay,
heat release rate, thermal and combustion efficiency, and emissions of CO₂, CO,
NOX, CH4 and CO2eq. The results indicate
that additized ethanol is a viable fuel for compression-ignition engines.