This article examines the CO2 emissions from the combustion of a biodiesel-diesel blend in stationary internal combustion engines to generate electricity. Emissions were analyzed according to the feedstock used for biodiesel production-soybean oil, palm oil, waste frying oil-through the methyl and ethyl routes. The chosen blends were composed of petroleum diesel and biodiesel, with the latter accounting for 20% or 50% of the blend. The results were analyzed using the Tukey test and showed, in general, that higher engine loads led to a decrease in CO2 emissions in comparison with the standard B4 (4% biodiesel) blend mandated in Brazil. Therefore, this paper provides an original and complete approach to analyze and compare in pairs the results of CO2 emissions of different biodiesel production routes, feedstocks and engine loads in order to find the best blend option for each load level.