Influences of entrainers to engine oil to improve the drag-out of biodiesel - Experiments and simulations

The results show the drag-out of biodiesel from the engine oil at temperatures of 160 °C and 180 °C by use of polyols and acids. Mono- and bivalent alcohols yield no drag-out. The number of the hydroxyl groups or the dipole moment of the entrainer does not correlate with removed biodiesel. Acids showed the highest ability for the drag-out of biodiesel (2.3% (m/m) in total for formic acid) and showed the strongest interaction with biodiesel (for formic acid). According to the results, this strong interaction is mainly formed by hydrogen bonds. Furthermore, biodiesel turns out to be a good hydrogen bond acceptor and can be removed by substances that are hydrogen bond donators (e.g. acids, polyols).