As a result of research made during EuroBioRef, five alternative bio based diesel fuels have been produced and tested. The fuels consisted of three different products made from castor oil: Esterol A, Esterol Lot BP093 and Methyl-UCT. The two remaining fuels were POM-Methyl 2.8 and 3-Methylheptane.
For the test, the fuels were blended with a reference diesel at a 30%vol ratio.
The fuels were tested in a euro 4, 1.6L light-duty high-speed road going turbocharged engine with an EGR-system. The engine was configured with standard injectors and standard ECU settings.
The tests were performed on an eddy current dynamometer in four different modes.
Analysis shows that the NOx level increased slightly for Esterol A, Methyl-UCT and POM-methyl 2.8. It also showed that CO level was higher for POM-Methyl 2.8 and 3-Methylheptane during highest speed and load.
A heat release analysis performed on each fuel in each mode showed a difference in combustion of the pilot injection at 2000rpm, where POM-Methyl 2.8 and 3-Methylheptane apparently did not obtain auto-ignite at pilot injection.
At highest speed and load, where the temperature of the system was higher, POM-Methyl 2.8 and 3-Methylheptan auto-ignited earlier in the cycle than the other fuels. This caused a slow burning rate due to incomplete fuel air mixing.
Based on the results, POM-Methyl 2.8 and 3-Methylheptane are inadvisable to use as alternative fuels for light-duty high-speed road engines. Esterol Lot BP093, Esterol A and Methyl-UCT are all excellent suggestions for blends with diesel and might be able to be certified after further analysis.