A 500 hours endurance test was performed with a heavy-duty
engine (Euro IV); MAN type D 0836 LFL 51 equipped with a PM-Kat®.
As fuel 100% biodiesel was used that met the European specification
EN 14214. The 500 hours endurance test included both the European
stationary and transient cycle (ESC and ETC) as well as longer
stationary phases. During the test, regulated emissions (carbon
monoxide, nitrogen oxides, hydrocarbons and particulate matter),
the particle number distribution and the aldehydes emission were
continuously measured. For comparison, tests with fossil diesel
fuel were performed before and after the endurance test.
During the endurance test, the engine was failure-free for 500
hours with the biogenic fuel. There were almost no differences in
specific fuel consumption during the test, but the average exhaust
gas temperature increased by about 15°C over the time.
Emissions changed only slightly during the test. Carbon
monoxide, hydrocarbons and aldehydes were effectively eliminated by
the oxidation catalyst as part of the PM-Kat®. The concentration of
hydrocarbons was partially under background level and the emissions
of hydrocarbons as well as carbon monoxide were well under the
regulatory requirements. Nitrogen oxides emissions increased, as
expected, by 10% when using biodiesel instead of fossil diesel
fuel. So they slightly exceeded the legal limit of Euro IV. During
the test, small increases of nitrogen oxides, particulate matter
and particle numbers were observed.
In all, the endurance test demonstrated clearly that the engine
can be driven with 100% biodiesel and the biogenic fuel has no
effect on the continuously operating PM-Kat®. However, the exhaust
gas system might have some optimization potential for
biodiesel.
