Environmental Engineering Reference
The biofuel that is the easiest to produce is bio-oil. Over 1000 plants with a high
amount of vegetable oil are usable in the production of bio-oil. The most popular
ones are rapeseed oil, soya oil and palm oil (Figure 12.13). Oil mills produce the
vegetable oil directly through either pressing or extraction processes. The residue
from the pressing can be reused as animal feed.
Figure 12.13 Oil-rich plants such as rapeseed and sunfl owers are raw material for vegetable oil.
Photo left: Günter Kortmann, North Rhine-Westphalia Chamber of Agriculture.
Very few older precombustion chamber diesel engines can be run on vegetable oil
without a problem unless they have been converted. Even engines like the Elsbett
engine, which were specifi cally developed to run on vegetable oil, have not yet
achieved any signifi cant market share. Vegetable oil is somewhat tougher than diesel
fuel and needs higher temperatures to fi re. However, even normal diesel engines
can be adapted and converted to run on vegetable oil.
Biodiesel comes closer to having the characteristics of conventional diesel fuel
than pure vegetable oil. Vegetable oil and animal fat are the raw materials used
to produce it. The Belgian G. Chavanne applied for a patent for a method to
produce biodiesel as early as 1937. Chemically, biodiesel is fatty acid methyl
ester ( FAME ).
In Central Europe rape is normally used to produce biodiesel. Oil mills extract the
raw material rapeseed oil from rapeseed seedlings. The by-product rapeseed animal
meal usually ends up in the animal feed industry. Rapeseed oil methyl ester (RME)
is then created from the rapeseed oil in a transesterifi cation facility.