Fuels in Transportation - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 22

Table 2.9 Use of synthetic and biogenic fuels in road vehicle engine
Biogenic diesel Poor biogenic oils pressed from plants of the first generation must be treated

by transesterification [ 26 ]. The reason for the procedure is to improve the
flowing and burning properties of the resinous raw biogenic oils. The end
product is FAME, which is optimally suitable for application in spark and
diesel engines

Alcohols Biomethanol (CH 3 OH) and bioethanol (CH 3 CH 2 OH) can be used in internal

combustion engines in 100% concentration and in blended fuels in
variable concentrations [ 27 ]. Although bioethanol has a higher RON than
fossil fuels, which allows increasing the compression ratio in the
combustion chamber, some experiences show early wear in the
combustion engine

Dimethyl ether Dimethyl ether (C 2 H 6 O) is a synthetic product with a high Cetane number

which can be burned in a self ignition engine without soot and with
reduced nitric oxide formation [ 28 ]. Due to the low density and the high
oxygen content dimethyl ether has a low heating value. In addition, it
requires customization of the injection equipment because of its gaseous
condition

Emulsions Emulsions of water or alcohols in diesel fuel can be optimally used in self

ignition engines [ 29 ]. However, alcohols, primarily methanol, are not or
only badly soluble in diesel fuel. Therefore effective emulgators are
needed to stabilize these mixtures. In addition, measures for anti-
corrosion protection are also necessary. Emulsions reduce soot and nitric
oxide emissions. But application have only been used in a few fleets up
till now. However, a broad testing of different injection systems could
play an increasing role in the future

Fatty acid methyl
ester

Fatty acid methyl ester (FAME) can be produced with an alkali-catalyzed
reaction between methanol and vegetable or animal fats which are
obtained from oils and greases, e.g., from canola, soya, sunflowers, etc.
[ 30 ]. FAME effectively increases the lubrication of fuels and determines
the quality of the combustion process. However, recent FAME is not
economically competitive with mineral oil-based fuels yet because its
production is too expensive

valve timing, spray angle,
beam swirl

feedback

A

E 10

combustion
engine

exhaust
system

OBM CPU

air HC, CO, NO

sensors

high capacity
micro
controller

A

temperature, pressure, mass flow feedback

A-actuators

Fig. 2.3 Measurement of the exhaust gas quality when using blended fuels