Environmental Engineering Reference
In-Depth Information
taBle 14.9
Influence of major Biodiesel Properties on quality of Biodiesel and engine Performance
Influence on engine
Performance
major Properties
Influence on Fuel quality
Investigator(s)
Density
Influence on cetane number and
heating value of fuel
Efficiency of fuel
atomization and engine
output power
Ryan et al. 1984; Bahadur et al.
1995; Tat and Gerpen 2000;
Tyson 2001; Demirbas 2008
Kinematic
viscosity
Flow characteristics.
Atomization quality,
combustion quality,
leakage in the fuel
system. Increases the
engine deposits. Needs
more energy to pump the
fuel and wears fuel
pump elements and
injectors.
Schwab et al. 1987; Heywood
1988; Tat and Gerpen 1999;
Kinast 2001; Encinar et al. 2005;
Tate et al. 2006; Knothe and
Steidley 2007
Cetane number
Fuel ignition quality and
increase level of unsaturation.
Affects the ignition delay
time and knocking
De Oliveira et al. 2006; Knothe
et al. 2006; Knothe et al. 2003
Flash point
Safety in storage, fuel handling,
and transportation
No direct effect on
combustion in diesel
engine
Owen and Coley 1995; Caro
et al. 2001
Acid value
Presence of FFAs. Oxidative
stability, kinematic viscosity
and lubricity
Damage to injector.
Deposits in fuel lines.
Affects the life of pumps
and filters. Not suitable
at low climatic
temperature.
Miyashita and Takagi 1986;
Frankel 2005; Knothe and
Steidley 2005a
Water and
sediment
Deterioration of oil due to
growth of microbes
Fuel fouling, deposits
clog fuel filters
Knothe 2005
Ash content
Residual catalyst
Wear of engine
components. Filter
plugging and injector
deposits.
Knothe and Steidley 2005b
Total glycerin and
free glycerin
Incomplete conversion, residual
mono-, di-, and triglycerides.
Affects the kinematic viscosity
Filter clogging and
injector deposits.
Low-temperature
operatibility.
Yu et al. 1998; Knothe and
Steidley 2005a
the ignition delay period, resulting in lower peak cylinder pressure and rate of pressure rise. The
peak cylinder pressure in CI engines is higher for JB and JBB as compared with JO because of
improvement in the preparation of the air-fuel mixture as a result of lower viscosity (Kumar et al.
2003a). Sivprakasam and Saravanan (2007) while studying the combustion characteristics of a
7.46-kW diesel engine when fueled with JB, JBB, and diesel reported that the peak pressure was
maximum at full load for a B20 blend (70 bar) followed by diesel (68 bar). Sahoo and Das (2009b)
studied combustion characteristics of JB in a 6-kW diesel engine, and this is presented in Figure
14.6. As compared with diesel, a 7.6% higher peak pressure has been reported for JB at full load of
the engine. A similar trend has also been observed during the entire range of engine operation at
no-load and half-load conditions. It is clear from Figure 14.6 that while running with biodiesel and
their blends, the peak pressure occurred definitely after top dead center (TDC) for safe and efficient
operation. Otherwise, a peak pressure occurring very close to TDC or before that causes severe
engine knock and thus affects engine durability.
