Environmental Engineering Reference
In-Depth Information
25.4.2 Combustion Parameters ........................................................................................ 643
25.4.2.1 Dynamic Injection Timing ................................................................. 643
25.4.2.2 Ignition Delay ...................................................................................... 645
25.4.2.3 Heat Release Rate ................................................................................ 647
25.4.2.4 Peak Cylinder Pressure........................................................................648
25.4.2.5 Brake Specific Energy Consumption .................................................. 649
25.4.2.6 Brake Thermal Efficiency ................................................................... 650
25.5 Conclusions ......................................................................................................................... 650
References ...................................................................................................................................... 651
25.1 IntroductIon
World energy consumption is increasing tremendously, but fossil fuel sources are limited and
decreasing rapidly. Burning of fossil fuels increases the carbon dioxide (CO
2
) in the atmosphere.
CO
2
emissions have risen over the last 2 decades, reaching an atmospheric content of 360 ppm, esti-
mating the world CO
2
emissions at approximately 26 billion tons/year, 80% of which comes from
the combustion of fossil combustibles such as coal, petroleum, and natural gas (Muezzinoglu et al.
1992; Tuer et al. 1997).
The use of vegetable oils in energy production has almost always concentrated on its use as a
substitute for diesel in cars, either directly or in the form of methyl or ethyl esters. The unrefined oils
have rarely been used as combustibles in the generation of thermal energy (Lopez Sastre et al. 1998).
Biomass already provides approximately 13% of global energy, but this is largely as domestic
firewood used inefficiently for cooking and heating in developing countries (Sims 2001). In devel-
oped countries, there is a growing trend toward using modern and efficient bioenergy conversion
technologies using a range of biofuels that are becoming commercially competitive with fossil fuels.
25.1.1 p
otEntial
of
n
onEdiBlE
m
inor
v
EgEtaBlE
o
ilS
in
i
ndia
Depending on the climate and soil conditions, different nations are looking into different vegetable
oils for diesel fuel substitutes. Being a tropical country, India is rich in forest resources with a wide
range of oil seeds. The potentials of vegetable oils in India are given in Table 25.1. From the table, it
is understood that there is a huge market for vegetable oils in India. And in the near future, vegetable
oils may play a vital role in the biofuel industry. The production of nonedible oils in India is given
in Table 25.2.
25.1.2
d
EScription
of
m
inor
S
EEd
o
ilS
25.1.2.1 neem (
Azadirachta indica
Juss)
Neem grows wild in dry forests and is adapted to all kinds of soils. It is adapted to a wide range
of climatic conditions: temperatures of 0-49°C, altitudes up to 1500 m, soil pH up to 8.5, and
varying soil depths. Although the tree establishes naturally, tissue culture and stem cuttings can
also propagate it. The tree starts producing seeds after 5-6 years. The flowering season spreads
over January to April in various parts of the country depending on the climatic conditions. The
fruit yield, approximately 37-55 kg/tree, is harvested from June to August. The kernels constitute
approximately 45% of the seed and contain 40-45% oil. The oil is dark and bitter with a disagreeable
odor. Small-scale laundry shop manufacturers mostly consume it, and the good-quality oil is used
for other processes.
25.1.2.2 mahua (
Mahuca indica
)
Mahua is a large deciduous tree with a short trunk, spreading branches, and large rounded crown.
It is found in Maharastra, Bengal, Orissa, in some South Indian forests and Ceylon. The flowering
