12
Alternative Fuels for Transportation
and diesel fuel evolved together. When the first energy crisis arose in the
1970s, the research on vegetable oil for fuel purposes picked up again. With
increases in crude oil prices, limited resources of fossil oil, and environmental concerns, there has been a renewed focus on vegetable oils and animal fats to make biodiesel fuels. Vegetable oil fuels are not now petroleum
competitive fuels because they are more expensive than petroleum fuels.
However, vegetable oils and derivatives have the potential to substitute for
a fraction of the petroleum distillates and petroleum-based petrochemicals
in the near future. Vegetable oil fueled engines require frequent maintenance (like injector and combustion chamber cleaning) and hence these
are suitable for stationary engines that are used for power generation and
generator-motor pump sets in rural areas. These could reduce a significant
amount of energy savings in terms of diesel or electricity consumption.
Biodiesel is methyl or ethyl esters of fatty acids derived from edible and
nonedible type vegetable oils (used or fresh) and animal fats. The major
sources for biodiesel production can be jatropha, karanji, palm, soy bean,
and sun flower. During the years 1970 and 1980, a significant amount of
research work was conducted with neat vegetable oil and its blends, partially
esterified oils in blends with diesel. Use of neat oils causes varieties of engine
problems. Based on the results obtained, research focused on esters due to
their superior fuel properties than neat vegetable oils.
Feedstock accounts for 60–80% of the production cost of biodiesel. The
biodiesel processing technologies—feed stock and by-product (glycerol)
utilization—play an important role in success of biodiesel against petroleum
diesel. Biodiesel can be blended with diesel at any ratio (however currently
the blend is limited to 20%) and operates the diesel engine, which requires
little or no modification. The use of biodiesel in conventional diesel engines
substantially reduces the exhaust emissions.
Well-to-wheel energy consumption of biodiesel is higher than for fossil
diesel but generally lower than for gasoline. Well-to-wheel emissions of
biodiesel are very similar to diesel emissions; that is, higher NO x and particulates but relatively low for CO and hydrocarbons and very low net CO 2
emissions because it is derived from biomass. Jatropha in India, palm oil in
Malaysia, and soybeans in the United States are the major feed stocks for
their biodiesel production. The annual production of biodiesel is increasing
rapidly worldwide, from 10,000 tons in the year 2000 to 3.5 million tons in 2006
(Pandey 2008). In this scenario, it is necessary to go for second-generation
biofuels (i.e., choose nonfood crops for biodiesel production) so the quantity
of biodiesel can be increased to sustain the market.
1.4.3 gaseous Fuels
1.4.3.1 Natural Gas
Natural gas has received a great deal of attention and has been successfully
implemented in various parts of the world, such as Argentina, Russia, Italy,
Alternative Fuels for Transportation
and diesel fuel evolved together. When the first energy crisis arose in the
1970s, the research on vegetable oil for fuel purposes picked up again. With
increases in crude oil prices, limited resources of fossil oil, and environmental concerns, there has been a renewed focus on vegetable oils and animal fats to make biodiesel fuels. Vegetable oil fuels are not now petroleum
competitive fuels because they are more expensive than petroleum fuels.
However, vegetable oils and derivatives have the potential to substitute for
a fraction of the petroleum distillates and petroleum-based petrochemicals
in the near future. Vegetable oil fueled engines require frequent maintenance (like injector and combustion chamber cleaning) and hence these
are suitable for stationary engines that are used for power generation and
generator-motor pump sets in rural areas. These could reduce a significant
amount of energy savings in terms of diesel or electricity consumption.
Biodiesel is methyl or ethyl esters of fatty acids derived from edible and
nonedible type vegetable oils (used or fresh) and animal fats. The major
sources for biodiesel production can be jatropha, karanji, palm, soy bean,
and sun flower. During the years 1970 and 1980, a significant amount of
research work was conducted with neat vegetable oil and its blends, partially
esterified oils in blends with diesel. Use of neat oils causes varieties of engine
problems. Based on the results obtained, research focused on esters due to
their superior fuel properties than neat vegetable oils.
Feedstock accounts for 60–80% of the production cost of biodiesel. The
biodiesel processing technologies—feed stock and by-product (glycerol)
utilization—play an important role in success of biodiesel against petroleum
diesel. Biodiesel can be blended with diesel at any ratio (however currently
the blend is limited to 20%) and operates the diesel engine, which requires
little or no modification. The use of biodiesel in conventional diesel engines
substantially reduces the exhaust emissions.
Well-to-wheel energy consumption of biodiesel is higher than for fossil
diesel but generally lower than for gasoline. Well-to-wheel emissions of
biodiesel are very similar to diesel emissions; that is, higher NO x and particulates but relatively low for CO and hydrocarbons and very low net CO 2
emissions because it is derived from biomass. Jatropha in India, palm oil in
Malaysia, and soybeans in the United States are the major feed stocks for
their biodiesel production. The annual production of biodiesel is increasing
rapidly worldwide, from 10,000 tons in the year 2000 to 3.5 million tons in 2006
(Pandey 2008). In this scenario, it is necessary to go for second-generation
biofuels (i.e., choose nonfood crops for biodiesel production) so the quantity
of biodiesel can be increased to sustain the market.
1.4.3 gaseous Fuels
1.4.3.1 Natural Gas
Natural gas has received a great deal of attention and has been successfully
implemented in various parts of the world, such as Argentina, Russia, Italy,