16
Alternative Fuels for Transportation
resulting in better fuel economy. The power of the hybrid vehicle’s internal
combustion engine generally ranges from 1/10th to 1/4th of the conventional
automobile. In a HEV, when the driver applies the brakes, the motor becomes
a generator, using the kinetic energy of the vehicle to generate electricity
that can be stored in the battery for later use. The high efficiency and fuel
economy are achieved by carefully adjusting the operating parameters of
power-plant (IC-engine or motor) always around optimum efficiency conditions. A hybrid can achieve the cruising range and performance advantages
of conventional vehicles with the low-noise, low-exhaust emissions, and
energy independence benefits of electric vehicles.
The fuel cell can be used in hybrid vehicles to charge the battery instead
of the internal combustion engine. Fuel cells are electrochemical devices
that convert the chemical energy of a reaction directly into electrical energy.
The basic physical structure or building block of a fuel cell consists of an
electrolyte layer in contact with a porous anode and cathode on either side.
Gaseous fuels are fed continuously to the anode (negative electrode) compartment and an oxidant (i.e., oxygen from air) is fed continuously to the
cathode (positive electrode) compartment; the electrochemical reactions
take place at the electrodes to produce an electric current. Biomass generated gaseous fuels such as hydrogen can also be used as fuel for the fuel
cells.
1.4.6 Future Fuels
Next generation fuels include biodiesel produced from algae or nonfood
products, cellulosic ethanol and fuels produced from gasification of biomass.
Synthetic fuel is a liquid fuel obtained from natural gas, coal, oil shale, and
biomass sources through the Fischer–Tropsch synthesis process. The production of synthetic fuel is generally the hydrogen addition process. The source
of hydrogen can be intramolecular in which a carbonaceous low–hydrogen
residue is produced. Hydrogenation can be either direct or indirect. Direct
hydrogenation involves exposing raw material to hydrogen at high pressure.
Indirect hydrogenation involves reaction of the feedstock with steam, and
hydrogen is generated within the system.
The Fischer–Tropsch diesel is manufactured by the liquefaction of synthesis gas (mixture of CO and H 2 ) produced from gasification of biomass and
fossil fuels. Depending upon the synthesis process, several types of fuels
can be produced. German scientists Franz Fischer and Hans Tropsch established Fischer–Tropsch synthesis in 1923. The Fischer–Tropsch synthesis
process, which produces diesel from gasification of biomass is called green
diesel.
Fischer–Tropsch (FT) diesel can be substituted directly for conventional (petroleum-derived) diesel to fuel diesel-powered vehicles, without
Alternative Fuels for Transportation
resulting in better fuel economy. The power of the hybrid vehicle’s internal
combustion engine generally ranges from 1/10th to 1/4th of the conventional
automobile. In a HEV, when the driver applies the brakes, the motor becomes
a generator, using the kinetic energy of the vehicle to generate electricity
that can be stored in the battery for later use. The high efficiency and fuel
economy are achieved by carefully adjusting the operating parameters of
power-plant (IC-engine or motor) always around optimum efficiency conditions. A hybrid can achieve the cruising range and performance advantages
of conventional vehicles with the low-noise, low-exhaust emissions, and
energy independence benefits of electric vehicles.
The fuel cell can be used in hybrid vehicles to charge the battery instead
of the internal combustion engine. Fuel cells are electrochemical devices
that convert the chemical energy of a reaction directly into electrical energy.
The basic physical structure or building block of a fuel cell consists of an
electrolyte layer in contact with a porous anode and cathode on either side.
Gaseous fuels are fed continuously to the anode (negative electrode) compartment and an oxidant (i.e., oxygen from air) is fed continuously to the
cathode (positive electrode) compartment; the electrochemical reactions
take place at the electrodes to produce an electric current. Biomass generated gaseous fuels such as hydrogen can also be used as fuel for the fuel
cells.
1.4.6 Future Fuels
Next generation fuels include biodiesel produced from algae or nonfood
products, cellulosic ethanol and fuels produced from gasification of biomass.
Synthetic fuel is a liquid fuel obtained from natural gas, coal, oil shale, and
biomass sources through the Fischer–Tropsch synthesis process. The production of synthetic fuel is generally the hydrogen addition process. The source
of hydrogen can be intramolecular in which a carbonaceous low–hydrogen
residue is produced. Hydrogenation can be either direct or indirect. Direct
hydrogenation involves exposing raw material to hydrogen at high pressure.
Indirect hydrogenation involves reaction of the feedstock with steam, and
hydrogen is generated within the system.
The Fischer–Tropsch diesel is manufactured by the liquefaction of synthesis gas (mixture of CO and H 2 ) produced from gasification of biomass and
fossil fuels. Depending upon the synthesis process, several types of fuels
can be produced. German scientists Franz Fischer and Hans Tropsch established Fischer–Tropsch synthesis in 1923. The Fischer–Tropsch synthesis
process, which produces diesel from gasification of biomass is called green
diesel.
Fischer–Tropsch (FT) diesel can be substituted directly for conventional (petroleum-derived) diesel to fuel diesel-powered vehicles, without