Alternative Fuels
Introduction
Fuel means, a material used to produce heat or power by burning. We drive vehicles that are powered by
petroleum based fossil fuels — gasoline or diesel. Some people are choosing to drive vehicles that run on
completely on other fuels. These advanced and alternative fuels help reduce our dependence on fossil fuels, save
us money and improve our air quality.
The average vehicle on the road today emits more than 600 pounds of air pollution each year. These pollutants
such as carbon monoxide, sulphur dioxide, nitrogen dioxide and particulate matter contribute to smog and too
many health problems. Vehicles through their combustion of fossil fuels, also emits greenhouse gases, causing
global warming. So by reducing emissions, advanced vehicle technologies help combat both air pollution and
global climate change.
Selecting a Fuel (Interactive)
1.
2.
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6.
1.
Bio Fuels
a. Bioethanol (as a substitute or additive for petrol)
b. Biodiesel (as a substitute for diesel)
c. Methanol
Electricity
Ethanol
Hydrogen
Natural Gas
Propane
Bio Fuels:
Bio fuels are liquid fuels, which are made from a variety of sources of biomass. They include plant materials,
types of crops and recycled or waste vegetable oils. Bio fuels can be used in internal combustion engines, as a
replacement or complement of petrol and diesel.
Reasons for promoting bio fuels are
 To contribute to the security of energy supply
 To contribute to the reduction of greenhouse gas emissions
 To promote a greater use of renewable energy
 To diversify agricultural economies into new markets
Types of Bio Fuels:
1
Bioethanol (as a substitute or additive for petrol):
The most widely used alternative transportation fuel is ethanol. Ethanol is an alcohol typically made
from corn or corn by products. Vehicles that run on ethanol have lower carbon monoxide and carbon
dioxide emissions than traditional vehicles. Today we have some vehicles that can use a higher blend
of ethanol up to 85 percent called E85. These vehicles, known as flexible fuel vehicles, can use E85,
gasoline or any mixture of the two.
Manufacturing process:
Ethanol is manufactured by extracting water from Rectified Spirit, which is 94.68% alcohol, and rest is
water. In order to extract water from alcohol it is necessary to use some dehydrate like quick line,
which is capable of separating, water from alcohol. This process is known as Molecular Sieve
Dehydration process.
2
Biodiesel (as a substitute for diesel):
Biodiesel is a general name for methyl esters from organic feedstock. Biodiesel can be made from a
wide range of vegetable oils; rapeseed (the most common one), sunflower, palm oil, canola, Jatropha
Curcas, soy and recycled cooking oils. Use of 100% biodiesel would reduce CO2 emissions by 40 to
50%. Biodiesel is biodegradable. Producing biodiesel from oil seeds costs about twice as much as
diesel from crude oil.
3
Methanol:
Methanol, another alcohol based fuel, is usually produced from natural gas, but it can also be
produced from biomass. Methanol powered vehicles emit smaller amounts of air pollutants, such as
hydrocarbons, particulate matter and nitrogen oxides.
It is most commonly used as a chemical feedstock, solvent and as a feedstock for producing methyl
tertiary butyl ether (MTBE), an octane (the higher the octane number, the more compression the fuel
can withstand before igniting) enhancing gasoline additive. It can also be used in 100% pure form as a
gasoline substitute or in gasoline blends such as M85 (85% methanol and 15% gasoline).
Most of the methanol produced in the United States today is made from natural gas. But methanol
can also be produced from other feed stocks including coal, biomass and residual oil. Cost-effective,
efficient and environmentally sound processes for producing methanol from biomass are being
pursued by both government and industry researchers.
Manufacturing process:
A. From Biomass: Methanol can be produced from biomass through a thermo chemical process
known as gasification. The biomass is subjected to elevated temperatures and pressures (in
some processes) to form a synthesis gas (syngas). After removing impurities and adjusting
the hydrogen to carbon monoxide ratio to 2 : l, the syngas is then reacted over a catalyst at
elevated temperatures and pressures to form methanol.
B. From Natural Gas: Methane component in natural gas is used for the production of
methanol. Methane reacts with steam on a nickel catalyst to produce syngas at a moderate
pressure of 10–20 atm and high temperature (around 850°C).
Environmental Effects
Methanol fuels produced from biomass feed stocks can reduce net greenhouse gases from
automobile emissions. It results in generally lower overall emissions and higher energy efficiency.
Production of methanol from biomass can turn wastes into energy resources.
Producers:
There are five main producers of methanol in India.
A.
B.
C.
D.
E.
Gujarat Narmada Valley Fertilizers Company Ltd (GNVFC)
Deepak Fertilisers
Assam Petrochemicals
Rashtriya Chemicals & Fertilizers Ltd (RCF)
National Fertilizers Ltd
Uses: Still Working
In India: Still Working
2.
Electricity
Electricity is considered as a fuel when used in vehicles. Electric vehicles use various types of batteries and
other energy storage mechanisms to store the electricity used to run a vehicle. Electricity can be produced
from a variety of primary energy sources, including oil, coal, nuclear energy, moving water, natural gas, wind
energy and solar energy. Plug in vehicles are capable of drawing electricity from off-board electrical power
sources and storing it in batteries.
Hybrid and Plug-In Electric Vehicles
Hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs) and all electric vehicles (EVs) also called
electric drive vehicles collectively use electricity either as their primary fuel or to improve the efficiency of
conventional vehicle designs.
Hybrid Electric Vehicles
HEVs are powered by an internal combustion engine or other propulsion source that runs on conventional or
alternative fuel and an electric motor that uses energy stored in a battery. The battery is charged through
regenerative braking and by the internal combustion engine and is not plugged in to charge.
Plug in Hybrid Electric Vehicles
PHEVs are powered by an internal combustion engine that can run on conventional or alternative fuel and an
electric motor that uses energy stored in a battery. The vehicle can be plugged into an electric power source
to charge the battery. Some types of PHEVs are also called extended range electric vehicles (EREVs).
Plug in cars link http://www.plugincars.com/cars
All-Electric Vehicles
EVs use a battery to store the electric energy that powers the motor. EV batteries are charged by plugging the
vehicle into an electric power source. EVs are sometimes referred to as battery electric vehicles (BEVs).
3.
Ethanol
Same as Bioethanol
4.
Hydrogen:
Hydrogen is a simple, abundant element found in organic matter, notably in the hydrocarbons that make up
many of our fuels, such as gasoline, natural gas, methanol and propane. Because the only by product of
hydrogen is water, only the engine lubricants from a hydrogen fuelled vehicle emit small amounts of air
pollutants. Hydrogen is already the fuel of choice for propelling space shuttles. It is also being explored for use
in internal combustion engines.
Hydrogen (H2) is a potentially emissions free alternative fuel that can be produced from domestic resources.
Although not widely used today as a transportation fuel, government and industry researchers are working
toward the goal of clean, economical and safe hydrogen production and fuel cell electric vehicles.
Hydrogen is locked up in enormous quantities in water (H2O), hydrocarbons (such as methane, CH4) and other
organic matter. Efficiently producing hydrogen from these compounds is one of the challenges of using
hydrogen as a fuel.
Currently, steam reforming of methane (natural gas) accounts for the majority of the hydrogen produced in
the United States. Almost all of the hydrogen produced here each year is used for refining petroleum, treating
metals, producing fertilizer and processing foods. Hydrogen has been used for space flight since the 1950s.
Hydrogen also can be used to power fuel cell electric vehicles, which are zero emission vehicles. Major R & D
works are aimed at making fuel cell electric vehicles practical for widespread use.
Hydrogen as an Alternative Fuel
The interest in hydrogen as an alternative transportation fuel stems from its ability to power fuel cells in zero
emission electric vehicles, its potential for domestic production and the fuel cell vehicle’s potential for high
efficiency—it is two to three times more efficient than an internal combustion engine.
Because hydrogen has a low volumetric energy density, it is important for a fuel cell vehicle to store enough
fuel on-board to have a driving range comparable to conventional vehicles.
Hydrogen can be stored in different forms:
1. In tanks
a. Compressed Gas
b. Cryogenic Liquid
2. And in materials
a. Surface Adsorption
b. Intermetallic Hydride
c. Complex Hydride
d. Chemical Hydride
3. Natural Gas
Natural gas is a mixture of hydrocarbons, mainly methane. It can be produced either from gas wells or in
conjunction with crude oil production. Natural gas is a clean burning; domestically produced fuel that generates
significantly less carbon monoxide, carbon dioxide, particulate matter and nitrous oxide compared to similar
fossil fuel vehicles. It is used in vehicles as compressed natural gas (CNG) or liquefied natural gas (LNG).
The Manufacturing Process
The methods used to extract, process, transport, store and distribute natural gas depend on the location and
composition of the raw gas and the location and application of the gas by the end users.
A. Extracting:
a. Some underground natural gas reservoirs are under enough internal pressure that the gas can flow
up the well and reach Earth's surface without additional help. However, most wells require a pump
to bring the gas and oil (if it is present) to the surface.
b. When the raw natural gas reaches the surface, it is separated from any oil that might be present
and is piped to a central gas processing plant nearby.
B. Processing:
a. Raw natural gas with little or no oil is easier to process than gas from oil wells. Most raw natural
gas contains dirt, sand and water vapour, which must be removed with filters or traps near the
well, before further processing to prevent contamination and corrosion. The water vapour is
usually removed by passing the gas through a tower filled with granules of a solid desiccant, such
as alumina or silica gel, or through a liquid desiccant, such as a glycol.
b. Raw natural gas contains a large amount of heavier hydrocarbon gases, such as propane and
butane. These are removed by passing the raw gas up through a tall, closed tower containing cold
absorption oil, similar to kerosene. The heavier hydrocarbon gases condense into liquids and are
trapped in the oil.
c. The lighter hydrocarbon gases, such as methane and ethane, do not condense into liquid and flow
out the top of the tower along with natural gas. To remove the ethane, the water vapour in the
gas is further reduced using one of several methods and the gas is then subjected to repeated
compression and expansion cycles to cool the ethane and capture it as a liquid.
d. Natural gas may also contain varying amounts of carbon dioxide and hydrogen sulphide which are
removed by flowing the gas up through a tower while a spray of water mixed with a solvent, such
as monoethanolamine. The solvent reacts with the chemicals and the solution is drained off.
e. Natural gas may also contain a high percentage of nitrogen which reduces the heating value of the
natural gas. The gas goes through a low temperature distillation process to liquefy and separate
the nitrogen.
f. If helium gas is to be captured, it is done after the nitrogen is removed. This involves a complex
distillation and purification process to isolate the helium from other gases.
C. Transporting:
a. Mercaptan is injected into the processed natural gas to give it a distinctive warning odour and the
gas is piped to a compressor station where the pressure is increased to about 1,380 to 10,350 kPa.
b. The gas is then transported across country through 20 to 42 inch pipelines installed underground.
About every 160 km, another compressor boosts the gas pressure to keep the gas flowing.
c. When the pressurized natural gas reaches the vicinity of its final destination, it is sometimes
injected back into the ground for storage in depleted underground gas and oil reservoirs, porous
rock layers known as aquifers, or subterranean salt caverns.
4.
Propane
Also known as liquefied petroleum gas (LPG) or autogas, propane is a clean-burning, high-energy alternative
fuel that's been used for decades to power light, medium and heavy duty propane vehicles. Propane is stored
under pressure inside a tank and is a colourless, odourless liquid. As pressure is released, the liquid propane
vaporizes and turns into gas that is used for combustion. An odorant, ethyl mercaptan, is added for leak
detection. Propane has a high octane rating and excellent properties for spark ignited internal combustion
engines. It is non-toxic and presents no threat to soil, surface water or groundwater.
Propane is produced as a by-product of natural gas processing and crude oil refining. A propane powered
vehicle can emits 64 percent less reactive organic compounds, 20 percent less nitrogen oxide and 20 percent
less carbon monoxide than a similar gasoline vehicle.
How Propane Vehicles Work
Propane vehicles work much like gasoline powered vehicles with spark ignited engines. Propane is stored as a
liquid in a relatively low pressure tank (about 150 pounds per square inch). In vapour injected systems, liquid
propane travels along a fuel line into the engine compartment. The supply of propane to the engine is
controlled by a regulator or vaporizer, which converts the liquid propane to a vapour. The vapour is fed to a
mixer located near the intake manifold, where it is metered and mixed with filtered air before being drawn
into the combustion chamber where it is burned to produce power, just like gasoline.
Liquid propane injection engines do not vaporize the propane. Instead, it is injected into the combustion
chamber in liquid form. Liquid injection systems have also proven reliable in terms of power, engine durability
and cold starting.
Emerging Fuels
P-Series
P-Series fuels are blends of natural gas liquids (pentanes plus), ethanol and methyltetrahydrofuran (MeTHF), a
biomass co-solvent. P-Series fuels are clear, colourless, high octane, liquid blends used either alone or mixed with
gasoline in any proportion in flexible fuel vehicles. These fuels are not produced in large quantities and not used
widely.
P-Series is the only fuel to be added to the Energy Policy Act of 1992 as an alternative fuel. It was added in 1999.
Benefits
P-Series fuels can be an alternative to conventional transportation fuels. The benefits of P-Series fuels include:
• More Flexibility: P-Series fuels can fuel modern flexible fuel vehicles.
• Fewer Emissions: Vehicles fuelled by P-Series fuels generally have fewer emissions than conventional vehicles
fuelled by gasoline.
 Increased Energy Security: P-Series fuels can be manufactured from domestic natural gas and biomass
feedstocks, reducing U.S. reliance on imported petroleum.
Because both the ethanol and the MeTHF can be produced from renewable biomass resources, emissions from
producing and using P-Series are substantially less than those from gasoline.