Transportation
Alicia Kettler, Dana Sweatlock, Elizabeth De Smet
History
• 3 types of engines
– Gas
– Diesel
• Daimler, Benz
– Steam
• Patented by Savery
• Improved by Watt
Gas, Diesel, & Steam
• Gas
– http://auto.howstuffworks.com/engine1.htm
• Diesel
• http://www.howstuffworks.com/diesel1.htm
• Steam
– http://www.howstuffworks.com/steam1.htm
Efficiency
• The efficiency of
engines whether
gasoline, diesel, or
steam are important
factors in pollution
and resource
consumption
Combustion
• There are two forms of combustion in engines
– Internal
• Where fuel is burned inside the engine
– External
• Where fuel is burned outside the engine
• Steam engines utilize external combustion
• Diesel and gasoline engines use internal
combustion
Steam Engines
• Steam engines are
only about 1-3%
efficient
• This is due to a loss
of heat to the
atmosphere
• A condenser can be
added with the
potential of higher
efficiency but the
difference is small
http://sitemanager.ncl.ac.uk/images/projects/s
wan_2774.jpg
Gasoline Engines
• Only 15% of the energy from fuel goes to
moving the car
• That does not take into consideration that
there is inefficiency in gas production
• Overall the engine is about 25% efficient
http://www.fueleconomy.gov/feg/tech/energy.gif
Diesel Engines
• About 3035% efficient
concerning
the energy
that goes to
movement
http://www.hydrogen-fc.com/wpcontent/uploads/2007/01/efficiency
_comparison.jpg
New Technologies
• In recent years, there have been many new
advancements in transportation technologies.
Some of these advancements include:
– Natural Gas Vehicles
– Electric Vehicles
– Hydrogen Fuel Cell Vehicles
Natural Gas Vehicles (NGV’s)
• 110,000 NGV’s on the road today – 11 million
worldwide
– 1,100 fueling stations in the US – half open to
public
• At the pump, natural gas costs about half as much as a
gallon of gasoline.
• Natural Gas is sold in gasoline gallon equivalents (GGE).
A GGE has the same energy content as a gallon of
unleaded gasoline without ethanol (125,000 Btu)
http://www.ngvc.org/about_ngv/index.html
Natural Gas Vehicles Cont…
• Benefits
– Less dependent on foreign oil
• 98% of natural gas used is produced in North America
– Reduced emissions
•
•
•
•
Carbon monoxide by 70-90%
Non-methane organic gas by 50-75%
Nitrogen oxides by 75-95%
Carbon dioxide by 20-30%
– Natural gas has less carbon than any other fossil fuel
http://www.ngvc.org/about_ngv/index.html
Natural Gas Vehicles Cont…
• Benefits
– Safety
• Natural gas dissipates into the atmosphere in the event
of an accident
– No pools on the ground, like gasoline, that could create a fire
hazard
• Fuel storage cylinders for natural gas are stronger than
those used for gasoline.
• Natural gas has a higher ignition temperature than
gasoline and a narrow range of flammability.
• Natural gas is not toxic or corrosive – will not
contaminate ground water
http://www.ngvc.org/about_ngv/index.html
Natural Gas Vehicles Cont…
• Target audience
– Lack of infrastructure – Fleets
• Fleets usually refuel in a central location and don’t
need a widespread infrastructure
• Many fleets are already beginning to use NGV’s
–
–
–
–
–
Taxi cabs
Transit buses
School buses
Delivery vehicles
Street sweepers
http://www.ngvc.org/about_ngv/index.html
Electric Vehicles
• Electric vehicles are propelled by an electric
motor powered by rechargeable battery pack.
• There are several advantages over internal
combustion engines, as well as several
significant disadvantages
http://www.fueleconomy.gov/feg/evtch.shtml
Electric Vehicles cont…
• Advantages
– Energy efficient- 75% of chemical energy from
battery goes to power the wheels
• Internal combustion engines only convert about 20%
– Environmentally friendly – no tailpipe pollution
• BUT not emission free if a fossil fuel power plant
generates the electricity to charge the vehicle
– Performance benefits – quiet smooth operation
http://www.fueleconomy.gov/feg/evtch.shtml
Electric Vehicles cont…
• Disadvantages
– Driving Range – EV’s can only go 100-200 miles
before needing to be recharged
• Gasoline vehicles on average can go about 300 miles
– Recharge time – full charge- 4-8 hours, “quick
charge” of 80% battery- 30 minutes.
– Battery cost – expensive and need to be replaced
more often than a battery in a gasoline car
– Bulk & Weight – battery packs are heavy and large
http://www.fueleconomy.gov/feg/evtch.shtml
Electric Vehicles Coming
The Nissan Leaf
The Mini Cooper Electric
Ford Focus Electric
Hydrogen
• Charged plates conduct hydrogen
– The electrons released create a current
– http://inventors.about.com/od/sstartinventions/s
s/Physics_Illustr_2.htm
• Water is released as a byproduct
Hydrogen Fuel Cell Efficiency
• A fuel cell’s
efficiency is
dependant on the
fuel that it is
charged with
• A cell powered by
pure hydrogen
can be 80%
efficient
http://i36.tinypic.com/n3nqz7.jpg
Conversion
• The energy taken from the hydrogen would be
converted to electrical energy and then to
mechanical work
• The electric motor and inverter perform this
process
• This step is about 80% efficient making the cell
only about 64% efficient under ideal
circumstances
Fuel
• If the fuel does not come from pure hydrogen
the vehicle requires the use of a transformer,
which will turn hydrocarbon and alcohol fuels
into hydrogen
• The heat given off in this process lowers the
efficiency of the system
Efficiency in Practice
• Fuel cell vehicles
are only about
40% efficient
• The losses that
come from the
production
(“power-plant-towheel”) lowers the
efficiency to 22%
for gaseous
hydrogen and 17%
for liquefied
hydrogen
http://www.blogcdn.com/green.autoblog.com
/media/2006/11/slides-for-sam.jpg
Benefits of Fuel Cells
• Fewer emissions/pollutants
– Tailpipe emits only heat and water
– Only pollutants and greenhouse gasses that are
emitted come from the fossil fuels used to
produce hydrogen
• Reduce oil dependence
– Hydrogen can be derived from domestic sources
• Fuel cells can store enough hydrogen to travel
about as far as a gasoline engine.
http://www.fueleconomy.gov/feg/fcv_benefits.shtml
Challenges of Fuel Cells
• Onboard Hydrogen Storage – systems are large, heavy, and
expensive
• Vehicle cost- too expensive to compete with hybrids and
gasoline/diesel vehicles
• Fuel Cell durability/reliability- not as durable as internal
combustion engines
• Lack of infrastructure
– There is currently no infrastructure in place to deliver hydrogen to
consumers. New facilities need to be made for producing,
transporting, and dispensing hydrogen to consumers
• Safety/Public Acceptance
– public does not now how to handle hydrogen – new fuel storage
– Fuel cell technology needs to be embraced by consumers before it is
economically viable.
http://www.fueleconomy.gov/feg/fcv_benefits.shtml
The Future of Hydrogen Fuel Cells
• Many car manufacturers are currently working
on hydrogen fuel cell vehicles
– BMW – CleanEnergy Education Program
– Chrystler – ecoVoyager concept vehicle
– Ford – fuel cell vehicles
– GM – Chevy Equinox fuel cell vehicle
– Honda – FCX Clarity fuel cell vehicle
– Nissan – X-Trail fuel cell vehicle
Honda FCX Fuel Cell
Chevy Equinox Fuel Cell
Nissan X-Trail Fuel Cell
BMW CleanEnergy Fuel Cell