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/swan_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 30-35% efficient concerning the energy that goes to movement

http://www.hydrogen-fc.com/wp-content/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/ss

/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-to-wheel”) 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

Chevy Equinox Fuel Cell

Honda FCX Fuel Cell

BMW CleanEnergy Fuel Cell

Nissan X-Trail Fuel Cell