Upload
scot-mckenzie
View
214
Download
0
Tags:
Embed Size (px)
Citation preview
1.
Eth
an
ol
1.
Eth
an
ol
Ethanol still releases greenhouse gases?– More than fossil fuels!– But they’re still better. Why?
Net amount entering the atmosphere is actually less than fossil fuels…
Oil Reserves
2.
Bio
die
sel
2.
Bio
die
sel
BiodieselBiodiesel• Made from long chain fats and lipids in fatty Made from long chain fats and lipids in fatty
plants (or animal fats)plants (or animal fats)
• Soybeans Soybeans • Can be used in any mixture with fossil dieselCan be used in any mixture with fossil diesel• Works the same way as standard diesel fuel in Works the same way as standard diesel fuel in
existing enginesexisting engines– Not a new technologyNot a new technology– What did the first diesel engine run on?What did the first diesel engine run on?– Peanut oilPeanut oil
• Requires lots of fertilizer and pesticides and huge amounts of Requires lots of fertilizer and pesticides and huge amounts of landland• Very energy intensiveVery energy intensive• Gels at cold temperatures in engines – requires simple Gels at cold temperatures in engines – requires simple modification of heating element in winter monthsmodification of heating element in winter months• Car may stink like food if you use recycled oilCar may stink like food if you use recycled oil• Still releases greenhouse gasesStill releases greenhouse gases• Drives up prices of food soyDrives up prices of food soy
• Can be free if you recycle used restaurant oil• Exhaust emissions are reduced vs. ff• Reduction of particulate (smoke) emissions by approximately 50%• Higher flashpoint (150C) than petro diesel (70C) =safer to handle • Runs in existing unmodified diesel engines (in most climates)• Integrates with the existing fueling infrastructure • Low-risk - simple to phase in and out of use • Local renewable source of energy • Improved Energy Security. • Less dependence on fuels from mineral oils •transported as a non-hazardous material •Non-toxic. Biodegradable Sulfur free
Pro’
sCon’s
A Promising Alternative to Soy
2. Biodiesel2. Biodiesel
A complete transition to biofuels could require boundless boundless amounts of land amounts of land if soy crops are used. • Algal oil is similar to soybean oil but …
• Algae can be grown on lands unsuitable for food crops • even grows in brackish water• Can use barren, sunny desert land, to produce enough biodiesel to replace all transportation fuel the country currently utilizes • algae farmers could utilize farm waste and excess carbon dioxide from factories to help speed the growth of the algae.
algae offers the highest yield feedstock for biodiesels
• oil-per-acre production rate 250 times the amount of soybeans.
• Can use vertical farms with zero runoff to fertilize the microalgae and reduce the amount of land needed
• Tiny simple molecules • Replaces natural gasnatural gas• Very clean burningclean burning!
– Least amount of greenhouse gas greenhouse gas emissions– Least amount of acid rain contributorsacid rain contributors
• No proteins, so no sulfur• No fats so no phosphates
• Result from decomposition of organic matter• In landfills, gasifiersgasifiers can capture methane produced by organic decomposition
3. Biomass 3. Biomass GasificationGasification
Weighing Alternatives to Fossil Fuels
• 40% of Greenhouse gases come from combustion of fossil fuels in Cars
• Acid Rain• Oil Spills and
natural disasters• National Security
and Oil
• Fuel cell splits hydrogen (H2) molecules
• Releases small burst of energy• Combines with oxygen (O2) in
the atmosphere to create water (H2 O)
6 H2 + 3 O2 6 H2 O + ENERGY
Hydrogen Fuel CellsHydrogen Fuel CellsHydrogen Fuel CellsHydrogen Fuel Cells
• Maintain the same infrastructure as fossil fuels
• Must be processed and shipped and cars go to gas stations to fill up
• Requires tremendous amount of energy to split the dihydrogen molecule
• Fuel cells are extremely heavy and extremely expensive
Hybrid vs. ElectricThere’s a LOT of confusion
surrounding hybrid technologyThree basic types:1. Gas-First Hybrid2. Electric -First Hybrid (Plug –in)3. Electric Only
Chevy Volt Plug-In
Toyota Prius Hybrid
Type How it Works Pro’s Con’s
Gas Powered Car
fuel tank, which supplies gasoline to the engine. The engine then turns a transmission, which turns the wheels.
CommonRelatively fast (high potential energy in fuel)
Expensive to maintain (lots of heat and friction
Gas-First Hybrid
Runs on gasoline, but at sustained speeds, it kicks over to the electric motor. Great for long commutes on highways
increase gas mileage reduce the emissionsOvercomes limitations of electric car
Electric motor doesn’t always kick in
Electric set of batteries that provides electricity to an electric motor. The motor turns a transmission, and the transmission turns the wheels.
produces almost no pollutionLittle maintenance, no oil changes needed
• can only go 50 - 100 miles between charges. • very slow • inconvenient to recharge (few stations)• VERY EXPENSIVE to buy and install •Greenness depends on how the electricity was produced to begin with
Electric –First Hybrid
electric motor on a hybrid car can put energy into the batteries as well as draw energy from themWhen it runs out of electricity, it then kicks over to gasoline
No gasoline at all during short commutesCan fill up in your own garageHighest fuel efficiency
Must install charging stationVery few public charging stationsWhere does electricity come from????
• Can extend useable life of gasoline• New technology- may need to work out the bugs and train
mechanics to work on new systems• Whether they are green or not depends on the original energy
source (may still be generated using fossil fuels or nuclear)• Good in places with renewable energy, close to hydroelectric
dam or geothermal power station• Low maintenance /cost of ownership (no oil changes on full
electric motors)• Relatively expensive to purchase vs. gas or flexfuel car• takes a long time (over 10 years at current gas prices) to
“recoup” money in gas savings• http://www.youtube.com/watch?v=MZVSQ3bvI10