Fossil fuels (download)

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Transcript Fossil fuels (download)

Energy for tomorrow
Dwindling supplies
Global warming
The race for alternatives: what, when
and how much?
Facts about fossil fuels
• Any carbon based energy source that is
derived from the decomposition of organic
matter
– Natural gas
– Oil
– Coal
• It is a remarkable energy source
• It is not renewable
• It contributes to greenhouse gases
The Big Three of energy
• Fossil fuels have always dominated
energy production – and continue to do so
• Nuclear has made slow to no progress
• Hydro and others are at the trace level
The challenge: fossil fuels are great
energy sources
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Easily transported
Flexible
High energy density
The energy content of 500 gallons of gasoline is
equivalent to
– ~ 3 short tons of coal
– ~ 60,000 cubic feet of natural gas
– ~ 450 gallons of diesel fuel
– ~ 991 gallons of methanol
– ~ 1925 gallons of liquid hydrogen gas (that’s pretty
cold)
– ~ 6060 gallons of high-pressure hydrogen gas
A change is gonna come
• Fossil fuels are not replaced and reserves
are finite – particularly gas and oil
• Carbon deposition in the atmosphere is
associated with global warming – societal
pressure to change
• Increased demand is beginning to outstrip
supply
• Alternatives to fossil fuels are required but
what and when?
Energy problems part I: sources
• Traditional sources will not keep up with demand
– They are finite in quantity
– More people want them
Millions of Barrels per day (“Oil Equivalent”)
300
200
100
0
1860
1900
1940
1980
2020
2060
2100
The illusion of energy
independence
• Oil imports were 35 % in
1973
• In 2003 imports were 55
%
• Other major industrialized
nations are worse off
• Reduced imports will not
reduce prices: oil is a
global commodity, the
price of which is
determined by global
markets
Energy problems part II: sinks
• Hazian logic and global
warming
– Increased CO2 causes
global warming
– Fossil fuels produce CO2
– Fossil fuels produce global
warming
People in glass houses…
• Consumption of fossil fuels produces CO2
– Greenhouse gas – absorbs IR radiation
• Higher energy radiation (UV and visible)
penetrates the atmosphere
• It is released as lower energy radiation (IR)
which does not escape
• 90 % likelihood that climate changed is manmade (increased CO2)
CO2: the three bears of climate
control
• Venus: way too much
• Mars: way too little
• Earth: just right (about 300 ppm)
– But there’s a fine edge
Greenhouse gases: it’s not all CO2
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Carbon dioxide (CO2)
Methane (CH4)
Water vapour (H2O)
Nitrous oxide (N2O)
Ozone (O3)
CFCs
Climate change: what we know
• Temperatures have been rising
• CO2 levels have been rising
• Connect the dots...
Climate change: what we speculate
• Models make predictions for the future
based on assumptions
• If global warming is entirely due to CO2
then…
– Educating Rita
– But what if it’s not…
Pascal’s wager: it’s safer to bet on
it than against it
• Alternative energy sources
• Reduction of CO2 emission from fossil
fuels
• Biomass – grow your own gas
– To be continued
Alternative energy sources
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Wind
Solar
Wave
Hydroelectric
Biodiesel
Ethanol
Nuclear fission
Nuclear fusion
Hydrogen
Kicking the fossil fuel habit
• Beyond the problem of providing
alternative fuels for transportation is the
broader question of providing alternative
means to generating energy
• Fossil fuels represent a remarkable energy
source:
– Almost 600 car batteries are required to store
the energy contained in one 15 gallon tank of
gasoline
Alternative fuels to petroleum
• LPG – liquefied petroleum gas (fossil fuel) –
clean burning
• Compressed natural gas (fossil fuel) – plentiful,
clean burning – requires compression
• Ethanol – biomass, renewable, efficient,
expensive, limited capacity
• Methanol – clean, efficient, corrosive, some
products are hazardous
A pact with the devil
• Nuclear power accounts for 70 % of nonfossil power
• It does not contribute to greenhouse gases
• Proven technology
• Waste disposal an enduring issue
• Connections with weapons and terrorism
are concerns
Let’s conserve our way out
• Current automobiles use 60 % of the fuel
used by 1972 models
• Refrigerators use 33 % of the electricity
• Current GDP requires about 50 % of the
energy required in 1973
• Demand has still increased overall by 30
%
• Did you know that plasma TV uses 10x
more electricity?
We will sacrifice for green?
• Perception: petrol prices are too high!!
• Reality: current energy costs are only 5 –
6 % of personal income
– In the 1980’s the costs were 8 – 9 %
• Perception: $2 gallon is too high
• Reality: $2 gallon is too low
– Hybrid vehicle sales are 1 – 2 %
– SUV sales are 25 %
The hydrogen economy: in our
lifetime?
• Hydrogen has the best energy content by the
pound: compare kcal/g of common fuels
Ethanol - 7.1
Bituminous coal - 6.8
Gasoline - 8.7
Natural gas -11.8
Hydrogen - 34.2
• Clean green: combustion product is water
• “The Department of Energy's plan shows that it
will take decades to fully realize the benefits of
hydrogen.” quote from C&E News August 22,
2005
Hype or hydrogen
• Hydrogen is an energy storage system – not a
source
• Hydrogen does not grow on trees (or come out
of the ground)
• It must be extracted from some other source
– Electrolysis of water (uses electricity)
– From decomposition of natural gas, coal or other
biomass (needs energy)
• The hydrogen economy still demands a solution
to the energy problem; it does not solve it by
itself
Caging the beast
• Hydrogen is a gas, a small molecule and
diffuses rapidly through leaks
• It is flammable
• Hydrogen storage is a major issue
Hydrogen and the fuel cell
• Fuel cells are like batteries except
reactants are supplied from without rather
than within
2H2 + O2 = 2H2O
• Electrical energy powers the car
• H2O is the only emission
• Hydrogen fuel cell vehicles will not achieve
volume until 2030 (it at all)
Hybrid vehicles: compromise
• Hybrids combine gas and electrical engines to
improve gas mileage
• Not a total solution to carbon deposition but a
practical intermediate
• Direction of resources to hydrogen fuel cells has
reduced emphasis on this technology
• Counterpoint: increased investment is required
in hydrogen technology to ensure success
Blowin’ in the wind
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Windpower costs have fallen 80 %
Solar power costs have decreased
Hydroelectric: rather depends on the rivers
Total markets for wind/solar/fuel cells
projected to increase from $16 bn in 2004
to $102 bn in 2014
Want to know more?
• Hydrogen economy
– http://www.hydrogennow.org/
– http://www1.eere.energy.gov/hydrogenandfuelcells/
• Solar power
– http://www.solarpower.com/
– http://www.eere.energy.gov/RE/solar.html
• Windpower
– http://www.awea.org/
• Biomass
– http://www.nrel.gov/biomass/
• Fuel cell and hybrid vehicles
– http://www.hybridcars.com/
– http://www.fueleconomy.gov/feg/fcv_whatsnew.shtml