2 Flashcards
Growth rate of developing countries
1.5% per year
Growth rate of developed countries
4% per year
Amount of energy to produce and deliver $1 of new goods
11 MJ
What % of co2 emissions are anthropogenic
4%
Define commercial energy
Energy sold to users, usually derived on a large scale from fossil fuel combustion, hydroelectric, and nuclear power. As opposed to the biomass used/collected by individuals
What is carbon intensity defined as for the economy?
CO2:GDP
Define carbon intensity for energy
CO2:energy (unit energy consumed )
Which country is most efficient ?
uK
Which country is most productive?
USA
Which countries have been most efficient in the last 50 years?
USA and India
What is an energy resource?
Actual known deposits which are obtainable at a fixed market price
What is an energy reserve
Entire known amount of a given energy source
What is the primary use of coal? Is it heat or work?
Generating electricity.
Work.
One disadvantage and one advantage of natural gas as a fuel source?
Produces less co2 then coal but when methane escapes pipelines it is a more potent ghg then co2
What is a CNG
Compressed natural gas
What is an LPG
Liquified petroleum gas
One advantage/disadvantage of CNG
Advantage- no carbon chains so when combusted it doesn’t release hydrocarbons or organic particles
Disadvantage- some methane escapes tail pipes and pipeline. Methane is a more potent ghg then co2
What is the advantage to making a transportation fuel liquid?
Liquids are denser then gas which allows it to take up less space. This lets you have more fuel in a smaller area.
Energy per unit volume is lower
Why is it possible to liquify propane but not methane at room temperature
Because methane has a very low critical point which forces you to go to very low temperatures before it can liquify and any pressure
Which component of petroleum is the most toxic when a pipeline leaks?
Aromatic hydrocarbons
Primary use of refined oil?
Heat or work?
Transportation
Work
Will we run out or oil in the short to medium term?
No because of increases in technology
Why does extraction of oil from Alberta bitumen reserves emit so much ghgs?
Extraction of oil from bitumen reserves because to separate the sand and bitumen you have to use water heated by natural gas
Using entropy why does it take so much energy to extract petroleum from Alberta’s oil sands
To separate the two requires organization which is anti-entropic. To do this cost energy which you pay in work
Does extracting oil from bitumen result in heat or work?
Work
Define knocking
When Unbranched alkanes and cycloalkanes (due to poor combustion characteristics) combusts unevenly or prematurely. Causing engine to knock
Define octane number?
A gasoline’s ability to generate power with out the engine knocking
ISO-octane = 100
What options do we have to reduce CO2
1) move to natural gas
- more energy per mole but can’t be liquid
2use biofuels that need CO2
- reduces cradle to grave, but to purify it you need to distill it which requires combustion to get to bps
3) switch to different vector
Releases co2 in pure form which makes it more efficient to sequester (h2 and ch3oh)
How do you raise the coat and number of gasoline?
Add btex
What is carbon sequestration?
Co2 is deposited underground or in the ocean to prevent it from being released into the air
What is ccs
Ccs is carbon capture and storage.
The overall process of carbon sequestration
Why do you have to concentrate co2 to sequester it?
It’s not economically feasible to transport and store huge volumes of it. Also you need to purify it
How much energy obtained from a fuel will have to be used to concentrate co2
1/3 - 1/2
What effect will ccs have on the energy intensity of a county?
It will increase it because energy demand will grow while gdp stays the same
Explain using le chateliers how can the reversible reaction above be used to purify co2
Adding heat will push reaction left which will purify co2
What gas must be purified in oxycombustion? Is the goal h or work?
Oxygen must be concentrated and the goal is organization
Give the balanced reaction for syn gas?
Ch4 + h2o -> ch2o + 2h2
What is the EOR and where is it in western Canada?
Enhanced oil recovery
Weyburn sask
3 methods to reduce methane emissions?
1) better maintenance of natural gas pipelines
2) capture/combustion of methane
3) change techniques for rice production
Rank coal, oil and natural gas in terms of moles of co2 released per kJ energy produced
Coal> oil>natural gas»_space; renewable and nuclear
Strategies for increasing std of living while keeping output of co2 steady?
1) production to information
2) renewables
Ipcc
Intergovernmental panel of climate change
Direct solar types
Thermal conversion
Photo conversion
What is indirect solar energy?
Indirect absorption from sunlight
Hydroelectric, wind, wave, tidal
What type of reservoirs exceed co2 releases from power plants?
Shallow large ones
How much of the potential power from wind is being tapped? How much could it potentially provide
- 0.05%
- 1/5
What if the most economic renewable?
Wind
Why can’t we replace the majority of electricity needs with wind?
Biggest turbines generate 5MW
Power plants generate 1000MW
What is a heat pump?
A device that draws heat energy from soil under the ground or from shallow underground river
What is thermal conversion
Sunlight is captured as heat energy by some absorbing material
What is photo conversion
Absorption of photons by photovoltaic materials.
What is the photovoltaic effect?
The creation of separated positive and negative charges in materials by light of an election
What would be needed for solar to replace other energy
Trillions of dollars and 26,000km^2
Just for the USA
Advantages of solar cells
1) cheaper then extending power lines a km
2) competitive cost compared to diesel generation
3) can be built piecemeal instead of all at once
3 disadvantages of solar cells
1) Pv cells generate dc (direct current) which needs to be transferred to ac which costs energy
2) cost of manufacturing not competitive w/ conventional power
3) can’t run at night
Practical long term solutions to the problem of energy storage?
1)Wind can be used to compress air to later be released and turn a turbine
Using solar/wind to pump water up a mountain to later be released
% of worlds energy from nuclear sources?
15%
Reaction of 235U with 1n are both reactive?
What makes the the reaction capable of a chain reaction?
Yes both
235U releases multiple 1n to readily react with 235 U
This induced rapid fission
What are control rods
Neutron absorbing metals to stop the chain reaction ie 235U
How do nuclear power plants make the turbines spin?
Fission rxn produced energy> boil water> generate steam> turn turbine> drive generator > generate electricity
Why is there a cooling tower?
To make tc as far away from th as possible
Which two isotopes are used in fuel rods of nuclear reactors? How are they produced/isolated?
235U and 238U
238U produced from Uo2^2+ (uranium oxide) in zirconium alloy (fuel rod)
Why are spent fuel rods so much more radioactive then original?
Radioactivity arises from both the actinides produced from intact uranium nuclei and from fission products generated when actinides undergo fission
What is reprocessing?
Separating certain actinide elements and use some of them for for nuclear fuel or other purposes (separate them from fuel rods)
Advantage/disadvantage of reprocessing?
Ad- less energy intensive
Did-terrorists
Define renewable
Their production creating low ghg emissions and who’s products can be sustained indefinitely
Define biofuel
Contemporary photosynthetic mass (biomass —-> fuel)
4 incentives for bio fuels
1) carbon neutral
2) renewable
3) oxygen content
4) they replace imported fuel
Give a issues for bio fuels
1) Clearing lots of land
2) biomass
What does E 10 mean?
Ethanol/gas fuel is 10% gas
Adv of bio over petrodiesel
1 better lube
- Biodegrades faster
Disadvantage of bio over petrodiesel
1 lower energy content
2) less offset of co2 due to land clearing
