Lecture 30: Energy Resources Flashcards
-Energy Cycle and Demand -Types of Energy Resource Deposits -Environmental Impacts of Energy Consumption
What are the three primary energy resources?
- Solar
- Hydrothermal
- Tidal
What are the two categories of non-renewable energy resources?
1) Hydrocarbons - coal, oil, and natural gas
2) Nuclear fuels
How much of the of the world’s energy is supplied by non-renewable energy?
90%
What are some examples of renewable energy sources?
- Hydroelectric
- Solar
- Wind
- Wave
- Alcohol
- Wood
How much energy is lost during the production/use of said energy?
51%
Which continent has the biggest per capita users of energy?
North America
What is the average amount of coal used per person on Earth per year?
2.7 metric tons
What are fossil fuels?
They are a class of energy resources that is formed from organic matter that is buried by sedimentary processes and is thus altered by heat, pressure, and the activity of microorganisms.
How is coal formed?
The deposition of vegetation in bogs and swamps over centuries and millennia leads to the formation of peat.
- Burial must be rapid enough to prevent oxidation of organic carbon, and the material cannot be eroded away.
- If there is sufficient pressure, temperature, and time peat turns into various grades of coal
What conditions is lignite coal formed in, what percent is carbon, and how valuable is it?
- Low pressure and temperature (shallow burial)
- 60%
- Least valuable
What conditions is bituminous coal formed in, what percent is carbon, and how valuable is it?
- Medium pressure and temperature (medium burial)
- 80%
- Average value
What conditions is anthracite coal formed in, what percent is carbon, and how valuable is it?
- High pressure and temperature (deep burial)
- 95%
- Most valuable
What is coalbed methane (CBM)?
Methane that becomes trapped in fractures within a coal seam.
How is the CBM recovered?
Water is pumped from the coal seam which reduces pressure and allows the methane to flow to the surface where it is compressed and transported by pipeline for use.
What organic matter is preserved black shale in small concentrations?
Phytoplankton
What is kerogen?
The organic matter in sediment
What happens when kerogen matures?
It gives off liquid and gaseous hydrocarbons, including bitumen and tar, oil, light condensates, and natural gas
What are petroleum traps?
Geological structures that prevent the escape of oil and gas from a source rock.
What are pools?
The result bodies of hydrocarbons from petroleum traps, they are held in place by an impermeable cap rock
What are the focuses on the exploration of oil and gas?
- Identifying potential source rocks
- Identifying reservoir rocks with high porosity
What is an example of a potential source rock?
Black shale
What is an example of a reservoir rock?
Sandstone or limestone
What is used to identify structures indicative of stratigraphic or structural traps?
Seismic surveys
What are the five steps of the hydraulic fracture water cycle?
1) Acquire water to be used for hydraulic fracturing
2) Mix the water with chemical additives to prepare hydraulic fracturing fluids
3) Inject the hydraulic fracturing fluids into the production well to create fractures in the targeted production zone
4) Collect the wastewater that returns through the well after injection
5) Manage the wastewater via disposal or reuse methods
What is hydraulic fracturing?
It is a process that injects mixtures of water and chemicals with a proppant (sand, ceramics) into a impermeable source rock in order to fracture it and release tightly-held oil and gas
What are tar (or oil) sands?
They are dense viscous deposits of asphalt-like oil that cannot be easily pumped
Where are tar sands formed?
In zones where lighter, volatile hydrocarbons have migrated away, leaving heavier material, or in areas of very low maturity.
What is crude oil?
Petroleum that reaches the surface
What is cracking and what is it used for?
- Breaking down the long-chain hydrocarbon molecule in crude oil.
- Used to produce products ranging from gases and gasoline to heavy oils, lubricants, and tars.
How much of the world’s energy is provided by nuclear energy?
14%
Where can uranium be found?
In sedimentary rocks.
-is concentrated by hydrothermal processes
What are two of the most important ore body types?
1) Unconformity-related ore deposits
2) Roll-front ore deposits
How is uranium formed in unconformity-related ore deposits?
Geofluids flow from fractures in uranium-containing basement rocks to overlying sedimentary rocks.
- The drop in temperature and pressure and redox reactions lead to the precipitate of uranium minerals.
- Uranium can then flow from the sedimentary rocks into fractures, where uranium is chemically reduced to form insoluble uranium minerals.
How is uranium formed in roll-front ore deposits?
Uranium-containing water flows through a sedimentary rock containing reduced minerals.
-As the water containing the oxidized uranium moves into the reduced zone, the uranium itself is reduced, immobilized, and thereby concentrated, creating a roll-front ore deposit
What is nuclear fission and how can it be used to generate power?
A process where the nucleus splits, releasing neutrons.
- Those free neutrons go on to cause other atoms to undergo fission, causing a chain reaction.
- This chain reaction releases large amounts of energy that, when controlled by a nuclear reactor, can be used to heat up water whose steam moves turbines that create energy
How can solar energy be used to generate electricity?
- Can be converted directly into electricity in photovoltaic cells (solar panels)
- Concentrated by mirrors to heat water, which drives electric turbines.
How is hydrogen fuel created?
Using the sun’s energy to split H20 into H2 and 02.
How can biomass be used for energy?
It can be burned directly for energy or pyrolyzed to produce biofuels and biochar
What are the four types of renewable energy that are powered by the sun?
1) Solar energy
2) Hydrogen Fuel
3) Wind energy
4) Biofuels
How is hydroelectric energy generated?
By the gravitational flow of water downhill, turning electric turbines.
How much of the world’s energy could hydroelectricity produce?
18%
What is tidal energy?
Energy generated from the gravitational interactions among the Earth, the Sun, and the Moon, where water is trapped in narrow bays and released to drive turbines
What is geothermal energy?
Energy that uses the heat of the Earth itself.
-Water is pumped into hot rocks, heated, and hot water is used to drive turbines that generate electricity
What are the consequences of hydrocarbon extraction?
- Removal of large rocks disturbs ecosystems and waste rock piles may create potentially toxic mine drainage.
- Petroleum production causes periodic accidental releases of oil and gas (spills) at the surface, and high sulfur gas resources are poisonous
- The water that is used to extract hydrocarbons becomes contaminated
What chemicals are in photochemical smog?
- Ozone
- Nitrous Oxides
How does smog form?
1) Nitric oxide can be present from combustion or generated by a photochemical reaction
2) Oxygen radical combines with oxygen gas to form ozone
3) Ozone can accelerate the oxidation of photochemically reduced NO
4) NO2 gas reacts with hydrocarbons that are present in exhaust to form harmful volatile organic compounds
How is acid rain created?
The addition of sulfur and nitrogen oxide gases from industrial air pollution can lead to acids, and these acidify rain often in the pH 3 to 5 (natural pH = 5.6).
-This acidification is particularly great in areas downwind of industrial regions and large cities.
What are some general impacts of the use of fossil fuels?
- Generates greenhouse gas emissions
- Increase global temperatures
- Production of particulate matter
