Environmental Geology: Fossil Fuels
Coal
- Carbon-rich sedimentary rock that burns to create energy - from PLANTS that have been buried and compressed in SWAMPS
Arab Oil Embargo: Early 1970s
- Gas prices skyrocketed, uncertain supply - Wake-up call: too much reliance on foreign oil
How is organic matter turned into petroleum?
- Heat and pressure - Time (millions of years!)
2008 Crisis
- Huge gas price increase in U.S - Less car driving during period of expensive gas (temporary change)
Oil problems
- Natural oil seeps = natural pollution - Oil spills (constant leaks, but big spills are the problem): cause local biological catastrophes
Keystone XL Pipeline Controversy
- Strip-mining uses lots of water and piles up tailings (waste left after the mining process) - Dirty, difficult to refine, and produces CO2 pollution
Renewable energy types
- Water energy (Mechanical energy of falling water turns turbines) - Wind energy (Mechanical energy of blowing wind turns turbines) Neither require combustion (burning up of resource)
Petroleum problems
- using up valuable resource - release of CO2 into atmosphere - Oil spills - Production of ground ozone
-How many barrels we have left in U.S -How many we use per year
-21 billion -7.5 billion
Natural gas supplies how much of US energy? Current reserves?
25% 200 trillion square feet (and declining)
1 barrel of oil =
42 gallons
Percentage of our energy that comes from fossil fuels
83%
Source rock
A rock rich in organic matter which, if heated sufficiently, will generate oil or gas. (most commonly shale, dark in color because of organic matter, not permeable)
ANWR and NPRA
ANWR: Arctic National Wildlife Refuge: 8 billion barrels NPRA: National Petroleum Reserve: 7 billion barrels
Permeable rock
Allows oil to migrate through and collect (sandstone is the best reservoir rock)
Tar Sands
Bitumen -thick, viscous, goopy "tar" - found in Canada... Keystone XL Pipeline from Alberta to U.S - mined, not drilled
Burning old organic matter releases
Carbon dioxide
Oil - Conservation efforts
Carpooling, energy-efficient transit systems, fuel-efficient automobiles, better insulation= less heating required, alternative energy
Industrial revolution fueled by
Coal (easy to harvest, but not very efficient or clean)
Light oil (conventional)
Easier to harvest, naturally rises to surface, thin fluid
Economic reserves vs. Sub-economic reserves
Economic: profitable Sub-economic: currently unprofitable because more difficult to acquire
Fossil fuels used for:
Energy (heating hot water), transportation (cars, planes, trains), petrochemicals (plastics, rubber, solvents, fertilizers)
Natural gas
Gaseous hydrocarbons (Methane, propane)
Heavy oil
Harder to harvest, cold, sticky, viscous
Anticline
High point where oil and gas collects
Peat
Immature coal that burns readily
Oil Shales
Immature hydrocarbons - rock with high level of KEROGIN (solid, organic-rich) - Precursor to oil, but can't be drilled... must be mined
How oil gets to surface
It is naturally buoyant, so it rises through porous, permeable rocks. If there is no cap rock, it bubbles up as a seep. If there is an impermeable cap rock, it is trapped and can be drilled out.
Oil
Liquid hydrocarbons (gasoline, etc.)
"Clean" Coal
Lower-grade coal: Less sulfur, but still lots of carbon dioxide emitted
Petroleum
Made from carbon from previously living creatures (Old decomposed ORGANIC matter, mostly from PLANKTON sediments built up on seafloor)
Fracking
Making cracks in an impermeable rock to pull out oil (increasing porocity) - Side effect: tiny earthquakes - Bigger concern: Chemical use
Middle East
More than half of world's supply of oil -Over 600 billion barrels - Geopolitical connection
Are fossil fuels renewable?
No - they take millions of years to form, and once they're gone, they're gone forever
Industrial Revolution (1770s-1880s)
People started using fossil fuels to run machinery, drastically improving standards of living and lengthening lifespans, but also dramatically raising CO2 levels in atmosphere
Impermeable rock
Prevents oil from bubbling out to surface in a seep (shale is the best cap rock)
Coal pros and cons
Pros: Cheapest energy source, massive amount of coal reserves that could fuel U.S for hundreds of years Cons: Huge source of pollution, release of toxic metals,soot, sulfur gases that lead to acid runoff
Alaskan Oil
Prudhoe Bay: 13 billion barrels of reserves total, 11 billion of which we've used up
Enhanced Oil Recovery
Pumping water, steam, CO2, or natural gas into a well to increase pressure so heavy oil can be drilled
Oil and gas found together
Since gas is lighter, it floats to the top. Lighter oil then sits below gas and heavier oil stays at the bottom
Peak oil
When we've used half of what is available on earth - Some people debate we've already reached it
Fossil Fuels
carbon-rich remains of ancient life -oil, natural gas, coal, etc.
Electricity process
heat energy -> mechanical energy -> electric energy
Oil seep
oil naturally rising to the surface
Consumption of fossil fuels is...
rising, especially in wealthier countries, because standards of living are rising