Lecture 4 - Non-renewable Resources Flashcards
What are commonly mined metals?
Nickel
Niobium
Aluminum
Platinum
Gold
Mining of uranium and plutonium as nuclear fuels
Nuclear Fuels: unstable isotopes of uranium and plutonium; decay through FISSION into lighter elements, use the released heat energy to produce steam (and then electricity)
Why we mine phosphorous and what are the risks
Phosphate is mined as ore but also for use in organic fertilizers, animal feed supplements, and pesticides
Associated risks with phosphate rock mining:
- air pollution
- water contamination
- wildlife habitat destruction
What are the problems associated with all mining activities?
- Erosion
- Acid drainage
- Toxic tailings
- Loss of habitat and biodiversity
ALL MINING IS UNSUSTAINABLE
Possible solutions:
- Fossil Fuels: Renewable energy forms
- Metals and Gems: Reduce-reuse-recycle
3.Nuclear Fuels: Safety and efficiency of nuclear fuels - Phosphorus: Using less fertilizers
Difference between renewable and nonrenewable resources
Renewable Resources: can be replenished over short periods of time
- sunlight, wind, organic matter, soil, groundwater
Non-renewable Resources: can not be replenished or take a very long time to be replenished
- fossil fuels, minerals, aquifer water
- finite quantity and do NOT regenerate
- stocks in environment become depleted as they are used
- can never be used in a sustainable fashion, they can only be “mined”
Concept of sustainability: which resources can be considered sustainable and which not
Sustainability: the process of living within the limits of available physical, natural and social resources in ways that allow the living systems in which humans are embedded to thrive in perpetuity
- 3 Scientific Principles of Sustainability: Solar Energy, Biodiversity, Chemical Cycling
- Non-renewable resources can never be sustainable
Non-renewable resources: fossil fuels
Fossil fuels: highly combustible substances formed from remains of organisms that accumulate over time in sediments.
1. Coal
2. Oil
3. Natural gas
Coal:
- What is it, how does it form, and how long does it take?
- How is electricity generated using coal?
- Mining techniques
Coal: organic material (with minimal decomposition) that has been so compressed it has become rock; produces the highest amount of CO2 per unit heat
Peat (coal precursor): compressed soil with decomposed organic matter; under high pressure and heat, it undergoes physical and chemical changes and becomes coal
Formation:
- plants that lived in swamps millions of yrs ago, accumulated after death in the soil/sediments
- over million of yrs, the plant dead matter was buried under water and sediment
- increasing heat and pressure as more sediments and rocks form above, turned the dead plants into coal
How Electricity is Generated:
- coal is burned to heat water (thermal energy) which is turned into steam; activates turbine and we get mechanical energy; activates a generator resulting in electric energy
Mining techniques:
1. subsurface mining
- traditional; shafts and tunnels to reach coal and blast
- very dangerous for workers
2. strip mining
- remove surface rocks to get coal, safer but huge enviro impact (causes massive erosion and acid drainage)
- acid mine drainage: outflow of acid water from mines; sulfuric acid produces when rocks containing sulfide are exposed to mining
Oil
- What is it, how does it form, and how long does it take?
- Mining techniques
- Peak oil theory
Most popular source of energy.
Formation
- anaerobic decay and kerogen formation; transformation of kerogen into fossil fuels due to heat and pressure over millions of years
- denser material at bottom, gas on top
How Oil is Extracted
- steam injected, heats ground water, applies pressure, oil is pumped out with oil extractor
- extracted from oil sands where oil is easier to access bc sediments are sandy
- problem: oil extracted is mixed w/ water, chemicals and sand so a new “secrete” composition of chemicals is used to separate oil; leftover mining material creates tailing ponds = air, water, and soil pollution
Peak Oil: The Hubbert Peak Theory
- point of maximum global production of oil
- oil production will eventually decline until all oil is depleted
What about “clean” coal?
Not really that clean…still produces massive amounts of CO2
- use methods to reduce the amount of SO2 and NOx emissions
- help but we still need to reduce our use
Natural gas
- What is it and how does it form?
- Biogenic vs. thermogenic vs. non-traditional sources (landfills and farms)
- Mining techniques (e.g. fracking)
- Are non-traditional sources potentially “renewable”?
Natural gas: mostly methane (CH4), with some additional volatile hydrocarbons; lowest CO2 release of all fossil fuels
Biogenic: formed at “shallow” depths via anaerobic decomposition or organic material by bacteria
Thermogenic: formed at deeper depths via compression and heating of organic materials; we are running out…
Non-Traditional Natural Gas (Landfills/Farms): converting methane gas into electricity
Fracking: pump water into ground, create high pressure, form cracks in rocks so gas flows out
Pros: get natural gas that is otherwise locked up and provides economic benefits to area
Cons: massive potential environmental implications, and it’s loud and ugly
Potentially “renewable” bc we produce a lot of waste
