Nonrenewable Energy Flashcards
Net Energy Yield
Amount of high-quality energy available from a resource minus the high-quality energy needed to make the energy
Cogeneration
When the heat produced from electricity generation is used to provide heat (air and hot water) to a building
CHP (Combined Heat and Power) systems
Close to 90% efficient (much better than coal/NG alone)
Fossil Fuels
Combustible deposits in the Earth’s crust [composed of the remnants (fossils) of prehistoric organisms that existed millions of years ago]
Fossil Fuel Formation
300 million years ago, climate was mild, vast swamps covered much of the land, dead plant material decayed slowly in the swamp environment
Coal
A solid fuel formed primarily from the remains of trees, ferns, and other plant materials
Big Reserves of Coal
US, Russia, China, Australia
Big Users of Coal
China, US, Japan, South Africa
Coal Cons
- contains impurities
- releases impurities (sulfur oxide – acid rain)
- trace metals
- combustion leads to increased levels air pollutants
- ash is left behind [can leak into ground/surface waters]
- high amounts of carbon released into the atmosphere
- habitat destruction
Coal Pros
- energy dense
- plentiful
- easy to exploit
- needs little refining
- inexpensive
- easy to handle
Coal: Ash deposit accident
2008, Knoxville TN, 4.1 billion liters of ash and water, 3 houses destroyed
Known coal deposits could last ________________
100 - 150 years
Scrubbers
Desulfurization systems: remove 98-99% of sulfur from power plant’s exhaust
Expensive
Sludge by product must be disposed of
Nationwide cap
of SO2 and nitrogen oxide emissions makes making coal a little better
Synfuels
A liquid or gaseous fuel that is synthesized from coal and other naturally occurring sources [substitute for oil or natural gas]
Petroleum
Organic material (phytoplankton) buried in sediment and subjected to high pressure and temperature
Crude Oil
Liquid petroleum removed from ground (needs to be refined)
Refineries separate crude oil into components such as ________________
gas, tar, and asphalt
Big Reserves of Oil
Venezuela, Saudi Arabia, Iran, Canada, Iraq
Big Users
US, China, Japan, India
Oil Drilling
Ultra deep wells are possible; directional drilling allows well heads to travel horizontally up to 6km away to reach the oil
We can recover about 40% of oil in a formation before it becomes uneconomical to continue
Petroleum Refining
Numerous hydrocarbons are separated[based on boiling point]
Natural gas contains far fewer hydrocarbons
- Methane, Ethane, Propane, and Butane
Other places to get oil
Shale oil: oil that is integrated within bodies of shale rock
Oil sands: another source of heavy oil; need to do clear cutting of forests and strip mine the land
Oil Pros
- convenient to transport (liquid)
- relatively energy-dense
- cleaner burning than coal
- oil is used in many other applications
Oil Cons
- releases co2 in atmosphere
- possibility of leaks and skills
- runoff enters marine waterways
- releases heavy metals into the atmosphere
- land affected through drilling [habitat destruction]
Environmental Consequences of Tar Sands
- habitat destruction
- ground or nearby surface water depletion
Environmental Consequences: crude oil
- possibility of spill
- habitat loss or fragmentation
How much time is left for oil?
50 years
Natural Gas
- composed of methane
- produces half as much co2 as equivalent amount of coal
- burns cleaner than oil and coal
- horizontal drilling and fracking in semi-permeable sedimentary rock
Natural Gas Reserves
Russia, Iran, Qatar, US, Saudi Arabia
Natural Gas Users
US, Russia, China, Iran
Natural Gas Pros
- contains fewer impurities
- emits only 60 percent as much carbon dioxide as coal
Natural Gas Cons
- potent greenhouse gas
- contaminate groundwater
Hydraulic fracturing aka fracking
- pumps high pressure chemicals into rocks to crack them
- breaks or fractures open porous rock that holds natural gas
Fracking Environmental Consequences
- Possibility of well leaking and contaminating groundwater with fracking fluid
- depletion of ground or surface water nearby [increased seismic activity]
How many years of natural gas do we have left?
50-60 years
