UNIT 4 - AOS 2 Flashcards
Fracking
- Method to extract natural gas from shale formations
- The gas collects beneath an impermeable rock = reservoir
- Takes several months to develop a well to collect the gas
Steps of fracking
- Vertical hole drilled and then horizontally (kick-off point)
- Hole is lined with steal and cement to create pipes
- The drill rig then lowers the frac gun to end of borehole and is fired to punch holes in steel& cement
- Water from stored onsite tanks is mixed with sand and chemicals to be pumped into the borehole with pumper trucks (high-pressure) = causes fractures in the shale layer to reach gas reserves.
- The segment is plugged and process is repeated further along the borehole.
- Plugs drilled out and gas extracted
- Waste removed after extraction
Benefits of fracking
- new supplies of gas around world
- Well can produce for many decades once established
- Burning natural gas for electricity = makes less CO2
- Creates jobs
Disadvantages of fracking
WASTE WATER
- Large amount containing chemicals, oil, gas and radioactive particles
AQUIFERS
- Chemicals and methane can leak (prevented with cement and steal)
EARTH TREMORS
USE OF WATER AND SAND
- Large amounts are used
- water cant go back into water cycle because it is contaminated.
FF use in pre-1750
- Before industrial revolution & wood was main energy source (biomass)
- Coal was shown to cave men for heating
- Romans then used coal
FF us in 1750-1850
- Industrial revolution (coal powered factories, ships, trains and heat for homes)
FF use in 1886
- Petrol engine invented
- 4-wheeled automobiles
FF use in early 1900s
- WW1 = first fossil fuel conflict
- ^ prod of vehicles, armour, guns, and ammunition
- First oil fueled airplane invented
FF use in 1960s
- Coal = major source of fuel used to generate electricity
FF use in 1970s
- Shortages due to oil embargo of key oil-producing countries (world energy crisis)
= ^ oil $ due to limited supply
The problem with fossil fuels
= non-renewable and consumed faster than can be replenished
Peak oil
“Point in time where rate of oil extraction will reach peak and then decline”
Predicted many times but never happened because:
- Unreliable patterns of energy use = wrong predictions
- Development of new energy sources (renewables)
- Changing oil prices change consumption rates
- Change of policies = decreased reliance of FF for energy
Notes about energy
- Transferred from 1 body to another
- Can be stored, transported, transformed, transferred, preserved, degraded
- Basic unit of energy = Juole (J)
the 2 main types of energy
Potential energy = Has the potential to move
Kinetic energy = All forms of kinetic energy (movement)
Types of potential energy
- GRAVITATIONAL POTENTIAL ENERGY
Something above ground that has the potential to fall (e.g. gate preventing water fall) - CHEMICAL POTENTIAL ENERGY
Energy produced by breaking of chemical bonds (e.g. combustion) - ELECTRICAL POTENTIAL ENERGY
Electricity can be used to make light, heat, sound and to make things move) - ELASTIC POTENTIAL ENERGY
A spring, compressed or extended, will move when let go
Types of kinetic energy
- MECHANICAL
Kinetic energy produced by a moving machine (gears) - RADIANT
Light movement and all electromagnetic waves - THERMAL
Heat is movement of atoms that something is made up of - CHEMICAL
Is released during a chemical reaction, often in form of heat - SOUND
movement of atoms or molecules
Energy transformations (def and types)
“Energy is changed from one form to another”
Single step (e.g. chemical (battery) -> radiant (torch))
Multi step (e.g. nuclear chemical -> thermal -> mechanical -> electrical)
The energy transformations poster
MAIN TRANSFORMATIONS
Combustion (Kinetic thermal)
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Steam (kinetic thermal)
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Turbine (kinetic mechanical)
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Generator (Kinetic electrical)
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Distribution
- COAL (Potential chemical) -> Combustion
- COAL SEAM GAS (potential chemical ) -> Combustion
- NATURAL GAS (potential chemical) -> combustion
(stops after combustion and goes straight to distribution) - NUCLEAR (potential chemical) -> Steam
- GEOTHERMAL -> Steam
- HYDRO-ELECTRIC (Gravitational potential) -> Water released from dam (Kinetic) -> Turbine
- WIND -> Turbine
- SOLAR(kinetic radiant) -> PVC cells (kinetic electric)
Laws of thermodynamics
1st LAW
Energy is not created or destroyed (it changes through different forms)
2nd LAW
When transformed, some energy is degraded to a lower quality form (energy is not 100% efficient)