8.1 & 8.2 - Fossil Fuels

8.1 - Energy and the Enviornment

Name the 3 fossil fuels

1. oil (petroleum

2. coal

3. natural gas

Facts about fossil fuels

• most fossil fuels formed long before dinosaurs, extinction = 65 million years ago

• they’re easy, cheap, reliable

• 80% of energy used in the US comes from burning fossil fuels

• nonrenewable carbon-based resources formed between 150-300 million years ago from remains of dead organisms

Photosynthesis

• process of turning light into energy

• only done by plants/producers

• consumers eat the plants and consume their energy

Energy in the US

% of fossil fuel usage in US

Combustion Reaction

• when carbon and hydrogen atoms from a fossil fuel combine with oxygen from the air to form carbon dioxide and water

• converts chemical potential energy stored within bonds of fossil fuel into thermal energy

Oil (Petroleum)

• partially decomposed ancient marine microorganisms sunk to ocean floor and over time, were buried under layers of sediment and rock

• made up of a mixture of hydrocarbons

C₄H₁₀

What does most oil and natural gas start life as?

• microscopic plants and animals that live in the ocean

• plant plankton

• animal plankton

How does oil form?

• sea creatures died, sediment built up, the trapped oil is in between layers

• scientists don’t really know what it is

What are some popular oil sites?

• Middle East

• east South America

• Russia

• scientists are debating whether to dig in Antarctica

• Wyoming

• West Virginia

• Kentucky

• Pennsylvania

Oil Transportation

• once extracted, oil and gas must be sent to a refinery for processing

• pipelines transport most of the world’s oil from refinery

• massive oil tankers also play an important role in distribution

• supertanker, train, truck, or pipeline

How is oil extracted?

• drilling, on land or at sea

• strip mining in the case of tar sands oil and shale

Oil’s Uses

• transportation fuels (gasoline)

• electrical generation

• asphalt

• plastic

Natural Gas (formation and composition)

• formed in the same way that oil forms

• due to density differences, natural gas is found trapped on top of petroleum deposits

• composed of mostly methane, but could also contain butane or propane

Natural Gas (sustainability)

• contains more chemical potential energy per kg than coal or oil = more efficient

• produces less CO2 (pollutants) than oil or coal when burned

Uses of Natural Gas

• cooking

• heating

• homes

• manufacturing

• it is federally mandated to add sulfer to prevent it from not smelling, which may lead to people not noticing gas leaks

what is the difference between conventional and unconventional natural gas?

• conventional - located in porous and permeable rock beds or mixed into oil reservoirs and can be accessed via standard drilling

• unconventional - any form of gas that is too difficult or expensive to extract via regular drilling, requiring a special stimulation technique, such as fracking

Hydroulic Fracturing “Fracking”

• uses chemically treated high pressure water to break apart rock containing natural gas

• risks include contamination of ground water and air pollution from methane release

Coal

• decomposing swamp plants buried under mud with no oxygen, these remains produced peat

  • peat = partially decayed vegetation

• over time, increased pressure and heat transformed this peat into the coal we use

Why do we use coal?

• safer to ship, cheaper to extract, abundant in US

  • Wyoming, Appalachian Mountains hold majority of US coal

• inexpensive

Cost of coal

• more air pollution than any other fossil fuel

  • CO2 released into the atmosphere leads to global warming

• Extraction = lots of environmental damage

  • many hazards associated with mining

how does a coal power plant work?

1. coal is burned in a furnace- converted to thermal energy

2. thermal energy heats water to make steam

3. steam turns turbine

4. turbine blades spin an electric generator

5. electrical current transmitted along power lines

What are the advantages and disadvantages of using fossil fuels to generate electricity?

• they convert chemical potential energy to thermal energy, which is then converted into other useful forms

• they are nonrenewable and bad for the environment

how does a nuclear power plant work?

• fission takes place in the reactor vessel, control rods are used to control the chain reaction

• it is encased in a concrete container/containment structure to cool the process

• water from the ocean is used to cool the very intense heat caused from the reaction

• the cooling creates steam which spins a turbine, which powers a generator, which powers other things, like telephone poles

In what ways do people use energy resources daily?

• charging cell phones

• logging onto the internet

• stoves

• furnaces

• air conditioners

• vehicles

How does the law of conservation of energy apply to the burning of fossil fuels?

• it isn’t created, since it comes from the energy of dead plants and animals

• it isn’t  destroyed because when it burns, the energy is converted into a new form, like thermal energy

Why are fossil fuels considered to be a nonrenewable resource?

• they take millions and millions of years to form

• they are being burned and used a much faster rate, which will lead to them eventually running out

What are the advantages and disadvantages of nuclear power plants and those that burn fossil fuels?

• they transform nuclear/chemical energy into electrical energy

• they aren’t renewable

What is nuclear fission? Example? Why does it release energy?

• an atom splits apart

• causes a tremendous amount of thermal energy to be formed from a small amount of mass

• concrete towers encase these processes, cooling it down by releasing waste heat

• doesn’t take as much energy to create as fusion, less cost

• ex: the energy from the sun

• releases energy because the smaller atoms don’t need as much energy as the bigger atoms, so they emit thermal energy

What is nuclear fusion?

• atoms combine at very high temperatures

• a small amount of mass creates a tremendous amount of thermal energy

• using this method as an energy source is problematic because their reactants require great amounts of energy and their high temperatures aren’t easy to contain

What is a chain reaction (fission)?

• when a neutron strikes the nucleus of a uranium atom

• causes it to split into two smaller atoms

• two or three neutrons are emitted

• the process continues

What are the different classifications of nuclear waste and what do they mean?

1. low-level waste - low levels of radioactive material

   • half-life = the time it takes for half of the radioactive atoms in a sample to decay into a different element or isotope

2. high-level waste - high levels of radioactive material

What are some indicators that our climate is changing?

• polar ice is melting

• shifts in animal locations/migrating (season’s timing)

• global temp is rising

• less snow

• hurricane season is longer

• ocean temp/level is rising

• less ozone

• traces of more green house gases

• pH is decreasing, more acidic oceans

Balance the chemical reaction for photosynthesis:

CO₂ + H₂O → C₆H₁₂O₆ + O₂ = carbon dioxide + water →glucose + oxygen

6CO₂ + 6H₂O → C₆H₁₂6O₆ = photosynthesis

Where does nuclear energy come from?

U₂₃₅ in the ground

What type of energy is the product of nuclear energy?

thermal energy

is nuclear energy a fossil fuel?

no

is nuclear energy organic

no, it does not contain carbon

is nuclear energy renewable?

no

where are nuclear power plants?

• located in 32 countries

• about 440 nuclear reactors in total

• 60 new power plants under construction

• lots on east coast of the us

• lots in europe

• few in other places

• not built near seismic zones

how many kg of coal is equal to 1 kg of uranium?

• 3 million

• overall efficiency of a nuclear power plant = 35%

Pros of nuclear energy output

• does not produce air pollutants that burning fossil fuels does

• no release of CO₂

• large amount of energy produced from small amount of uranium

cons of nuclear energy output

• disposing of nuclear waste is difficult

• uranium is not renewable

• power plants expensive to build, takes 10+ years

• radioactive material harmful to living organisms and the environment