Nonrenewable Energy Resources Chapter 12 Nonrenewable Energy Resources

Chapter Introduction 1969 Santa Barbara, CA “Blowout” – 3 million gallons of oil 1989 Prince William Sound, Alaska “Exxon Valdez” – 11 million gallons of oil 2010 Gulf of Mexico “BP Deepwater Horizon” – 206 million gallons of oil Various other mine explosion, collapes, etc.

Nonrenewable Energy Nonrenewable energy resources- fossil fuels (coal, oil, natural gas) and nuclear fuels.

Nonrenewable Energy Two Categories: Fossil Fuels Three major fossil fuels are coal , oil and natural gas. Nuclear From radioactive material that gives off energy. Energy is harnessed by the transferring of heat. Giga joule (GJ) 1 x109 Exajoule (EJ) 1 x 109 gigajoules In the U.S. we use a “Quad” 1x1015 btu or 1.055 EJ.

Energy Use Commercial energy sources- those that are bought and sold, such as coal, oil and natural gas. Subsistence energy sources- those gathered by individuals for their own use such as wood, charcoal and animal waste. Some wood, charcoal and animal waste are sold commerically.

History of Energy in the US Always used wood 1875 coal came into wider use. Early 1900’s oil and natural gas became widely used as well. 1950 Nuclear Energy joined the mix and hydroelectric became more widely use. 1970 use of coal declined and oil increased

Energy Types and Quality Obtaining the fuel? What we get out of the fuel? Natural Gas – burns clean, little refining (low cost) Oil/Gasoline – start quick, high energy to mass ratio, refining (high cost), pollution Coal – starts slow Wood - starts slow, low energy to mass ratio Right fuel for the right job? Water Heater Example of efficiency : 99% (35%) electric vs 80% (little less than 80%) natural gas

Energy Types and Quality Quantifying Energy Efficiency Calculate the energy return on the energy investment (EROEI) EROEI = Energy Obtained/Energy invested Example:

Process of Energy Use

Overall Fuel Efficiency of U.S. Automobiles

Energy Efficiency and Transportation Nearly 30% of energy in the US is used for transportation What is more efficient? What is most efficient? What would increase energy efficiency of transportation?

Electricity Generation

Electricity Generation Electricity is a secondary source of energy (we obtain it from a primary source) and is an “energy carrier”. The burning fuel from coal transfers energy to water, which becomes steam. The kinetic energy contained within the steam is transferred to the blades of a turbine, a large device that resembles a fan. As the energy in the steam turns the turbine, the shaft in the center of the turbine turns the generator. This mechanical motion generates energy.

Energy Efficiency Most coal burning power plants are about 35% efficient. 50% of US water consumptions is used for thermal energy production Waste products of CO2 and Ash

Efficiency of Electricity Generation New plants can have as high as 60% efficiency How? Combined Cycle using Natural Gas A typical power plant (fossil fuel) in the US has an energy capacity (electrical output) of about 500 MW per hour. (12,000 MWh in a day) So 12,000,000 kWh (kilowatt hours) per day Capacity Factor is what the plants actually run during the year

Cogeneration Cogeneration- using a fuel to generate electricity and to produce heat. Example- If steam is used for industrial purposes or to heat buildings it is diverted to turn a turbine first. This improves the efficiency to as high as 90%.

Fossil Fuels Most of the worlds energy developing or developed rely on fossil fuels Fossil Fuels – coal, oil and natural gas Fossil fuel formed 50 million to 350 million years ago.

Coal Coal- a solid fuel formed primarily from the remains of trees, ferns, and other plant materials that were preserved 280-360 million years ago. Four types of coal ranked from lesser to greater age, exposure to pressure, and energy content. These four types are: lignite, sub-bituminous, bituminous, and anthracite. The largest coal reserves are in the United States, Russia, China, and India.

Coal

Advantages and Disadvantages of Coal Energy-dense Contains impurities Plentiful ( 1,450 coal mines in 2008 producing 1 billion metric tons) Release impurities into air when burned Easy to exploit by surface mining Trace metals like mercury, lead, and arsenic are found in coal Technological demands are small Combustion leads to increased levels of sulfur dioxide and other air pollutants into the atmosphere. Economic costs are low Ash is left behind (3%-10%) Easy to handle and transport Carbon is released into the atmosphere which contributes to climate change (60%-80% of coal is carbon) Needs little refining

Petroleum Has a fluid nature Formed from the remains of phytoplankton, 50- 150 million years ago. Porous rock like sandstone is capped by non-porous rock. Petroleum contains natural gas as well. When removed from the ground it is known as crude oil. Most refer to oil, crude oil and petroleum as the same things. Crude oil can be refined into tar, asphalt, gasoline, diesel, and kerosene.

Petroleum

Petroleum Petroleum- a mixture of hydrocarbons, water, and sulfur that occurs in underground deposits. Oil and gasoline make this ideal for mobile combustion, such as vehicles. Formed from the remains of ocean-dwelling phytoplankton that died 50-150 million years ago. Countries with the most petroleum are Saudi Arabia, Russia, the United States, Iran, China, Canada, and Mexico.

Petroleum Refining is complex and dangerous. We use 3.1 billion liters per day (1 barrel is 160 liters or 42 gallons) 50% of use is gasoline. Petroleum is also used to make other products like plastics, lubricants, cleaning solvents.

Advantages and Disadvantages of Petroleum Convenient to transport and use Releases carbon dioxide into atmosphere Relatively energy-dense Possibility of leaks when extracted and transported Cleaner-burning than coal 85% of oil entering water ways comes from runoff. Pipelines create habitat fragmentation Releases sulfur, mercury, lead, and arsenic into the atmosphere when burned

Natural Gas Natural gas- exists as a component of petroleum in the ground as well as in gaseous deposits separate from petroleum. Contains 80 to 95 percent methane and 5 to 20 percent ethane, propane, and butane. Can be extracted with petroleum or separate. Can compressed and be used as fuel for cars

Advantages and Disadvantages Natural Gas Contains fewer impurities and therefore emits almost no sulfur dioxide or particulates When unburned, methane escapes into the atmosphere (25x more potent GHG than CO2) Emits only 60% as much carbon dioxide as coal Exploration of natural gas has the potential of contaminating groundwater (Fracking) Cheaper and abundant Large quantities of water used in extraction Disposal of “produced” water

Other Fossil Fuels Oil sands- slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay. Bitumen (tar or pitch)- a degraded type of petroleum that forms when a petroleum migrates close to the surface, where bacteria metabolize some of the light hydrocarbons and others evaporate. Much more energy intensive process. Increased water contamination. Low energy efficiency and increase CO2 emissions

Other Fossil Fuels CTL (coal to liquid) - Expensive 1,000x more energy in coal reserve than petroleum. - But 2x the amount of greenhouse emissions than oil.

Fossil Fuel are Finite Limited amount Can technology extend the amount we have left? “We did not move on from the stone age because we ran out of stones.”

The Hubbert Curve Hubbert curve- a graph that shows the point at which world oil production would reach a maximum and the point at which we would run out of oil.

The Future of Fossil Fuel Use If current global use continues, we will run out of conventional oil in less than 40 years. Natural gas will last longer than oil. Coal supplies will last for at least 200 years, and probably much longer.

Nuclear Energy 20% of US Energy is Nuclear (104 plants) Fission- a nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts.

Nuclear Reactors

Nuclear Reactors Fuel rods- the cylindrical tubes that house the nuclear fuel used in a nuclear power plant. Nuclear power plants work by using heat from nuclear fission to heat water. This water produces the steam to turn the turbine, which turns a generator. Control rods- cylindrical devices that can be inserted between the fuel rods to absorb excess neutrons, thus slowing or stopping the fission reaction.

Advantages and Disadvantages of Nuclear Energy No air pollution is produced Possibility of accidents (meltdown) Countries can limit their need for imported oil Disposal of the radioactive waste 1 g of 235U contain 2-3 million times more energy than 1 g of coal. Mining: use of fossil fuels, slag piles or mine tailings.

Major Nuclear Accidents Three Mile Island in Pennsylvania – 1979 Chernobyl – 1986 Fukushima Daiichi – 2011 (Tsunami/earth quake) http://www.cnn.com/2014/02/19/world/asia/japan-fukushima-daiichi-water-leak/

Radioactive Waste Radioactive waste- once the nuclear fuel can not produce enough heat to be used in a power plant but it continues to emit radioactivity. This waste must be stored in special, highly secure locations because of the danger to living organisms.

Radioactive Waste High-level radioactive waste- the form used in fuel rods. Low-level radioactive waste- the protective clothing, tools, rags, and other items used in routine plant maintenance (mine tailings).

Fusion Nuclear fusion- the reaction that powers the Sun and other stars. This occurs when lighter nuclei are forced together to produce heavier nuclei and heat is released. Fusion is a promising, unlimited source of energy in the future, but so far scientists have had difficulty cotaining the heat that is produced.