Chapter 12

Nonrenewable Energy Resources

Laws of thermodynamics

1. Conservation of Energy which states energy is not

created nor destroyed, it is conversed…..transferred

forms

2. When energy is transformed, its ability to do work

(force applied x distance in the direction of force)

diminishes, some energy is “lost” during each

conversion (entropy)

• Energy is degraded (heat), as it moves up the trophic

levels…converted into other forms of energy (total

energy before = total energy after)

• Energy is spontaneously regenerated by the sun…we have

matter on Earth that the sun gives energy (producers grow

100%) we eat and get that energy (10% rule)…

⬜ Nonrenewable energy resources- substances that once used up, cannot be replenished (need to be replaced, finite)

2 types of nonrenewable resources:

1. Fossil Fuels – derived from biological material that became fossilized millions of years ago.

◼ Coal, Oil (Petroleum), Natural Gas – burned to harness the heat energy from combustion.

2. Nuclear Fuels- derived from radioactive material that gives off energy.

◼ Harness energy by transferring heat.

Nonrenewable Energy

Coal, Oil, Natural gas are major sources of energy for the world

Peat, precursor to

coal, sometimes

combined with coal,

mostly in developing

countries.

⬜ Commercial energy sources- those that are bought and sold, such as coal, oil and natural gas. ⬜ As nations become more developed….the demand for

commercial energy sources increases.

⬜ Subsistence energy sources- those gathered by individuals for their own use such as wood, charcoal and animal waste.

Energy Use

Fossils fuels (such as coal) are

projected to rise due to

developing nations (such as

China and India) increasing use

Process of Energy Use

Overall Fuel Efficiency of U.S. Automobiles

Electricity Generation

⬜ 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.

⬜ Potential to kinetic (generates electricity through the use of turbines)

Electricity Generation

⬜ Most coal burning power plants are about 35% efficient.

Energy Efficiency (Singapore)

⬜ Cogeneration (combined heat and power)- using a fuel to generate electricity and to produce heat. (using the steam generated as thermal energy)⬜ (Ex)- If steam is used for industrial purposes or to heat

buildings it is diverted to turn a turbine first.

⬜ This improves the efficiency (not 100%) to as high as 90%, whereas steam heating alone is 75% and electricity alone is 35%.

⬜ We measure Energy efficiency by…. both the efficiency of the process of obtaining the fuel and the process that converts it into the work that is needed (how we use it). Risk vs. Benefit

Cogeneration

⬜ Coal- a solid fuel formed primarily from the remains of trees, ferns, and other plant materials (ancient biomass) that were preserved 280-360 million years ago.◼ The efficiency of the transfer of energy from a fuel to electricity for a

coal-fired power plant is approximately 35%

⬜ These four types are: lignite, sub-bituminous, bituminous, and anthracite ranked from lesser to greater age, exposure to pressure, and energy content.⬜ The largest coal reserves are in the United States,

Russia, China, and India.⬜ Ideal fuel for stationary combustion applications,

such as power plants, and industry

1. Coal

Liquified Coal (CTL)

⬜ Coal liquefaction is a process of converting coal into

liquid hydrocarbons: liquid fuels and petrochemicals

◼ most common process chain is "Coal to Liquid Fuels"

(CTL).

⬜ Advantage:

◼ lower greenhouse emissions than regular coal, but

more than petroleum

⬜ Disadvantage:

large demand for water

◼ large demand for energy needed to process coal

◼ land degradation in the United States

Coal

Material is buried under layers of sediment & exposed to heat

and pressure, the organic compounds chemically transformed

into high-energy solid, liquid, & gaseous components that are

easily combusted

Advantages Disadvantages

Energy-dense Contains impuritiesPlentiful (abundant in U.S) Release impurities into air when

burnedEasy to exploit by surface mining

Trace metals like mercury, lead, and arsenic are found in coal

Technological demands are small (capabilities to manufacture)

Combustion leads to increased levels of sulfur dioxide and other air pollutants into the atmosphere.

Economic costs are low Ash is left behindEasy to handle and transport Carbon is released into the

atmosphere which contributes to climate change

Needs little refining

Advantages and Disadvantages of Coal

⬜ 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. ⬜ Ideal fuel for mobile combustion, vehicles.

2. Petroleum

PetroleumPetroleum

migrates to the

highest point in

a formation of

porous rock and

accumulates

there. Liquid

petroleum

(crude oil) can

be removed by

drilling a well.

Refined into

asphalt,

gasoline, diesel,

kerosene…

Advantages Disadvantages

Convenient to transport and use Releases carbon dioxide into

atmosphere (other pollutants, S,

Hg, Pb, As like coal)

Relatively energy-dense Possibility of leaks when

extracted and transported

Cleaner-burning than coal Not abundant in the U.S. (get

from outside the states)

Releases sulfur, mercury, lead,

and arsenic into the atmosphere

when burned

85% of oil entering marine

waterways come from runoff from

land, rivers, airplanes, boats, and

accidental spills (Killing birds and

marine life)

Advantages and Disadvantages of Petroleum

⬜ Natural gas- exists as a component of petroleum in the ground as well as in gaseous deposits separate from petroleum (typically extracted with petroleum).

⬜ Contains 80 to 95 percent methane and 5 to 20 percent ethane, propane, and butane.

⬜ Largest uses of natural gas is electricity generation and industrial processes (24% of energy used in U.S)⬜ Be used as nitrogen fertilizer, residential efficient fuel (one-half U.S

uses to heat homes)

3. Natural Gas

Advantages Disadvantages

Considered to be the “clean” fossil fuel

Contains fewer impurities and therefore emits almost no sulfur dioxide or particulates (lower per unit energy obtained)

When unburned, methane escapes into the atmosphere

Exploration of natural gas has the potential of contaminating groundwater flow, causing areas to flood or wells to go dry

Emits only 60% as much carbon dioxideas coal

Unburned natural gas-methane-escapes into the atmosphere is a potent greenhouse gas that is 25x more efficient at absorbing Infrared energy than CO2

Disturb soil (“thumper trucks” generating seismic vibrations in order to identify natural gas deposits)

Process of drilling & opening up rock in order to release natural gas is called Hydraulic Fracturing/Fracking (pipelines in sensitive areas)….large qualities of water is used in this process, water becomes contaminated

Advantages and Disadvantages Natural Gas

⬜ 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. (extracted by surface mining)

⬜ Extend our oil supply, but much more energy-intensive than conventional drilling for oil. ***requires so much energy to refine, resulting CO2

release greater.

Other Fossil Fuels

⬜ 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. (reach a peak than steadily decrease)

The Hubbert Curve

⬜ If current global use continues, we will run out of conventional oil in less than 40 years.

⬜ Coal supplies will last for at least 200 years, and probably much longer.

⬜ Advances in techn, a shift to non-fossil fuels, changes in social choices, and/or population patterns could alter the values above.

The theory to the Future of Fossil Fuel Use

Nuclear Energy

⬜ Same basic process as electricity generation

from fossil fuels…steam turns a turbine that

turns a generator that generates energy.

⬜ Difference is that a nuclear power plant uses

radioactive isotopes (uranium-235) as its

fuel source.

⬜ Uranium-235 is a great fuel source due to its

ability to conduct fission efficiency

⬜ Fission- a nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts.

Nuclear Energy

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⬜ 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….prevent meltdowns!!

Nuclear Reactors

Nuclear Reactors

Light-water reactor…found in U.S

Control rods – absorbs excess neutrons, slowing or stopping the fission

reaction (checks and balances)

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Stream leads to turn

the turbine that

generates electricity

(generator)

Cooling water so the

reactor core doesn’t

overheat and have a

“meltdown”

Advantages Disadvantages

No air pollution is produced Possibility of accidents (nuclear meltdowns –radiation released into environment….Chernobyl)

Countries can limit their need for imported oil

Disposal of the radioactive waste (based on half life will determine the disposal method). The longer the half-life, the longer it will take to decay

Advantages and Disadvantages of Nuclear Energy

⬜ 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.

Waste cannot be incinerated, safely destroyed using chemicals,

shot into space, dumped on the ocean floor, or buried….because

all these options can put damage our oceans and atmosphere.

Waste should be stored in a geologically stable site away from

humans habitation.

On average, it takes a fuel rod at least 10 half-lives to decay in

order to reduce the threat on human health

Only option is to store into something that doesn’t allow leaching

into our groundwater or otherwise escape into the environment.

Radioactive Waste

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Copyright©2000 by Houghton Mifflin Company. All rights reserved. *

⬜ 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 containing the heat that is produced.

⬜ Trying to mimic the SUN ☺

Fusion