THE NEED FOR ENERGY

Objectives: Students will be able to explain how changes in human societies have changed the

demands for energy and describe the structure of organic fuels.

Forms of Energy

Heat Light Electricity Mechanical Chemical Nuclear All meet the needs of people on Earth

Law of Physics

Energy cannot be created nor destroyed

It can, however, be changed from one form to another

The storage, transfer, and conversion of energy are the driving forces behind all life on Earth

Fuel

What is fuel?

Is any substance from which energy can be obtained

Electricity

Much of the energy needed by today’s society is used to generate electricity.

Electricity is not a form of energy commonly found in nature except for lightning.

Conversion of energy from one form to another is never 100% efficient.

Some is lost during the conversion usually in the form of heat, light, or both.

Changing Energy Needs

Energy needs of most nations of the world change over time

History of Energy:Hunter-gatherer-very little

need, only for light, heat, and cooking, wood meet these needs

Agricultural Societies-domesticated animals became the power sources

Changing Energy Needs

Industrial Revolution- growing populations, animals were overtaken by machines

Factories-as populations grew the needs for energy increased

Fuels from Organisms Organic Fuels

Fuels made from organismsContain carbon-based molecules that were

formed by living thingsAlso contain Hydrogen

HydrocarbonA compound composed only of carbon and

hydrogenExamples:

○ Methane (CH4)

○ Ethane (C2H6)

○ Octane (C8H18)

Impurities

Organic fuels contain more than hydrocarbonsSulfurLeadTypically improve the ability of fuel to

provide usable energyDownfall is that they lead to the pollution

released when fuels burn

Fossil Fuels

Original energy is provided by sun and converted to stored chemical energy in plants

Passed on to animals who eat plants When plants and animals die, energy

stored in cells remains Energy stored in organisms who died

millions of years ago is used as fuel today.

Fossil Fuels

Fuels derived from the remains of organisms that lived long ago

Three kindsCoalPetroleumNatural Gas

Quiz

What is a fuel? How can you recognize a hydrocarbon

from its molecular structure? Make a list of four activities in your daily

life that can be accomplished with or without tools that require energy. Example: You can open a can manually or you can use an electric can opener.

17.1 COAL

Objectives: Students will be able to list the stages of coal formation and describe the characteristics of each

stage. Students will also be able to locate the major coal deposites on a map of the U.S.

Intro to Coal

After years and years of plants dying and layers and layers of sediments piling up, heat and pressure produced by the weight of the sediments caused chemical changes to occur within the plant matter.

At the same time, water was forced out causing the plant material to form into solid rock called coal.

Coal Formation

Occurs in stages, each with distinct physical and chemical properties

PEATCompacted mass of twigs, leaves, and branchesIs a brittle, brown plant material containing a great deal of

water and a low percentage of carbonNot a form of coal, but is first stage in coal formationResembles wood and is located near surface of earthBurns quicklyGives off large amounts of smoke because of high

percentage of water and impurities.

Lignite

2nd Stage Heat and pressure compress PEAT

changing it to LIGNITE Is a soft, brown coal composed of about

40% carbon. Burns quickly and give off very little

smoke Located below Earth’s surface and must

be mined.

Bituminous Coal

3rd stage Heat and pressure change LIGNITE into a purer form called

BITUMINOUS Coal Is a soft coal located deep in Earth’s Crust Deep shafts are used to take miners down into ground to

remove coal Most abundant type of coal mined in U.S. Has less water and fewer impurities Higher carbon content and burns hotter and with less smoke Main fuel used in industry and is used by many power

plants to produce electricity Many homes use BITUMINOUS Coal

Anthracite Coal 4th Stage Extreme pressure and heat change the sedimentary

bituminous coal into a metamorphic rock called anthracite coal or hard coal

Shiny black color and is located deeper into Earth than any other form of coal

Has less water and fewer impurities Burns the hottest Highest carbon content Clean burning and almost smokeless (considered best form

of coal) Most often used to heat homes Less abundant because of location making it most expensive.

Diamonds Coal that is subject to extreme

increase in heat and pressure turns into Diamonds

Mined deep in Earth’s crust Most diamond mines are found in

South Africa Hardest mineral known Used for cutting and drilling tools

Quiz

What is the most common type of coal in the U.S.?

Why is anthracite coal the most expensive type of coal?

Explain why peat is not considered to be a fossil fuel.

Assignment Many households use more than one kind of

fuel to meet their energy needs. Conduct a survey of five families outside of your

classmates to find out what kinds of fuels they use in their homes.

Try to interview families that live in different areas.

Include information in your survey about what energy sources are used for cooking, home heating, and for the heating of hot water.

Graph the results of your survey.

States of Matter

Fossil Fuels take all formsCoal is solidPetroleum is liquidNatural Gas is Gas

Petroleum

AKA Crude Oil Formed from the remains of plankton

and other organisms living in the shallow seas

Forms the same way coal does in that sediments build up and up causing more pressure and heat

Seeped in to pores and cracks of sedimentary rock

Petroleum Cont.

When petroleum became covered by nonporous rock it became trapped below surface

Water and Natural Gas also collected in these pools

When a well is drilled into the ground the oil shoots upward due to the pressure is under forming a gusher.

Must be pumped when no/limited pressure exists.

Petroleum

One of worlds most important resources Must be separated (refined) after its

drilled to make a variety of products

Petroleum Products Gasoline and Jet Fuels Diesel Fuel used by trucks, ships, and trains Fuel Oil used to heat homes and produce

electricity Grease and other lubricants Asphalt Nylon and polyester Plastics

Petroleum

Takes too many years to forms so it’s a nonrenewable resource

As population increases so does petroleum demand

Industrialized nations are becoming more and more dependent on petroleum to meet the energy needs of it’s people.

Natural Gas

Mixture of methane, ethane, propane, and small amts. of hydrogen sulfide, carbon dioxide, nitrogen, and helium

Burns cleaner than coal or petroleum Because it doesn’t have to be converted

to electricity first, it’s more energy efficient and less expensive to use.

Natural Gas

Common household appliances that use NGStovesWater heatersClothes dryers

Forms the same way Petroleum does Sometimes viewed as a waste or by-

product of petroleum

Quiz

List five different products made from petroleum. Include fuels and other products in your list.

Why is using natural gas as a fuel for cooking more efficient than using electicity.

Compare and Contrast the formation of petroleum and the formation of coal. A vendiagram works best to do this.

Problems with fossil fuels Two types of problems

Availability ○ Fuels aren’t renewable○ All coal, NG, and Petroleum available to

humans is already formedPollution

○ Wherever exploration for new resources is done the risk of environmental damage is greatly increased.

○ Oil Spills○ Widespread habitat alteration

Problems Cont. Pollution

Using fossil fuels caused air pollution○ Increase in amt. of CO2 in

the airCould raise temperature and

aid in global warming is the fear

Dangerous to obtainExtremely combustibleMiners becoming trapped

and suffocate○ Breathe in coal dust