Chapter 15 The need for energy

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Chapter 15

Energy from Organic Fuels

The need for energy

• What are some forms of energy that you know about?

– Heat– Light– Electricity

– Food!

The need for energy

• According to the laws of thermodynamics, energy cannot be created or destroyed; however, it can be changed from one form to anotherto another.

• Almost all energy starts out as sunlight

The need for energy

• Sunlight energy is converted into other types of energy that we use

– It gets converted to wind energy by heating air

– It gets converted to food energy through photosynthesis

The need for energy

• Wind and food energy are both used as sources of fuel

• A fuel is any substance from which energy can be obtained

The need for energy• What are some other types of fuel we’re familiar

with?

SolarFoodWind

– Oil– Gas– Coal– Natural Gas (methane)– Ethanol

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The need for energy

• Is electricity a fuel ?? NO.

– It is a form of energy that is produced from burning fuels.

• Most of the fuel consumed by today’s societies is used to generate electricity.

The need for energy

• Human’s need for energy has changed a lot over time.

Hunter-gatherer societies only needed energy – Hunter-gatherer societies only needed energy for light, heat, and cooking.

• These needs were often metby burning wood.

http://www.kiwanja.net/blogpics/huntergatherers.jpg

The need for energy

• Early agricultural societies met many of their new energy needs through animal power

– i.e. horses, mules, and oxen powered plows and other farm equipment by physically pulling them

http://www.geneandmatttractorsales.com/site-images/old-plow.jpg

The need for energy

• The human population began to grow rapidly during the industrial revolution.

– Societies needed to meet the needs of their growing populations

– Tasks once performed by animals were taken over by machines (i.e. tractors)

– Making these new machines required large amounts of energy, as did using the machines themselves

The need for energy

• Fuel consumption was also increased by factories manufacturing items needed by the growing population

– Clothing– Furniture – Building materials

• Additional fuel was also needed for distribution and marketing of these items

The need for energy

• Societies have continued to develop

• Growing societies rely on a growing economyeconomy– New needs are invented– Example: cars, computers, mp3 players, cell

phones

• Energy demands continue to increase as a result

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The need for energy

• Many of the things we take for granted today did not exist 100 years ago…

http://s1.hubimg.com/u/402336_f520.jpg http://www.antiquewoodcameras.com/Nodark_advert_1900-Ladies_Home_Journal-website.jpg

The need for energy

70000

230000

Post-industrialAgriculture

Modern Industrial

5000

12000

26000

Hunter-Gatherer

Early Agriculture

Pre-industrialAgriculture

Agriculture

Energy use per person per day (kilocalories)

Info from page 239 of textbook

The need for energy

• So, as a society, we’ve gotten to a point where we need all kinds of things

All these things require energy to make • All these things require energy to make, transport, market, consume, and use

• But where does all this energy come from?!

Fuels from organisms

• Organic fuels are fuels that contain carbon compounds that were once part of living organisms.– These fuels also contain hydrogenThese fuels also contain hydrogen

• Hydrocarbon is a compound composed only of carbon and hydrogen– Examples include methane, ethane, propane,

and octane

All of these areHydrocarbons


• Octane is a hydrocarbon fuel you are probably familiar with from the gas pump

The octane rating of gasoline is derived – The octane rating of gasoline is derived from a complex formula based on the amount of energy contained in the gasoline compared to the energy of pure iso-octane

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http://media.photobucket.com/image/minimum%20octane%20rating%20gasoline/RMartin631/mower%20stuff/DSCN0340.jpg

Section 15.2

Coal

http://media.photobucket.com/image/minimum%20octane%20rating%20gasoline/RMartin631/mower%20stuff/DSCN0340.jpg


• Fossil fuels are fuels derived from the remains of organisms that lived long ago

– Ancient plants trapped and converted the sun’s Ancient plants trapped and converted the sun s energy into biomass, which was eventually eaten by consumers

– When these ancient plants and animals died, some energy remained stored in their cells

– If they became buried and did not decay, this energy remained stored within the Earth


• Examples of fossil fuels include:– Coal– Petroleum – Natural gasNatural gas

• Extracting many of these fuels have environmental costs of their own…

http://www.treehugger.com/fossil-fuels-production-photo345462543.jpg

Coal

• Millions of years ago, many parts of the Earth that are now dry land were covered by humid swampswith large plant populations

• As these plants died, their remains accumulatedand were gradually covered by layers of sediment

• Over time, these layers piled up.

– The heat and pressure from these sediments caused chemical changes to occur within the plant remains

– At the same time, water was forced out

Coal

• Coal is a solid fossil fuel

• Coal formation occurs in stages over millions of years.

• With each stage, the plant matter loses more and more Hydrogen and Oxygen

• At the same time, the remaining Carbon in the plant matter becomes increasingly concentrated

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Coal

• As the concentration of carbonincreases, so ,does the amount of energy

http://www.greenepages.com/mgreene/pics/CoalBurning.jpg

Coal

• There are several types of coal that are mined and used for energy

These different types are based on their • These different types are based on their stage of development:

1.Peat2.Lignite3.Bituminous coal 4.Anthracite coal

Coal

• The first stage is peat, which is a brittle, brown plant material containing a great deal of water and a low percentage of carbon

– It is not actually a form of coal yet

– It looks like decaying wood– Is usually located at, or near, the Earth’s surface

– When burned it gives off high amounts of smoke because of its water content and impurities

Peat

http://geology.com/rocks/pictures/coal-peat.jpg

Coal

• The second stage is Lignite, which is a soft, brown coal composed of about 40% carbon

– Is the product of millions of years of sediment that’s d it d t f tdeposited on top of peat

– It burns quickly and gives off less smoke than peat

– Is found below the Earth’s surface, so must be mined

Lignite

http://geology.com/rocks/pictures/coal-lignite.jpg

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Coal

• The third stage is Bituminous Coal, which is a soft coal composed of up to 85% carbon

– Changed from lignite by heat and pressure, over time.

– It is formed deep in the Earth’s crust, and is the most abundant type of coal that is mined in the U.S.

– Is widely used in industry, especially in power plants, because it burns hotter and with less smoke than lignite

Bituminous Coal

http://www.caer.uky.edu/kyasheducation/images/ccbs/Bituminous600.jpg

Coal• The final stage is Anthracite Coal,which is a

hard coal made up of up to 95% carbon

– Formed from extreme pressure and heat on bituminous coalbituminous coal

– Has a shiny black color

– Burns hottest with least amount of smoke

– Is often found deeper in ground than all other forms

– Is the most expensive kind because of its quality and limited availability

Anthracite Coal

http://geology.com/rocks/coal.shtml

Coal Deposits in U.S.http://pubs.usgs.gov/circ/c1143/html/fig4.jpg

Section 15.3

Petroleum &N t l GNatural Gas

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Petroleum & Natural Gas• Petroleum is a liquid fossil fuel, which is sometimes

called crude oil

• Petroleum is believed to have formed from the remains of plankton and aquatic plants and animalsremains of plankton and aquatic plants and animalsthat lived in the shallow seas millions of years ago

• Covered by sediments, which exerted pressure and heat on the remains, just as seen with coal

Petroleum & Natural Gas• Pressure from overlying rocks forces petroleum to

move upward, through porous rocks, until it reaches nonporous cap rocks, such as shale

www.tutorvista.com/search/mining

Petroleum & Natural Gas• Pressure builds up in a pool of

trapped oil; when a well is drilled into this pool, the pressure forces the petroleum to h t lik shoot up like a geyser

• In places where there isn’t any pressure, the oil must be pumped to the surface, for extraction

http://www.chem-export.com/images/up_product/pic_20061027_173121_3028.jpg

Petroleum & Natural Gas• Petroleum is one of the world’s most

important resources

• It is refined and used to make:– Gasoline– Jet Fuel– Diesel Fuel– Motor Oil – Lubricants – Plastic– Nylon and polyester– Asphalt

http://www.highlightskids.com/Science/ScienceQuestions/images/h1sciQmakingPlastic.gif

Petroleum & Natural Gas

• As with all fossil fuels, because it takes millions of years to form, petroleum is not a renewable resourcenot a renewable resource

• As the human population continues to grow, so does the demand for petroleum

http://www.transitionguelph.org/images/peakoil.jpg


• Natural Gas is a fossil fuel found in the gaseous state

N t l G i i t f tl g – Natural Gas is a mixture of mostly gaseous hydrocarbons

– Is primarily composed of methane

– May also contain ethane, and trace amounts of hydrogen sulfide, carbon dioxide, nitrogen, and helium

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• Natural gas forms in much the same way as petroleum

I ft t d i k t – Is often trapped in same pockets as petroleum

– Sometimes viewed as a “waste” or “by-product” of petroleum drilling

– Some petroleum processing plants burn off the natural gas

http://farm1.static.flickr.com/88/254212887_b429a05772.jpg


• The Chinese used bamboo poles to extract natural gas over 2,000 years ago, to boil seawater and obtain boil seawater and obtain salt

• The Italians used it in the 1800s to light the streets of Genoa at night

http://farm1.static.flickr.com/5/8957596_7f7a53f621.jpg?v=0


• Today, natural gas is widely used in industry, homes, and businesses because it burns cleaner

• Appliances such as stoves, water heaters, and clothes dryers can be powered by natural gas

• Because it doesn’t have to be converted to electricity first, it is more efficient and cheaper

http://upload.wikimedia.org/wikipedia/commons/9/99/Gas_stove.jpg

Section 15.4

Other Organic Fuels

Problems with fossil fuels

• Some problems with fossil fuels are driving scientists to develop alternative fuels

M t f th bl ith f il f l h • Most of the problems with fossil fuels have to do with:

– Availability– Pollution


• Fossil fuels are considered non-renewable because it takes millions of years for fossil fuels to form, and all the fossil fuels that will ever be available to humans have will ever be available to humans have already been formed

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• To reach these resources, we have to keep digging deeper into the Earth, and must continue to disrupt more natural areas– Arctic National Wildlife Refuge (ANWR)– Arctic National Wildlife Refuge (ANWR)– Offshore drilling– Mining

http://scottgsanders.files.wordpress.com/2008/09/anwr-drilling-companysmall.jpg

http://socioeconomic.files.wordpress.com/2009/02/strip_coal_mining3.jpg

http://themoderatevoice.com/wordpress-engine/files/2008-june/oil_platform.jpg


• Wherever exploration of fossil fuels takes place, there’s a risk of environmental damage– Oil spills– Oil spills– Other forms of widespread habitat destruction

http://cccpublishing.com/files/images/oil-spill-sign2.jpg http://vallescaldera.com/wp-content/uploads/skyphotos/1549NorthRimLoggingRoads2.jpg


• The edge of a habitat / ecosystem is where one habitat / ecosystem meets another

– An edge may have two different sets of abiotic g yfactors

– Edges also tend to have greater biodiversitybecause different habitats with different species are brought together

– When an edge changes, animals from one habitat may migrate to another, causing different species to come in contact with each other


• If a piece of land is cleared or divided by a new road, then habitat fragmentationoccurs and new edges are created

– This may expose new organisms at the once-interior to new predators or competitors

On the right is a “greenway” which has littler interior


• Edge Effect is an issue that results from activities related to oil exploration

I d t t t th l b li d t • In order to get to the places believed to have fossil fuel deposits, roads have to be carved out

• These roads expose pristine natural areas to invasive species, and can severely disrupt ecosystem balances

Edge Effect not good!

http://vallescaldera.com/wp-content/uploads/skyphotos/1549NorthRimLoggingRoads2.jpg

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• Pollution from burning fossil fuels is also a major problem

– When burned, they release CO2 (Carbon Dioxide) , y 2 ( )into the atmosphere

– Since the Industrial Revolution, the amount of CO2 in the atmosphere has increased by 20%

– Many scientists believe this is causing a greenhouse effect, resulting in global climate change


• Obtaining fossil fuels can also be very dangerous

– Natural gas is highly combustible

http://umwa.org/index.php?q=content/black-lung http://www.foxnews.com/images/303326/16_61_080607_Mine01.jpg

– Mining for coal can result in explosions, black lung disease, and mine collapses

Alternative Fuels

• Biomass Fuel is a fuel formed from the products of living organisms

S i l d• Sources include:– Wood– Methane– Alcohol– Garbage

http://www.toonpool.com/user/328/files/natural_gas_112835.jpg

Alternative Fuels

• Wood

– No longer used as a primary energy source in the U.S.

– Still used in developing nations because it is cheaper and more readily available

– Advantages: is available throughout the world, is cheap, is a renewable source of energy

– Disadvantages: give off lots of smoke and CO2, using them can be very damaging to natural forests

Alternative Fuels

• Garbage

– About 2/3 of the household waste that is thrown away is organic waste such as food scraps and away is organic waste, such as food scraps and paper.

– This waste can be separated and burned, to produce steam, which is used to generate electricity

– CO2 is released when garbage is burned

Alternative Fuels

• Methane

– Comes from a variety of sources:Swamps• Swamps

• Decaying garbage• Livestock flatulence (aka cow farts)

– The methane from garbage is harvested, and is used in the same way as natural gas

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Alternative Fuels

• Alcohol

Bioconversion is the conversion of organic

www.b12partners.net/mt/archives/2006/06/

– Bioconversion is the conversion of organic materials into fuels

• Example: the use of plants of make alcohol

• Plants used to do this are sugarcane and corn

Alternative Fuels

• An alcohol is a hydrocarbon in which one of the hydrogen atoms has been replaced by an -OH (hydroxyl group)

• Ethanol, aka Ethyl Alcohol, is made by fermenting plant biomass with yeast

Alternative Fuels

• Many gasoline products sold now contain some percentage of ethanol

• Some issues with ethanol:– Clearing additional

forest land to grow corn – Continued emission of

CO2

http://www.odec.ca/projects/2007/truo7j2/ethanol_pick_heater.jpg http://raymondpronk.files.wordpress.com/2009/02/ethanol_fuel_pump.jpg

Chapter 15 The need for energy

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Transcript of Chapter 15 The need for energy