Transcript Chapter 15 *Organic Fuels

Mrs. Paul
Environmental Science
Pgs 234 - 249
 Many
forms of energy to meet the needs
of people on Earth.
• Heat, light, energy, mechanical energy, chemical
energy, nuclear energy.
 Energy
cannot be created or destroyed,
only changed from one form to another.
 Example:
• Energy from the sun
converted to chemical
energy stored in plants.
• When you eat, the stored
energy is converted to
heat, mechanical energy,
and chemical energy
used to carry out life
processes.
• Food is a form of fuel
that your body uses for
energy.
 Called
organic fuels.
 Contain carbon-based molecules formed
by living things as well as carbon.
 Hydrocarbon: compound made of only
carbon and hydrogen.
• Example: methane, ethane, octane
 Many
organic fuels contain other
chemicals as well (considered to be
impurities in fuel).
 Fuel: any
substance from which energy
can be obtained.
 Fossil fuel: remains of ancient organisms
that changed into coal, oil, or natural gas.
• Central to life in modern societies.
• 2 main problems:
 1. supply of fossil fuel is limited.
 2. obtaining and using them causes environmental
problems.
5
main purposes of fuels:
• 1. cooking
• 2. transportation
• 3. manufacturing
• 4. heating and cooling buildings
• 5. generating electricity to run appliances.
 How
suitable the fuel is depends on:
• Energy content, cost, availability, safety, and
byproducts of use.
 Energy
in fuel often converted into
electrical energy to power machines.
 More convenient to use than coal, etc.
 How is electricity generated?
• Electric Generator: machine that converts
mechanical energy (motion) into electrical
energy.
• Do this by moving electrically conductive
material inside a magnetic field.
• Most electric generators convert the movement
of a turbine into electrical energy.
• Turbine: wheel that changes the force of a
moving gas or liquid into energy that can do
work.
 Usually, steam turns the turbine.
 World Patterns
• People in developed societies use more energy than
people in developing countries.
• Differences within developed countries too.
• Ex: Canada/US uses 2x that of Japan or Switzerland.
 Energy Use in the United States
• Uses more energy than all except Canada and
United Arab Emirates.
• Uses more than 25% to transport goods and people
by truck and personal vehicle.
• Lowest fuel cost = little incentive to conserve.
• Japan and Switzerland have minimal fossil fuel and
supplement with other energy sources.
 Give
2 reasons why the United States uses
more energy per person compared with
most other countries.

Not
distributed
evenly.
 Coal Formation
• Forms from remains of plants that lived in swamps
• Much in US formed 320 to 300 million years ago (vast
swampland covered eastern US).
 Coal in western US only 100 – 40 million years ago.
• Ocean levels rose and fell = swamps covered with
sediment.
 First forms Peat: brittle, brown plant material containing a
great deal of water and low percentage of carbon.
 Layers of sediment compress the peat into lignite: soft,
brown coal composed of about 40% carbon; it burns
quickly and gives off little smoke.
• Sediment compressed plant remains and heat and
pressure within Earth’s crust caused coal to form.
 Oil
and Natural Gas Formation
• Result from decay of tiny marine organisms that
accumulate on bottom of ocean millions of years
ago.
• Remains buried by sediments and heated =
became complex energy-rich carbon-based
molecules.
 Molecules migrated into porous rocks.
 Most
of fossil fuel reserves made of coal.
 ½ of electricity in US comes from coal
fired plants
 Advantages:
• Inexpensive
• Need little refining after mining.

Coal Mining and the Environment
• Underground = minimal effect at surface.
• Surface mining
 Remove top of entire mountain to reach coal.
 Toxic chemicals can leach into nearby water sources.

Air Pollution
• High grade coal produces less pollution and more heat.
 Ex: bituminous coal: soft coal located deep in Earth’s crust
 Anthracite coal: metamorphic rock made when extreme
pressure and heat act on bituminous coal. Clean-burning and
almost smokeless; fewest impurities of all coal.
• Low grade coal produces more pollution and less heat
 Ex: lignate
• Sulfur found in coal = pollution
 Petroleum: oil
that is pumped from the
ground, aka crude oil.
 Petroleum product: anything made from
crude oil.
• Ex: fuels, chemicals, plastics
 Accounts
for 45% of world’s commercial
energy use.
 Nonrenewable resource.
 Locating
Oil Deposits
• Found in and around geologic features (folds,
faults, salt domes) that trap oil as it moves in
Earth’s crust.
• Exploration wells drilled to determine volume
and availability of deposit.
• Wells drilled and oil pumped or flows to surface.
• Oil transported to refinery to convert to fuel and
other petroleum products.
 Natural
Gas
• 20% of nonrenewable energy comes from
natural gas.
• Methane
• Recovered from many oil wells.
• Produces fewer pollutants than other fossil fuels.
 Fossil
fuels supply 90% of the energy
used in developed countries.
 It is projected that by 2050, our energy
needs will have DOUBLED.
 Predicting Oil Production
• Still increasing, but slowly.
• Factors considered in oil predictions:
 Oil Reserves: oil deposits that can be extracted
profitably at current prices using current technology.
 Some oil deposits have not been discovered or
become commercial.
 Changes in technology to allow more oil to be
extracted.
 Relative cost of obtaining oil.
 Future
Oil Reserves
• Geologists predict that oil production from fields
accessible from land will peak in 2010.
• Additional oil under ocean floor = more
expensive.
 The
Environmental Effects of Using Oil
• Pollution released into the air.
• Contribute to formation of smog and cause
health problems.
• Carbon Dioxide released may contribute to
global warming.
• Oil spills
 Biomass
Fuels: a fuel formed from the
products of living organims.
• Ex: wood, garbage, methane, alcohol.
• Renewable resources
 Garbage
• The materials you throw away; composed mostly
of organic material.
• 2/3 of material in it can be burned; some cities
burning garbage to generate electricity.
 Methane
• Swamp gas produced in swamps from decaying
plants.
 A naturally produced form of methane.
 Alcohol
• Bioconversion: conversion of organic materials
into fuels.
• A hydrocarbon in which one of the hydrogens is
replaced with an oxygen-hydrogen group.