Transcript Energy and Waste Chapters 15, 16, and 22 Living in the
Nonrenewable Energy
1. Energy Resources
2. Oil 3. Natural Gas 4. Coal 5. Nuclear Energy
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Energy Sources
Modern society requires large quantities of energy that are generated from the earth’s natural resources.
Primary Energy Resources: The fossil fuels(oil, gas, and coal), nuclear energy, falling water, geothermal, and solar energy.
Secondary Energy Resources: Those sources which are derived from primary resources such as electricity, fuels from coal, (synthetic natural gas and synthetic gasoline), as well as alcohol fuels.
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
Thermodynamics
The laws of thermodynamics tell us two things about converting heat energy from steam to work: 1) The conversion of heat to work cannot be 100 % efficient because a portion of the heat is wasted.
2) The efficiency of converting heat to work increases as the heat temperature increases.
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
Energy Units and Use
Btu (British thermal unit) - amount of energy required to raise the temperature of 1 lb of water by 1 ºF.
cal (calorie) - the amount of energy required to raise the temperature of 1 g of water by 1 ºC. Commonly, kilocalorie (kcal) is used.
1 Btu = 252 cal = 0.252 kcal 1 Btu = 1055 J (joule) = 1.055 kJ 1 cal = 4.184 J www.lander.edu/rlayland/Chem%20103/chap_12.ppt
Energy Units and Use
Two other units that are often seen are the horsepower and the watt. These are not units of energy, but are units of power.
1 watt (W) = 3.412 Btu / hour 1 horsepower (hp) = 746 W Watt-hour - Another unit of energy used only to describe electrical energy. Usually we use kilowatt hour (kW-h) since it is larger.
quad (Q) - used for describing very large quantities of energy. 1 Q = 10 15 Btu www.lander.edu/rlayland/Chem%20103/chap_12.ppt
Evaluating Energy Resources
U.S. has
4.6% 24%
of world population; uses of the world’s energy;
84%
from nonrenewable fossil fuels (oil, coal, & natural gas);
7%
from nuclear power;
9%
from renewable sources (hydropower, geothermal, solar, biomass).
Changes in U.S. Energy Use
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Energy resources removed from the earth’s crust include: oil, natural gas, coal, and uranium www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Fossil Fuels
Fossil fuels originated from the decay of living organisms millions of years ago, and account for about 80% of the energy generated in the U.S.
The fossil fuels used in energy generation are: Natural gas, which is 70 - 80% methane (CH 4 ) Liquid hydrocarbons obtained from the distillation of petroleum Coal - a solid mixture of large molecules with a H/C ratio of about 1 www.lander.edu/rlayland/Chem%20103/chap_12.ppt
Problems with Fossil Fuels
Fossil fuels are nonrenewable resources At projected consumption rates, natural gas and petroleum will be depleted before the end of the 21st century Impurities in fossil fuels are a major source of pollution Burning fossil fuels produce large amounts of CO 2 , which contributes to global warming www.lander.edu/rlayland/Chem%20103/chap_12.ppt
1. Energy Resources
2. Oil
3. Natural Gas 4. Coal 5. Nuclear Energy
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Oil
Deposits of crude oil often are trapped within the earth's crust and can be extracted by drilling a well Fossil fuel, produced by the decomposition of deeply buried organic matter from plants & animals Crude oil: complex liquid mixture of hydrocarbons, with small amounts of S, O, N impurities How Oil Drilling Works by Craig C. Freudenrich, Ph.D.
Sources of Oil
•Organization of Petroleum Exporting Countries (OPEC) --
13 countries have 67%
world reserves: • Algeria, Ecuador, Gabon, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, & Venezuela •Other important producers: Alaska, Siberia, & Mexico.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
•
2.3%
of world
Oil in U.S.
reserves •uses nearly
30%
of world reserves; •65% for transportation; •increasing
dependence on imports
.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Low oil prices have stimulated economic growth, they have discouraged / prevented improvements in energy efficiency and alternative technologies favoring renewable resources.
www.bio.miami
• Burning any fossil fuel releases carbon dioxide into the atmosphere and thus promotes global warming.
• Comparison of CO 2 emitted by fossil fuels and nuclear power.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Oil
Crude oil is transported to a refinery where distillation produces petrochemicals How Oil Refining Works by Craig C. Freudenrich, Ph.D.
1. Energy Resources 2. Oil
3. Natural Gas
4. Coal 5. Nuclear Energy
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Natural Gas - Fossil Fuel
• Mixture •50–90% Methane (CH
4
) •Ethane (C
2
H
6
) •Propane (C
3
H
8
) •Butane (C
4
H
10
) •Hydrogen sulfide (H
2
S)
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Sources of Natural Gas
•Russia & Kazakhstan - almost 40% of world's supply.
•Iran (15%), Qatar (5%), Saudi Arabia (4%), Algeria (4%), United States (3%), Nigeria (3%), Venezuela (3%); •90–95% of natural gas in U.S. domestic (~411,000 km = 255,000 miles of pipeline).
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
billion cubic metres
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Natural Gas
Experts predict increased use of natural gas during this century
Natural Gas
When a natural gas field is tapped, propane and butane are liquefied and removed as liquefied petroleum gas (LPG) The rest of the gas (mostly methane) is dried, cleaned, and pumped into pressurized pipelines for distribution Liquefied natural gas (LNG) can be shipped in refrigerated tanker ships
1. Energy Resources 2. Oil 3. Natural Gas
4. Coal
5. Nuclear Energy
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Coal: Supply and Demand
Coal exists in many forms therefore a chemical formula cannot be written for it.
Coalification: After plants died they underwent chemical decay to form a product known as peat Over many years, thick peat layers formed. Peat is converted to coal by geological events such as land subsidence which subject the peat to great pressures and temperatures.
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
garnero101.asu.edu/glg101/Lectures/L37.ppt
Ranks of Coal
Anthracite :A hard, black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Energy content of about 14,000 Btu/lb..
Bituminous: most common coal is dense and black (often with well-defined bands of bright and dull material). Its moisture content usually is less than 20 percent. Energy content about 10,500 Btu / lb..
Subbituminous: Black lignite, is dull black and generally contains 20 to 30 percent moisture Energy content is 8,300 BTU/lb.
Lignite: A brownish-black coal of low quality (i.e., low heat content per unit) with high inherent moisture and volatile matter. Energy content is lower 4000 www.uvawise.edu/philosophy/Hist%20295/ Powerpoint%5CCoal.ppt BTU/lb.
PEAT LIGNITE
garnero101.asu.edu/glg101/Lectures/L37.ppt
BITUMINOUS ANTHRACITE
garnero101.asu.edu/glg101/Lectures/L37.ppt
Main Coal Deposits
Bituminous Subbituminous Lignite Anthracite
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
garnero101.asu.edu/glg101/Lectures/L37.ppt
Advantages and Disadvantages
Pros
•Most abundant fossil fuel •Major U.S. reserves •300 yrs. at current consumption rates •High net energy yield
Cons
•Dirtiest fuel, highest carbon dioxide •Major environmental degradation •Major threat to health © Brooks/Cole Publishing Company / ITP www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Sulfur in Coal
When coal is burned, sulfur is released primarily as sulfur dioxide (SO 2 pollutant) - serious Coal Cleaning - Methods of removing sulfur from coal include cleaning, solvent refining, gasification, and liquefaction Scrubbers are used to trap SO 2 when coal is burned Two chief forms of sulfur is inorganic (FeS 2 CaSO 4 ) and organic (Sulfur bound to Carbon) or www.lander.edu/rlayland/Chem%20103/chap_12.ppt
Coal
Coal gasification Synthetic natural gas (SNG) Coal liquefaction Liquid fuels Disadvantage Costly High environmental impact
1. Energy Resources 2. Oil 3. Natural Gas 4. Coal
5. Nuclear Energy
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Nuclear Energy
In a conventional nuclear power plant a controlled nuclear fission chain reaction heats water produce high-pressure steam that turns turbines generates electricity.
Nuclear Energy
Controlled Fission Chain Reaction neutrons split the nuclei of atoms such as of Uranium or Plutonium release energy (heat) www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Controlled Nuclear Fission Reaction
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Radioactivity
• Radioactive decay continues until the the original isotope is changed into a stable isotope that is not radioactive • Radioactivity: Nuclear changes in which unstable (radioactive) isotopes emit particles & energy www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Radioactivity
• Types •
Alpha particles
consist of 2 protons and 2 neutrons, and therefore are positively charged • •
Beta particles
are negatively charged (electrons)
Gamma rays
have no mass or charge, but are a form of electromagnetic radiation (similar to X-rays) • Sources of natural radiation • Soil • Rocks • Air • Water • Cosmic rays www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Relative Doses from Radiation Sources
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
Half-Life
The time needed for
one-half
of the nuclei in a radioisotope to decay and emit their radiation to form a different isotope Uranium 235 Plutonium 239
Half-time
710 million yrs 24.000 yrs
emitted
alpha, gamma alpha, gamma During operation, nuclear power plants produce radioactive wastes, including some that remain dangerous for tens of thousands www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
of years
Diagram of Radioactive Decay
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
Effects of Radiation
• Genetic damages: from mutations that alter genes • Genetic defects can become apparent in the next generation • Somatic damages: to tissue, such as burns, miscarriages & cancers www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
Radioactive Waste
1. Low-level radiation (Gives of low amount of radiation) • Sources: nuclear power plants, hospitals & universities • 1940 – 1970 most was dumped into the ocean • Today deposit into landfills 2. High-level radiation (Gives of large amount of radiation) • Fuel rods from nuclear power plants • Half-time of Plutonium 239 is 24000 years • No agreement about a safe method of storage www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Radioactive Waste
1
.
Bury it deep underground
. •
Problems
: i.e. earthquake, groundwater…
2
.
Shoot it into space or into the sun
.
•
Problems
: costs, accident would affect large area.
3
.
Bury it under the Antarctic ice sheet
.
•
Problems
: long-term stability of ice is not known, global warming
4. Most likely plan for the US
• Bury it into Yucca Mountain in desert of Nevada • Cost of over $ 50 billion • 160 miles from Las Vegas • Transportation across the country via train & truck www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Yucca Mountain
www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
Plutonium Breeding
238 U is the most plentiful isotope of Uranium Non-fissionable - useless as fuel Reactors can be designed to convert 238 U into a fissionable isotope of plutonium, 239 Pu www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
Conversion of
238
U to
239
Pu
Under appropriate operating conditions, the neutrons given off by fission reactions can "
breed
" more fuel, from otherwise non fissionable isotopes, than they consume www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
Reprocess Nuclear Fuel
During the operation of a nuclear reactor the uranium runs out Accumulating fission products hinder the proper function of a nuclear reactor Fuel needs to be (partly) renewed every year www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
Plutonium in Spent Fuel
Spent nuclear fuel contains many newly formed plutonium atoms Miss out on the opportunity to split Plutonium in nuclear waste can be separated from fission products and uranium Cleaned Plutonium can be used in a different Nuclear Reactor www.geology.fau.edu/course_info/fall02/ EVR3019/Nuclear_Waste.ppt
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Nuclear Energy
Concerns about the safety, cost, and liability have slowed the growth of the nuclear power industry Accidents at Chernobyl and Three Mile Island showed that a partial or complete meltdown is possible
Nuclear Power Plants in U.S.
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
Three Mile Island
•March 29, 1979, a reactor near Harrisburg, PA lost coolant water because of mechanical and human errors and suffered a partial meltdown • 50,000 people evacuated & another 50,000 fled area • Unknown amounts of radioactive materials released • Partial cleanup & damages cost $1.2 billion • Released radiation increased cancer rates.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Chernobyl
• April 26, 1986, reactor explosion (Ukraine) flung radioactive debris into atmosphere • Health ministry reported 3,576 deaths • Green Peace estimates32,000 deaths; • About 400,000 people were forced to leave their homes • ~160,000 sq km (62,00 sq mi) contaminated • > Half million people exposed to dangerous levels of radioactivity • Cost of incident > $358 billion www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Nuclear Energy
Nuclear plants must be decommissioned after 15-40 years New reactor designs are still proposed Experimental breeder nuclear fission reactors have proven too costly to build and operate Attempts to produce electricity by nuclear fusion have been unsuccessful
Use of Nuclear Energy
• U.S. phasing out • Some countries (France, Japan) investing increasingly • U.S. currently ~7% of energy nuclear • No new U.S. power plants ordered since 1978 • 40% of 105 commercial nuclear power expected to be retired by 2015 and all by 2030 • North Korea is getting new plants from the US • France 78% energy nuclear www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Phasing Out Nuclear Power
•Multi-billion-$$ construction costs •High operation costs •Frequent malfunctions •False assurances and cover–ups •Overproduction of energy in some areas •Poor management •Lack of public acceptance www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
Energy & Mineral resources
2) Energy
garnero101.asu.edu/glg101/Lectures/L37.ppt