Minerals Oil Natural Gas and Coal NONRENEWABLE RESOURCES
Minerals, Oil, Natural Gas, and Coal NONRENEWABLE RESOURCES
Finding, Removing, and Processing MINERAL RESOURCES
CATEGORIES � � Reserves Economical Identified Undiscovered Other resources Not economical � Identified—deposits with a known location, quantity, quality, or based on actual measurements. Undiscovered—potential supplies assumed to exist based on geological theory Reserves—identified resources from which extraction could occur profitably Other—not classified as reserves Decreasing cost of extraction � Decreasing certainty Existence Known
REMOVING SHALLOW DEPOSITS � Surface mining (shallow deposits) Overburden: soil and rock that is stripped away (waste materials— spoils) � Open-pit � Dredging � Area strip mining � Contour strip mining Open Pit � Dredging Area Strip Contour Strip Mountaintop Removal
SURFACE MINING CONTROL AND RECLAMATION ACT OF 1977 � Requires companies to restore most surfacemined land so it can be used for the same purpose as before it was mined. � Taxes applied on mining companies to restore land disturbed by surface mining before the law was passed. � How do you think this is actually working?
REMOVING DEEP DEPOSITS � Subsurface � Removes No, that’s just Grumpy’s black lung cough… Is that a cave-in I hear? mining coal and metal ores that are too deep to be extracted by surface mining. � Dig deep vertical shafts, blast tunnels, use machinery to remove mineral and transport it to the surface. � Disturbs less land, but leaves much of the resource behind. � Hazards include cave-ins, explosions, and lung diseases.
ENVIRONMENTAL EFFECTS
ENVIRONMENTAL EFFECTS Steps Mining exploration, extraction Processing transportation, purification, manufacturing Use transportation or transmission to individual user, eventual use, and discarding Environmental Effects Disturbed land; mining accidents; health hazards; mine waste dumping; oil spills and blowouts; noise; ugliness; heat Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat Noise; ugliness thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat
SUPPLIES OF MINERAL RESOURCES � Depletion time —how long it takes to use up a certain proportion (80%) of the reserves of a mineral at a given rate of use
Oil, Natural Gas, and Coal ENERGY RESOURCES
EVALUATING ENERGY RESOURCES Nuclear power 6% � Renewable energy � Non-renewable energy � Future availability � Net energy yield � Cost � Environmental effects Natural Gas 23% Coal 22% Hydropower, geothermal, Solar, wind 7% Biomass 12% Oil 30% World
IMPORTANT ENERGY SOURCES Oil and Natural Gas Floating oil drilling platform Oil drilling platform on legs Geothermal Energy Hot water storage Contour strip mining Oil storage Geothermal power plant Oil well Gas well Coal Valves Pipeline Mined coal Area strip mining Drilling tower Pump Underground coal mine Water is heated and brought up as dry steam or wet steam Impervious rock Natural gas Coal seam Oil Water Hot rock Water Magma Pipeline Water penetrates down through the rock
NORTH AMERICAN ENERGY SOURCES ALASKA Trans Alaska oil pipeline Prudhoe Bay Beaufort Sea Arctic Ocean Coal Gas Arctic National Wildlife Refuge Oil Prince William Sound Gulf of Alaska High potential areas Valdez CANADA Pacific Ocean UNITED STATES Grand Banks Atlantic Ocean MEXICO
HISTORY OF ENERGY CONSUMPTION
COAL � Rock formed in Earth with several stages � Buried remains of Carboniferous period subjected to heat and pressure � Mostly carbon with some water � Sulfur is gradually incorporated into the coal as it forms � Three types � Lignite - brown coal, low heat and sulfur content, limited supplies � Bituminous - soft coal, most commonly used, high heat content, large supplies, high sulfur � Anthracite - hard coal, high heat content, takes longest to form, expensive, fewer supplies, low sulfur
FORMATION OF COAL
HOW IS COAL USED? � 25% of world’s commercial energy � � Generating Electricity � � � used to generate 39% of world’s electricity and 75% of world’s steel China is world’s largest consumer (76% of their energy) Coal supplies 57% of the U. S. electricity Coal is ground into a fine powder (increase surface area) and burned at a high temperature Steel pipes filled with water run through the fire producing high pressure steam The steam is used to turn a turbine The turbine spins a generator which produces electricity Conversion � � � Coal liquefaction - conv. to methanol Coal gasification - conv. to synthetic natural gas or hydrogen gas lower air pollution, BUT low energy yield because energy is lost in conversion would increase use of coal because 30 -40% of energy is lost in conversion more mining
TRADE-OFFS OF COAL USE � Advantages � � � Ample supplies (225 -900 yrs. ) High net energy yield Low cost (with subsidies) Mining and combustion technology welldeveloped Air pollution can be reduced with improved technology � Disadvantages � � � Very high environmental impact Severe land disturbance, air pollution, and water pollution High land use Severe threat to human health High CO 2 emissions when burned Releases radioactive particles and toxic mercury into air
NATURAL GAS � � Natural Gas is the third most important fuel It is mixture of 50 -90% methane and small amounts of ethane, propane, butane, and hydrogen sulfide. Conventional N. G. lies on top of crude oil Unconventional N. G. lies on top of coal, dissolved in water, underground sands; unconventional sources have promise in future because of abundance. Who Has It?
TRADE-OFFS OF NATURAL GAS USE � Advantages � � � � abundant, cleaner burning (50% CO 2 of coal) cheaper than oil reserves should last 80200 years at current levels can be transported easily over land by pipeline high net energy yield extraction doesn’t damage the environment so much as coal or uranium ore easy to process can be used to power vehicles � Disadvantages � � Some toxic sulfur gases are produced must be converted to liquid form before transport leakage into air can increase global warming OVERALL: considered to be the best fuel in our conversion to renewable energy sources
OIL � Three sources � � � Crude from underground deposits--produced by the decomposition of deeply buried organic material from plants and animals under high temperatures and pressures over millions of years. Natural gas and crude oil are found together. Oil shale--fine grained rock that contains a mixture of hydrocarbon compounds called kerogen. Once brought to the surface, the shale can be crushed and heated, vaporizing the kerogen. The kerogen vapor is then condensed to make shale oil. Tar sands--mixture of clay, sand, water, and bitumen (a high sulfur oil). The bitumen is removed by heating the sand until the bitumen softens and floats to the surface. Then it is refined into traditional crude oil.
CRUDE OIL RECOVERY Primary Oil Recovery � drilling a well and pumping out oil that flows by gravity into the well Secondary Oil Recovery � injection of water into nearby wells to force the heavy oil into the well Tertiary Oil Recovery � injection of steam or CO 2 into wells to force oil out Average yields are only 30 -50% at which time it becomes too expensive to extract more
REFINING � Crude oil is a mixture of many different hydrocarbons that can be separated with distillation � From heaviest to lightest: 1. 2. 3. 4. 5. 6. 7. 8. asphalt Wax Naptha diesel oil heating oil jet fuel Gasoline cooking gases (propane, butane)
WHAT IS OPEC? � Organization of Petroleum Exporting Countries—have 78% of the world’s estimated crude oil reserves. Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, and Venezuela. � Controls prices of gas—sets production targets for its member nations, when targets are reduced, oil prices increase. � Political stability is a key factor for United States and other oil-dependent countries. �
PRODUCTION OF CO 2 The Downside of All Fossil Fuel Use
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