9 Coal (cont.)Coal typically found in seams underground primarily in Northern Hemisphere w/ largest deposits in U.S., Russia, China, Australia, India, Germany & South AfricaU.S. has __% of world’s coal supply
10 Coal Mining 2 types of coal mining Surface mining (__% coal in U.S.) StripPitDraglineSubsurface mining (__% coal in U.S.)
11 Mining Control1977 Surface Mining Control & Reclamation Act- requires closure & reclamation of surface coal mines postAlso prohibits coal mining in sensitive areasAlso requires gradual restoration of mines abandoned prior to 1977Scrubbers- clean power plants exhaust by removing sulfur emission (or other chemical)Removes __% of sulfur & __% particlesIn line scrubbers, lines & water neutralize acidic gases such as sulfur dioxide
12 Resource RecoveryUsing treatment residues as marketable product (e.g. sulfur from geothermal emissions or calcium sulfate for making wall board from treating sulfur dioxide w/ lime scrubber)1990 Clean Air Act AmendmentRequired coal burning power plants to cut sulfur dioxide emissions
13 Clean Coal Technologies Methods to burn coal w/ fewer emissions=>_____________Mix crushed coal & limestone in strong air current during combustion. Sulfur in coal reacts w/ limestone to form calcium sulfate which precipitates out during burning rather than removing later.Gives off more heat per amt of coalDone at high pressure so can do combustion at low temps.
14 Energy U.S. Energy breakdown: Coal- __%Nuclear- __%Hydropower- __%Oil & Natural Gas- __%Petroleum/Crude oil- liquid composed of hundreds of hydrocarbon compoundsSeparated during refiningNatural gas has fewer different hydrocarbons
19 Oil (cont.) Natural gas- Cogeneration- Natural gas burns clearer but costs 4x as much to transport as oil
20 PetroleumPetroleum (oil & natural gas) found in structural traps geologic structures that tend to trap any oil or natural gas2 examples of geologic structures are anticlines (upward folding of rock strata) and salt domes (underground columns of salt) [salt domes formed from salt deposits at surface from water evaporation. As salt is less dense than rock, salt tends to rise above the rock. Traps are formed as the rock & salt deform]
22 Reserves> ___ of Worlds Oil Reserve in Persian Gulf region w/ major fields in U.S., Venezuela, Mexico, Russia & Libya~ __ of world’s natural gas is in Russia & IranFuture reserves => continental shelves, ocean floor & Antartica
23 How long will oil last?How long gas/oil will last depends on economic factors & consumption, production rate
24 Problems with Petroleum Problems w/ petroleum use:CombustionProduction/TransportationOil Pollution Act of establishes liability for damage to natural resources from oil spills
25 Other fuels Synthetic Fuels (Synfuels) Derived from coal & other natural substancesInclude tar sands, oil shale, gas hydrates, liquefied coal & coal gasTar Sands (Oil Sands)- underground sand deposits permeated w/ tar or oil so thick & heavy it doesn’t moveOily Rocks (Oil Shale)- sedimentary rocks containing oil that can be refined by crushing, heating, & refining
26 Gas Hydrates (Methane Hydrates) Reserves of iceEncrusted natural gas located deep underground in porous rockCoal Liquefaction- Creation of liquid fuel from coal. Can be cleaned before burning.Coal Gasification- production of methane by “cracking” coal.
27 U.S. Energy Strategy Objective: Increase energy efficiency & conservationSecure future fossil fuel suppliesDevelop alternative energy sourcesMeet objectives #1-3 w/o further environmental damage