Energy Classifications

Transcription

1 FOSSIL FUELS

2 Energy Classifications Renewable Energy any source of energy that can be replaced as fast as it is used Examples: wind, hydroelectric, biofuels, solar, others Nonrenewable Energy any source of energy that is used faster than it is replaced Examples: coal, oil, natural gas, nuclear

3 Fossil Fuels Fossil fuels are literally decomposed organisms that have chemically converted to a usable fuel. (FOSSILS FUELS)! shocking name! These include: petroleum (or oil), coal, natural gas

4 How is Electricity Made From Fossil Fuels? 1) Burn the fossil fuels. 2) The heat from combustion of fuels will be used to heat water and create steam. 3) Steam will be used to turn a turbine. 4) The turbine is connected to generator. The generator creates electricity. 5) Electricity is distributed to users.

5 Generating Electricity Coal Example

6 Petroleum (Crude oil) Made from decayed marine animals pressurized over time. Oil indicates water must have been in that location at some point! (Huh? Saudi Arabia was an ocean?) Oil needs to be taken to a refinery. Boil oil slowly to separate parts of it out, which is called fractional distillation What boils out?: gasoline, wax, asphalt, jet fuel, and more!!

7 Crude Oil Production Oil is the world s largest business. OPEC (Organization of Petroleum Exporting Countries) group of 11 nations that control over 78% of the world s oil production They control production, pricing, exporting. The U.S. is NOT in this group (despite our high use of oil). Locations of Prime Oil Production: Saudi Arabia, Canada, Iran, Iraq, Kuwait. Production predicted to peak in next 30 years, then start to see declines due to depletion of existing oil reserves.

8 Tar Sands (Oil Sands) Tar sands are sandy earth layers with combustible oily material called bitumen. How are they used? Tar sands are mined. Sands are washed with hot water to separate out the bitumen. Bitumen then processed into low quality oil. Alberta, Canada has a large area of oil sands and is increasing their production

9 Tar Sands Problems With Tar Sands Destruction of land in mining Large air pollution emissions from tar sands and their extraction Large use of water and creation of wastewater, which requires storage or treatment Water becomes polluted with bitumen chemicals and sludgy wastes Contaminated water runoff and leachate enters aquifers and surface waters Produces more greenhouse gases than regular petroleum Toxicity of organisms exposed to air and water pollutants

10 Current Events with Tar Sands Keystone XL Pipeline The Keystone Pipeline already exists and carries oil sands from Canada to Illinois and Oklahoma The XL Pipeline is an extension to the pipeline. The southern extension links the pipeline to Texas, where there are oil refineries. This has gone operational. The northern extension cuts through Montana, S. Dakota, and Nebraska. This is still highly debated.

11 Pros Job creation Keystone XL Pipeline More money flowing into the US economy Enhanced trade with Canada The oil is going to be made, so the US should capitalize on the situation Potential to reduce need for oil imports from other nations Cons Tar sands extraction results in a lot of pollution. Tar sands extraction creates 15% more greenhouse gases than normal oil. Potential for spills/leaks into water sources like the Ogallala Aquifer High cost Loss of land for construction

12 Oil Advantages Supply good for another years Low cost Versatile Easily transported High energy yield Low land use Well established understanding/technology Well established infrastructure for oil Disadvantages Reserves limited in long term supply Government subsidizes oil imports Oil prices do NOT include environmental costs Releases CO 2 when burned Creates air pollution Can pollute water with spills (Ex: Exxon Valdez in Alaska) Dependency on foreign oil for U.S.

13 Natural Gas Mixture of gases, with most of it (50-90%) being methane Also has heavier hydrocarbons (ethane, propane, butane) Conventional NG deposits found above oil (drillable deposits) If NG is used, a pipeline is built; If NG is unused, it is burned to get to oil Unconventional NG gas found in other forms Liquefied Natural Gas Methane Hydrate Mining Big Natural Gas Producers: Russia, US, Canada, Iran, Qatar Most Natural Gas used for cooking and heating

14 Natural Gas Advantages Greater supplies than oil High energy yield Low cost Much less air pollution created compared to other fossil fuels Less CO 2 than other fossil fuels Easily transported Versatile Low land use (no mining) Disadvantages Releases greenhouse gases Is essentially methane greenhouse gas that is released when drilled for Not priced with environmental costs Difficult to mass transport from country to country (political issues) Can really only be shipped safely in pipelines Still creates some air pollution

15 A recent technique to get more natural gas, oil, & coal gas Fracking stands for hydraulic fracturing. How does it work? A normal well is drilled. Large amounts of pressurized fluid (usually water) is injected into the well to cause fissures in the rock the resource is stored in. The fluid cracks rock, letting more gas or oil more easily get to the surface. Fracking

16 Problems with Fracking Gas wells and fracking occurs lower than aquifers thus fracking often contaminates aquifers with natural gas Fracking uses water infused with hundreds of different chemicals. The chemicals are VOCs and are highly toxic. These chemicals also can get into groundwater sources. Fracking uses large quantities of water Wastewater from fracking needs to be stored in their own separate waste lagoons

17 Problems with Fracking Small earthquakes can occur at fracking sites and at deep well disposal sites for fracking water Methane can leak into air during drilling (greenhouse gas) Habitat destruction/fragmentation from setting up drill site and roads Some sites spray wastewater onto land, leading to salinization and heavy metal contamination of land Sometimes water is infused with radioactive tracers, which can get into the environment

18 Coal The fossilized remains of plants under heat and pressure with time. Mainly carbon-filled, but also contains sulfur. Generates 40% of world s electricity Most abundant fossil fuel Nations with lots of coal reserves: U.S. (Wyoming, West Virginia), Russia, China, India

19 Formation of Coal From least time and fossilization to most Peat (not coal) partially decayed plant matter; high moisture; low heat; found in bogs Lignite Coal low heat and sulfur Bituminous Coal high heat and high sulfur; most coal is this form Anthracitic Coal high heat and low sulfur; limited supplies; most desirable coal

20 Coal Advantages Large supplies (at least 200 years worth maybe more) High energy yield Versatile Low cost Established infrastructure Transportable Found in lots of areas Disadvantages High land destruction with mining Lots of air pollution Produces greenhouse gases Linked to acid rain (SO 2 ) Mercury emissions Environmental cost not included in pricing Acid mine drainage

21 Coal Advances & Technologies Clean Coal Technology Washes coal before burning to remove many impurities Try to wash air pollutant stream before entering the air Not truly clean but it is cleaner. Also more expensive Coal Gasification/Coal Liquefaction Two processes that convert coal into alternate fuels like gasoline or natural gas (syngas synthetically made fuels) Expensive and less energy efficient, but does make new forms of energy sources in need.

22 Turn, Turn, Turn Everyone get up and choose a different table. You must have at least 2 new people at your new table. Answer the given a question. Select a starting person and go clockwise. Each person must provide an answer that is new and different from the others given. Once everyone gives a unique answer, move to the next question.

23 Meet & Review Questions 1) Identify 4 environmental benefits for using natural gas versus using coal and/or petroleum. 2) Identify 4 environmental drawbacks of fracking for natural gas. Only 2 of these drawbacks may discuss water.