Energy: Fossil Fuels

Transcription

1 Energy: Fossil Fuels

2 Power Units Power is the at which work is done/energy is consumed. Energy= to do work. The joule is a unit of both work and energy. Power = energy/time or work/time Power Units: Watt = I Joule/second Kilowatt (kw) = 10 3 W Megawatt(MW) = 10 6 W Gigawatt (GW) = 10 9 W Terawatt (TW) = W

3 Discuss with your table partner: Rewrite the power formula to solve for energy. Determine which of the following is a correct unit for energy and explain why. A. Watt/hour C. Watt B/ Watt-hour D. Hour/Watt

4 Energy Laws first law of thermodynamics: energy is neither created nor destroyed, but may be from one form to another. energy is ; implication that bookkeeping is possible, e.g., in ecological study, energy flow can be followed; also stated, "you can't get something for nothing", in terms of energy quantity. Einstein showed energy & matter can be interconverted; E = mc 2

5 Energy Laws Second Law of Thermodynamics: when energy is converted from one form to another, some of the useful energy is always degraded to energy. Also can be stated: entropy increases. entropy is a measure of disorder; increased entropy means increased randomness or dispersion; degraded energy generally in form of ;

6 Evaluating Energy Resources Most commercial energy: nonrenewable fossil fuels Less developed countries use more renewable sources than more developed countries. More Developed Nations Less Developed Nations

7 Fig. S10-1, p. S59

8 Energy Use in the U.S. The United States is the largest user (& waster) of commercial energy. U.S. has 4.6% of world population, but uses of the commercial energy; 84% of the U.S. commercial energy comes from nonrenewable fossil fuels (oil, coal, & natural gas); 8% of the U.S. commercial energy comes from power; only of the U.S. commercial energy comes from renewable sources (hydropower, geothermal, biomass). solar,

9 Nuclear power 6% Geothermal, solar, wind 2.5% Hydropower 4.5% Nuclear power 8% Geothermal, solar, wind 1% Hydropower 3% Natural gas 21% Natural gas 23% Coal 22% Oil 33% Biomass 11% Coal 23% Oil 39% Biomass 3% World United States

10 Energy consumption in the US: Past and Near Future Oil Coal Natural gas Nonhydro renewables Nuclear Hydropower Fig. S10-3, p. S60

11 Total Energy Consumption and Per Capita Energy Consumption in the United States Fig. S10-2, p. S60

12 What is Net Energy? Net energy: the total useful energy from a resource over its lifetime minus the amount of energy, automatically wasted, & unnecessarily wasted to find, process, & transport it. example: if 8 units of energy are wasted for every 10 units extracted, then there is a net energy of 2 units; Net energy ratio is the ratio of useful energy produced to the useful energy used to produce it; the the ratio the the net energy yield; example: for the above problem the net energy ratio is 10/8 = 1.25.

13 Net Energy Ratios Space Heating Passive solar 5.8 Natural gas 4.9 Oil 4.5 Active solar 1.9 Coal gasification 1.5 Electric heating (coal-fired plant) 0.4 Electric heating (natural-gas-fired plant) 0.4 Electric heating (nuclear plant) 0.3 High-Temperature Industrial Heat Surface-mined coal 28.2 Underground-mined coal 25.8 Natural gas 4.9 Oil 4.7 Coal gasification 1.5 Direct solar (concentrated) 0.9 Transportation Ethanol from sugarcane residue 8.0 Ethanol from switchgrass 5.4 Natural gas 4.9 Gasoline (refined crude oil) 4.1 Coal liquefaction 1.4 Oil shale 1.2 Ethanol from corn 1.1 (but can reach 1.5) Fig. 15-A, p. 374

14 How to Evaluate Energy Resources? Criteria: How much of an energy source is available? - near future = next 15 years - intermediate future = next 30 years - long term = next 50 years What is the source's net energy yield? How much does it cost to develop, phase in, & use? How does extraction, transport, & use affect the environment? What will using an energy source do to help sustain humans & other species living on Earth?

15 Oil Petroleum or crude oil is a fossil fuel, produced by the decomposition of deeply buried organic matter from plants & animals. is a complex liquid mixture of hydrocarbons, with small amounts of sulfur, oxygen, & nitrogen impurities; primary oil recovery involves drilling a well & pumping oil that flows by gravity into the bottom of the well; secondary oil recovery involves injecting in nearby wells to force remaining heavy oil to the surface; tertiary or enhanced oil recovery involves using or CO 2 gas to force still more oil into the well.

16 Crude oil and natural gas are generally found together in sedimentary rock layers, with the oil dispersed in pores and cracks of the rock formation. Oil storage Oil drilling platform Oil well Pipeline Gas well Pump Mined coal Coal seam

17 Low Boiling point High Boiling point Crude Oil Refining Refining of crude oil involves separating components based on their. gasoline & aviation fuel are among the most volatile components; heating oil is less volatile, but still burns readily; diesel oil is still less volatile, and is a common fuel for trucks, buses, & heavy machinery; grease, wax, & asphalt are the least volatile, most dense materials separated; petrochemicals derived from oil are used for synthesizing industrial organic chemicals, pesticides, plastics, synthetic fibers, paints, medicines, & many other products.

18 Lowest Boiling Point Gases Gasoline Aviation fuel Heating oil Diesel oil Naphtha Heated crude oil Furnace Grease and wax Asphalt Highest Boiling Point

19 World Oil Consumption Fig. S10-4, p. S61

20 World Oil Consumption consumption: 1000 barrels/day Change in consumption since 1990

21 Organization of Petroleum Exporting Countries (OPEC) In 2006 OPEC produced of the world's oil (down from in 1973) OPEC members: Algeria, Ecuador, Gabon, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, UAE & Venezuela Important Non-OPEC oil producers include Mexico and Canada (oil sand) 1 barrel = 42 gal

22 Crude Oil Sources Thirteen countries that make up the Organization of Petroleum Exporting Countries (OPEC) have 67% of the world's reserves of oil. = OPEC Member in 1997 OPEC produced 40% of the world's oil (down from 65% in 1973); by 2010 OPEC is expected to supply almost half of the world's oil; OPEC members: Algeria, Ecuador, Gabon, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, & Venezuela; other important oil producers include Alaska, Siberia, & Mexico.

23 Oil Production in 2003 and Change in Production

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25 Fig. S10-6, p. S62

26 ANWR (Arctic National Wildlife Reserves) potential oil 14 supply compared to US projected demand. Barrels of oil per year (billions) Projected U.S. oil consumption Arctic refuge oil output over 50 years Year

27 Conventional Oil: Advantages Ample supply for years cost Easily within & between countries Low land use Technology is well developed distribution system

28 Conventional Oil: Disadvantages Releases CO 2 when burned Can cause pollution Pollutes air when produced and burned. Will need to find substitute in the future Large government Environmental costs not included in market price Artificially low price encourages and discourages search

29 Oil Sands and Oil Shale Oil Sand Synthetic crude oil can be produced from oil shale or from tar sands. However of landscape Damage to Rivers/Lakes Large Quantities of CO 2 released Net Energy yield Oil Shale

30 Oil Sands and Oil Shale Reserves Oil Shale Deposits Oil Sands Deposits Oil Shale

31 Mining Terms : The layer of material that lies over the mineral resource. : The material (overburden) that has been removed from over a mineral resource. Overburden Mineral Resource Spoil

32 Oil Sands (Tar Sands) Oil sand, tar sand -contains bitumen Canada and Venezuela: -oil sands have more oil than in Saudi Arabia Extraction metric tons of overburden removed to produce metric ton of bitumen Each barrel of oil requires 4-5 barrels of Releases times as much CO 2 as conventional oil net energy yield: Is it cost effective?

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34 Oil Shales Oil shales contain kerogen After distillation: shale oil 72% of the world s reserve is in arid areas of western Locked up in Lack of needed for extraction and processing Low yield

35 TRADE-OFFS Heavy Oils from Oil Shale and Oil Sand Advantages Moderate cost (oil sand) Disadvantages High cost (oil shale) Large potential supplies, especially oil sands in Canada Easily transported within and between countries Efficient distribution system in place Technology welldeveloped (oil sand) Low net energy yield Environmental costs not included in market price Large amounts of water needed for processing Severe land disruption Severe water pollution Air pollution and CO 2 emissions when produced and burned

36 Oil Reserves and How Long They Will Last

37 CAFE Standards: Corporate Average Fuel Economy After the 1973, the US Energy Policy & Conservation Act of 1975 set standards for the average fuel efficiency for each car manufacturer. From , the CAFE standards were mpg for passenger vehicles and mpg for light trucks/suv s Increases in standards through both the EISA (Energy Independence and Security Act in 2007 and Obama Administration regulations. Increases to mpg average for (new) passenger vehicles by 2025.

38 Since standards are lower for light trucks than for cars, manufacturers developed the for large-scale consumer use to get around the higher CAFE standard for passenger cars. Many manufacturers of SUV s chose to pay the fines since profits from SUV sales were large even with the fines The average mpg for all vehicles dropped from from This was due to the average weight of vehicles increasing from 3,220 to 4,066 lb when light truck (mainly SUV ownership) went from 28% to 53% CAFE Standards

39 Europe has a higher percentage of diesel cars, which have a better fuel efficiency.

40 The Price of Oil

41 The Price of Oil Oil field in Kuwait Oil prices can be highly volatile due to several factors: Instability in the Middle East Increase in global (i.e. China and India s growth) such as Hurricane Katrina Hurricane Katrina Damage

42 The Price of Oil Oil price increases affect not only gas prices, but the cost of most goods, since fuel is needed to manufacture and transport goods

43 The Price of Oil For the first time, Americans are driving less and are SUV s are losing popularity

44 Oil Spills Crude & refined petroleum are accidentally and deliberately released into the environment from various sources. most oil is released in operation of offshore wells, from washing tankers, & pipeline & storage tank leaks; tanker & offshore drilling rig accidents can release large amounts of oil in a short period of time

45 Oil Spills Some effects of oil on marine ecosystems: - volatile organics immediately kill of many aquatic organisms (especially plankton & larvae), as well as contaminate fish; - floating oil coats birds & marine mammals, destroying natural & buoyancy, & causing deaths; - heavy oil sinks to ocean bottom & washes into estuaries where it contaminates crabs, oysters, mussels, clams, etc. - oil slicks on beaches harm intertidal life & cause economic losses to tourism & fishing industries. - cleaning oil spills with high-powered jets of water can kill plants and animals in the rocks.

46 Exxon Valdez Oil Spill March 24, 1989, Exxon Valdez spilled oil in Prince William Sound Over 1,600 km ( ) of shoreline was coated Exxon spent $2.2 billion on cleanup Exxon ruled negligent in 1991federal lawsuit, and paid $1 billion to Alaska in fines Exxon ruled guilty in 1994 lawsuit, and fishing industry, landowners, and AK residents awarded $5 billion in damages. To date, Exxon has paid ~2.3 billion in damages

47 Exxon Valdez Oil Spill A may have prevented the catastrophe, but this requirement has been dropped by the government due to pressure from the oil industry All new tankers must have a double hull, and all single-hulled tankers are supposed to be phased out by 2015, but the oil industry is working to weaken these requirements. No more than of the oil from a spill can be recovered, even with a fast response of 1990 was supposed to regulate supertankers, but oil companies have found a way around the law by operating barges instead of tankers

48 Ocean Pollution: Oil Spills In late March, 2010, President Obama called for oil and natural gas exploration off the eastern coast of the US, from Delaware to Florida, approximately 167 million acres He also opened up exploration in parts of offshore Northern AK

49 Deep Horizon Oil Spill: Gulf of Mexico On April 20 th, 2010, methane in a BP s deep water oil well, Macondo, caused an explosion on the ship Deep Horizon. men were killed. For 3 months oil gushed into the deep ocean before being permanently capped on July 15 th, 2010 An estimated 4.9 million barrels ( million gallons) spilled.

50 Deep Horizon Oil Spill: Gulf of Mexico About more oil was spilled than in the Exxon Valdex spill Offshore drilling (drilling at >500 m depth) was suspended for 6 months until it could be determined that deepwater wells were safe This was challenged by oil companies and the rule was overturned in federal court

51 Deep Horizon Oil Spill: Gulf of Mexico Total miles of shoreline affected as of Nov., 2010: miles. Good news: spill did not reach the gulf stream as some feared, which would have polluted shorelines along east coast.

52 Deep Horizon Oil Spill: Gulf of Mexico While the oil has largely disappeared, as of Jan, 2011, tar balls continue to wash up on shorelines

53 Deep Horizon Oil Spill: Gulf of Mexico Initally, about were closed to fishing, but most areas were re-opened by mid-nov. In late November, 2011, due to tar balls appearing in shrimp nets, 4,200 mi 2 of the gulf was re-closed to shrimping.

54 Deep Horizon Oil Spill: Gulf of Mexico Clean-up efforts included: Burning Removal from beaches Use of However, up to 79% of the oil might still be in the gulf

55 Deep Horizon Oil Spill: Gulf of Mexico Corexit was the primary dispersant used and was highly controversial. Initally, BP was spraying gal/day Corexit is a with the potential to bioaccumulate. The OSHA Materials Safety Data Sheet (MSDS) states: No toxicity studies have been conducted on this product. On May 19 th, the EPA gave BP 24 hours to choose a less toxic dispersant. By May 26 th, BP had reduced its use to 23,250 gal/day (a 9% decrease). By July 30 th, about 1.8 million gallons of dispersant, mostly Corexit, had been deployed.

56 Deep Horizon Oil Spill: Gulf of Mexico On Aug 2, the EPA said that dispersants were no more harmful to the environment than the oil itself. Besides the potential toxic effects, some scientists believe that the small droplets of oil that dispersants create make it easier for oil to enter the food chain. The addition of dispersants creates very toxic substances called poly-aromatic hydrocarbons (PAHs) when mixed with crude oil. PAHs contain compounds that have been identified as carcinogenic, mutagenic, and teratogenic. The dispersants added to the water cause chemical compounds to become water soluble, which then makes it impossible to remove them.

57 Deep Horizon Oil Spill: Gulf of Mexico As of November 2, 6,814 dead animals had been collected, including 6,104 birds, 609 sea turtles, 100 dolphins and other mammals, and 1 other reptile. One estimate states that about 20% of juvenile blue fin tuna in the gulf were killed when a major spawning ground was damaged. Total damage to the ecosystem is unknown.

58 Deep Horizon Oil Spill: Gulf of Mexico As of Oct., 2010, a deep plume of oily water 35 km long was still detected in the Gulf at 1,100 m depth In places, up to 2 in. of oil-laden sediment sits on top of the ocean floor. Effects on deep-sea ecosystems might be severe, but it will be hard to determine exact levels of damage, since these systems have not been extensively studied. A ghost crab eats oil from the Gulf of Mexico spill, shown glowing yellow-orange under ultraviolet light, at Gulf Islands National Seashore near Pensacola, FL. Credit: National Geographic

59 Deep Horizon Oil Spill Methane: About 200,000 tons of CH 4 were released into the ocean during the spill As of Sept., 2010, most of the methane appeared to be gone Methane-eating microbes (methanotrophs) are probably responsible Downside: is consumed in the process, so waters became oxygen depleted. Some microbes also digest oil, but they mostly break up the oil into smaller droplets.

60 Deep Horizon Oil Spill: Gulf of Mexico Costs to BP (in billions): Plugging well, cleaning up spilled oil, paying claims: 10.7 Fund set up for individuals and businesses that were affected by spill: 20 (to date: 2.7 billion paid) Fines 5.4 to 21.1 (depend on whether BP is found grossly negligent with regard to cause of accident) Legal fees: up to 2 Lawsuits: up to 6 BP s stock value dropped to $27/share in June, By Jan, 2011, it had risen to $60.5

61 Pros: Pros & Cons of Oil oil is still relatively cheap; economy (infrastructure) is set up around use of oil; many useful products can be readily synthesized from oil; Cons: supply is limited pollution & environmental degradation result from extraction, processing, transport, & use, including global warming Many reserves are located in politically unstable countries Recent volatility of oil prices accidents can be environmentally devastating

62 TRADE-OFFS Advantages Conventional Oil Ample supply for years Low cost High net energy yield Easily transported within and between countries Low land use Technology is well developed Efficient distribution system Disadvantages Need to find substitutes within 50 years Large government subsidies Environmental costs not included in market price Artificially low price encourages waste and discourages search for alternatives Pollutes air when produced and burned Releases CO 2 when burned Can cause water pollution