Presentation on theme: "Non-Renewable Energy From “Living in the Environment” by Miller and Spoolman."— Presentation transcript:
Non-Renewable Energy From “Living in the Environment” by Miller and Spoolman
I. Thinking About Energy A.Currently most commercial energy (energy sold) comes from extracting and burning nonrenewable energy resources obtained from the Earth’s crust; primarily from carbon- containing fossil fuels – oil, natural gas, and coal. B.About 82% of the commercial energy consumed in the world comes from non- renewable resources – 76% from fossil fuels, 6% from nuclear.
I. Thinking About Energy C. Scientists think energy resources should be evaluated on the basis of their supplies, the environmental impact of our using them, and how much useful energy they actually provide. D. The usable amount of high-quality energy available from a give resource is its net energy. It is the total amount of useful energy available from an energy resource minus the energy needed to find, extract, process, and get the energy to consumers.
I. Thinking About Energy E. Net energy can be expressed as a ratio of energy produced to the energy used to produce it. For example, if it takes 8 units of energy to produce 10 units of energy from a coal mine, the net energy ratio would be 10/8, or 1.25. F. Energy ratios for heating: Passive solar 5.8, Natural gas 4.9, Oil 4.5 Electric heating (coal-fired plant) 0.4
I. Thinking About Energy G. Net energy ratios for transportation: Ethanol from sugarcane: 8.0 Gasoline 4.1 Oil Shale 1.2 Ethanol from corn 1.1 H. Considering net energy ratios are very important when deciding energy policy or where to invest R&D dollars to develop new technology.
I. Thinking About Energy I. The laws of thermodynamics are also important to keep in mind when thinking about energy: 1 st law of thermodynamics- Energy is never created or destroyed, it just changes form 2 nd law of thermodynamics- When changing energy from one form to another, we always end up with less useful energy than what we started (some energy is given off to the environment in the form of heat).
II. Oil A.Petroleum (AKA crude, conventional, or light oil) is a thick and gooey liquid consisting of hundreds of different combustible hydrocarbons along with small amounts of sulfur, oxygen, and nitrogen impurities.
B. Petroleum was formed from the decaying remains of organisms that lived 100-500 million years ago. Fossil fuels are formed only when organic material is broken down in an anaerobic environment, such as the bottom of deep lakes, swamps, or shallow seas. Which fossil fuel forms depends on the chemical composition of starting material, temperatures and pressures, and the presence or absence of anaerobic decomposers.
II. Oil C. Deposits of oil and natural gas are often trapped together under a dome deep within the earth’s crust. The crude oil is dispersed in pores and cracks in underground rock formations.
D. Crude oil is refined by heating and distilling the different types of hydrocarbons present – refining is all based on differences in boiling points of hydrocarbons.
II. Oil E. Gases and gasoline have the lowest boiling points, followed by aviation fuel, heating oil, diesel, naphtha, and the residues left over are used for asphalt. F. Some of the products of oil distillation, called petrochemicals, are used as raw materials in cleaning fluids, pesticides, fertilizers, plastics, synthetic fibers, paints, and medicines.
By the Numbers…. G. Projected global reserves of conventional oil will be 80% depleted sometime between 2050 and 2100, using the current rate of use of oil reserves of 2.8% a year. Between 2000-2007, the world used nine times more oil than the oil industry discovered. The U.S. produces about 9% of the world’s oil, but uses 24% of the world’s oil production. The U.S. imports about 60% of its oil. Global oil production has leveled off since 2005.
II. Oil Basics H. Oil is now the single largest source of commercial energy in the world, and in the U.S. as well. Since the world is so dependent on oil, the oil industry (both private 25% and governmental 75%) is the largest industry in the world. “Control of oil reserves is the single greatest source of global economic and political power.” – Miller and Spoolman
II. Oil Basics I. The Organization of Petroleum Exporting Countries (OPEC) have at least 60% of the world’s crude reserves, and produce 43% of the world’s oil. OPEC is somewhat secretive about the true size of member countries’ oil reserves, so in truth no one really knows the exact size of world oil reserves. Saudi Arabia has 25% of the world’s largest crude oil reserves.
J. OPEC members are Algeria, Angola, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the United Arab Emirates (UAE).
K. What about U.S. reserves? I heard we just need to “Drill Baby, Drill.” There are potentially vast reserves beneath federal lands and coastal waters (a huge find in the Gulf of Mexico in early September). Even if all projected reserves are completely developed (a perfect world scenario), the oil would only meet current U.S. needs for 5 years.
II. Oil Basics L. Most of these projected reserves are in hard to reach areas, and will take billions of dollars to develop and be brought to market at very high cost.
II. Oil Basics M. Remember back to net energy – the ratio of the amount of energy produced to the amount of energy needed to produce the energy. The U.S. produces most of its dwindling domestic supply of oil at a high cost, about $7.50 to $10 per barrel on dry land, and $35-$40 per barrel for taping deep water resources (Saudi Arabia produces for about $2 a barrel).
N. How about Alaskan Oil? 1. The estimated reserves under Alaska’s North Slope – the largest crude reserves ever found in North America – would meet current world demand for 6 months, or U.S. demand for 3 years. 2. Of this oil, the reserves under Alaska’s Arctic National Wildlife Refuge (ANWR) would meet world oil demand for 1-5 months and U.S. demand for 7 to 24 months.
3. ANWR is tundra habitat home to polar bears, arctic foxes, and peregrine flacons. It serves as summer breeding ground for millions of migratory birds and one of North America’s last great herds of caribou.
4. Opponents say getting relatively little oil from the ANWR’s costal plain is not worth the permanent environmental degradation to a pristine tundra habitat. If vehicle fuel efficiency for new cars, SUVs, and light trucks was improved by just 1 mile per gallon, the U.S. would save far more oil than what is ever likely to be pulled from the ANWR deposit.
Trade-Offs for Conventional (Light) Oil AdvantagesDisadvantages Ample supply for 42-93 yearsNeed to find permanent substitute within 50 years Low costLarge government subsidies, environmental cost not included in market price High net energy yieldArtificially low price encourages waste and discourages search for alternatives Easily transported within and between countries Pollutes air when produced and burned Low land useReleases CO 2 when burned (43% of global CO 2 emissions) Technology is well developed, with efficient distribution system Can case water pollution (Exxon Valdez oil spill ect.)
III. Heavy Oils A.Heavy oil is extracted from either oil sand or tar sand, or oil shale. B.Oil sand or tar sand is a mixture of clay, sand, water, and a combustible organic material called bitumen (a thick, sticky heavy oil with a high sulfur content that makes up about 10% of tar sand).
C. Northeastern Alberta in Canada has three-fourths of the world’s oil sand underneath boreal forests. Other deposits are in Venezuela, Colombia, Russia, and Utah. Together the oil sands of Canada and Venezuela contain more oil than is found in Saudi Arabia.
III. Heavy Oils D. How to extract oil from the tar sands of Alberta (which is done through strip-mining): 1)Clear cut boreal forest, drain wetlands, and divert rivers and streams. 2)Remove the overburden of soil, rocks, and clay to expose oil sand deposits. 3)Dig out oil sands and carry it to upgrading plants – at the upgrading plants, mix with hot water and steam to extract bitumen.
III. Heavy Oils 4) Heat bitumen via natural gas in huge cookers to convert to low-sulfur, synthetic crude oil, which can then be refined using traditional refining methods. E. About 4 metric tons of overburden are removed to produce 1 metric ton of bitumen. The mining process produces huge pits, as well as huge ponds of toxic mine tailings and other wastes stored as liquid slurries that are extremely toxic to aquatic life and birds.
III. Heavy Oils F. The process results in much more water and air pollution than is produced in traditional crude production, and releases at least three times more CO 2 than conventional oil. G. The environmental defense fund called Canada’s oil sands industry the most destructive project on Earth, and for each barrel of oil produced, the energy input needed is 0.7 barrels of oil.
III. Heavy Oils H. Oily rocks, called oil shales, are another potential source of heavy oil. When oil shales are heated, a hydrocarbon mix called kerogen is produced. I. About 72% of the world’s oil shale reserves are in the western U.S., beneath an area called the Green River Formation (Arid lands of Colorado, Wyoming, and Utah. The federal government owns 80% of this land.
III. Heavy Oils J. It is estimated that these deposits contain an amount of recoverable heavy oil equal to almost four times the size of Saudi Arabia’s reserves. So yea! Is it time to ….
K. Not quite… most of these deposits are locked up in ore of such low grade that it would take a lot of energy to mine and process the rock to extract the oil. The net energy is even lower than that of the oil sands. L. It also takes A LOT of water to extract oil from oil shale. As most of the deposits are in arid areas of the west that are already having extreme water issues, it seems implausible that water could be used in the amount needed.
III. Heavy Oils M. Pollution issues are huge with oil shale too – you have to process 1 ton of oil shale to produce 1 barrel of oil. All of the same toxicity issues apply to oil shale mine tailings and slurry as well.
Trade-Offs for Heavy Oil AdvantagesDisadvantages Moderate cost (oil sands)High cost (oil shale) Large potential supplies, especially in the Canadian oil sands Low net energy yield Easily transported within and between countries Environmental costs not included in market price Efficient distribution system in placeLarge amounts of water needed for processing Technology well developed (oil sands)Severe land disruption Severe water pollution Air pollution and CO 2 emissions when burned (at about 3x the rate as light oil)
IV. Natural Gas A.Natural gas is a mixture of gases which contains between 50-90% methane (CH 4 ). Natural gas also contains smaller amounts of ethane (C 2 H 6 ), propane (C 3 H 8 ), and butane (C 4 H 10 ), and small amounts of highly toxic hydrogen sulfide (H 2 S). B.Conventional natural gas is often found in reservoirs above crude oil deposits, but can not be used unless a natural gas pipeline has been built.
IV. Natural Gas C. Russia is the Saudi Arabia of gas, having 27% of gas reserves, followed by Iran (15%) and Qatar (14%). The U.S. has only 3% of the world’s proven gas reserves, but uses 27% of the world’s annual production. D. Methane gas can be burned to heat space and water or produce electricity or propel vehicles with only minor modifications.
IV. Natural Gas E. Natural gas turbines to produce electricity are almost twice as energy efficient as coal- burning nuclear power plants. F. Burning natural gas releases CO 2 into the air, but releases much less CO 2 per unit of energy than coal or oil. G. To transport natural gas across oceans, it is converted to liquefied natural gas (LNG) at very low temps and high pressure.
IV. Natural Gas H. LNG is very flammable and shipped aboard refrigerated tanker ships, then reheated to gas at regasification plants before being distributed via pipeline. I. LNG has a low net energy yield – the equivalent of more than a third of its energy content is needed to compress, decompress, refrigerate, and transport it long distances.
IV. Natural Gas J. The long-term outlook for natural gas is better than for oil – current reserves are estimated to last 65-125 years.
Trade-Offs for Natural Gas AdvantagesDisadvantages Ample supplyNonrenewable resource High net energy yieldReleases CO 2 when burned Low costGovernment subsidies Less air pollution than other fossil fuelsEnvironmental costs not included in market price Lower CO 2 emissions than other fossil fuels Methane (potent greenhouse gas) can leak from pipelines Easily transported by pipelineDifficult to transfer from one country to another Low land useCan be shipped across ocean only as highly explosive LNG Good fuel for fuel cells, gas turbines, and motor vehicles
V. Coal A.Coal is a solid fossil fuel formed from the remnants of land plants that were buried 300-400 years ago. B.Coal is burned to generate approximately 40% of the world’s electricity. Coal is also used in various industrial plants, for example in blast furnaces to make steel or iron. C.Using a coal-burning power plant is essentially a complex and inefficient way to boil water and produce steam.
V. Coal D. The three largest coal-burning countries in the world are China, the U.S., and India. By 2025 China is expected to burn twice as much coal as the U.S., and India’s coal use is expected to quadruple. E. In the U.S., coal produces 49% of our electricity (followed by natural gas 21%, nuclear 19% and renewable (9%).
F. Coal is the world’s most abundant fossil fuel. According the USGS, global coal supplies could last from 214 – 1,125 years, depending on use. G. The U.S. is the Saudi Arabia of Coal, with 25% of world-wide coal reserves. Russia has 15%, India and China both have 13%, Australia has 8% and South Africa.
H. Different estimates put U.S. coal supplying U.S. needs for either 100 or 250 years. I. Without sophisticated and expensive pollution control devices, burning coal severely pollutes the air. Coal is mostly carbon, but also contains small amounts of sulfur, which is released into the air as sulfur dioxide (SO 2 ). Burning coal also releases large amounts of particulates (soot), carbon dioxide, trace amounts of mercury and radioactive materials.
J. Coal-burning power plants account for 25% of world-wide CO 2 emissions, and 40% of U.S. CO 2 emissions. K. Coal is the single biggest air polluter in coal- burning nations.
L. China and Coal 1)China burns a third of the world’s coal, to produce 80% of its electricity. 2)China is adding the equivalent of three large coal-burning power plants per week. 3)Pollution controls on older, inefficient plants in China are almost non-existent, and even the newest coal-burning plants are inefficient and have inadequate air-pollution control systems.
4) Since 2005, China has been the world’s leading source of SO 2, which can cause respiratory and cardiovascular disease, as well as cause acid rain. In 2008 China became the world’s leading producer of CO 2. 5) Major Chinese cities are in an almost perpetual haze from particulates and other pollutants released from burning coal, and China contains 20 of the top 30 most polluted cities in the world.
6) According to a World Bank study, indoor and outdoor air pollution, mostly from coal burning, contributes to 650,000 to 700,000 premature deaths a year.
Trade-Offs for Coal AdvantagesDisadvantages Ample supplies (225 – 900 years)Severe land disturbance, air pollution, and water pollution High net energy yieldSevere threat to human health when burned Low costEnvironmental costs not included in market price Well-developed technologyLarge government subsidies Air pollution can be reduced with improved technology High carbon dioxide emissions when produced and burned Radioactive particles and toxic mercury emissions