APES Chapter 15 Review

Natural Gas

A fossil fuel in the gaseous state

Coal

A fossil fuel that forms underground from partially decomposed plant material

Petroleum

Another name for oil

Petrochemicals

Compounds that are made from oil

What is coal and how is it formed? How does a coal-burning power plant work? What three countries have the largest proven reserves of coal? Describe the use of coal in China. Describe the problem of coal ash waste. Explain why there is no such thing as clean coal. What are the major advantages and disadvantages of using coal as an energy resource?

Conventional coal is plentiful and has a high net energy yield at low costs, but using it results in a very high environmental impact. We can produce gaseous and liquid fuels from coal, but they have lower net energy yields and using them would result in higher environmental impacts than those of conventional coal. Coal is a solid fossil fuel formed from the remains of land plants that were buried 300-400 millions years ago and exposed to intense heat and pressure over millions of years. The problem is that coal is by far the dirtiest of all fossil fuels. Even when costly air-pollution-control technologies are used, burning coal pollutes the air and creates a toxic ash that is difficult to deal with. And the processes of making coal available severely degrade land and pollute water and air. Coal is mostly carbon but contains small amounts of sulfur, which is converted to the air pollutant sulfur dioxide when the coal burns. Burning coal also releases large amounts of black carbon particulates, or soot, and much smaller, fine particles of air pollutants such as mercury. The fine particles can get past to our bodies' natural defenses that help to keep our lungs clean. Coal-burning power and industrial plants are among the largest emitters of the greenhouse gas carbon dioxide. Another problem with burning coal is that it emits trace amounts of radioactive materials as well as toxic and indestructible mercury into the atmosphere. Finally, burning coal and removing some of the pollutants it releases from smokestack emissions produce a highly toxic ash. The ash stored underground can slowly leach into groundwater, and the wet slurry can break through a pond's earthen walls, as it did at a coal ash storage pond near Knoxville, Tennessee in 2008. We can convert solid coal into synthetic natural gas by a process called coal gasification, which removes sulfur and most other impurities from coal. We can also convert it into liquid fuels such as methanol and synthetic gasoline through a process called coal liquefaction. Theses fuels, called synfuels, are often referred to as cleaner versions of coal.

What is crude oil (petroleum) and how is it extracted from the earth and refined? What percentages of the commercial energy use in the world and in the United States are provided by crude oil? What is the peak production for an oil well and for the world? What is a petrochemical and why are such chemicals important? What are proven oil reserves? Describe two types of unproven reserves. Discuss the question of how long global and U. S. supplies of conventional crude oil might last. What are the major advantages and disadvantages of using conventional oil as an energy resource?

Conventional crude oil is abundant and has a medium net energy yield, but using it causes air and water pollution and releases greenhouse gases to the atmosphere. Unconventional heavy oil from oil shale rock and tar sands exists in potentially large supplies but has a low net energy yield and a higher environmental impact than conventional oil has. Crude oil, or petroleum, is a black, gooey liquid consisting mostly of a mix of different combustible hydrocarbons along with small amounts of sulfur, oxygen, and nitrogen impurities. It is also known as conventional or light crude oil. It was formed from the decayed remains of ancient organisms that were crushed beneath layers of rock for millions of years. After years of pumping, usually a decade or so, the pressure in a well drops and its rate of crude oil production starts to decline. This point in time is referred to as peak production for the well. The same thing can happen to a large oil field when the overall rate of production from its numerous wells begins to drop. Crude oil from a well cannot be used as it is. It is transported to a refinery by pipeline, truck, rail, or ship where it is heated to separate it into various fuels and other components with different boiling points in a complex process called refining. This process, like all other steps in the cycle of oil production and use, requires and input of high-quality energy and decreases the net energy yield of oil. About 2% of the products of refining, called petrochemicals, are used as raw materials to make industrial organic chemicals, cleaning fluids, pesticides, plastics, synthetic fibers, paints, medicines, cosmetics, ice cream, and many other products. Saudi Arabia, with the world's second largest crude oil reserves, could supply the world's demand for oil for about 7 years. Estimated unproven crude oil reserves under Alaska's Arctic National Wildlife Refuge would meet the world's demand for 1-5 months and U.S. demand for 7-24 months. The Arctic Circle holds enough technically recoverable crude oil to meet the global demand for about 3 years at high production costs. Bottom line: to keep using conventional light oil at the projected rate of increase, we must expand global proven crude oil reserves by an amount equal to Saudi Arabia's current reserves every 7 years. Most oil geologists say this is highly unlikely.

Define natural gas, liquefied petroleum gas (LPG), and liquefied natural gas (LNG)? What three countries have most of the world's natural gas reserves? What are the major advantages and disadvantages of using conventional natural gas as an energy resource? What are three sources of unconventional natural gas and what major problems are related to the use of these resources?

Conventional natural gas is more plentiful than oil, has a medium net energy yield and a fairly low production cost, and is clean-burning fuel, but producing it has created environmental problems. Natural gas is a mixture of gases of which 50-90% is methane. It also contains smaller amounts of heavier gaseous hydrocarbons such as propane and butane, and small amounts of highly toxic hydrogen sulfide. When a natural gas deposit is tapped, propane and butane gases can be liquefied under high pressure and removed as liquefied petroleum gas. LPG is stored in pressurized tanks for use mostly in rural areas not served by natural gas pipelines. Natural gas can also be transported across oceans, by converting it to liquefied natural gas at a high pressure and at a very low temperature. There are two major sources of unconventional natural gas that are both difficult and costly to exploit without high environmental impacts. One source is coal bed methane gas found in coal beds near the earth's surface across parts of the United States and Canada. The environmental impacts of using this resource would include scarring of land, depletion of some water sources, and possible pollution of aquifers. So far it has not been economical to exploit this resource. The other source of unconventional natural gas is methane hydrate--methane trapped in icy, cage-like structures of water molecules buried under arctic permafrost in tundra areas of North America, northern Europe, and Siberia. Methane hydrate is also found lying on the ocean floor in several areas of the world. So far, it costs too much to get natural gas from methane hydrates. Also scientists warn that the projected large-scale release of methane to the atmosphere during removal and processing of this resource would likely speed up atmospheric warming and the resulting projected climate disruption.

Tar Sand

Deposit of a mixture of clay, sand, water, and varying amounts of a tarlike heavy oil known as bitumen. Bitumen can be extracted from tar sand by heating. It is then purified and upgraded to synthetic crude oil.

Synthetic Natural Gas

Gaseous fuel containing mostly methane produced from solid coal.

Proven Oil Reserves

Identified deposits from which conventional crude oil can be extracted profitably at current prices with current technology.

Liquefied Natural Gas

Natural gas converted to liquid form by cooling it at a very low temperature

What is nuclear fusion and what is its potential as an energy resource? Describe what happened to conventional nuclear power and its possible role in the future.

Nuclear fusion is a nuclear change at the atomic level in which the nuclei of two isotopes of a light element such as hydrogen are forced together at extremely high temperatures until they fuse to form a heavier nucleus, releasing energy in the process Potential as an energy source is that controlled nuclear fusion will provide an almost limitless source of energy. there would be no risk of a meltdown or of a release of large amounts of radioactive materials from a terrorist attack, and little risk of the additional spread of nuclear weapons, because bomb- grade materials are not required for fusion energy. Fusion power might also be used to destroy toxic wastes and to supply electricity for desalinating water and for decomposing water to produce hydrogen fuel.conventional and proposed new-generation nuclear power plants will not compete in today's energy market unless they are shielded from open-market competition by government subsidies and tax breaks.

Peak Production

Point in time when the pressure in an oil well drops and its rate of conventional crude oil production starts declining, usually a decade or so; for a group of wells or for a nation, the point at which all wells on average have passed peak production.

Shale Oil

Slow-flowing, dark brown, heavy oil obtained when kerogen in oil shale is vaporized at high temperatures and then condensed. Shale oil can be refined to yield gasoline, heating oil, and other petroleum products.

What is tar sand, or oil sand, and how is it extracted and converted to heavy oil? What are some environmental problems related to the use of this resource? What is shale oil and how is it produced? What are the major advantages and disadvantages of using heavy oils produced from tar sand and shale oil as energy resources?

The extraction, processing, and burning of conventional crude oil has severe environmental impacts, including land disruption, greenhouse gas emissions, and other forms of air pollution, water pollution, and loss of biodiversity. However, we do not know how much of the oil held tightly in shale rock deposits can be extracted profitably and at an acceptable environmental cost. For example, horizontal drilling and fracking produce massive amounts of contaminated wastewater. And there is no guarantee that the well pipes and casing in any fracking operation will not leak the toxic chemicals used in and produced by fracking into underground drinking water supplies. In addition, experience indicates that production of oil from shale rock beds drops off about twice as fast as it does in most conventional oil fields. Thus long-term profitable oil production from these resources may be overestimated. And producing oil from shale rock using current technology will be profitable only as long as the pro=ice of oil is at least $50 a barrel. In addition, this oil would be developed with high production costs, lower net energy yields, and potentially high environmental impacts. A potential supply of heavy oil is shale oil. It is produced by mining, crushing, and heating oil shale rock to extract a mixture of hydrocarbons called kerogen that can be distilled to produce shale oil. Before the thick shale oil is sent by pipe line to a refinery, it must be heated to increase its flow rate and processed to remove sulfur, nitrogen, and other m=impurities, which decreases its net energy yield. A growing source of heavy oil is tar sands, or oil sands, which are a mixture of clay, sand, water, and a combustible organic material called bitumen--a thick, sticky, tar-like heavy oil with a high sulfur content.

Describe our history of energy use over the last three hundred years. What is net energy and why is it important for evaluating energy resources? Explain why the nuclear fuel cycle has a low net energy yield and thus must be subsidized to compete in the open marketplace.

The steps involved require more power than the amount of power you actually get from the nuclear reaction. It must be subsidized to compete in the open marketplace because it costs a lot

Net Energy

Total amount of useful energy available from an energy resource or energy system over its lifetime, minus the amount of energy used (the first energy law), automatically wasted (the second energy law), and unnecessarily wasted in finding, processing, concentrating, and transporting it to users.

What is synthetic natural gas (SNG)? What are the major advantages and disadvantages of using liquid and gaseous synfuels produced from coal?

We can convert solid coal into synthetic natural gas by a process called coal gasification, which removes sulfur and most other impurities from coal. We can also convert it into liquid fuels such as methanol and synthetic gasoline through a process called coal liquefaction. Theses fuels, called synfuels, are often referred to as cleaner versions of coal.

Oil Sand

a deposit of moist sand and clay that can be mined to extract bitumen, an oil-rich hydrocarbon

Nuclear Fusion

a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.

Liquefied Petroleum Gas

mixture of liquefied propane and butane gas removed from natural gas and used as a fuel

Unproven Reserves

other deposits of potentially recoverable oil.

Crude Oil

petroleum that has not been processed

How do nuclear power plant operators store highly radioactive spent fuel rods? Why are spent fuel rods vulnerable to terrorist acts? What is the connection between commercial nuclear power plants and the spread of nuclear weapons? How can we deal with the highly radioactive wastes produced by the nuclear fuel cycle? What can we do with worn out nuclear power plants? Discuss whether using nuclear power can reduce U.S. dependence on imported oil. What role is nuclear power likely to play in slowing projected global climate disruption caused in part by emissions of carbon dioxide? What role might new-generation nuclear power plants play?

spent fuel rods are removed and stored in a deep pool of water contained in a steel-lined concrete basin (left) for cooling. After about 5 years of cooling, the fuel rods can be stored upright on concrete pads (right) in sealed dry-storage casks made of heat-resistant metal alloys and concrete.They can be used to make bombs so when transported are vulnerable With the spread of commercial nuclear power plants you provide power to the area and spread nuclear weapons because the spent rods can be used to make them Highly radioactive waste- They must be stored safely for at least 10,000 years and, by some estimates, up to 240,000 years if long-lived plutonium-235 is not removed from the wastes.One strategy is to dismantle the plant after it is decommissioned (closed) and to store its radioactive parts in a secure repository, which so far no country has built and tested. A second approach is to install a physical barrier around the plant and set up full-time security for 30-100 years, until the plant can be dismantled after its radioactivity has reached safer levels. These levels would still be high enough to require safe storage of leftover parts for thousands of years. A third option is to enclose the entire plant in a concrete and steel-reinforced tomb, called a contain ment structure.Critics also point out that increased use of nuclear power in the United States will make the country even more dependent on imports of uranium needed to fuel the plants. Currently, about 95% of the uranium used to fuel U.S. nuclear plants is imported, mostly from Russia.Nuclear power advocates also contend that increased use of nuclear power will greatly reduce or eliminate CO2 emissions and, in turn, reduce the projected threat of climate change caused by atmospheric warming. Critics point out that the nuclear power industry has mounted a misleading but effective public relations campaign to convince the public that nuclear power does not involve emissions of CO2 and other green- house gases.They argue that such reactors would be much cheaper and safer, and would cut nuclear wastes in half and reduce the spread of nuclear weapons technology. But decades of research must be done to test such claims.Also, most new-generation reactors will probably run at higher temperatures to improve their energy efficiency.