Environmental problems are created by drilling oil wells and extracting fluids because the petroleum pumped up from deep reservoir rocks is often accompanied by large volumes of salt water.
This brine contains numerous impurities, so it must either be injected back into the reservoir rocks or treated for safe surface disposal.
Petroleum usually must also be transported long distances by tanker or pipeline to reach a refinery.
Transport of petroleum occasionally leads to accidental spills.
Oil spills, especially in large volumes, can be detrimental to wildlife and habitat
Tuesday, March 10, 2009
Alternative Energy Sources
The prospect of reducing the world’s dependence on fossil fuels is problematic. Alternative energy industries, such as nuclear energy, hydroelectric energy, solar energy, wind energy, and geothermal energy exist, but these energy sources currently only account for a combined 14 percent of energy consumed worldwide. To date, alternative energy sources have been hindered by technological and environmental difficulties.
For instance, although the uranium that fuels nuclear power is abundant, the risk of nuclear accidents and the difficulty associated with safe disposal of radioactive waste have led to the decline of the nuclear power industry. Conversely, solar and wind power seem environmentally safe, but they are unreliable as steady sources of energy.
As global energy consumption grows each year, development of certain alternative energy sources becomes increasingly important. Because the global economy is powered by fossil fuels, it is critical to know how long world reserves will last. However, estimating the world’s remaining fossil fuel reserves requires extensive information, including comprehensive geological maps of the world’s sedimentary basins, models of energy production systems, and data showing world energy consumption patterns and trends.
For instance, although the uranium that fuels nuclear power is abundant, the risk of nuclear accidents and the difficulty associated with safe disposal of radioactive waste have led to the decline of the nuclear power industry. Conversely, solar and wind power seem environmentally safe, but they are unreliable as steady sources of energy.
As global energy consumption grows each year, development of certain alternative energy sources becomes increasingly important. Because the global economy is powered by fossil fuels, it is critical to know how long world reserves will last. However, estimating the world’s remaining fossil fuel reserves requires extensive information, including comprehensive geological maps of the world’s sedimentary basins, models of energy production systems, and data showing world energy consumption patterns and trends.
Fuel cell
Fuel Cell, device in which the energy of a chemical reaction is converted directly into electricity. Unlike a battery, a fuel cell does not run down; it operates as long as fuel and an oxidant are supplied continuously from outside the cell. Several companies are developing fuel cells that they hope will replace conventional internal-combustion engines in automobiles over the next few decades.
A fuel cell consists of an anode, the positive end of an electric circuit, and a cathode, the negative end of an electric circuit, separated by an electrolyte. Electrolytes are substances that allow ions (particles formed when a neutral atom or molecule gains or loses one or more electrons) to pass through them. Fuel flows to the anode, and an oxidant flows to the cathode. The chemical reaction between the fuel and the oxidant produces an electric current. Various fuels may be used, but research and development in recent years has focused on hydrogen fuel cells.
In a hydrogen fuel cell, hydrogen is supplied to the fuel cell’s anode, and an oxidant, commonly the oxygen present in air, is supplied to the cathode. The fuel cell strips electrons from the hydrogen atoms. These electrons move from the anode through the electric circuit to the cathode, creating an electric current that can be tapped to provide power.
The electron-deficient hydrogen atoms meanwhile pass through the electrolyte to the cathode. There the electrons that passed through the circuit recombine with the electron-deficient hydrogen atoms. Oxygen (from the air) reacts with this reformed hydrogen, producing water. Water produced at the cathode has to be removed continuously to avoid flooding the cell.
Hydrogen fuel cells hold great promise as low-pollution automobile engines if certain difficulties can be overcome.
Water, the only waste product of a hydrogen-oxygen fuel cell, is nonpolluting and can be used to cool the engine. The oxygen the cells need is readily available in air. Hydrogen, however, is not so readily available, and there is no existing delivery system to convey hydrogen to all the places people would need it to power their cars.
In addition, pure hydrogen is not abundant enough to provide power for all the cars on the road today. Instead, hydrogen would need to be extracted from other substances, a process that requires energy and produces pollutants.
A fuel cell consists of an anode, the positive end of an electric circuit, and a cathode, the negative end of an electric circuit, separated by an electrolyte. Electrolytes are substances that allow ions (particles formed when a neutral atom or molecule gains or loses one or more electrons) to pass through them. Fuel flows to the anode, and an oxidant flows to the cathode. The chemical reaction between the fuel and the oxidant produces an electric current. Various fuels may be used, but research and development in recent years has focused on hydrogen fuel cells.
In a hydrogen fuel cell, hydrogen is supplied to the fuel cell’s anode, and an oxidant, commonly the oxygen present in air, is supplied to the cathode. The fuel cell strips electrons from the hydrogen atoms. These electrons move from the anode through the electric circuit to the cathode, creating an electric current that can be tapped to provide power.
The electron-deficient hydrogen atoms meanwhile pass through the electrolyte to the cathode. There the electrons that passed through the circuit recombine with the electron-deficient hydrogen atoms. Oxygen (from the air) reacts with this reformed hydrogen, producing water. Water produced at the cathode has to be removed continuously to avoid flooding the cell.
Hydrogen fuel cells hold great promise as low-pollution automobile engines if certain difficulties can be overcome.
Water, the only waste product of a hydrogen-oxygen fuel cell, is nonpolluting and can be used to cool the engine. The oxygen the cells need is readily available in air. Hydrogen, however, is not so readily available, and there is no existing delivery system to convey hydrogen to all the places people would need it to power their cars.
In addition, pure hydrogen is not abundant enough to provide power for all the cars on the road today. Instead, hydrogen would need to be extracted from other substances, a process that requires energy and produces pollutants.
Friday, March 6, 2009
SOLAR ENERGY
Solar energy does not refer to a single energy technology but rather covers a diverse set of renewable energy technologies that are powered by the Sun’s heat. Some solar energy technologies, such as heating with solar panels, utilize sunlight directly.
Other types of solar energy, such as hydroelectric energy and fuels from biomass (wood, crop residues, and dung), rely on the Sun’s ability to evaporate water and grow plant material, respectively. The common feature of solar energy technologies is that, unlike oil, gas, coal, and present forms of nuclear power, solar energy is inexhaustible.
Solar energy can be divided into three main groups—heating and cooling applications, electricity generation, and fuels from biomass.
The Sun has been used for heating for centuries. The Mesa Verde cliff dwellings in Colorado, which date from AD 600, were constructed with rock projections that provide shade from the high (and hot) summer Sun but allow the rays of the lower winter Sun to penetrate.
Today a design with few or no moving parts that takes advantage of the Sun is called passive solar heating. Beginning in the late 1970s, architects increasingly became familiar with passive solar techniques. In the future, more and more new buildings will be designed to capture the Sun’s winter rays and keep out the summer rays.
Active solar heating and solar hot-water heating are variations on one theme, differing principally in cost and scale. A typical active solar-heating unit consists of tubes installed in panels that are mounted on a roof. Water (or sometimes another fluid) flowing through the tubes is heated by the Sun and is then used as a source of hot water and heat for the building.
Although the number of active solar-heating installations has grown rapidly since the 1970s, the industry has encountered simple installation and maintenance problems, involving such commonplace occurrences as water leakage and air blockage in the tubes.
Solar cooling requires a higher technology installation in which a fluid is cooled by being heated to an intermediate temperature so that it can be used to drive a refrigeration cycle. To date, relatively few commercial installations have been made.
Generation of Electricity
Large-scale hydroelectric projects are still being pursued in many developing countries. The simplest form of solar-powered electricity generation is the use of an array of collectors that heat water to produce steam to turn a turbine. Several of these facilities are in existence.
Other sources of Sun-derived electricity involve high-technology options that remain unproven commercially on a large scale. Photovoltaic cells, which convert sunlight directly into electricity, are currently being used for remote locations to power orbiting space satellites, gates at unattended railroad crossings, and irrigation pumps.
Progress is needed to lower costs before widespread use of photovoltaic cells is possible. The commercial development of still other methods seems far in the future. Ocean thermal conversion (OTC) generates electricity on offshore platforms; a turbine is turned by the power generated when cold seawater moves from great depths up to a warm surface. Also still highly speculative is the notion of using space satellites to beam electricity via microwaves down to Earth.
Electricity can be generated by a variety of technologies that ultimately depend on the effects of solar radiation. Windmills and waterfalls (themselves very old sources of mechanical energy) can be used to turn turbines to generate electricity. The energies of wind and falling water are considered forms of solar energy, because the Sun’s heating power creates wind and replenishes the water in rivers and streams.
Most existing windmill installations are relatively small, containing ten or more windmills in a grid configuration that takes advantage of wind shifts. In contrast, most electricity from hydroelectric installations comes from giant dams. Many sites suitable for large dams have already been tapped, especially in the industrialized nations. However, during the 1970s small dams used years earlier for mechanical energy were retrofitted to generate electricity.
Biomass
Fuels from biomass encompass several different forms, including alcohol fuels (mentioned earlier), dung, and wood. Wood and dung are still major fuels in some developing countries, and high oil prices have caused a resurgence of interest in wood in industrialized countries. Researchers are giving increasing attention to the development of so-called energy crops (perennial grasses and trees grown on agricultural land). There is some concern, however, that heavy reliance on agriculture for energy could drive up prices of both food and land.
D Current Status
The total amount of solar energy now being used may never be accurately estimated, because some sources are not recorded. In the early 1980s, however, two main sources of solar energy, hydroelectric energy and biomass, contributed more than twice as much as nuclear energy to the world energy supply.
Nevertheless, these two sources are limited by the availability of dam sites and the availability of land to grow trees and other plant materials, so the future development of solar energy will depend on a broad range of technological advances.
The potential of solar energy, with the exception of hydroelectricity, will remain underutilized well beyond the year 2000, because solar energy is still much more expensive than energy derived from fossil fuels. The long-term outlook for solar energy depends heavily on whether the prices of fossil fuels increase and whether environmental regulations become stricter.
For example, stricter environmental controls on burning fossil fuels may increase coal and oil prices, making solar energy a less expensive energy source in comparison.
Other types of solar energy, such as hydroelectric energy and fuels from biomass (wood, crop residues, and dung), rely on the Sun’s ability to evaporate water and grow plant material, respectively. The common feature of solar energy technologies is that, unlike oil, gas, coal, and present forms of nuclear power, solar energy is inexhaustible.
Solar energy can be divided into three main groups—heating and cooling applications, electricity generation, and fuels from biomass.
The Sun has been used for heating for centuries. The Mesa Verde cliff dwellings in Colorado, which date from AD 600, were constructed with rock projections that provide shade from the high (and hot) summer Sun but allow the rays of the lower winter Sun to penetrate.
Today a design with few or no moving parts that takes advantage of the Sun is called passive solar heating. Beginning in the late 1970s, architects increasingly became familiar with passive solar techniques. In the future, more and more new buildings will be designed to capture the Sun’s winter rays and keep out the summer rays.
Active solar heating and solar hot-water heating are variations on one theme, differing principally in cost and scale. A typical active solar-heating unit consists of tubes installed in panels that are mounted on a roof. Water (or sometimes another fluid) flowing through the tubes is heated by the Sun and is then used as a source of hot water and heat for the building.
Although the number of active solar-heating installations has grown rapidly since the 1970s, the industry has encountered simple installation and maintenance problems, involving such commonplace occurrences as water leakage and air blockage in the tubes.
Solar cooling requires a higher technology installation in which a fluid is cooled by being heated to an intermediate temperature so that it can be used to drive a refrigeration cycle. To date, relatively few commercial installations have been made.
Generation of Electricity
Large-scale hydroelectric projects are still being pursued in many developing countries. The simplest form of solar-powered electricity generation is the use of an array of collectors that heat water to produce steam to turn a turbine. Several of these facilities are in existence.
Other sources of Sun-derived electricity involve high-technology options that remain unproven commercially on a large scale. Photovoltaic cells, which convert sunlight directly into electricity, are currently being used for remote locations to power orbiting space satellites, gates at unattended railroad crossings, and irrigation pumps.
Progress is needed to lower costs before widespread use of photovoltaic cells is possible. The commercial development of still other methods seems far in the future. Ocean thermal conversion (OTC) generates electricity on offshore platforms; a turbine is turned by the power generated when cold seawater moves from great depths up to a warm surface. Also still highly speculative is the notion of using space satellites to beam electricity via microwaves down to Earth.
Electricity can be generated by a variety of technologies that ultimately depend on the effects of solar radiation. Windmills and waterfalls (themselves very old sources of mechanical energy) can be used to turn turbines to generate electricity. The energies of wind and falling water are considered forms of solar energy, because the Sun’s heating power creates wind and replenishes the water in rivers and streams.
Most existing windmill installations are relatively small, containing ten or more windmills in a grid configuration that takes advantage of wind shifts. In contrast, most electricity from hydroelectric installations comes from giant dams. Many sites suitable for large dams have already been tapped, especially in the industrialized nations. However, during the 1970s small dams used years earlier for mechanical energy were retrofitted to generate electricity.
Biomass
Fuels from biomass encompass several different forms, including alcohol fuels (mentioned earlier), dung, and wood. Wood and dung are still major fuels in some developing countries, and high oil prices have caused a resurgence of interest in wood in industrialized countries. Researchers are giving increasing attention to the development of so-called energy crops (perennial grasses and trees grown on agricultural land). There is some concern, however, that heavy reliance on agriculture for energy could drive up prices of both food and land.
D Current Status
The total amount of solar energy now being used may never be accurately estimated, because some sources are not recorded. In the early 1980s, however, two main sources of solar energy, hydroelectric energy and biomass, contributed more than twice as much as nuclear energy to the world energy supply.
Nevertheless, these two sources are limited by the availability of dam sites and the availability of land to grow trees and other plant materials, so the future development of solar energy will depend on a broad range of technological advances.
The potential of solar energy, with the exception of hydroelectricity, will remain underutilized well beyond the year 2000, because solar energy is still much more expensive than energy derived from fossil fuels. The long-term outlook for solar energy depends heavily on whether the prices of fossil fuels increase and whether environmental regulations become stricter.
For example, stricter environmental controls on burning fossil fuels may increase coal and oil prices, making solar energy a less expensive energy source in comparison.
Current Status
In 2001 a total of 435 nuclear plants operated worldwide. Another 35 reactors were under construction. Eighteen countries generate at least 20 percent of their electricity from nuclear power.
The largest nuclear power industries are located in the United States (104 reactors).
France (59)
Japan (52)
Britain (35)
Russia (29)
Germany (19)
In the United States, no new reactors have been ordered for more than 20 years. Public opposition, high construction costs, strict building and operating regulations, and high costs for waste disposal make nuclear power plants much more expensive to build and operate than plants that burn fossil fuels.
In some industrialized countries, the electric power industry is being restructured to break up monopolies (the provision of a commodity or service by a single seller or producer) at the generation level.
Because this trend is pressuring nuclear plant owners to cut operating expenses and become more competitive, the nuclear power industry in the United States and other western countries may continue to decline if existing nuclear power plants are unable to adapt to changing market conditions.
Asia is widely viewed as the only likely growth area for nuclear power in the near future. Japan, South Korea, Taiwan, and China all had plants under construction at the end of the 20th century. Conversely, a number of European nations were rethinking their commitments to nuclear power.
C1 Sweden
Sweden’s political parties have committed to phasing out nuclear power by 2010, after Swedish citizens voted in 1980 against future development of this energy source. However, industry is challenging the policy in court. In addition, critics argue that Sweden cannot fulfill its commitment to reducing emissions of greenhouse gases without relying on nuclear power.
C2 France
France generates about 75 percent of its electricity from nuclear power. However, it has canceled several planned reactors and may replace aging nuclear plants with fossil-fuel plants for environmental reasons. As a result, the government-owned electricity utility, Electricité de France, plans to diversify the country’s electricity-generating sources.
C3 Germany
The German government announced in 1998 a plan to phase out nuclear power. However, as in Sweden, nuclear plant owners may take the government to court to seek compensation for plants shut down before the end of their operating lives.
C4 Japan
In Japan, several accidents at nuclear facilities in the mid-1990s have undercut public support for nuclear power. Japan’s growing stockpile of plutonium and its shipments of spent nuclear fuel to Europe have drawn international criticism.
C5 China
China, which currently operates only three nuclear power plants, has plans to expand its nuclear capabilities. However, whether China will be able to obtain sufficient financing or whether it can develop the necessary skilled work force to expand is uncertain.
C6 Eastern Europe
A number of eastern European countries—including Russia, Ukraine, Bulgaria, the Czech Republic, Hungary, Lithuania, and Slovakia—generate electricity from Soviet-designed nuclear reactors that have various safety flaws. Some of these reactors have the same design as the Chernobyl reactor that exploded in 1986. The United States and other western countries are working to address these design problems and to improve operations, maintenance, and training at these plants.
The largest nuclear power industries are located in the United States (104 reactors).
France (59)
Japan (52)
Britain (35)
Russia (29)
Germany (19)
In the United States, no new reactors have been ordered for more than 20 years. Public opposition, high construction costs, strict building and operating regulations, and high costs for waste disposal make nuclear power plants much more expensive to build and operate than plants that burn fossil fuels.
In some industrialized countries, the electric power industry is being restructured to break up monopolies (the provision of a commodity or service by a single seller or producer) at the generation level.
Because this trend is pressuring nuclear plant owners to cut operating expenses and become more competitive, the nuclear power industry in the United States and other western countries may continue to decline if existing nuclear power plants are unable to adapt to changing market conditions.
Asia is widely viewed as the only likely growth area for nuclear power in the near future. Japan, South Korea, Taiwan, and China all had plants under construction at the end of the 20th century. Conversely, a number of European nations were rethinking their commitments to nuclear power.
C1 Sweden
Sweden’s political parties have committed to phasing out nuclear power by 2010, after Swedish citizens voted in 1980 against future development of this energy source. However, industry is challenging the policy in court. In addition, critics argue that Sweden cannot fulfill its commitment to reducing emissions of greenhouse gases without relying on nuclear power.
C2 France
France generates about 75 percent of its electricity from nuclear power. However, it has canceled several planned reactors and may replace aging nuclear plants with fossil-fuel plants for environmental reasons. As a result, the government-owned electricity utility, Electricité de France, plans to diversify the country’s electricity-generating sources.
C3 Germany
The German government announced in 1998 a plan to phase out nuclear power. However, as in Sweden, nuclear plant owners may take the government to court to seek compensation for plants shut down before the end of their operating lives.
C4 Japan
In Japan, several accidents at nuclear facilities in the mid-1990s have undercut public support for nuclear power. Japan’s growing stockpile of plutonium and its shipments of spent nuclear fuel to Europe have drawn international criticism.
C5 China
China, which currently operates only three nuclear power plants, has plans to expand its nuclear capabilities. However, whether China will be able to obtain sufficient financing or whether it can develop the necessary skilled work force to expand is uncertain.
C6 Eastern Europe
A number of eastern European countries—including Russia, Ukraine, Bulgaria, the Czech Republic, Hungary, Lithuania, and Slovakia—generate electricity from Soviet-designed nuclear reactors that have various safety flaws. Some of these reactors have the same design as the Chernobyl reactor that exploded in 1986. The United States and other western countries are working to address these design problems and to improve operations, maintenance, and training at these plants.
Safety Problems
Questions about the safety and economy of nuclear power created perhaps the most emotional battle fought over energy. As the battle heated during the late 1970s, nuclear advocates argued that no realistic alternative existed to increased reliance on nuclear power.
They recognized that some problems remain but maintained that solutions would be found. Nuclear opponents, on the other hand, emphasized a number of unanswered questions about the environment:
What are the effects of low-level radiation over long periods?
What is the likelihood of a major accident at a nuclear power plant?
What would be the consequences of such an accident?
How can nuclear power’s waste products, which will remain dangerous for centuries, be permanently isolated from the environment?
These safety questions helped cause changes in specifications for and delays in the construction of nuclear power plants, further driving up costs.
They also helped create a second controversy:
Is electricity from nuclear power plants less costly, equally costly, or more costly than electricity from coal-fired plants?
Despite rapidly escalating oil and gas prices in the late 1970s and early 1980s, these political and economic problems caused an effective moratorium in the United States on new orders for nuclear power plants.
This moratorium took effect even before the 1979 near meltdown
(melting of the nuclear fuel rods)
At the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, and the 1986 partial meltdown at the Chernobyl’ plant north of Kyiv in Ukraine .
The latter accident caused some fatalities and cases of radiation sickness, and it released a cloud of radioactivity that traveled widely across the northern hemisphere.
They recognized that some problems remain but maintained that solutions would be found. Nuclear opponents, on the other hand, emphasized a number of unanswered questions about the environment:
What are the effects of low-level radiation over long periods?
What is the likelihood of a major accident at a nuclear power plant?
What would be the consequences of such an accident?
How can nuclear power’s waste products, which will remain dangerous for centuries, be permanently isolated from the environment?
These safety questions helped cause changes in specifications for and delays in the construction of nuclear power plants, further driving up costs.
They also helped create a second controversy:
Is electricity from nuclear power plants less costly, equally costly, or more costly than electricity from coal-fired plants?
Despite rapidly escalating oil and gas prices in the late 1970s and early 1980s, these political and economic problems caused an effective moratorium in the United States on new orders for nuclear power plants.
This moratorium took effect even before the 1979 near meltdown
(melting of the nuclear fuel rods)
At the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, and the 1986 partial meltdown at the Chernobyl’ plant north of Kyiv in Ukraine .
The latter accident caused some fatalities and cases of radiation sickness, and it released a cloud of radioactivity that traveled widely across the northern hemisphere.
Development
Britain took an early lead in developing nuclear power. By the mid-1950s, several nuclear reactors were producing electricity in that country. The first nuclear reactor to be connected to an electricity distribution network in the United States began operation in 1957 at Shippingport, Pennsylvania.
Six years later, the first order was placed for a commercial nuclear power plant to be built without a direct subsidy from the federal government. This order marked the beginning of an attempt to convert rapidly the world’s electricity-generating systems from reliance on fossil fuels to reliance on nuclear energy.
By 1970, 90 nuclear power plants were operating in 15 countries. In 1980, 253 nuclear power plants were operating in 22 countries, and by 2001 there were 435 nuclear plants operating in 33 countries. Despite this increase, the attempt to move from fossil fuels to nuclear energy faltered because of rapidly increasing costs, regulatory delays, declining demand for electricity, and a heightened concern for safety.
Six years later, the first order was placed for a commercial nuclear power plant to be built without a direct subsidy from the federal government. This order marked the beginning of an attempt to convert rapidly the world’s electricity-generating systems from reliance on fossil fuels to reliance on nuclear energy.
By 1970, 90 nuclear power plants were operating in 15 countries. In 1980, 253 nuclear power plants were operating in 22 countries, and by 2001 there were 435 nuclear plants operating in 33 countries. Despite this increase, the attempt to move from fossil fuels to nuclear energy faltered because of rapidly increasing costs, regulatory delays, declining demand for electricity, and a heightened concern for safety.
NUCLEAR ENERGY
Nuclear energy is generated by the splitting, or fissioning, of atoms of uranium or heavier elements. The fission process releases heat, which is used to produce steam to drive a turbine to generate electricity. The operation of a nuclear reactor and the related electricity-generating equipment is only one part of an interconnected set of activities.
The production of a reliable supply of electricity from nuclear fission requires mining, milling, and transporting uranium; enriching uranium (increasing the percentage of the uranium isotope U-235) and packing it in appropriate form; building and maintaining the reactor and associated generating equipment; and treating and disposing of spent fuel. These activities require extremely sophisticated and interactive industrial processes and many specialized skills.
The Palo Verde Nuclear Power Facility in Arizona, like other nuclear power plants, was built to harness nuclear energy for controlled use by humans. Nuclear power is a controversial energy source: it is inexpensive and creates no air pollution, but the radioactivity released during accidents at nuclear power plants has caused deaths and environmental damage.
The production of a reliable supply of electricity from nuclear fission requires mining, milling, and transporting uranium; enriching uranium (increasing the percentage of the uranium isotope U-235) and packing it in appropriate form; building and maintaining the reactor and associated generating equipment; and treating and disposing of spent fuel. These activities require extremely sophisticated and interactive industrial processes and many specialized skills.
The Palo Verde Nuclear Power Facility in Arizona, like other nuclear power plants, was built to harness nuclear energy for controlled use by humans. Nuclear power is a controversial energy source: it is inexpensive and creates no air pollution, but the radioactivity released during accidents at nuclear power plants has caused deaths and environmental damage.
Synthetic Fuels
Synthetic fuels do not occur in nature but are made from natural materials. Gasohol, for example, is a mixture of gasoline and alcohol made from sugars produced by living plants.
Although making various types of fuel from coal is possible, the large-scale production of fuel from coal will likely be limited by high costs and pollution problems, some of which are not yet known.
The manufacture of alcohol fuels in large quantities will likely be restricted to regions, such as parts of Brazil, where a combination of low-cost labor and land, plus a long growing season, make it economical. Thus, synthetic fuels are unlikely to make an important contribution to the world’s energy supply anytime soon.
Although making various types of fuel from coal is possible, the large-scale production of fuel from coal will likely be limited by high costs and pollution problems, some of which are not yet known.
The manufacture of alcohol fuels in large quantities will likely be restricted to regions, such as parts of Brazil, where a combination of low-cost labor and land, plus a long growing season, make it economical. Thus, synthetic fuels are unlikely to make an important contribution to the world’s energy supply anytime soon.
Coal
Coal is a general term for a wide variety of solid materials that are high in carbon content. Most coal is burned by electric utility companies to produce steam to turn their generators. Some coal is used in factories to provide heat for buildings and industrial processes. A special, high-quality coal is turned into metallurgical coke for use in making steel.
A. Reserves
The world’s coal reserves are vast. The amount of coal (as measured by energy content) that is technically and economically recoverable under present conditions is five times as large as the reserves of crude oil. Just four regions contain three-fourths of the world’s recoverable coal reserves: the Asia Pacific, including Australia, 29.7 percent; North America, 26.1 percent; Russia and the countries of the former Union of Soviet Socialist Republics (USSR), 23.4 percent; and Europe, excluding the former USSR, 12.4 percent. China possesses 11 percent of the world’s total coal reserves.
B. Current Trends
In industrialized countries, the greater convenience and lower costs of oil and gas in the earlier 20th century virtually forced coal out of the market for heating homes and offices and driving locomotives. Oil and gas also ate heavily into the industrial market for coal. Only an expanding utility market enabled coal output in the United States, for example, to remain relatively constant between 1948 and 1973.
Even in the utility market, as oil and gas captured a greater share, coal’s contribution to the total energy picture dropped dramatically—in the United States, for instance, from about one-half to less than one-fifth. The dramatic jumps in oil prices after 1973, however, gave coal a major cost advantage for utilities and large industrial customers, and coal began to recapture some of its lost markets.
In contrast to the industrialized countries, developing countries that have large coal reserves (such as China and India) continue to use coal for industrial and heating purposes.
The average price of coal has remained virtually unchanged since the early 1980s and is forecast to decline in the early part of the 21st century. However, in industrialized countries the need to comply with stricter environmental regulations has made burning coal more costly.
C. Pollution Problems
Despite coal’s relative cheapness and huge reserves, the growth in the use of coal since 1973 has been much less than expected, because coal is associated with many more environmental problems than is oil. Underground mining can result in black lung disease for miners, the sinking of the land over mines, and the drainage of acid into water tables. Surface mining requires careful reclamation, or the unrestored land will remain scarred and unproductive.
In addition, the burning of coal causes emission of sulfur dioxide particles, nitrogen oxide, and other impurities. Acid rain—rainfall and other forms of precipitation with a relatively high acidity that is damaging lakes and some forests in many regions—is believed to be caused in part by such emissions . The U.S. Clean Air Act of 1970 (revised in 1970 and 1990) provides the federal legal basis for controlling air pollution.
This legislation has significantly reduced emissions of sulfur oxides—known as acid gases. For example, the Clean Air Act requires facilities such as coal-burning power plants to burn low-sulfur coal. In the 1990s concern over the possible warming of the planet as a result of the greenhouse effect caused many governments to consider policies to reduce the carbon dioxide emissions produced by burning coal, oil, and natural gas.
During the world’s rapid industrialization through the 19th and 20th centuries, levels of carbon dioxide in the atmosphere increased approximately 28 percent from pre-industrial levels. Solving these problems is costly, and who should pay is a matter of controversy. As a result, coal consumption may continue to grow more slowly than would otherwise be expected. The vast coal reserves, the improved technologies to reduce pollution, and the further development of coal gasification still indicate, however, that the market for coal will increase in coming years.
A. Reserves
The world’s coal reserves are vast. The amount of coal (as measured by energy content) that is technically and economically recoverable under present conditions is five times as large as the reserves of crude oil. Just four regions contain three-fourths of the world’s recoverable coal reserves: the Asia Pacific, including Australia, 29.7 percent; North America, 26.1 percent; Russia and the countries of the former Union of Soviet Socialist Republics (USSR), 23.4 percent; and Europe, excluding the former USSR, 12.4 percent. China possesses 11 percent of the world’s total coal reserves.
B. Current Trends
In industrialized countries, the greater convenience and lower costs of oil and gas in the earlier 20th century virtually forced coal out of the market for heating homes and offices and driving locomotives. Oil and gas also ate heavily into the industrial market for coal. Only an expanding utility market enabled coal output in the United States, for example, to remain relatively constant between 1948 and 1973.
Even in the utility market, as oil and gas captured a greater share, coal’s contribution to the total energy picture dropped dramatically—in the United States, for instance, from about one-half to less than one-fifth. The dramatic jumps in oil prices after 1973, however, gave coal a major cost advantage for utilities and large industrial customers, and coal began to recapture some of its lost markets.
In contrast to the industrialized countries, developing countries that have large coal reserves (such as China and India) continue to use coal for industrial and heating purposes.
The average price of coal has remained virtually unchanged since the early 1980s and is forecast to decline in the early part of the 21st century. However, in industrialized countries the need to comply with stricter environmental regulations has made burning coal more costly.
C. Pollution Problems
Despite coal’s relative cheapness and huge reserves, the growth in the use of coal since 1973 has been much less than expected, because coal is associated with many more environmental problems than is oil. Underground mining can result in black lung disease for miners, the sinking of the land over mines, and the drainage of acid into water tables. Surface mining requires careful reclamation, or the unrestored land will remain scarred and unproductive.
In addition, the burning of coal causes emission of sulfur dioxide particles, nitrogen oxide, and other impurities. Acid rain—rainfall and other forms of precipitation with a relatively high acidity that is damaging lakes and some forests in many regions—is believed to be caused in part by such emissions . The U.S. Clean Air Act of 1970 (revised in 1970 and 1990) provides the federal legal basis for controlling air pollution.
This legislation has significantly reduced emissions of sulfur oxides—known as acid gases. For example, the Clean Air Act requires facilities such as coal-burning power plants to burn low-sulfur coal. In the 1990s concern over the possible warming of the planet as a result of the greenhouse effect caused many governments to consider policies to reduce the carbon dioxide emissions produced by burning coal, oil, and natural gas.
During the world’s rapid industrialization through the 19th and 20th centuries, levels of carbon dioxide in the atmosphere increased approximately 28 percent from pre-industrial levels. Solving these problems is costly, and who should pay is a matter of controversy. As a result, coal consumption may continue to grow more slowly than would otherwise be expected. The vast coal reserves, the improved technologies to reduce pollution, and the further development of coal gasification still indicate, however, that the market for coal will increase in coming years.
Reserves
Oil shale, heavy oil deposits, and tar sands are the most prevalent forms of petroleum found in the world. Reserves of these sources are many times more abundant than the world’s total known reserves of crude oil. Because of the high cost of converting shale oil and tar sands into usable petroleum products, however, only a small percentage of the available material is processed commercially.
An industry to make oil products from tar sands has been started in Canada, and Venezuela is looking at the prospects of developing the vast reserves of tar sands in its Orinoco River basin. Nevertheless, the quantity of oil products produced from these two raw materials is small compared with the total production of conventional crude oil.
Until world petroleum prices increase, the quantity of oil produced from oil shale and tar sands will likely remain small relative to the production of conventional crude oil.
An industry to make oil products from tar sands has been started in Canada, and Venezuela is looking at the prospects of developing the vast reserves of tar sands in its Orinoco River basin. Nevertheless, the quantity of oil products produced from these two raw materials is small compared with the total production of conventional crude oil.
Until world petroleum prices increase, the quantity of oil produced from oil shale and tar sands will likely remain small relative to the production of conventional crude oil.
Pollution Problems
In its early days, the oil industry generated considerable environmental pollution. Through the years, however, under the dual influences of improved technology and more stringent regulations, it has become much cleaner. The effluents from refineries have decreased greatly and, although well blowouts still occur, new technology has tended to make them relatively rare.
The policing of the oceans, on the other hand, is much more difficult. Oceangoing ships are still a major source of oil spills. In 1990 the Congress of the United States passed legislation requiring tankers to be double hulled by the end of the decade.
Another source of pollution connected with the oil industry is the sulfur in crude oil. Regulations of national and local governments restrict the amount of sulfur dioxide that can be discharged by factories and utilities burning fuel oil. Because removing sulfur is expensive, however, regulations still allow some sulfur dioxide to be discharged into the air.
Many scientists believe that another potential environmental problem from refining and burning large amounts of oil and other fossil fuels (such as coal and natural gas) occurs when carbon dioxide (a by-product of the burning of fossil fuels), methane (which exists in natural gas and is also a by-product of refining petroleum), and other by-product gases accumulate in the atmosphere (see Greenhouse Effect).
These gases are known as greenhouse gases, because they trap some of the energy from the Sun that penetrates Earth’s atmosphere. This energy, trapped in the form of heat, maintains Earth at a temperature that is hospitable to life. Certain amounts of greenhouse gases occur naturally in the atmosphere.
However, the immense quantities of petroleum, coal, and other fossil fuels burned during the world’s rapid industrialization over the last 200 years are a contributing source of higher levels of carbon dioxide in the atmosphere. During that time period, these levels have increased by about 28 percent.
This increase in atmospheric carbon dioxide, coupled with the continuing loss of the world’s forests (which absorb carbon dioxide), has led many scientists to predict a rise in global temperature. This increase in global temperature might disrupt weather patterns, disrupt ocean currents, lead to more violent storms, and create other environmental problems (see Global Warming).
In 1992 representatives of over 150 countries convened in Rio de Janeiro, Brazil, and agreed on the need to reduce the world’s emissions of greenhouse gases. In 1997 world delegations again convened, this time in Kyōto, Japan. During the Kyōto meeting, representatives of 160 nations, including the United States, signed an agreement known as the Kyōto Protocol, which would require 38 industrialized nations to limit emissions of greenhouse gases to levels that are an average of 5 percent below the emission levels of 1990.
In order to reduce their fossil fuel emissions to achieve these levels, the industrialized nations would have to shift their energy mix toward energy sources that do not produce as much carbon dioxide, such as natural gas, or to alternative energy sources, such as hydroelectric energy, solar energy, wind energy, or nuclear energy.
While the governments of some industrialized nations have ratified the Kyōto Protocol, others have not. A major blow to the protocol came in March 2001 when United States president George W. Bush rejected it, saying it would damage the U.S. economy. Under the previous administration of President Bill Clinton, the United States had volunteered to reduce greenhouse gas emissions to 7 percent below 1990 levels.
Bush’s rejection meant that the world’s largest consumer of fossil fuels would not participate in the Kyōto Protocol.
The policing of the oceans, on the other hand, is much more difficult. Oceangoing ships are still a major source of oil spills. In 1990 the Congress of the United States passed legislation requiring tankers to be double hulled by the end of the decade.
Another source of pollution connected with the oil industry is the sulfur in crude oil. Regulations of national and local governments restrict the amount of sulfur dioxide that can be discharged by factories and utilities burning fuel oil. Because removing sulfur is expensive, however, regulations still allow some sulfur dioxide to be discharged into the air.
Many scientists believe that another potential environmental problem from refining and burning large amounts of oil and other fossil fuels (such as coal and natural gas) occurs when carbon dioxide (a by-product of the burning of fossil fuels), methane (which exists in natural gas and is also a by-product of refining petroleum), and other by-product gases accumulate in the atmosphere (see Greenhouse Effect).
These gases are known as greenhouse gases, because they trap some of the energy from the Sun that penetrates Earth’s atmosphere. This energy, trapped in the form of heat, maintains Earth at a temperature that is hospitable to life. Certain amounts of greenhouse gases occur naturally in the atmosphere.
However, the immense quantities of petroleum, coal, and other fossil fuels burned during the world’s rapid industrialization over the last 200 years are a contributing source of higher levels of carbon dioxide in the atmosphere. During that time period, these levels have increased by about 28 percent.
This increase in atmospheric carbon dioxide, coupled with the continuing loss of the world’s forests (which absorb carbon dioxide), has led many scientists to predict a rise in global temperature. This increase in global temperature might disrupt weather patterns, disrupt ocean currents, lead to more violent storms, and create other environmental problems (see Global Warming).
In 1992 representatives of over 150 countries convened in Rio de Janeiro, Brazil, and agreed on the need to reduce the world’s emissions of greenhouse gases. In 1997 world delegations again convened, this time in Kyōto, Japan. During the Kyōto meeting, representatives of 160 nations, including the United States, signed an agreement known as the Kyōto Protocol, which would require 38 industrialized nations to limit emissions of greenhouse gases to levels that are an average of 5 percent below the emission levels of 1990.
In order to reduce their fossil fuel emissions to achieve these levels, the industrialized nations would have to shift their energy mix toward energy sources that do not produce as much carbon dioxide, such as natural gas, or to alternative energy sources, such as hydroelectric energy, solar energy, wind energy, or nuclear energy.
While the governments of some industrialized nations have ratified the Kyōto Protocol, others have not. A major blow to the protocol came in March 2001 when United States president George W. Bush rejected it, saying it would damage the U.S. economy. Under the previous administration of President Bill Clinton, the United States had volunteered to reduce greenhouse gas emissions to 7 percent below 1990 levels.
Bush’s rejection meant that the world’s largest consumer of fossil fuels would not participate in the Kyōto Protocol.
Production
As crude oil or natural gas is produced from an oil or gas field, the pressure in the reservoir that forces the material to the surface gradually declines. Eventually, the pressure will decline so much that the remaining oil or gas will not migrate through the porous rock to the well. When this point is reached, most of the gas in a gas field will have been produced, but less than one-third of the oil will have been extracted.
Part of the remaining oil can be recovered by using water or carbon dioxide gas to push the oil to the well, but even then, one-fourth to one-half of the oil is usually left in the reservoir. In an effort to extract this remaining oil, oil companies have begun to use chemicals to push the oil to the well, or to use fire or steam in the reservoir to make the oil flow more easily. New techniques that allow operators to drill horizontally, as well as vertically, into very deep structures have dramatically reduced the cost of finding natural gas and oil supplies.
Crude oil is transported to refineries by pipelines, barges, or giant oceangoing tankers. Refineries contain a series of processing units that separate the different constituents of the crude oil by heating them to different temperatures, chemically modifying them, and then blending them to make final products. These final products are principally gasoline, kerosene, diesel oil, jet fuel, home heating oil, heavy fuel oil, lubricants, and feedstocks, or starting materials, for petrochemicals.
Natural gas is transported, usually by pipelines, to customers who burn it for fuel or, in some cases, make petrochemicals from chemicals extracted, or “stripped,” from it. Natural gas can be liquefied at very low temperatures and transported in special ships. This method is much more costly than transporting oil by tanker. Oil and natural gas compete in a number of markets, especially in generating heat for homes, offices, factories, and industrial processes.
Part of the remaining oil can be recovered by using water or carbon dioxide gas to push the oil to the well, but even then, one-fourth to one-half of the oil is usually left in the reservoir. In an effort to extract this remaining oil, oil companies have begun to use chemicals to push the oil to the well, or to use fire or steam in the reservoir to make the oil flow more easily. New techniques that allow operators to drill horizontally, as well as vertically, into very deep structures have dramatically reduced the cost of finding natural gas and oil supplies.
Crude oil is transported to refineries by pipelines, barges, or giant oceangoing tankers. Refineries contain a series of processing units that separate the different constituents of the crude oil by heating them to different temperatures, chemically modifying them, and then blending them to make final products. These final products are principally gasoline, kerosene, diesel oil, jet fuel, home heating oil, heavy fuel oil, lubricants, and feedstocks, or starting materials, for petrochemicals.
Natural gas is transported, usually by pipelines, to customers who burn it for fuel or, in some cases, make petrochemicals from chemicals extracted, or “stripped,” from it. Natural gas can be liquefied at very low temperatures and transported in special ships. This method is much more costly than transporting oil by tanker. Oil and natural gas compete in a number of markets, especially in generating heat for homes, offices, factories, and industrial processes.
Drilling
Geologists and other scientists have developed techniques that indicate the possibility of oil or gas being found deep in the ground. These techniques include taking aerial photographs of special surface features, sending shock waves through the earth and reflecting them back into instruments, and measuring the earth’s gravity and magnetic field with sensitive meters.
Nevertheless, the only method by which oil or gas can be found is by drilling a hole into the reservoir. In some cases oil companies spend many millions of dollars drilling in promising areas, only to find dry holes. For a long time, most wells were drilled on land, but after World War II drilling commenced in shallow water from platforms supported by legs that rested on the sea bottom.
Later, floating platforms were developed that could drill at water depths of 1,000 m (3,300 ft) or more. Large oil and gas fields have been found offshore: in the United States, mainly off the Gulf Coast; in Europe, primarily in the North Sea; in Russia, in the Barents Sea and the Kara Sea; and off Newfoundland and Labrador, and Brazil.
Most major finds in the future may be offshore.A semisubmersible oil-production rig sits in the waters off Pascagoula, Mississippi. Anchored in place, a semisubmersible rig has legs that fill with air, allowing the production platform to float above the surface of the water. Offshore wells produce about 25 percent of the world’s annual output of oil.
Nevertheless, the only method by which oil or gas can be found is by drilling a hole into the reservoir. In some cases oil companies spend many millions of dollars drilling in promising areas, only to find dry holes. For a long time, most wells were drilled on land, but after World War II drilling commenced in shallow water from platforms supported by legs that rested on the sea bottom.
Later, floating platforms were developed that could drill at water depths of 1,000 m (3,300 ft) or more. Large oil and gas fields have been found offshore: in the United States, mainly off the Gulf Coast; in Europe, primarily in the North Sea; in Russia, in the Barents Sea and the Kara Sea; and off Newfoundland and Labrador, and Brazil.
Most major finds in the future may be offshore.A semisubmersible oil-production rig sits in the waters off Pascagoula, Mississippi. Anchored in place, a semisubmersible rig has legs that fill with air, allowing the production platform to float above the surface of the water. Offshore wells produce about 25 percent of the world’s annual output of oil.
Petroleum and Natural gas
Petroleum (crude oil) and natural gas are found in commercial quantities in sedimentary basins in more than 50 countries in all parts of the world.
The largest deposits are in the Middle East, which contains more than half the known oil reserves and almost one-third of the known natural-gas reserves.
The United States contains only about 2 percent of the known oil reserves and 3 percent of the known natural-gas reserves.
The largest deposits are in the Middle East, which contains more than half the known oil reserves and almost one-third of the known natural-gas reserves.
The United States contains only about 2 percent of the known oil reserves and 3 percent of the known natural-gas reserves.
Wednesday, March 4, 2009
Growth of Petroleum Use
Although for centuries petroleum (also known as crude oil) had been used in small quantities for purposes as diverse as medicine and ship caulking, the modern petroleum era began when a commercial well was brought into production in Pennsylvania in 1859.
The oil industry in the United States expanded rapidly as refineries sprang up to make oil products from crude oil. The oil companies soon began exporting their principal product, kerosene—used for lighting—to all areas of the world.
The development of the internal-combustion engine and the automobile at the end of the 19th century created a vast new market for another major product, gasoline. A third major product, heavy oil, began to replace coal in some energy markets after World War II.
The major oil companies, which are based principally in the United States, initially found large oil supplies in the United States. As a result, oil companies from other countries—especially Britain, the Netherlands, and France—began to search for oil in many parts of the world, especially the Middle East.
The British brought the first field there (in Iran) into production just before World War I (1914-1918). During World War I, the U.S. oil industry produced two-thirds of the world’s oil supply from domestic sources and imported another one-sixth from Mexico.
At the end of the war and before the discovery of the productive East Texas fields in 1930, however, the United States, with its reserves strained by the war, became a net oil importer for a few years.
During the next three decades, with occasional federal support, the U.S. oil companies were enormously successful in expanding in the rest of the world. By 1955 the five major U.S. oil companies produced two-thirds of the oil for the world oil market (not including North America and the Soviet bloc).
Two British-based companies produced almost one-third of the world’s oil supply, and the French produced a mere one-fiftieth. The next 15 years were a period of serenity for energy supplies.
The seven major U.S. and British oil companies provided the world with increasing quantities of cheap oil. The world price was about a dollar a barrel, and during this time the United States was largely self-sufficient, with its imports limited by a quota.
The oil industry in the United States expanded rapidly as refineries sprang up to make oil products from crude oil. The oil companies soon began exporting their principal product, kerosene—used for lighting—to all areas of the world.
The development of the internal-combustion engine and the automobile at the end of the 19th century created a vast new market for another major product, gasoline. A third major product, heavy oil, began to replace coal in some energy markets after World War II.
The major oil companies, which are based principally in the United States, initially found large oil supplies in the United States. As a result, oil companies from other countries—especially Britain, the Netherlands, and France—began to search for oil in many parts of the world, especially the Middle East.
The British brought the first field there (in Iran) into production just before World War I (1914-1918). During World War I, the U.S. oil industry produced two-thirds of the world’s oil supply from domestic sources and imported another one-sixth from Mexico.
At the end of the war and before the discovery of the productive East Texas fields in 1930, however, the United States, with its reserves strained by the war, became a net oil importer for a few years.
During the next three decades, with occasional federal support, the U.S. oil companies were enormously successful in expanding in the rest of the world. By 1955 the five major U.S. oil companies produced two-thirds of the oil for the world oil market (not including North America and the Soviet bloc).
Two British-based companies produced almost one-third of the world’s oil supply, and the French produced a mere one-fiftieth. The next 15 years were a period of serenity for energy supplies.
The seven major U.S. and British oil companies provided the world with increasing quantities of cheap oil. The world price was about a dollar a barrel, and during this time the United States was largely self-sufficient, with its imports limited by a quota.
Analyzing Today's Situation
Wood was the first and, for most of human history, the major source of energy. It was readily available, because extensive forests grew in many parts of the world and the amount of wood needed for heating and cooking was relatively modest.
Certain other energy sources, found only in localized areas, were also used in ancient times: asphalt, coal, and peat from surface deposits and oil from seepages of underground deposits.
This situation changed when wood began to be used during the Middle Ages to make charcoal. The charcoal was heated with metal ore to break up chemical compounds and free the metal.
As forests were cut and wood supplies dwindled at the onset of the Industrial Revolution in the mid-18th century, charcoal was replaced by coke (produced from coal) in the reduction of ores. Coal, which also began to be used to drive steam engines, became the dominant energy source as the Industrial Revolution proceeded.
Certain other energy sources, found only in localized areas, were also used in ancient times: asphalt, coal, and peat from surface deposits and oil from seepages of underground deposits.
This situation changed when wood began to be used during the Middle Ages to make charcoal. The charcoal was heated with metal ore to break up chemical compounds and free the metal.
As forests were cut and wood supplies dwindled at the onset of the Industrial Revolution in the mid-18th century, charcoal was replaced by coke (produced from coal) in the reduction of ores. Coal, which also began to be used to drive steam engines, became the dominant energy source as the Industrial Revolution proceeded.
Nations Attempt To Meet Energy Needs
Energy Supply, World, combined resources by which the nations of the world attempt to meet their energy needs. Energy is the basis of industrial civilization; without energy, modern life would cease to exist.
During the 1970s the world began a painful adjustment to the vulnerability of energy supplies. In the long run, conserving energy resources may provide the time needed to develop new sources of energy, such as hydrogen fuel cells, or to further develop alternative energy sources, such as solar energy and wind energy.
While this development occurs, however, the world will continue to be vulnerable to disruptions in the supply of oil, which, after World War II (1939-1945), became the most favored energy source..
During the 1970s the world began a painful adjustment to the vulnerability of energy supplies. In the long run, conserving energy resources may provide the time needed to develop new sources of energy, such as hydrogen fuel cells, or to further develop alternative energy sources, such as solar energy and wind energy.
While this development occurs, however, the world will continue to be vulnerable to disruptions in the supply of oil, which, after World War II (1939-1945), became the most favored energy source..
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