Chapter 18
Describe how coal is formed.
Partially decomposed vegetation, when buried in a sedimentary environment, may slowly be transformed into the solid, brittle, carbonaceous rock, coal.
What is strip mining? What are the environmental effects of this kind of mining?
Strip mining is a surface mining process in which the overlying layer of soil and rock is stripped off to reach the coal. The impact of strip mines varies from region to region, depending on topography, climate, and reclamation practices. One serious problem in areas with abundant rainfall is acid mine drainage-the drainage of acidic water from mine sites, which pollutes runoff and water sources. In arid areas, the land is so sensitive that the tire tracks remain for years, Strip mining has the potential to pollute or damage water, land, and biological sources.
What are tar sands? What are the pros and cons of using tar sands?
Tar sands are sedimentary rocks or sands impregnated with tar oil, asphalt, or bitumen. Some pros of tar sands: It produces about 15% of North America's production of oil. Some cons of tar sands: It destroys fragile environments, and there is a waste-disposal problem because of the volume of the unmined material.
What is likely to happen as we begin to experience shortages of oil and natural gas in the coming decades? Why will this have a significant impact on the environment?
As we begin to see real shortages of oil and gas, they will put pressure on the coal industry to open more and larger mines in both eastern and western coal beds of the United States. Increased use of coal will have significant environmental impacts that will include: More and more land will be strip mined, and thus will require careful and expensive restoration. Burning more coal produces large amounts of air pollutants, and waste from combustion products. Aesthetic degradation, noise, dust, and pollutants will be produced.
How is coal classified? In which type of coal is energy content greatest? Least?
Coal is classified according to its energy and sulfur content as anthracite, bituminous, subbituminous, or lignite. Energy content is greatest in anthracite coal, and lowest in lignite coal.
How much of the US's electricity is supplied by coal? How much coal do we have?
Coal produces nearly 60% of the energy consumed in the US.
. Explain the environmental effects associated with the recovery, refining, delivery and use of oil and natural gas. (Be specific for each step).
Environmental effects associated with the recovery of oil include: pollution of surface waters and groundwater from leaks from broken pipes or tanks containing oil, accidental release of air pollutants, loss or disruption and damage to fragile ecosystems, use of land to construct pads for wells, pipelines, etc., and land sinking as oil and gas are withdrawn. Environmental impacts associated with oil production include: oil seepage into the sea from normal operations or large spills, release of drilling muds containing heavy metals that may be toxic, and aesthetic degradation from the presence of offshore oil drilling platforms. Some environmental effects of oil refining include: accidental spills and slow leaks of gasoline, polluting soil and groundwater resources below the site, and the releasement of a variety of pollutants due to the industrial process. Some environmental effects of delivery and use include: oil spills, and air pollution.
What is allowance trading? What are the pros and cons of allowance trading?
In allowance trading, the EPA grants utility companies tradable allowances for polluting. One allowance is goof for 1 ton of sulfur dioxide emissions per year. In theory, some companies would not need all of their allowances, so their extra allowances could be traded and sold by brokers to other utility companies that are unable to stay within their allocated emission levels. Some pros of allowance trading are: it encourages competition in the utility industry, reduces overall pollution through economic market forces, and encourages new technology to reduce emissions. Some cons of allowance trading are: Some believe companies should not be allowed to buy their way out of pollution problems, and that this is just allowing more pollutants into our air.
What indicators do we have that we are heading toward a potential crisis in the availability of crude oil?
Indicators that we are heading toward a potential crisis in availability of crude oil include: We are approaching the time when approximately 50% of the total crude oil available will have been consumed. We are using what of left-3 trillion barrels-fast-at a rate of 82 million barrels per day. Today, for every three barrels of oil we consume, we are finding only one barrel. Most oil experts believe peak oil is only a few decades away. In the United States, it is expected that the production of oil as we know it now will end by 2090. World Production of oil will be nearly exhausted by 2100.
Why is it more important to know when we will reach peak oil production rather than how long oil is likely to last?
It is important to know when we will reach peak oil production because following peak production, less oil will be available, leading to shortages and price shocks. We need to be prepared, and this is why it is more important than how long oil will last. Some oil will always remain in the ground because at some point it will not be cost effective to extract.
What is coal-bed methane? What are the pros and cons of using coal-bed methane?
Methane can be stored within the surfaces of the organic matter in coal, and because there are so many large internal surfaces in coal, the amount of methane for a given volume of rock is huge. Some pros of coal-bed methane are it is inexpensive, is a relatively clean-burning fuel, and it would decrease importation of energy sources. Some cons include that migration of methane may contaminate groundwater or migrate into residential areas, and it requires the disposal of large volumes of water, some with high salt content.
What are methane hydrates? What are the pros and cons of using methane hydrates?
Methane hydrates are white, ice-like compounds made up of molecules of methane gas in molecular cages of frozen water. Some pros of methane hydrates include: Methane hydrates are a potential energy source with approximately twice as much energy as all the known natural gas, oil and coal deposits on Earth. Some cons of methane hydrates are that mining them will be a difficult task, since they are found deep in water. Drilling cannot operate safely at these depths, and transporting the gas to land would be challenging.
What is natural gas? What are the pros and cons of using natural gas?
Natural gas is derived from organic materials, mostly plants, that were buried with marine or lake sediments in what are known as depositional basins. Some pros of natural gas are it is a clean fuel, it produces fewer pollutants than does burning coal and oil, so it causes fewer environmental problems. Some cons are that the supply is finite, is found deeper than oil and must be transported by pipelines.
What is oil shale? What are the pros and cons of using oil shale?
Oil shale is a fine-grained sedimentary rock containing organic matter. When heated to 500 degrees C, in a process known as destructive distillation, oil shale yields up to nearly 60 L of oil per ton of shale. Some pros of oil shale are: More oil can be easily recovered per ton, and it can be used in case of crude oil shortages. Some cons of oil shale are: Waste disposal is a problem, and significant environmental, social, and economic impacts in oil shale areas would result from rapid urbanization for the large workforce, construction of industrial facilities, and an increased demand on water resources.
Explain "peak oil". Why is there controversy over when we might reach peak oil?
Peak oil is the time when one-half of Earth's oil has been exploited. There is controversy over when this might be due to possible new sources or lessening of demand that could change what time we reach peak oil.
Explain the difference between primary production and enhanced production.
Primary production involves simply pumping the oil from wells, but this will only recover 25 percent of the petroleum. In enhanced production, steam, water, or chemicals, such as carbon dioxide or nitrogen gas, are injected into the oil reservoir to push the oil up toward the wells, where it can be more easily discovered by pumping.
What is the ANWR? What are the arguments for and against drilling in the ANWR?
The ANWR is the Arctic National Wildlife Refuge on the North slope of Alaska. It is one of the few pristine wilderness areas remaining in the world, however it is estimated to contain about 3 billion bbl of recoverable oil. Some arguments in favor of drilling in the ANWR include: The US needs the oil and it will help us be more independent of imported oil, new oil facilities will bring jobs and dollars to Alaska, new exploration tools to evaluate the subsurface for oil pools require far fewer exploratory wells, land area affected will be small relative to the total area, and new drilling practices will have much less impact on the environment. Some Arguments against drilling in the ANWR include: Some wilderness should remain wilderness, drilling will forever change the pristine environment of the North Slope, even with the best technology, oil exploration and development will impact the ANWR, will probably disrupt wildlife, building roads would require massive amounts of water, heavy vehicles used in exploration will permanently scar the ground, accidents may occur, and oil development is inherently damaging because it involves massive industrial complex of people, vehicles, equipment, pipelines, and support facilities.
What would be the best way to deal with this potential crisis?
The best way to deal with this crisis is to : Educate people and governments of the potential depletion of crude oil and the consequences of shortages. Plan and action are necessary to avoid military confrontation, food shortages, and social disruption. We need to develop alternative energy sources before significant shortages of oil occur.
What are the major fossil fuels? What percentage of our energy do they provide?
The major fossil fuels are crude oil, natural gas, and coal. They provide approximately 90 percent of the energy consumed.
Briefly describe how fossil fuels are produced. Explain the following: source rock, reservoir rock, trap, and cap rock.
The source material, or source rock, for oil and gas is fine-grained organic rich sediment buried, where it is subjected to increased heat and pressure. The elevated temperature and pressure initiate the chemical transformation of the organic material in the sediment into oil and gas. The elevated pressure and temperature initiate the upward migration of oil and gas, which are relatively light, to a lower-pressure environment, or reservoir rock. The oil and gas fields from which we extract resources are places where the natural upward migration of the oil and gas to the surface is interrupted or blocked by what is known as a trap. The rock that helps form the trap, known as the cap rock, is usually a very fine-grained sedimentary rock, which is necessary to form traps. The oil and gas are discovered and extracted.
Why is sulfur content of coal important?
The sulfur content of coal is important because low-sulfur emits less sulfur dioxide, and as a result is more desirable as a fuel for power plants.
How is the transport of coal a major environmental problem?
The transport of coal can be an environmental problem because it requires large volumes of water, and it can inefficient, and expensive.
What is being done to limit the environmental effects of burning coal?
To limit the environmental effects of coal, options are being used or develop to include the following: Chemical and/or physical cleaning of coal prior to combustion. New boiler designs that permit a lower temperature of combustion, which reduces emissions of nitrogen oxides. Injection of material rich in calcium carbonate into the gases following the burning of coal; this practice, known as scrubbing, removes sulfur dioxides. Conversion of coal at power plants into a gas before burning. Consumer education about energy conservation and efficiency to reduce the demand for energy and thus the amount of coal burned and emissions released. Development of zero emission coal-burning electric power plants.
What is underground mining? What are the environmental effects of this kind of mining?
Underground mining environmental impacts include: Acid mine drainage from the mines and waste piles, that pollutes streams, land subsidence, and coal fires erupt, which may expose smoke and hazardous fumes.
